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introduce a variable replace order in grafana collector
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Signed-off-by: Augustin Husson <[email protected]>
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@Nexucis
Nexucis committed Nov 6, 2024
1 parent 0cb7d41 commit 389272f
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Showing 4 changed files with 382 additions and 34 deletions.
165 changes: 133 additions & 32 deletions source/grafana/grafana.go
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Original file line number Diff line number Diff line change
Expand Up @@ -34,40 +34,126 @@ import (
"github.com/sirupsen/logrus"
)

type variableTuple struct {
name string
value string
}

var (
labelValuesRegexp = regexp.MustCompile(`(?s)label_values\((.+),.+\)`)
labelValuesNoQueryRegexp = regexp.MustCompile(`(?s)label_values\((.+)\)`)
queryResultRegexp = regexp.MustCompile(`(?s)query_result\((.+)\)`)
variableRangeQueryRangeRegex = regexp.MustCompile(`\[\$?\w+?]`)
variableSubqueryRangeRegex = regexp.MustCompile(`\[\$?\w+:\$?\w+?]`)
globalVariableList = map[string]string{
"__interval": "20m",
"interval": "20m",
"__interval_ms": "1200000",
"resolution": "5m",
"__rate_interval": "20m",
"rate_interval": "20m",
"__rate_interval_ms": "1200000",
"__range": "1d",
"__range_s:glob": "15",
"__range_s": "15",
"__range_ms": "15",
"__from": "1594671549254",
"__from:date": "2020-07-13T20:19:09.254Z",
"__from:date:iso": "2020-07-13T20:19:09.254Z",
"__from:date:seconds": "1594671549",
"__from:date:YYYY-MM": "2020-07",
"__to": "1594671549254",
"__to:date": "2020-07-13T20:19:09.254Z",
"__to:date:iso": "2020-07-13T20:19:09.254Z",
"__to:date:seconds": "1594671549",
"__to:date:YYYY-MM": "2020-07",
"__user": "foo",
"__org": "perses",
"__name": "john",
"__dashboard": "the_infamous_one",
globalVariableList = []variableTuple{
// Don't change the order.
// The order matters because, when replacing the variable with its value in the expression, if, for example,
// __interval is replaced before __interval_ms, then you might have partially replaced the variable.
// Example: 1 / __interval_ms will give 1 / 20m_s which is not a correct PromQL expression.
// So we need to replace __interval_ms before __interval.
// Same thing applied for every variable starting with the same prefix. Like __from, __to.
{
name: "__interval_ms",
value: "1200000",
},
{
name: "__interval",
value: "20m",
},
{
name: "interval",
value: "20m",
},
{
name: "resolution",
value: "5m",
},
{
name: "__rate_interval_ms",
value: "1200000",
},
{
name: "__rate_interval",
value: "20m",
},
{
name: "rate_interval",
value: "20m",
},
{
name: "__range_s:glob",
value: "15",
},
{
name: "__range_s",
value: "15",
},
{
name: "__range_ms",
value: "15",
},
{
name: "__range",
value: "1d",
},
{
name: "__from:date:YYYY-MM",
value: "2020-07",
},
{
name: "__from:date:seconds",
value: "1594671549",
},
{
name: "__from:date:iso",
value: "2020-07-13T20:19:09.254Z",
},
{
name: "__from:date",
value: "2020-07-13T20:19:09.254Z",
},
{
name: "__from",
value: "1594671549254",
},
{
name: "__to:date:YYYY-MM",
value: "2020-07",
},
{
name: "__to:date:seconds",
value: "1594671549",
},
{
name: "__to:date:iso",
value: "2020-07-13T20:19:09.254Z",
},
{
name: "__to:date",
value: "2020-07-13T20:19:09.254Z",
},
{
name: "__to",
value: "1594671549254",
},
{
name: "__user",
value: "foo",
},
{
name: "__org",
value: "perses",
},
{
name: "__name",
value: "john",
},
{
name: "__dashboard",
value: "the_infamous_one",
},
}
variableReplacer = strings.NewReplacer(generateGrafanaVariableSyntaxReplacer(globalVariableList)...)
variableReplacer = strings.NewReplacer(generateGrafanaTupleVariableSyntaxReplacer(globalVariableList)...)
)

func NewCollector(db database.Database, cfg config.GrafanaCollector) (async.SimpleTask, error) {
Expand Down Expand Up @@ -100,8 +186,9 @@ func NewCollector(db database.Database, cfg config.GrafanaCollector) (async.Simp
}

type logError struct {
msg string
err error
msg string
warn error
err error
}

type grafanaCollector struct {
Expand Down Expand Up @@ -130,7 +217,11 @@ func (c *grafanaCollector) Execute(ctx context.Context, _ context.CancelFunc) er
c.logger.Debugf("extracting metrics for the dashboard %s with UID %q", h.Title, h.UID)
metrics, errs := extractMetrics(dashboard)
for _, extractError := range errs {
c.logger.WithError(extractError.err).Error(extractError.msg)
if extractError.warn != nil {
c.logger.WithError(extractError.warn).Warning(extractError.msg)
} else {
c.logger.WithError(extractError.err).Error(extractError.msg)
}
}
metricUsage := c.generateUsage(metrics, dashboard)
c.logger.Infof("%d metrics usage has been collected for the dashboard %q with UID %q", len(metricUsage), h.Title, h.UID)
Expand Down Expand Up @@ -221,6 +312,14 @@ func generateGrafanaVariableSyntaxReplacer(variables map[string]string) []string
return result
}

func generateGrafanaTupleVariableSyntaxReplacer(variables []variableTuple) []string {
var result []string
for _, v := range variables {
result = append(result, fmt.Sprintf("$%s", v.name), v.value, fmt.Sprintf("${%s}", v.name), v.value)
}
return result
}

func extractMetrics(dashboard *simplifiedDashboard) ([]string, []logError) {
staticVariables := strings.NewReplacer(generateGrafanaVariableSyntaxReplacer(extractStaticVariables(dashboard.Templating.List))...)
m1, err1 := extractMetricsFromPanels(dashboard.Panels, staticVariables, dashboard)
Expand Down Expand Up @@ -264,9 +363,11 @@ func extractMetricsFromVariables(variables []templateVar, staticVariables *strin
}
query, err := v.extractQueryFromVariableTemplating()
if err != nil {
// It appears when there is an issue, we cannot do anything about it actually and usually the variable is not the one we are looking for.
// So we just log it as a warning
errs = append(errs, logError{
err: err,
msg: fmt.Sprintf("failed to extract query in variable %q for the dashboard %s/%s", v.Name, dashboard.Title, dashboard.UID),
warn: err,
msg: fmt.Sprintf("failed to extract query in variable %q for the dashboard %s/%s", v.Name, dashboard.Title, dashboard.UID),
})
continue
}
Expand Down
7 changes: 6 additions & 1 deletion source/grafana/grafana_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -30,10 +30,15 @@ func TestExtractMetrics(t *testing.T) {
resultMetrics: []string{"run", "service_color"},
},
{
name: "loading runtime variable",
name: "use static variable",
dashboardFile: "tests/d2.json",
resultMetrics: []string{"gacms_svc_elapsed_time_seconds_bucket"},
},
{
name: "variable replace order",
dashboardFile: "tests/d3.json",
resultMetrics: []string{"probe_success"},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
Expand Down
2 changes: 1 addition & 1 deletion source/grafana/model.go
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Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,7 @@ func (v templateVar) extractQueryFromVariableTemplating() (string, error) {
return query, nil
}
}
return "", fmt.Errorf("query variable %q doesn't have the right type (string, or JSON object). It is of type %T", v.Name, v.Query)
return "", fmt.Errorf("unable to extract the query expression from the variable %q", v.Name)
}

type simplifiedDashboard struct {
Expand Down
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