Introduce TSDB service (#31520)

* Introduce TSDB service

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

Co-authored-by: Erik Sundell <erik.sundell87@gmail.com>
Co-authored-by: Will Browne <will.browne@grafana.com>
Co-authored-by: Torkel Ödegaard <torkel@grafana.org>
Co-authored-by: Will Browne <wbrowne@users.noreply.github.com>
Co-authored-by: Zoltán Bedi <zoltan.bedi@gmail.com>

pkg/plugins/manager/dashboard_import.go

@@ -0,0 +1,170 @@
+package manager
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+
+	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/plugins"
+	"github.com/grafana/grafana/pkg/services/dashboards"
+	"github.com/grafana/grafana/pkg/tsdb/tsdbifaces"
+)
+
+var varRegex = regexp.MustCompile(`(\$\{.+?\})`)
+
+type ImportDashboardInput struct {
+	Type     string `json:"type"`
+	PluginId string `json:"pluginId"`
+	Name     string `json:"name"`
+	Value    string `json:"value"`
+}
+
+type DashboardInputMissingError struct {
+	VariableName string
+}
+
+func (e DashboardInputMissingError) Error() string {
+	return fmt.Sprintf("Dashboard input variable: %v missing from import command", e.VariableName)
+}
+
+func (pm *PluginManager) ImportDashboard(pluginID, path string, orgID, folderID int64, dashboardModel *simplejson.Json,
+	overwrite bool, inputs []ImportDashboardInput, user *models.SignedInUser,
+	requestHandler tsdbifaces.RequestHandler) (plugins.PluginDashboardInfoDTO, error) {
+	var dashboard *models.Dashboard
+	if pluginID != "" {
+		var err error
+		if dashboard, err = pm.LoadPluginDashboard(pluginID, path); err != nil {
+			return plugins.PluginDashboardInfoDTO{}, err
+		}
+	} else {
+		dashboard = models.NewDashboardFromJson(dashboardModel)
+	}
+
+	evaluator := &DashTemplateEvaluator{
+		template: dashboard.Data,
+		inputs:   inputs,
+	}
+
+	generatedDash, err := evaluator.Eval()
+	if err != nil {
+		return plugins.PluginDashboardInfoDTO{}, err
+	}
+
+	saveCmd := models.SaveDashboardCommand{
+		Dashboard: generatedDash,
+		OrgId:     orgID,
+		UserId:    user.UserId,
+		Overwrite: overwrite,
+		PluginId:  pluginID,
+		FolderId:  folderID,
+	}
+
+	dto := &dashboards.SaveDashboardDTO{
+		OrgId:     orgID,
+		Dashboard: saveCmd.GetDashboardModel(),
+		Overwrite: saveCmd.Overwrite,
+		User:      user,
+	}
+
+	savedDash, err := dashboards.NewService(requestHandler).ImportDashboard(dto)
+	if err != nil {
+		return plugins.PluginDashboardInfoDTO{}, err
+	}
+
+	return plugins.PluginDashboardInfoDTO{
+		PluginId:         pluginID,
+		Title:            savedDash.Title,
+		Path:             path,
+		Revision:         savedDash.Data.Get("revision").MustInt64(1),
+		FolderId:         savedDash.FolderId,
+		ImportedUri:      "db/" + savedDash.Slug,
+		ImportedUrl:      savedDash.GetUrl(),
+		ImportedRevision: dashboard.Data.Get("revision").MustInt64(1),
+		Imported:         true,
+		DashboardId:      savedDash.Id,
+		Slug:             savedDash.Slug,
+	}, nil
+}
+
+type DashTemplateEvaluator struct {
+	template  *simplejson.Json
+	inputs    []ImportDashboardInput
+	variables map[string]string
+	result    *simplejson.Json
+}
+
+func (e *DashTemplateEvaluator) findInput(varName string, varType string) *ImportDashboardInput {
+	for _, input := range e.inputs {
+		if varType == input.Type && (input.Name == varName || input.Name == "*") {
+			return &input
+		}
+	}
+
+	return nil
+}
+
+func (e *DashTemplateEvaluator) Eval() (*simplejson.Json, error) {
+	e.result = simplejson.New()
+	e.variables = make(map[string]string)
+
+	// check that we have all inputs we need
+	for _, inputDef := range e.template.Get("__inputs").MustArray() {
+		inputDefJson := simplejson.NewFromAny(inputDef)
+		inputName := inputDefJson.Get("name").MustString()
+		inputType := inputDefJson.Get("type").MustString()
+		input := e.findInput(inputName, inputType)
+
+		if input == nil {
+			return nil, &DashboardInputMissingError{VariableName: inputName}
+		}
+
+		e.variables["${"+inputName+"}"] = input.Value
+	}
+
+	return simplejson.NewFromAny(e.evalObject(e.template)), nil
+}
+
+func (e *DashTemplateEvaluator) evalValue(source *simplejson.Json) interface{} {
+	sourceValue := source.Interface()
+
+	switch v := sourceValue.(type) {
+	case string:
+		interpolated := varRegex.ReplaceAllStringFunc(v, func(match string) string {
+			replacement, exists := e.variables[match]
+			if exists {
+				return replacement
+			}
+			return match
+		})
+		return interpolated
+	case bool:
+		return v
+	case json.Number:
+		return v
+	case map[string]interface{}:
+		return e.evalObject(source)
+	case []interface{}:
+		array := make([]interface{}, 0)
+		for _, item := range v {
+			array = append(array, e.evalValue(simplejson.NewFromAny(item)))
+		}
+		return array
+	}
+
+	return nil
+}
+
+func (e *DashTemplateEvaluator) evalObject(source *simplejson.Json) interface{} {
+	result := make(map[string]interface{})
+
+	for key, value := range source.MustMap() {
+		if key == "__inputs" {
+			continue
+		}
+		result[key] = e.evalValue(simplejson.NewFromAny(value))
+	}
+
+	return result
+}