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Alerting: Add doc comments to classic.go (#56724)

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This commit is contained in:
George Robinson
2022-10-12 10:55:48 +01:00
committed by GitHub
parent dd9e1498f9
commit 67d93ceea0
4 changed files with 153 additions and 121 deletions
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pkg/expr/classic/classic.go
+99 -69
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@@ -11,92 +11,71 @@ import (
"github.com/grafana/grafana/pkg/expr/mathexp"
)
// ConditionsCmd is command for the classic conditions
// expression operation.
// ConditionsCmd is a command that supports the reduction and comparison of conditions.
//
// A condition in ConditionsCmd can reduce a time series, contain an instant metric, or the
// result of another expression; and checks if it exceeds a threshold, falls within a range,
// or does not contain a value.
//
// If ConditionsCmd contains more than one condition, it reduces the boolean outcomes of the
// threshold, range or value checks using the logical operator of the right hand side condition
// until all conditions have been reduced to a single boolean outcome. ConditionsCmd does not
// follow operator precedence.
//
// For example if we have the following classic condition:
//
// min(A) > 5 OR max(B) < 10 AND C = 1
//
// which reduces to the following boolean outcomes:
//
// false OR true AND true
//
// then the outcome of ConditionsCmd is true.
type ConditionsCmd struct {
Conditions []condition
refID string
RefID string
}
// ClassicConditionJSON is the JSON model for a single condition.
// It is based on services/alerting/conditions/query.go's newQueryCondition().
type ClassicConditionJSON struct {
Evaluator ConditionEvalJSON `json:"evaluator"`
Operator struct {
Type string `json:"type"`
} `json:"operator"`
Query struct {
Params []string `json:"params"`
} `json:"query"`
Reducer struct {
// Params []interface{} `json:"params"` (Unused)
Type string `json:"type"`
} `json:"reducer"`
}
type ConditionEvalJSON struct {
Params []float64 `json:"params"`
Type string `json:"type"` // e.g. "gt"
}
// condition is a single condition within the ConditionsCmd.
// condition is a single condition in ConditionsCmd.
type condition struct {
QueryRefID string
Reducer classicReducer
Evaluator evaluator
Operator string
}
InputRefID string
type classicReducer string
// Reducer reduces a series of data into a single result. An example of a reducer is the avg,
// min and max functions.
Reducer reducer
// Evaluator evaluates the reduced time series, instant metric, or result of another expression
// against an evaluator. An example of an evaluator is checking if it exceeds a threshold,
// falls within a range, or does not contain a value.
Evaluator evaluator
// Operator is the logical operator to use when there are two conditions in ConditionsCmd.
// If there are more than two conditions in ConditionsCmd then operator is used to compare
// the outcome of this condition with that of the condition before it.
Operator string
}
// NeedsVars returns the variable names (refIds) that are dependencies
// to execute the command and allows the command to fulfill the Command interface.
func (ccc *ConditionsCmd) NeedsVars() []string {
func (cmd *ConditionsCmd) NeedsVars() []string {
vars := []string{}
for _, c := range ccc.Conditions {
vars = append(vars, c.QueryRefID)
for _, c := range cmd.Conditions {
vars = append(vars, c.InputRefID)
}
return vars
}
// EvalMatch represents the series violating the threshold.
// It goes into the metadata of data frames so it can be extracted.
type EvalMatch struct {
Value *float64 `json:"value"`
Metric string `json:"metric"`
Labels data.Labels `json:"labels"`
}
func (em EvalMatch) MarshalJSON() ([]byte, error) {
fs := ""
if em.Value != nil {
fs = strconv.FormatFloat(*em.Value, 'f', -1, 64)
}
return json.Marshal(struct {
Value string `json:"value"`
Metric string `json:"metric"`
Labels data.Labels `json:"labels"`
}{
fs,
em.Metric,
em.Labels,
})
}
// Execute runs the command and returns the results or an error if the command
// failed to execute.
func (ccc *ConditionsCmd) Execute(ctx context.Context, vars mathexp.Vars) (mathexp.Results, error) {
func (cmd *ConditionsCmd) Execute(_ context.Context, vars mathexp.Vars) (mathexp.Results, error) {
firing := true
newRes := mathexp.Results{}
noDataFound := true
matches := []EvalMatch{}
for i, c := range ccc.Conditions {
querySeriesSet := vars[c.QueryRefID]
for i, c := range cmd.Conditions {
querySeriesSet := vars[c.InputRefID]
nilReducedCount := 0
firingCount := 0
for _, val := range querySeriesSet.Values {
@@ -184,19 +163,70 @@ func (ccc *ConditionsCmd) Execute(ctx context.Context, vars mathexp.Vars) (mathe
return newRes, nil
}
// EvalMatch represents the series violating the threshold.
// It goes into the metadata of data frames so it can be extracted.
type EvalMatch struct {
Value *float64 `json:"value"`
Metric string `json:"metric"`
Labels data.Labels `json:"labels"`
}
func (em EvalMatch) MarshalJSON() ([]byte, error) {
fs := ""
if em.Value != nil {
fs = strconv.FormatFloat(*em.Value, 'f', -1, 64)
}
return json.Marshal(struct {
Value string `json:"value"`
Metric string `json:"metric"`
Labels data.Labels `json:"labels"`
}{
fs,
em.Metric,
em.Labels,
})
}
// ConditionJSON is the JSON model for a single condition in ConditionsCmd.
// It is based on services/alerting/conditions/query.go's newQueryCondition().
type ConditionJSON struct {
Evaluator ConditionEvalJSON `json:"evaluator"`
Operator ConditionOperatorJSON `json:"operator"`
Query ConditionQueryJSON `json:"query"`
Reducer ConditionReducerJSON `json:"reducer"`
}
type ConditionEvalJSON struct {
Params []float64 `json:"params"`
Type string `json:"type"` // e.g. "gt"
}
type ConditionOperatorJSON struct {
Type string `json:"type"`
}
type ConditionQueryJSON struct {
Params []string `json:"params"`
}
type ConditionReducerJSON struct {
Type string `json:"type"`
// Params []interface{} `json:"params"` (Unused)
}
// UnmarshalConditionsCmd creates a new ConditionsCmd.
func UnmarshalConditionsCmd(rawQuery map[string]interface{}, refID string) (*ConditionsCmd, error) {
jsonFromM, err := json.Marshal(rawQuery["conditions"])
if err != nil {
return nil, fmt.Errorf("failed to remarshal classic condition body: %w", err)
}
var ccj []ClassicConditionJSON
var ccj []ConditionJSON
if err = json.Unmarshal(jsonFromM, &ccj); err != nil {
return nil, fmt.Errorf("failed to unmarshal remarshaled classic condition body: %w", err)
}
c := &ConditionsCmd{
refID: refID,
RefID: refID,
}
for i, cj := range ccj {
@@ -208,12 +238,12 @@ func UnmarshalConditionsCmd(rawQuery map[string]interface{}, refID string) (*Con
cond.Operator = cj.Operator.Type
if len(cj.Query.Params) == 0 || cj.Query.Params[0] == "" {
return nil, fmt.Errorf("condition %v is missing the query refID argument", i+1)
return nil, fmt.Errorf("condition %v is missing the query RefID argument", i+1)
}
cond.QueryRefID = cj.Query.Params[0]
cond.InputRefID = cj.Query.Params[0]
cond.Reducer = classicReducer(cj.Reducer.Type)
cond.Reducer = reducer(cj.Reducer.Type)
if !cond.Reducer.ValidReduceFunc() {
return nil, fmt.Errorf("invalid reducer '%v' in condition %v", cond.Reducer, i+1)
}