Merge branch 'master' into feature/discord

pkg/components/dashdiffs/compare.go

@@ -0,0 +1,149 @@
+package dashdiffs
+
+import (
+	"encoding/json"
+	"errors"
+
+	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/log"
+	"github.com/grafana/grafana/pkg/models"
+	diff "github.com/yudai/gojsondiff"
+	deltaFormatter "github.com/yudai/gojsondiff/formatter"
+)
+
+var (
+	// ErrUnsupportedDiffType occurs when an invalid diff type is used.
+	ErrUnsupportedDiffType = errors.New("dashdiff: unsupported diff type")
+
+	// ErrNilDiff occurs when two compared interfaces are identical.
+	ErrNilDiff = errors.New("dashdiff: diff is nil")
+
+	diffLogger = log.New("dashdiffs")
+)
+
+type DiffType int
+
+const (
+	DiffJSON DiffType = iota
+	DiffBasic
+	DiffDelta
+)
+
+type Options struct {
+	OrgId    int64
+	Base     DiffTarget
+	New      DiffTarget
+	DiffType DiffType
+}
+
+type DiffTarget struct {
+	DashboardId      int64
+	Version          int
+	UnsavedDashboard *simplejson.Json
+}
+
+type Result struct {
+	Delta []byte `json:"delta"`
+}
+
+func ParseDiffType(diff string) DiffType {
+	switch diff {
+	case "json":
+		return DiffJSON
+	case "basic":
+		return DiffBasic
+	case "delta":
+		return DiffDelta
+	}
+	return DiffBasic
+}
+
+// CompareDashboardVersionsCommand computes the JSON diff of two versions,
+// assigning the delta of the diff to the `Delta` field.
+func CalculateDiff(options *Options) (*Result, error) {
+	baseVersionQuery := models.GetDashboardVersionQuery{
+		DashboardId: options.Base.DashboardId,
+		Version:     options.Base.Version,
+		OrgId:       options.OrgId,
+	}
+
+	if err := bus.Dispatch(&baseVersionQuery); err != nil {
+		return nil, err
+	}
+
+	newVersionQuery := models.GetDashboardVersionQuery{
+		DashboardId: options.New.DashboardId,
+		Version:     options.New.Version,
+		OrgId:       options.OrgId,
+	}
+
+	if err := bus.Dispatch(&newVersionQuery); err != nil {
+		return nil, err
+	}
+
+	baseData := baseVersionQuery.Result.Data
+	newData := newVersionQuery.Result.Data
+
+	left, jsonDiff, err := getDiff(baseData, newData)
+	if err != nil {
+		return nil, err
+	}
+
+	result := &Result{}
+
+	switch options.DiffType {
+	case DiffDelta:
+
+		deltaOutput, err := deltaFormatter.NewDeltaFormatter().Format(jsonDiff)
+		if err != nil {
+			return nil, err
+		}
+		result.Delta = []byte(deltaOutput)
+
+	case DiffJSON:
+		jsonOutput, err := NewJSONFormatter(left).Format(jsonDiff)
+		if err != nil {
+			return nil, err
+		}
+		result.Delta = []byte(jsonOutput)
+
+	case DiffBasic:
+		basicOutput, err := NewBasicFormatter(left).Format(jsonDiff)
+		if err != nil {
+			return nil, err
+		}
+		result.Delta = basicOutput
+
+	default:
+		return nil, ErrUnsupportedDiffType
+	}
+
+	return result, nil
+}
+
+// getDiff computes the diff of two dashboard versions.
+func getDiff(baseData, newData *simplejson.Json) (interface{}, diff.Diff, error) {
+	leftBytes, err := baseData.Encode()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	rightBytes, err := newData.Encode()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	jsonDiff, err := diff.New().Compare(leftBytes, rightBytes)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if !jsonDiff.Modified() {
+		return nil, nil, ErrNilDiff
+	}
+
+	left := make(map[string]interface{})
+	err = json.Unmarshal(leftBytes, &left)
+	return left, jsonDiff, nil
+}

pkg/components/dashdiffs/formatter_basic.go

@@ -0,0 +1,425 @@
+package dashdiffs
+
+import (
+	"bytes"
+	"html/template"
+
+	diff "github.com/yudai/gojsondiff"
+)
+
+// A BasicDiff holds the stateful values that are used when generating a basic
+// diff from JSON tokens.
+type BasicDiff struct {
+	narrow     string
+	keysIdent  int
+	writing    bool
+	LastIndent int
+	Block      *BasicBlock
+	Change     *BasicChange
+	Summary    *BasicSummary
+}
+
+// A BasicBlock represents a top-level element in a basic diff.
+type BasicBlock struct {
+	Title     string
+	Old       interface{}
+	New       interface{}
+	Change    ChangeType
+	Changes   []*BasicChange
+	Summaries []*BasicSummary
+	LineStart int
+	LineEnd   int
+}
+
+// A BasicChange represents the change from an old to new value. There are many
+// BasicChanges in a BasicBlock.
+type BasicChange struct {
+	Key       string
+	Old       interface{}
+	New       interface{}
+	Change    ChangeType
+	LineStart int
+	LineEnd   int
+}
+
+// A BasicSummary represents the changes within a basic block that're too deep
+// or verbose to be represented in the top-level BasicBlock element, or in the
+// BasicChange. Instead of showing the values in this case, we simply print
+// the key and count how many times the given change was applied to that
+// element.
+type BasicSummary struct {
+	Key       string
+	Change    ChangeType
+	Count     int
+	LineStart int
+	LineEnd   int
+}
+
+type BasicFormatter struct {
+	jsonDiff *JSONFormatter
+	tpl      *template.Template
+}
+
+func NewBasicFormatter(left interface{}) *BasicFormatter {
+	tpl := template.Must(template.New("block").Funcs(tplFuncMap).Parse(tplBlock))
+	tpl = template.Must(tpl.New("change").Funcs(tplFuncMap).Parse(tplChange))
+	tpl = template.Must(tpl.New("summary").Funcs(tplFuncMap).Parse(tplSummary))
+
+	return &BasicFormatter{
+		jsonDiff: NewJSONFormatter(left),
+		tpl:      tpl,
+	}
+}
+
+// Format takes the diff of two JSON documents, and returns the difference
+// between them summarized in an HTML document.
+func (b *BasicFormatter) Format(d diff.Diff) ([]byte, error) {
+	// calling jsonDiff.Format(d) populates the JSON diff's "Lines" value,
+	// which we use to compute the basic dif
+	_, err := b.jsonDiff.Format(d)
+	if err != nil {
+		return nil, err
+	}
+
+	bd := &BasicDiff{}
+	blocks := bd.Basic(b.jsonDiff.Lines)
+	buf := &bytes.Buffer{}
+
+	err = b.tpl.ExecuteTemplate(buf, "block", blocks)
+	if err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// Basic transforms a slice of JSONLines into a slice of BasicBlocks.
+func (b *BasicDiff) Basic(lines []*JSONLine) []*BasicBlock {
+	// init an array you can append to for the basic "blocks"
+	blocks := make([]*BasicBlock, 0)
+
+	for _, line := range lines {
+		if b.returnToTopLevelKey(line) {
+			if b.Block != nil {
+				blocks = append(blocks, b.Block)
+			}
+		}
+
+		// Record the last indent level at each pass in case we need to
+		// check for a change in depth inside the JSON data structures.
+		b.LastIndent = line.Indent
+
+		if line.Indent == 1 {
+			if block, ok := b.handleTopLevelChange(line); ok {
+				blocks = append(blocks, block)
+			}
+		}
+
+		// Here is where we handle changes for all types, appending each change
+		// to the current block based on the value.
+		//
+		// Values which only occupy a single line in JSON (like a string or
+		// int, for example) are treated as "Basic Changes" that we append to
+		// the current block as soon as they're detected.
+		//
+		// Values which occupy multiple lines (either slices or maps) are
+		// treated as "Basic Summaries". When we detect the "ChangeNil" type,
+		// we know we've encountered one of these types, so we record the
+		// starting position as well the type of the change, and stop
+		// performing comparisons until we find the end of that change. Upon
+		// finding the change, we append it to the current block, and begin
+		// performing comparisons again.
+		if line.Indent > 1 {
+			// check to ensure a single line change
+			if b.isSingleLineChange(line) {
+				switch line.Change {
+				case ChangeAdded, ChangeDeleted:
+
+					b.Block.Changes = append(b.Block.Changes, &BasicChange{
+						Key:       line.Key,
+						Change:    line.Change,
+						New:       line.Val,
+						LineStart: line.LineNum,
+					})
+
+				case ChangeOld:
+					b.Change = &BasicChange{
+						Key:       line.Key,
+						Change:    line.Change,
+						Old:       line.Val,
+						LineStart: line.LineNum,
+					}
+
+				case ChangeNew:
+					b.Change.New = line.Val
+					b.Change.LineEnd = line.LineNum
+					b.Block.Changes = append(b.Block.Changes, b.Change)
+
+				default:
+					//ok
+				}
+
+				// otherwise, we're dealing with a change at a deeper level. We
+				// know there's a change somewhere in the JSON tree, but we
+				// don't know exactly where, so we go deeper.
+			} else {
+
+				// if the change is anything but unchanged, continue processing
+				//
+				// we keep "narrowing" the key as we go deeper, in order to
+				// correctly report the key name for changes found within an
+				// object or array.
+				if line.Change != ChangeUnchanged {
+					if line.Key != "" {
+						b.narrow = line.Key
+						b.keysIdent = line.Indent
+					}
+
+					// if the change isn't nil, and we're not already writing
+					// out a change, then we've found something.
+					//
+					// First, try to determine the title of the embedded JSON
+					// object. If it's an empty string, then we're in an object
+					// or array, so we default to using the "narrowed" key.
+					//
+					// We also start recording the basic summary, until we find
+					// the next `ChangeUnchanged`.
+					if line.Change != ChangeNil {
+						if !b.writing {
+							b.writing = true
+							key := b.Block.Title
+
+							if b.narrow != "" {
+								key = b.narrow
+								if b.keysIdent > line.Indent {
+									key = b.Block.Title
+								}
+							}
+
+							b.Summary = &BasicSummary{
+								Key:       key,
+								Change:    line.Change,
+								LineStart: line.LineNum,
+							}
+						}
+					}
+					// if we find a `ChangeUnchanged`, we do one of two things:
+					//
+					// - if we're recording a change already, then we know
+					// we've come to the end of that change block, so we write
+					// that change out be recording the line number of where
+					// that change ends, and append it to the current block's
+					// summary.
+					//
+					// - if we're not recording a change, then we do nothing,
+					// since the BasicDiff doesn't report on unchanged JSON
+					// values.
+				} else {
+					if b.writing {
+						b.writing = false
+						b.Summary.LineEnd = line.LineNum
+						b.Block.Summaries = append(b.Block.Summaries, b.Summary)
+					}
+				}
+			}
+		}
+	}
+
+	return blocks
+}
+
+// returnToTopLevelKey indicates that we've moved from a key at one level deep
+// in the JSON document to a top level key.
+//
+// In order to produce distinct "blocks" when rendering the basic diff,
+// we need a way to distinguish between different sections of data.
+// To do this, we consider the value(s) of each top-level JSON key to
+// represent a distinct block for Grafana's JSON data structure, so
+// we perform this check to see if we've entered a new "block". If we
+// have, we simply append the existing block to the array of blocks.
+func (b *BasicDiff) returnToTopLevelKey(line *JSONLine) bool {
+	return b.LastIndent == 2 && line.Indent == 1 && line.Change == ChangeNil
+}
+
+// handleTopLevelChange handles a change on one of the top-level keys on a JSON
+// document.
+//
+// If the line's indentation is at level 1, then we know it's a top
+// level key in the JSON document. As mentioned earlier, we treat these
+// specially as they indicate their values belong to distinct blocks.
+//
+// At level 1, we only record single-line changes, ie, the "added",
+// "deleted", "old" or "new" cases, since we know those values aren't
+// arrays or maps. We only handle these cases at level 2 or deeper,
+// since for those we either output a "change" or "summary". This is
+// done for formatting reasons only, so we have logical "blocks" to
+// display.
+func (b *BasicDiff) handleTopLevelChange(line *JSONLine) (*BasicBlock, bool) {
+	switch line.Change {
+	case ChangeNil:
+		if line.Change == ChangeNil {
+			if line.Key != "" {
+				b.Block = &BasicBlock{
+					Title:  line.Key,
+					Change: line.Change,
+				}
+			}
+		}
+
+	case ChangeAdded, ChangeDeleted:
+		return &BasicBlock{
+			Title:     line.Key,
+			Change:    line.Change,
+			New:       line.Val,
+			LineStart: line.LineNum,
+		}, true
+
+	case ChangeOld:
+		b.Block = &BasicBlock{
+			Title:     line.Key,
+			Old:       line.Val,
+			Change:    line.Change,
+			LineStart: line.LineNum,
+		}
+
+	case ChangeNew:
+		b.Block.New = line.Val
+		b.Block.LineEnd = line.LineNum
+
+		// For every "old" change there is a corresponding "new", which
+		// is why we wait until we detect the "new" change before
+		// appending the change.
+		return b.Block, true
+	default:
+		// ok
+	}
+
+	return nil, false
+}
+
+// isSingleLineChange ensures we're iterating over a single line change (ie,
+// either a single line or a old-new value pair was changed in the JSON file).
+func (b *BasicDiff) isSingleLineChange(line *JSONLine) bool {
+	return line.Key != "" && line.Val != nil && !b.writing
+}
+
+// encStateMap is used in the template helper
+var (
+	encStateMap = map[ChangeType]string{
+		ChangeAdded:   "added",
+		ChangeDeleted: "deleted",
+		ChangeOld:     "changed",
+		ChangeNew:     "changed",
+	}
+
+	// tplFuncMap is the function map for each template
+	tplFuncMap = template.FuncMap{
+		"getChange": func(c ChangeType) string {
+			state, ok := encStateMap[c]
+			if !ok {
+				return "changed"
+			}
+			return state
+		},
+	}
+)
+
+var (
+	// tplBlock is the container for the basic diff. It iterates over each
+	// basic block, expanding each "change" and "summary" belonging to every
+	// block.
+	tplBlock = `{{ define "block" -}}
+{{ range . }}
+<div class="diff-group">
+	<div class="diff-block">
+		<h2 class="diff-block-title">
+			<i class="diff-circle diff-circle-{{ getChange .Change }} fa fa-circle"></i>
+			<strong class="diff-title">{{ .Title }}</strong> {{ getChange .Change }}
+		</h2>
+
+
+		<!-- Overview -->
+		{{ if .Old }}
+			<div class="diff-label">{{ .Old }}</div>
+			<i class="diff-arrow fa fa-long-arrow-right"></i>
+		{{ end }}
+		{{ if .New }}
+				<div class="diff-label">{{ .New }}</div>
+		{{ end }}
+
+		{{ if .LineStart }}
+			<diff-link-json
+				line-link="{{ .LineStart }}"
+				line-display="{{ .LineStart }}{{ if .LineEnd }} - {{ .LineEnd }}{{ end }}"
+				switch-view="ctrl.getDiff('html')"
+			/>
+		{{ end }}
+
+	</div>
+
+	<!-- Basic Changes -->
+	{{ range .Changes }}
+		<ul class="diff-change-container">
+		{{ template "change" . }}
+		</ul>
+	{{ end }}
+
+	<!-- Basic Summary -->
+	{{ range .Summaries }}
+		{{ template "summary" . }}
+	{{ end }}
+
+</div>
+{{ end }}
+{{ end }}`
+
+	// tplChange is the template for basic changes.
+	tplChange = `{{ define "change" -}}
+<li class="diff-change-group">
+	<span class="bullet-position-container">
+		<div class="diff-change-item diff-change-title">{{ getChange .Change }} {{ .Key }}</div>
+
+		<div class="diff-change-item">
+			{{ if .Old }}
+				<div class="diff-label">{{ .Old }}</div>
+				<i class="diff-arrow fa fa-long-arrow-right"></i>
+			{{ end }}
+			{{ if .New }}
+					<div class="diff-label">{{ .New }}</div>
+			{{ end }}
+		</div>
+
+		{{ if .LineStart }}
+			<diff-link-json
+				line-link="{{ .LineStart }}"
+				line-display="{{ .LineStart }}{{ if .LineEnd }} - {{ .LineEnd }}{{ end }}"
+				switch-view="ctrl.getDiff('json')"
+			/>
+		{{ end }}
+	</span>
+</li>
+{{ end }}`
+
+	// tplSummary is for basic summaries.
+	tplSummary = `{{ define "summary" -}}
+<div class="diff-group-name">
+	<i class="diff-circle diff-circle-{{ getChange .Change }} fa fa-circle-o diff-list-circle"></i>
+
+	{{ if .Count }}
+		<strong>{{ .Count }}</strong>
+	{{ end }}
+
+	{{ if .Key }}
+		<strong class="diff-summary-key">{{ .Key }}</strong>
+		{{ getChange .Change }}
+	{{ end }}
+
+	{{ if .LineStart }}
+		<diff-link-json
+			line-link="{{ .LineStart }}"
+			line-display="{{ .LineStart }}{{ if .LineEnd }} - {{ .LineEnd }}{{ end }}"
+			switch-view="ctrl.getDiff('json')"
+		/>
+	{{ end }}
+</div>
+{{ end }}`
+)

pkg/components/dashdiffs/formatter_json.go

@@ -0,0 +1,477 @@
+package dashdiffs
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"html/template"
+	"sort"
+
+	diff "github.com/yudai/gojsondiff"
+)
+
+type ChangeType int
+
+const (
+	ChangeNil ChangeType = iota
+	ChangeAdded
+	ChangeDeleted
+	ChangeOld
+	ChangeNew
+	ChangeUnchanged
+)
+
+var (
+	// changeTypeToSymbol is used for populating the terminating characer in
+	// the diff
+	changeTypeToSymbol = map[ChangeType]string{
+		ChangeNil:     "",
+		ChangeAdded:   "+",
+		ChangeDeleted: "-",
+		ChangeOld:     "-",
+		ChangeNew:     "+",
+	}
+
+	// changeTypeToName is used for populating class names in the diff
+	changeTypeToName = map[ChangeType]string{
+		ChangeNil:     "same",
+		ChangeAdded:   "added",
+		ChangeDeleted: "deleted",
+		ChangeOld:     "old",
+		ChangeNew:     "new",
+	}
+)
+
+var (
+	// tplJSONDiffWrapper is the template that wraps a diff
+	tplJSONDiffWrapper = `{{ define "JSONDiffWrapper" -}}
+	{{ range $index, $element := . }}
+		{{ template "JSONDiffLine" $element }}
+	{{ end }}
+{{ end }}`
+
+	// tplJSONDiffLine is the template that prints each line in a diff
+	tplJSONDiffLine = `{{ define "JSONDiffLine" -}}
+<p id="l{{ .LineNum }}" class="diff-line diff-json-{{ cton .Change }}">
+	<span class="diff-line-number">
+		{{if .LeftLine }}{{ .LeftLine }}{{ end }}
+	</span>
+	<span class="diff-line-number">
+		{{if .RightLine }}{{ .RightLine }}{{ end }}
+	</span>
+	<span class="diff-value diff-indent-{{ .Indent }}" title="{{ .Text }}">
+		{{ .Text }}
+	</span>
+	<span class="diff-line-icon">{{ ctos .Change }}</span>
+</p>
+{{ end }}`
+)
+
+var diffTplFuncs = template.FuncMap{
+	"ctos": func(c ChangeType) string {
+		if symbol, ok := changeTypeToSymbol[c]; ok {
+			return symbol
+		}
+		return ""
+	},
+	"cton": func(c ChangeType) string {
+		if name, ok := changeTypeToName[c]; ok {
+			return name
+		}
+		return ""
+	},
+}
+
+// JSONLine contains the data required to render each line of the JSON diff
+// and contains the data required to produce the tokens output in the basic
+// diff.
+type JSONLine struct {
+	LineNum   int         `json:"line"`
+	LeftLine  int         `json:"leftLine"`
+	RightLine int         `json:"rightLine"`
+	Indent    int         `json:"indent"`
+	Text      string      `json:"text"`
+	Change    ChangeType  `json:"changeType"`
+	Key       string      `json:"key"`
+	Val       interface{} `json:"value"`
+}
+
+func NewJSONFormatter(left interface{}) *JSONFormatter {
+	tpl := template.Must(template.New("JSONDiffWrapper").Funcs(diffTplFuncs).Parse(tplJSONDiffWrapper))
+	tpl = template.Must(tpl.New("JSONDiffLine").Funcs(diffTplFuncs).Parse(tplJSONDiffLine))
+
+	return &JSONFormatter{
+		left:      left,
+		Lines:     []*JSONLine{},
+		tpl:       tpl,
+		path:      []string{},
+		size:      []int{},
+		lineCount: 0,
+		inArray:   []bool{},
+	}
+}
+
+type JSONFormatter struct {
+	left      interface{}
+	path      []string
+	size      []int
+	inArray   []bool
+	lineCount int
+	leftLine  int
+	rightLine int
+	line      *AsciiLine
+	Lines     []*JSONLine
+	tpl       *template.Template
+}
+
+type AsciiLine struct {
+	// the type of change
+	change ChangeType
+
+	// the actual changes - no formatting
+	key string
+	val interface{}
+
+	// level of indentation for the current line
+	indent int
+
+	// buffer containing the fully formatted line
+	buffer *bytes.Buffer
+}
+
+func (f *JSONFormatter) Format(diff diff.Diff) (result string, err error) {
+	if v, ok := f.left.(map[string]interface{}); ok {
+		f.formatObject(v, diff)
+	} else if v, ok := f.left.([]interface{}); ok {
+		f.formatArray(v, diff)
+	} else {
+		return "", fmt.Errorf("expected map[string]interface{} or []interface{}, got %T",
+			f.left)
+	}
+
+	b := &bytes.Buffer{}
+	err = f.tpl.ExecuteTemplate(b, "JSONDiffWrapper", f.Lines)
+	if err != nil {
+		fmt.Printf("%v\n", err)
+		return "", err
+	}
+	return b.String(), nil
+}
+
+func (f *JSONFormatter) formatObject(left map[string]interface{}, df diff.Diff) {
+	f.addLineWith(ChangeNil, "{")
+	f.push("ROOT", len(left), false)
+	f.processObject(left, df.Deltas())
+	f.pop()
+	f.addLineWith(ChangeNil, "}")
+}
+
+func (f *JSONFormatter) formatArray(left []interface{}, df diff.Diff) {
+	f.addLineWith(ChangeNil, "[")
+	f.push("ROOT", len(left), true)
+	f.processArray(left, df.Deltas())
+	f.pop()
+	f.addLineWith(ChangeNil, "]")
+}
+
+func (f *JSONFormatter) processArray(array []interface{}, deltas []diff.Delta) error {
+	patchedIndex := 0
+	for index, value := range array {
+		f.processItem(value, deltas, diff.Index(index))
+		patchedIndex++
+	}
+
+	// additional Added
+	for _, delta := range deltas {
+		switch delta.(type) {
+		case *diff.Added:
+			d := delta.(*diff.Added)
+			// skip items already processed
+			if int(d.Position.(diff.Index)) < len(array) {
+				continue
+			}
+			f.printRecursive(d.Position.String(), d.Value, ChangeAdded)
+		}
+	}
+
+	return nil
+}
+
+func (f *JSONFormatter) processObject(object map[string]interface{}, deltas []diff.Delta) error {
+	names := sortKeys(object)
+	for _, name := range names {
+		value := object[name]
+		f.processItem(value, deltas, diff.Name(name))
+	}
+
+	// Added
+	for _, delta := range deltas {
+		switch delta.(type) {
+		case *diff.Added:
+			d := delta.(*diff.Added)
+			f.printRecursive(d.Position.String(), d.Value, ChangeAdded)
+		}
+	}
+
+	return nil
+}
+
+func (f *JSONFormatter) processItem(value interface{}, deltas []diff.Delta, position diff.Position) error {
+	matchedDeltas := f.searchDeltas(deltas, position)
+	positionStr := position.String()
+	if len(matchedDeltas) > 0 {
+		for _, matchedDelta := range matchedDeltas {
+
+			switch matchedDelta.(type) {
+			case *diff.Object:
+				d := matchedDelta.(*diff.Object)
+				switch value.(type) {
+				case map[string]interface{}:
+					//ok
+				default:
+					return errors.New("Type mismatch")
+				}
+				o := value.(map[string]interface{})
+
+				f.newLine(ChangeNil)
+				f.printKey(positionStr)
+				f.print("{")
+				f.closeLine()
+				f.push(positionStr, len(o), false)
+				f.processObject(o, d.Deltas)
+				f.pop()
+				f.newLine(ChangeNil)
+				f.print("}")
+				f.printComma()
+				f.closeLine()
+
+			case *diff.Array:
+				d := matchedDelta.(*diff.Array)
+				switch value.(type) {
+				case []interface{}:
+					//ok
+				default:
+					return errors.New("Type mismatch")
+				}
+				a := value.([]interface{})
+
+				f.newLine(ChangeNil)
+				f.printKey(positionStr)
+				f.print("[")
+				f.closeLine()
+				f.push(positionStr, len(a), true)
+				f.processArray(a, d.Deltas)
+				f.pop()
+				f.newLine(ChangeNil)
+				f.print("]")
+				f.printComma()
+				f.closeLine()
+
+			case *diff.Added:
+				d := matchedDelta.(*diff.Added)
+				f.printRecursive(positionStr, d.Value, ChangeAdded)
+				f.size[len(f.size)-1]++
+
+			case *diff.Modified:
+				d := matchedDelta.(*diff.Modified)
+				savedSize := f.size[len(f.size)-1]
+				f.printRecursive(positionStr, d.OldValue, ChangeOld)
+				f.size[len(f.size)-1] = savedSize
+				f.printRecursive(positionStr, d.NewValue, ChangeNew)
+
+			case *diff.TextDiff:
+				savedSize := f.size[len(f.size)-1]
+				d := matchedDelta.(*diff.TextDiff)
+				f.printRecursive(positionStr, d.OldValue, ChangeOld)
+				f.size[len(f.size)-1] = savedSize
+				f.printRecursive(positionStr, d.NewValue, ChangeNew)
+
+			case *diff.Deleted:
+				d := matchedDelta.(*diff.Deleted)
+				f.printRecursive(positionStr, d.Value, ChangeDeleted)
+
+			default:
+				return errors.New("Unknown Delta type detected")
+			}
+
+		}
+	} else {
+		f.printRecursive(positionStr, value, ChangeUnchanged)
+	}
+
+	return nil
+}
+
+func (f *JSONFormatter) searchDeltas(deltas []diff.Delta, position diff.Position) (results []diff.Delta) {
+	results = make([]diff.Delta, 0)
+	for _, delta := range deltas {
+		switch delta.(type) {
+		case diff.PostDelta:
+			if delta.(diff.PostDelta).PostPosition() == position {
+				results = append(results, delta)
+			}
+		case diff.PreDelta:
+			if delta.(diff.PreDelta).PrePosition() == position {
+				results = append(results, delta)
+			}
+		default:
+			panic("heh")
+		}
+	}
+	return
+}
+
+func (f *JSONFormatter) push(name string, size int, array bool) {
+	f.path = append(f.path, name)
+	f.size = append(f.size, size)
+	f.inArray = append(f.inArray, array)
+}
+
+func (f *JSONFormatter) pop() {
+	f.path = f.path[0 : len(f.path)-1]
+	f.size = f.size[0 : len(f.size)-1]
+	f.inArray = f.inArray[0 : len(f.inArray)-1]
+}
+
+func (f *JSONFormatter) addLineWith(change ChangeType, value string) {
+	f.line = &AsciiLine{
+		change: change,
+		indent: len(f.path),
+		buffer: bytes.NewBufferString(value),
+	}
+	f.closeLine()
+}
+
+func (f *JSONFormatter) newLine(change ChangeType) {
+	f.line = &AsciiLine{
+		change: change,
+		indent: len(f.path),
+		buffer: bytes.NewBuffer([]byte{}),
+	}
+}
+
+func (f *JSONFormatter) closeLine() {
+	leftLine := 0
+	rightLine := 0
+	f.lineCount++
+
+	switch f.line.change {
+	case ChangeAdded, ChangeNew:
+		f.rightLine++
+		rightLine = f.rightLine
+
+	case ChangeDeleted, ChangeOld:
+		f.leftLine++
+		leftLine = f.leftLine
+
+	case ChangeNil, ChangeUnchanged:
+		f.rightLine++
+		f.leftLine++
+		rightLine = f.rightLine
+		leftLine = f.leftLine
+	}
+
+	s := f.line.buffer.String()
+	f.Lines = append(f.Lines, &JSONLine{
+		LineNum:   f.lineCount,
+		RightLine: rightLine,
+		LeftLine:  leftLine,
+		Indent:    f.line.indent,
+		Text:      s,
+		Change:    f.line.change,
+		Key:       f.line.key,
+		Val:       f.line.val,
+	})
+}
+
+func (f *JSONFormatter) printKey(name string) {
+	if !f.inArray[len(f.inArray)-1] {
+		f.line.key = name
+		fmt.Fprintf(f.line.buffer, `"%s": `, name)
+	}
+}
+
+func (f *JSONFormatter) printComma() {
+	f.size[len(f.size)-1]--
+	if f.size[len(f.size)-1] > 0 {
+		f.line.buffer.WriteRune(',')
+	}
+}
+
+func (f *JSONFormatter) printValue(value interface{}) {
+	switch value.(type) {
+	case string:
+		f.line.val = value
+		fmt.Fprintf(f.line.buffer, `"%s"`, value)
+	case nil:
+		f.line.val = "null"
+		f.line.buffer.WriteString("null")
+	default:
+		f.line.val = value
+		fmt.Fprintf(f.line.buffer, `%#v`, value)
+	}
+}
+
+func (f *JSONFormatter) print(a string) {
+	f.line.buffer.WriteString(a)
+}
+
+func (f *JSONFormatter) printRecursive(name string, value interface{}, change ChangeType) {
+	switch value.(type) {
+	case map[string]interface{}:
+		f.newLine(change)
+		f.printKey(name)
+		f.print("{")
+		f.closeLine()
+
+		m := value.(map[string]interface{})
+		size := len(m)
+		f.push(name, size, false)
+
+		keys := sortKeys(m)
+		for _, key := range keys {
+			f.printRecursive(key, m[key], change)
+		}
+		f.pop()
+
+		f.newLine(change)
+		f.print("}")
+		f.printComma()
+		f.closeLine()
+
+	case []interface{}:
+		f.newLine(change)
+		f.printKey(name)
+		f.print("[")
+		f.closeLine()
+
+		s := value.([]interface{})
+		size := len(s)
+		f.push("", size, true)
+		for _, item := range s {
+			f.printRecursive("", item, change)
+		}
+		f.pop()
+
+		f.newLine(change)
+		f.print("]")
+		f.printComma()
+		f.closeLine()
+
+	default:
+		f.newLine(change)
+		f.printKey(name)
+		f.printValue(value)
+		f.printComma()
+		f.closeLine()
+	}
+}
+
+func sortKeys(m map[string]interface{}) (keys []string) {
+	keys = make([]string, 0, len(m))
+	for key := range m {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+	return
+}

pkg/components/dashdiffs/formatter_test.go

@@ -0,0 +1,131 @@
+package dashdiffs
+
+import (
+	"testing"
+
+	"github.com/grafana/grafana/pkg/components/simplejson"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestDiff(t *testing.T) {
+	// Sample json docs for tests only
+	const (
+		leftJSON = `{
+			"key": "value",
+			"object": {
+				"key": "value",
+				"anotherObject": {
+					"same": "this field is the same in rightJSON",
+					"change": "this field should change in rightJSON",
+					"delete": "this field doesn't appear in rightJSON"
+				}
+			},
+			"array": [
+				"same",
+				"change",
+				"delete"
+			],
+			"embeddedArray": {
+				"array": [
+					"same",
+					"change",
+					"delete"
+				]
+			}
+		}`
+
+		rightJSON = `{
+			"key": "differentValue",
+			"object": {
+				"key": "value",
+				"newKey": "value",
+				"anotherObject": {
+					"same": "this field is the same in rightJSON",
+					"change": "this field should change in rightJSON",
+					"add": "this field is added"
+				}
+			},
+			"array": [
+				"same",
+				"changed!",
+				"add"
+			],
+			"embeddedArray": {
+				"array": [
+					"same",
+					"changed!",
+					"add"
+				]
+			}
+		}`
+	)
+
+	Convey("Testing dashboard diffs", t, func() {
+
+		// Compute the diff between the two JSON objects
+		baseData, err := simplejson.NewJson([]byte(leftJSON))
+		So(err, ShouldBeNil)
+
+		newData, err := simplejson.NewJson([]byte(rightJSON))
+		So(err, ShouldBeNil)
+
+		left, jsonDiff, err := getDiff(baseData, newData)
+		So(err, ShouldBeNil)
+
+		Convey("The JSONFormatter should produce the expected JSON tokens", func() {
+			f := NewJSONFormatter(left)
+			_, err := f.Format(jsonDiff)
+			So(err, ShouldBeNil)
+
+			// Total up the change types. If the number of different change
+			// types is correct, it means that the diff is producing correct
+			// output to the template rendered.
+			changeCounts := make(map[ChangeType]int)
+			for _, line := range f.Lines {
+				changeCounts[line.Change]++
+			}
+
+			// The expectedChangeCounts here were determined by manually
+			// looking at the JSON
+			expectedChangeCounts := map[ChangeType]int{
+				ChangeNil:       12,
+				ChangeAdded:     2,
+				ChangeDeleted:   1,
+				ChangeOld:       5,
+				ChangeNew:       5,
+				ChangeUnchanged: 5,
+			}
+			So(changeCounts, ShouldResemble, expectedChangeCounts)
+		})
+
+		Convey("The BasicFormatter should produce the expected BasicBlocks", func() {
+			f := NewBasicFormatter(left)
+			_, err := f.Format(jsonDiff)
+			So(err, ShouldBeNil)
+
+			bd := &BasicDiff{}
+			blocks := bd.Basic(f.jsonDiff.Lines)
+
+			changeCounts := make(map[ChangeType]int)
+			for _, block := range blocks {
+				for _, change := range block.Changes {
+					changeCounts[change.Change]++
+				}
+
+				for _, summary := range block.Summaries {
+					changeCounts[summary.Change]++
+				}
+
+				changeCounts[block.Change]++
+			}
+
+			expectedChangeCounts := map[ChangeType]int{
+				ChangeNil:     3,
+				ChangeAdded:   2,
+				ChangeDeleted: 1,
+				ChangeOld:     3,
+			}
+			So(changeCounts, ShouldResemble, expectedChangeCounts)
+		})
+	})
+}

pkg/components/imguploader/azureblobuploader.go

@@ -0,0 +1,320 @@
+package imguploader
+
+import (
+	"bytes"
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"mime"
+	"net/http"
+	"net/url"
+	"os"
+	"path"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/grafana/grafana/pkg/log"
+	"github.com/grafana/grafana/pkg/util"
+)
+
+type AzureBlobUploader struct {
+	account_name   string
+	account_key    string
+	container_name string
+	log            log.Logger
+}
+
+func NewAzureBlobUploader(account_name string, account_key string, container_name string) *AzureBlobUploader {
+	return &AzureBlobUploader{
+		account_name:   account_name,
+		account_key:    account_key,
+		container_name: container_name,
+		log:            log.New("azureBlobUploader"),
+	}
+}
+
+// Receive path of image on disk and return azure blob url
+func (az *AzureBlobUploader) Upload(ctx context.Context, imageDiskPath string) (string, error) {
+	// setup client
+	blob := NewStorageClient(az.account_name, az.account_key)
+
+	file, err := os.Open(imageDiskPath)
+
+	if err != nil {
+		return "", err
+	}
+	randomFileName := util.GetRandomString(30) + ".png"
+	// upload image
+	az.log.Debug("Uploading image to azure_blob", "conatiner_name", az.container_name, "blob_name", randomFileName)
+	resp, err := blob.FileUpload(az.container_name, randomFileName, file)
+	if err != nil {
+		return "", err
+	}
+
+	if resp.StatusCode > 400 && resp.StatusCode < 600 {
+		body, _ := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+		aerr := &Error{
+			Code:   resp.StatusCode,
+			Status: resp.Status,
+			Body:   body,
+			Header: resp.Header,
+		}
+		aerr.parseXML()
+		resp.Body.Close()
+		return "", aerr
+	}
+
+	if err != nil {
+		return "", err
+	}
+
+	url := fmt.Sprintf("https://%s.blob.core.windows.net/%s/%s", az.account_name, az.container_name, randomFileName)
+	return url, nil
+}
+
+// --- AZURE LIBRARY
+type Blobs struct {
+	XMLName xml.Name `xml:"EnumerationResults"`
+	Items   []Blob   `xml:"Blobs>Blob"`
+}
+
+type Blob struct {
+	Name     string   `xml:"Name"`
+	Property Property `xml:"Properties"`
+}
+
+type Property struct {
+	LastModified  string `xml:"Last-Modified"`
+	Etag          string `xml:"Etag"`
+	ContentLength int    `xml:"Content-Length"`
+	ContentType   string `xml:"Content-Type"`
+	BlobType      string `xml:"BlobType"`
+	LeaseStatus   string `xml:"LeaseStatus"`
+}
+
+type Error struct {
+	Code   int
+	Status string
+	Body   []byte
+	Header http.Header
+
+	AzureCode string
+}
+
+func (e *Error) Error() string {
+	return fmt.Sprintf("status %d: %s", e.Code, e.Body)
+}
+
+func (e *Error) parseXML() {
+	var xe xmlError
+	_ = xml.NewDecoder(bytes.NewReader(e.Body)).Decode(&xe)
+	e.AzureCode = xe.Code
+}
+
+type xmlError struct {
+	XMLName xml.Name `xml:"Error"`
+	Code    string
+	Message string
+}
+
+const ms_date_layout = "Mon, 02 Jan 2006 15:04:05 GMT"
+const version = "2017-04-17"
+
+var client = &http.Client{}
+
+type StorageClient struct {
+	Auth      *Auth
+	Transport http.RoundTripper
+}
+
+func (c *StorageClient) transport() http.RoundTripper {
+	if c.Transport != nil {
+		return c.Transport
+	}
+	return http.DefaultTransport
+}
+
+func NewStorageClient(account, accessKey string) *StorageClient {
+	return &StorageClient{
+		Auth: &Auth{
+			account,
+			accessKey,
+		},
+		Transport: nil,
+	}
+}
+
+func (c *StorageClient) absUrl(format string, a ...interface{}) string {
+	part := fmt.Sprintf(format, a...)
+	return fmt.Sprintf("https://%s.blob.core.windows.net/%s", c.Auth.Account, part)
+}
+
+func copyHeadersToRequest(req *http.Request, headers map[string]string) {
+	for k, v := range headers {
+		req.Header[k] = []string{v}
+	}
+}
+
+func (c *StorageClient) FileUpload(container, blobName string, body io.Reader) (*http.Response, error) {
+	blobName = escape(blobName)
+	extension := strings.ToLower(path.Ext(blobName))
+	contentType := mime.TypeByExtension(extension)
+	buf := new(bytes.Buffer)
+	buf.ReadFrom(body)
+	req, err := http.NewRequest(
+		"PUT",
+		c.absUrl("%s/%s", container, blobName),
+		buf,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	copyHeadersToRequest(req, map[string]string{
+		"x-ms-blob-type": "BlockBlob",
+		"x-ms-date":      time.Now().UTC().Format(ms_date_layout),
+		"x-ms-version":   version,
+		"Accept-Charset": "UTF-8",
+		"Content-Type":   contentType,
+		"Content-Length": strconv.Itoa(buf.Len()),
+	})
+
+	c.Auth.SignRequest(req)
+
+	return c.transport().RoundTrip(req)
+}
+
+func escape(content string) string {
+	content = url.QueryEscape(content)
+	// the Azure's behavior uses %20 to represent whitespace instead of + (plus)
+	content = strings.Replace(content, "+", "%20", -1)
+	// the Azure's behavior uses slash instead of + %2F
+	content = strings.Replace(content, "%2F", "/", -1)
+
+	return content
+}
+
+type Auth struct {
+	Account string
+	Key     string
+}
+
+func (a *Auth) SignRequest(req *http.Request) {
+	strToSign := fmt.Sprintf("%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s",
+		strings.ToUpper(req.Method),
+		tryget(req.Header, "Content-Encoding"),
+		tryget(req.Header, "Content-Language"),
+		tryget(req.Header, "Content-Length"),
+		tryget(req.Header, "Content-MD5"),
+		tryget(req.Header, "Content-Type"),
+		tryget(req.Header, "Date"),
+		tryget(req.Header, "If-Modified-Since"),
+		tryget(req.Header, "If-Match"),
+		tryget(req.Header, "If-None-Match"),
+		tryget(req.Header, "If-Unmodified-Since"),
+		tryget(req.Header, "Range"),
+		a.canonicalizedHeaders(req),
+		a.canonicalizedResource(req),
+	)
+	decodedKey, _ := base64.StdEncoding.DecodeString(a.Key)
+
+	sha256 := hmac.New(sha256.New, []byte(decodedKey))
+	sha256.Write([]byte(strToSign))
+
+	signature := base64.StdEncoding.EncodeToString(sha256.Sum(nil))
+
+	copyHeadersToRequest(req, map[string]string{
+		"Authorization": fmt.Sprintf("SharedKey %s:%s", a.Account, signature),
+	})
+}
+
+func tryget(headers map[string][]string, key string) string {
+	// We default to empty string for "0" values to match server side behavior when generating signatures.
+	if len(headers[key]) > 0 { // && headers[key][0] != "0" { //&& key != "Content-Length" {
+		return headers[key][0]
+	}
+	return ""
+}
+
+//
+// The following is copied ~95% verbatim from:
+//  http://github.com/loldesign/azure/ -> core/core.go
+//
+
+/*
+Based on Azure docs:
+  Link: http://msdn.microsoft.com/en-us/library/windowsazure/dd179428.aspx#Constructing_Element
+
+  1) Retrieve all headers for the resource that begin with x-ms-, including the x-ms-date header.
+  2) Convert each HTTP header name to lowercase.
+  3) Sort the headers lexicographically by header name, in ascending order. Note that each header may appear only once in the string.
+  4) Unfold the string by replacing any breaking white space with a single space.
+  5) Trim any white space around the colon in the header.
+  6) Finally, append a new line character to each canonicalized header in the resulting list. Construct the CanonicalizedHeaders string by concatenating all headers in this list into a single string.
+*/
+func (a *Auth) canonicalizedHeaders(req *http.Request) string {
+	var buffer bytes.Buffer
+
+	for key, value := range req.Header {
+		lowerKey := strings.ToLower(key)
+
+		if strings.HasPrefix(lowerKey, "x-ms-") {
+			if buffer.Len() == 0 {
+				buffer.WriteString(fmt.Sprintf("%s:%s", lowerKey, value[0]))
+			} else {
+				buffer.WriteString(fmt.Sprintf("\n%s:%s", lowerKey, value[0]))
+			}
+		}
+	}
+
+	splitted := strings.Split(buffer.String(), "\n")
+	sort.Strings(splitted)
+
+	return strings.Join(splitted, "\n")
+}
+
+/*
+Based on Azure docs
+  Link: http://msdn.microsoft.com/en-us/library/windowsazure/dd179428.aspx#Constructing_Element
+
+1) Beginning with an empty string (""), append a forward slash (/), followed by the name of the account that owns the resource being accessed.
+2) Append the resource's encoded URI path, without any query parameters.
+3) Retrieve all query parameters on the resource URI, including the comp parameter if it exists.
+4) Convert all parameter names to lowercase.
+5) Sort the query parameters lexicographically by parameter name, in ascending order.
+6) URL-decode each query parameter name and value.
+7) Append each query parameter name and value to the string in the following format, making sure to include the colon (:) between the name and the value:
+    parameter-name:parameter-value
+
+8) If a query parameter has more than one value, sort all values lexicographically, then include them in a comma-separated list:
+    parameter-name:parameter-value-1,parameter-value-2,parameter-value-n
+
+9) Append a new line character (\n) after each name-value pair.
+
+Rules:
+  1) Avoid using the new line character (\n) in values for query parameters. If it must be used, ensure that it does not affect the format of the canonicalized resource string.
+  2) Avoid using commas in query parameter values.
+*/
+func (a *Auth) canonicalizedResource(req *http.Request) string {
+	var buffer bytes.Buffer
+
+	buffer.WriteString(fmt.Sprintf("/%s%s", a.Account, req.URL.Path))
+	queries := req.URL.Query()
+
+	for key, values := range queries {
+		sort.Strings(values)
+		buffer.WriteString(fmt.Sprintf("\n%s:%s", key, strings.Join(values, ",")))
+	}
+
+	splitted := strings.Split(buffer.String(), "\n")
+	sort.Strings(splitted)
+
+	return strings.Join(splitted, "\n")
+}

pkg/components/imguploader/azureblobuploader_test.go

@@ -0,0 +1,24 @@
+package imguploader
+
+import (
+	"context"
+	"testing"
+
+	"github.com/grafana/grafana/pkg/setting"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestUploadToAzureBlob(t *testing.T) {
+	SkipConvey("[Integration test] for external_image_store.azure_blob", t, func() {
+		err := setting.NewConfigContext(&setting.CommandLineArgs{
+			HomePath: "../../../",
+		})
+
+		uploader, _ := NewImageUploader()
+
+		path, err := uploader.Upload(context.Background(), "../../../public/img/logo_transparent_400x.png")
+
+		So(err, ShouldBeNil)
+		So(path, ShouldNotEqual, "")
+	})
+}

pkg/components/imguploader/gcsuploader.go

@@ -0,0 +1,92 @@
+package imguploader
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path"
+
+	"github.com/grafana/grafana/pkg/log"
+	"github.com/grafana/grafana/pkg/util"
+	"golang.org/x/oauth2/google"
+)
+
+const (
+	tokenUrl  string = "https://www.googleapis.com/auth/devstorage.read_write"
+	uploadUrl string = "https://www.googleapis.com/upload/storage/v1/b/%s/o?uploadType=media&name=%s&predefinedAcl=publicRead"
+)
+
+type GCSUploader struct {
+	keyFile string
+	bucket  string
+	path    string
+	log     log.Logger
+}
+
+func NewGCSUploader(keyFile, bucket, path string) *GCSUploader {
+	return &GCSUploader{
+		keyFile: keyFile,
+		bucket:  bucket,
+		path:    path,
+		log:     log.New("gcsuploader"),
+	}
+}
+
+func (u *GCSUploader) Upload(ctx context.Context, imageDiskPath string) (string, error) {
+	fileName := util.GetRandomString(20) + ".png"
+	key := path.Join(u.path, fileName)
+
+	u.log.Debug("Opening key file ", u.keyFile)
+	data, err := ioutil.ReadFile(u.keyFile)
+	if err != nil {
+		return "", err
+	}
+
+	u.log.Debug("Creating JWT conf")
+	conf, err := google.JWTConfigFromJSON(data, tokenUrl)
+	if err != nil {
+		return "", err
+	}
+
+	u.log.Debug("Creating HTTP client")
+	client := conf.Client(ctx)
+	err = u.uploadFile(client, imageDiskPath, key)
+	if err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("https://storage.googleapis.com/%s/%s", u.bucket, key), nil
+}
+
+func (u *GCSUploader) uploadFile(client *http.Client, imageDiskPath, key string) error {
+	u.log.Debug("Opening image file ", imageDiskPath)
+
+	fileReader, err := os.Open(imageDiskPath)
+	if err != nil {
+		return err
+	}
+
+	reqUrl := fmt.Sprintf(uploadUrl, u.bucket, key)
+	u.log.Debug("Request URL: ", reqUrl)
+
+	req, err := http.NewRequest("POST", reqUrl, fileReader)
+	if err != nil {
+		return err
+	}
+
+	req.Header.Add("Content-Type", "image/png")
+	u.log.Debug("Sending POST request to GCS")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != 200 {
+		return fmt.Errorf("GCS response status code %d", resp.StatusCode)
+	}
+
+	return nil
+}

pkg/components/imguploader/gcsuploader_test.go

@@ -0,0 +1,24 @@
+package imguploader
+
+import (
+	"context"
+	"testing"
+
+	"github.com/grafana/grafana/pkg/setting"
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestUploadToGCS(t *testing.T) {
+	SkipConvey("[Integration test] for external_image_store.gcs", t, func() {
+		setting.NewConfigContext(&setting.CommandLineArgs{
+			HomePath: "../../../",
+		})
+
+		gcsUploader, _ := NewImageUploader()
+
+		path, err := gcsUploader.Upload(context.Background(), "../../../public/img/logo_transparent_400x.png")
+
+		So(err, ShouldBeNil)
+		So(path, ShouldNotEqual, "")
+	})
+}

pkg/components/imguploader/imguploader.go

@@ -1,20 +1,22 @@
 package imguploader
 
 import (
+	"context"
 	"fmt"
+	"github.com/grafana/grafana/pkg/log"
 	"regexp"
 
 	"github.com/grafana/grafana/pkg/setting"
 )
 
 type ImageUploader interface {
-	Upload(path string) (string, error)
+	Upload(ctx context.Context, path string) (string, error)
 }
 
 type NopImageUploader struct {
 }
 
-func (NopImageUploader) Upload(path string) (string, error) {
+func (NopImageUploader) Upload(ctx context.Context, path string) (string, error) {
 	return "", nil
 }
 
@@ -27,15 +29,27 @@ func NewImageUploader() (ImageUploader, error) {
 			return nil, err
 		}
 
+		bucket := s3sec.Key("bucket").MustString("")
+		region := s3sec.Key("region").MustString("")
+		path := s3sec.Key("path").MustString("")
 		bucketUrl := s3sec.Key("bucket_url").MustString("")
 		accessKey := s3sec.Key("access_key").MustString("")
 		secretKey := s3sec.Key("secret_key").MustString("")
-		info, err := getRegionAndBucketFromUrl(bucketUrl)
-		if err != nil {
-			return nil, err
+
+		if path != "" && path[len(path)-1:] != "/" {
+			path += "/"
 		}
 
-		return NewS3Uploader(info.region, info.bucket, "public-read", accessKey, secretKey), nil
+		if bucket == "" || region == "" {
+			info, err := getRegionAndBucketFromUrl(bucketUrl)
+			if err != nil {
+				return nil, err
+			}
+			bucket = info.bucket
+			region = info.region
+		}
+
+		return NewS3Uploader(region, bucket, path, "public-read", accessKey, secretKey), nil
 	case "webdav":
 		webdavSec, err := setting.Cfg.GetSection("external_image_storage.webdav")
 		if err != nil {
@@ -47,10 +61,39 @@ func NewImageUploader() (ImageUploader, error) {
 			return nil, fmt.Errorf("Could not find url key for image.uploader.webdav")
 		}
 
+		public_url := webdavSec.Key("public_url").String()
 		username := webdavSec.Key("username").String()
 		password := webdavSec.Key("password").String()
 
-		return NewWebdavImageUploader(url, username, password)
+		return NewWebdavImageUploader(url, username, password, public_url)
+	case "gcs":
+		gcssec, err := setting.Cfg.GetSection("external_image_storage.gcs")
+		if err != nil {
+			return nil, err
+		}
+
+		keyFile := gcssec.Key("key_file").MustString("")
+		bucketName := gcssec.Key("bucket").MustString("")
+		path := gcssec.Key("path").MustString("")
+
+		return NewGCSUploader(keyFile, bucketName, path), nil
+	case "azure_blob":
+		azureBlobSec, err := setting.Cfg.GetSection("external_image_storage.azure_blob")
+		if err != nil {
+			return nil, err
+		}
+
+		account_name := azureBlobSec.Key("account_name").MustString("")
+		account_key := azureBlobSec.Key("account_key").MustString("")
+		container_name := azureBlobSec.Key("container_name").MustString("")
+
+		return NewAzureBlobUploader(account_name, account_key, container_name), nil
+	case "local":
+		return NewLocalImageUploader()
+	}
+
+	if setting.ImageUploadProvider != "" {
+		log.Error2("The external image storage configuration is invalid", "unsupported provider", setting.ImageUploadProvider)
 	}
 
 	return NopImageUploader{}, nil

pkg/components/imguploader/imguploader_test.go

@@ -96,5 +96,70 @@ func TestImageUploaderFactory(t *testing.T) {
 			So(original.username, ShouldEqual, "username")
 			So(original.password, ShouldEqual, "password")
 		})
+
+		Convey("GCS uploader", func() {
+			var err error
+
+			setting.NewConfigContext(&setting.CommandLineArgs{
+				HomePath: "../../../",
+			})
+
+			setting.ImageUploadProvider = "gcs"
+
+			gcpSec, err := setting.Cfg.GetSection("external_image_storage.gcs")
+			gcpSec.NewKey("key_file", "/etc/secrets/project-79a52befa3f6.json")
+			gcpSec.NewKey("bucket", "project-grafana-east")
+
+			uploader, err := NewImageUploader()
+
+			So(err, ShouldBeNil)
+			original, ok := uploader.(*GCSUploader)
+
+			So(ok, ShouldBeTrue)
+			So(original.keyFile, ShouldEqual, "/etc/secrets/project-79a52befa3f6.json")
+			So(original.bucket, ShouldEqual, "project-grafana-east")
+		})
+
+		Convey("AzureBlobUploader config", func() {
+			setting.NewConfigContext(&setting.CommandLineArgs{
+				HomePath: "../../../",
+			})
+			setting.ImageUploadProvider = "azure_blob"
+
+			Convey("with container name", func() {
+				azureBlobSec, err := setting.Cfg.GetSection("external_image_storage.azure_blob")
+				azureBlobSec.NewKey("account_name", "account_name")
+				azureBlobSec.NewKey("account_key", "account_key")
+				azureBlobSec.NewKey("container_name", "container_name")
+
+				uploader, err := NewImageUploader()
+
+				So(err, ShouldBeNil)
+				original, ok := uploader.(*AzureBlobUploader)
+
+				So(ok, ShouldBeTrue)
+				So(original.account_name, ShouldEqual, "account_name")
+				So(original.account_key, ShouldEqual, "account_key")
+				So(original.container_name, ShouldEqual, "container_name")
+			})
+		})
+
+		Convey("Local uploader", func() {
+			var err error
+
+			setting.NewConfigContext(&setting.CommandLineArgs{
+				HomePath: "../../../",
+			})
+
+			setting.ImageUploadProvider = "local"
+
+			uploader, err := NewImageUploader()
+
+			So(err, ShouldBeNil)
+			original, ok := uploader.(*LocalUploader)
+
+			So(ok, ShouldBeTrue)
+			So(original, ShouldNotBeNil)
+		})
 	})
 }

pkg/components/imguploader/localuploader.go

@@ -0,0 +1,22 @@
+package imguploader
+
+import (
+	"context"
+	"path"
+	"path/filepath"
+
+	"github.com/grafana/grafana/pkg/setting"
+)
+
+type LocalUploader struct {
+}
+
+func (u *LocalUploader) Upload(ctx context.Context, imageOnDiskPath string) (string, error) {
+	filename := filepath.Base(imageOnDiskPath)
+	image_url := setting.ToAbsUrl(path.Join("public/img/attachments", filename))
+	return image_url, nil
+}
+
+func NewLocalImageUploader() (*LocalUploader, error) {
+	return &LocalUploader{}, nil
+}

pkg/components/imguploader/localuploader_test.go

@@ -0,0 +1,18 @@
+package imguploader
+
+import (
+	"context"
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+)
+
+func TestUploadToLocal(t *testing.T) {
+	Convey("[Integration test] for external_image_store.local", t, func() {
+		localUploader, _ := NewLocalImageUploader()
+		path, err := localUploader.Upload(context.Background(), "../../../public/img/logo_transparent_400x.png")
+
+		So(err, ShouldBeNil)
+		So(path, ShouldContainSubstring, "/public/img/attachments")
+	})
+}

pkg/components/imguploader/s3uploader.go

@@ -1,6 +1,7 @@
 package imguploader
 
 import (
+	"context"
 	"os"
 	"time"
 
@@ -8,6 +9,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/aws/aws-sdk-go/aws/credentials/ec2rolecreds"
 	"github.com/aws/aws-sdk-go/aws/ec2metadata"
+	"github.com/aws/aws-sdk-go/aws/endpoints"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/s3"
 	"github.com/grafana/grafana/pkg/log"
@@ -17,16 +19,18 @@ import (
 type S3Uploader struct {
 	region    string
 	bucket    string
+	path      string
 	acl       string
 	secretKey string
 	accessKey string
 	log       log.Logger
 }
 
-func NewS3Uploader(region, bucket, acl, accessKey, secretKey string) *S3Uploader {
+func NewS3Uploader(region, bucket, path, acl, accessKey, secretKey string) *S3Uploader {
 	return &S3Uploader{
 		region:    region,
 		bucket:    bucket,
+		path:      path,
 		acl:       acl,
 		accessKey: accessKey,
 		secretKey: secretKey,
@@ -34,7 +38,7 @@ func NewS3Uploader(region, bucket, acl, accessKey, secretKey string) *S3Uploader
 	}
 }
 
-func (u *S3Uploader) Upload(imageDiskPath string) (string, error) {
+func (u *S3Uploader) Upload(ctx context.Context, imageDiskPath string) (string, error) {
 	sess, err := session.NewSession()
 	if err != nil {
 		return "", err
@@ -53,8 +57,10 @@ func (u *S3Uploader) Upload(imageDiskPath string) (string, error) {
 		Credentials: creds,
 	}
 
-	key := util.GetRandomString(20) + ".png"
-	log.Debug("Uploading image to s3", "bucket = ", u.bucket, ", key = ", key)
+	s3_endpoint, _ := endpoints.DefaultResolver().EndpointFor("s3", u.region)
+	key := u.path + util.GetRandomString(20) + ".png"
+	image_url := s3_endpoint.URL + "/" + u.bucket + "/" + key
+	log.Debug("Uploading image to s3", "url = ", image_url)
 
 	file, err := os.Open(imageDiskPath)
 	if err != nil {
@@ -77,6 +83,5 @@ func (u *S3Uploader) Upload(imageDiskPath string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-
-	return "https://" + u.bucket + ".s3.amazonaws.com/" + key, nil
+	return image_url, nil
 }

pkg/components/imguploader/s3uploader_test.go

@@ -1,6 +1,7 @@
 package imguploader
 
 import (
+	"context"
 	"testing"
 
 	"github.com/grafana/grafana/pkg/setting"
@@ -8,14 +9,14 @@ import (
 )
 
 func TestUploadToS3(t *testing.T) {
-	SkipConvey("[Integration test] for external_image_store.webdav", t, func() {
+	SkipConvey("[Integration test] for external_image_store.s3", t, func() {
 		setting.NewConfigContext(&setting.CommandLineArgs{
 			HomePath: "../../../",
 		})
 
 		s3Uploader, _ := NewImageUploader()
 
-		path, err := s3Uploader.Upload("../../../public/img/logo_transparent_400x.png")
+		path, err := s3Uploader.Upload(context.Background(), "../../../public/img/logo_transparent_400x.png")
 
 		So(err, ShouldBeNil)
 		So(path, ShouldNotEqual, "")

pkg/components/imguploader/webdavuploader.go

@@ -2,6 +2,7 @@ package imguploader
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io/ioutil"
 	"net"
@@ -14,14 +15,17 @@ import (
 )
 
 type WebdavUploader struct {
-	url      string
-	username string
-	password string
+	url        string
+	username   string
+	password   string
+	public_url string
 }
 
 var netTransport = &http.Transport{
+	Proxy: http.ProxyFromEnvironment,
 	Dial: (&net.Dialer{
-		Timeout: 60 * time.Second,
+		Timeout:   60 * time.Second,
+		DualStack: true,
 	}).Dial,
 	TLSHandshakeTimeout: 5 * time.Second,
 }
@@ -31,9 +35,10 @@ var netClient = &http.Client{
 	Transport: netTransport,
 }
 
-func (u *WebdavUploader) Upload(pa string) (string, error) {
+func (u *WebdavUploader) Upload(ctx context.Context, pa string) (string, error) {
 	url, _ := url.Parse(u.url)
-	url.Path = path.Join(url.Path, util.GetRandomString(20)+".png")
+	filename := util.GetRandomString(20) + ".png"
+	url.Path = path.Join(url.Path, filename)
 
 	imgData, err := ioutil.ReadFile(pa)
 	req, err := http.NewRequest("PUT", url.String(), bytes.NewReader(imgData))
@@ -53,13 +58,20 @@ func (u *WebdavUploader) Upload(pa string) (string, error) {
 		return "", fmt.Errorf("Failed to upload image. Returned statuscode %v body %s", res.StatusCode, body)
 	}
 
+	if u.public_url != "" {
+		publicURL, _ := url.Parse(u.public_url)
+		publicURL.Path = path.Join(publicURL.Path, filename)
+		return publicURL.String(), nil
+	}
+
 	return url.String(), nil
 }
 
-func NewWebdavImageUploader(url, username, passwrod string) (*WebdavUploader, error) {
+func NewWebdavImageUploader(url, username, password, public_url string) (*WebdavUploader, error) {
 	return &WebdavUploader{
-		url:      url,
-		username: username,
-		password: passwrod,
+		url:        url,
+		username:   username,
+		password:   password,
+		public_url: public_url,
 	}, nil
 }

pkg/components/imguploader/webdavuploader_test.go

@@ -1,18 +1,28 @@
 package imguploader
 
 import (
+	"context"
 	"testing"
 
 	. "github.com/smartystreets/goconvey/convey"
 )
 
 func TestUploadToWebdav(t *testing.T) {
-	webdavUploader, _ := NewWebdavImageUploader("http://localhost:9998/dav/", "username", "password")
 
+	// Can be tested with this docker container: https://hub.docker.com/r/morrisjobke/webdav/
 	SkipConvey("[Integration test] for external_image_store.webdav", t, func() {
-		path, err := webdavUploader.Upload("../../../public/img/logo_transparent_400x.png")
+		webdavUploader, _ := NewWebdavImageUploader("http://localhost:8888/webdav/", "test", "test", "")
+		path, err := webdavUploader.Upload(context.Background(), "../../../public/img/logo_transparent_400x.png")
 
 		So(err, ShouldBeNil)
-		So(path, ShouldNotEqual, "")
+		So(path, ShouldStartWith, "http://localhost:8888/webdav/")
+	})
+
+	SkipConvey("[Integration test] for external_image_store.webdav with public url", t, func() {
+		webdavUploader, _ := NewWebdavImageUploader("http://localhost:8888/webdav/", "test", "test", "http://publicurl:8888/webdav")
+		path, err := webdavUploader.Upload(context.Background(), "../../../public/img/logo_transparent_400x.png")
+
+		So(err, ShouldBeNil)
+		So(path, ShouldStartWith, "http://publicurl:8888/webdav/")
 	})
 }

pkg/components/renderer/renderer.go

@@ -1,6 +1,7 @@
 package renderer
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -15,19 +16,25 @@ import (
 
 	"github.com/grafana/grafana/pkg/log"
 	"github.com/grafana/grafana/pkg/middleware"
+	"github.com/grafana/grafana/pkg/models"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util"
 )
 
 type RenderOpts struct {
-	Path     string
-	Width    string
-	Height   string
-	Timeout  string
-	OrgId    int64
-	Timezone string
+	Path           string
+	Width          string
+	Height         string
+	Timeout        string
+	OrgId          int64
+	UserId         int64
+	OrgRole        models.RoleType
+	Timezone       string
+	IsAlertContext bool
+	Encoding       string
 }
 
+var ErrTimeout = errors.New("Timeout error. You can set timeout in seconds with &timeout url parameter")
 var rendererLog log.Logger = log.New("png-renderer")
 
 func isoTimeOffsetToPosixTz(isoOffset string) string {
@@ -65,38 +72,58 @@ func RenderToPng(params *RenderOpts) (string, error) {
 		localDomain = setting.HttpAddr
 	}
 
-	url := fmt.Sprintf("%s://%s:%s/%s", setting.Protocol, localDomain, setting.HttpPort, params.Path)
+	// &render=1 signals to the legacy redirect layer to
+	// avoid redirect these requests.
+	url := fmt.Sprintf("%s://%s:%s/%s&render=1", setting.Protocol, localDomain, setting.HttpPort, params.Path)
 
 	binPath, _ := filepath.Abs(filepath.Join(setting.PhantomDir, executable))
 	scriptPath, _ := filepath.Abs(filepath.Join(setting.PhantomDir, "render.js"))
 	pngPath, _ := filepath.Abs(filepath.Join(setting.ImagesDir, util.GetRandomString(20)))
 	pngPath = pngPath + ".png"
 
-	renderKey := middleware.AddRenderAuthKey(params.OrgId)
+	orgRole := params.OrgRole
+	if params.IsAlertContext {
+		orgRole = models.ROLE_ADMIN
+	}
+	renderKey := middleware.AddRenderAuthKey(params.OrgId, params.UserId, orgRole)
 	defer middleware.RemoveRenderAuthKey(renderKey)
 
+	timeout, err := strconv.Atoi(params.Timeout)
+	if err != nil {
+		timeout = 15
+	}
+
+	phantomDebugArg := "--debug=false"
+	if log.GetLogLevelFor("png-renderer") >= log.LvlDebug {
+		phantomDebugArg = "--debug=true"
+	}
+
 	cmdArgs := []string{
 		"--ignore-ssl-errors=true",
 		"--web-security=false",
+		phantomDebugArg,
 		scriptPath,
 		"url=" + url,
 		"width=" + params.Width,
 		"height=" + params.Height,
 		"png=" + pngPath,
 		"domain=" + localDomain,
+		"timeout=" + strconv.Itoa(timeout),
 		"renderKey=" + renderKey,
 	}
 
+	if params.Encoding != "" {
+		cmdArgs = append([]string{fmt.Sprintf("--output-encoding=%s", params.Encoding)}, cmdArgs...)
+	}
+
 	cmd := exec.Command(binPath, cmdArgs...)
-	stdout, err := cmd.StdoutPipe()
+	output, err := cmd.StdoutPipe()
 
 	if err != nil {
+		rendererLog.Error("Could not acquire stdout pipe", err)
 		return "", err
 	}
-	stderr, err := cmd.StderrPipe()
-	if err != nil {
-		return "", err
-	}
+	cmd.Stderr = cmd.Stdout
 
 	if params.Timezone != "" {
 		baseEnviron := os.Environ()
@@ -105,29 +132,27 @@ func RenderToPng(params *RenderOpts) (string, error) {
 
 	err = cmd.Start()
 	if err != nil {
+		rendererLog.Error("Could not start command", err)
 		return "", err
 	}
 
-	go io.Copy(os.Stdout, stdout)
-	go io.Copy(os.Stdout, stderr)
+	logWriter := log.NewLogWriter(rendererLog, log.LvlDebug, "[phantom] ")
+	go io.Copy(logWriter, output)
 
 	done := make(chan error)
 	go func() {
-		cmd.Wait()
+		if err := cmd.Wait(); err != nil {
+			rendererLog.Error("failed to render an image", "error", err)
+		}
 		close(done)
 	}()
 
-	timeout, err := strconv.Atoi(params.Timeout)
-	if err != nil {
-		timeout = 15
-	}
-
 	select {
 	case <-time.After(time.Duration(timeout) * time.Second):
 		if err := cmd.Process.Kill(); err != nil {
 			rendererLog.Error("failed to kill", "error", err)
 		}
-		return "", fmt.Errorf("PhantomRenderer::renderToPng timeout (>%vs)", timeout)
+		return "", ErrTimeout
 	case <-done:
 	}
 

pkg/components/securejsondata/securejsondata.go

@@ -1,6 +1,7 @@
 package securejsondata
 
 import (
+	"github.com/grafana/grafana/pkg/log"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/util"
 )
@@ -10,7 +11,12 @@ type SecureJsonData map[string][]byte
 func (s SecureJsonData) Decrypt() map[string]string {
 	decrypted := make(map[string]string)
 	for key, data := range s {
-		decrypted[key] = string(util.Decrypt(data, setting.SecretKey))
+		decryptedData, err := util.Decrypt(data, setting.SecretKey)
+		if err != nil {
+			log.Fatal(4, err.Error())
+		}
+
+		decrypted[key] = string(decryptedData)
 	}
 	return decrypted
 }
@@ -18,7 +24,12 @@ func (s SecureJsonData) Decrypt() map[string]string {
 func GetEncryptedJsonData(sjd map[string]string) SecureJsonData {
 	encrypted := make(SecureJsonData)
 	for key, data := range sjd {
-		encrypted[key] = util.Encrypt([]byte(data), setting.SecretKey)
+		encryptedData, err := util.Encrypt([]byte(data), setting.SecretKey)
+		if err != nil {
+			log.Fatal(4, err.Error())
+		}
+
+		encrypted[key] = encryptedData
 	}
 	return encrypted
 }