Allow configuration of Prometheus log level (#2484) (#2487)

Signed-off-by: Gaurav Kumar <gaurav.kumar9825@gmail.com>

chart/templates/prometheus.yaml

@@ -91,6 +91,7 @@ spec:
         - "--storage.tsdb.path=/{{.Values.PrometheusVolumeName}}"
         - "--storage.tsdb.retention=6h"
         - "--config.file=/etc/prometheus/prometheus.yml"
+        - "--log.level={{.Values.PrometheusLogLevel}}"
         readinessProbe:
           httpGet:
             path: /-/ready

cli/cmd/install.go

@@ -35,6 +35,7 @@ type installConfig struct {
 	UUID                        string
 	CliVersion                  string
 	ControllerLogLevel          string
+	PrometheusLogLevel          string
 	ControllerComponentLabel    string
 	CreatedByAnnotation         string
 	EnableTLS                   bool
@@ -149,6 +150,11 @@ func validateAndBuildConfig(options *installOptions) (*installConfig, error) {
 		return nil, err
 	}
 
+	prometheusLogLevel := options.controllerLogLevel
+	if prometheusLogLevel == "panic" || prometheusLogLevel == "fatal" {
+		prometheusLogLevel = "error"
+	}
+
 	return &installConfig{
 		Namespace:                   controlPlaneNamespace,
 		ControllerImage:             fmt.Sprintf("%s/controller:%s", options.dockerRegistry, options.linkerdVersion),
@@ -162,6 +168,7 @@ func validateAndBuildConfig(options *installOptions) (*installConfig, error) {
 		UUID:                        uuid.NewV4().String(),
 		CliVersion:                  k8s.CreatedByAnnotationValue(),
 		ControllerLogLevel:          options.controllerLogLevel,
+		PrometheusLogLevel:          prometheusLogLevel,
 		ControllerComponentLabel:    k8s.ControllerComponentLabel,
 		ControllerUID:               options.controllerUID,
 		CreatedByAnnotation:         k8s.CreatedByAnnotation,

cli/cmd/install_test.go

@@ -33,6 +33,7 @@ func TestRender(t *testing.T) {
 		UUID:                        "UUID",
 		CliVersion:                  "CliVersion",
 		ControllerLogLevel:          "ControllerLogLevel",
+		PrometheusLogLevel:          "PrometheusLogLevel",
 		ControllerComponentLabel:    "ControllerComponentLabel",
 		CreatedByAnnotation:         "CreatedByAnnotation",
 		EnableTLS:                   true,

cli/cmd/testdata/install_default.golden

@@ -625,6 +625,7 @@ spec:
         - --storage.tsdb.path=/data
         - --storage.tsdb.retention=6h
         - --config.file=/etc/prometheus/prometheus.yml
+        - --log.level=info
         image: prom/prometheus:v2.7.1
         imagePullPolicy: IfNotPresent
         livenessProbe:

cli/cmd/testdata/install_ha_output.golden

@@ -643,6 +643,7 @@ spec:
         - --storage.tsdb.path=/data
         - --storage.tsdb.retention=6h
         - --config.file=/etc/prometheus/prometheus.yml
+        - --log.level=info
         image: prom/prometheus:v2.7.1
         imagePullPolicy: IfNotPresent
         livenessProbe:

cli/cmd/testdata/install_ha_with_overrides_output.golden

@@ -643,6 +643,7 @@ spec:
         - --storage.tsdb.path=/data
         - --storage.tsdb.retention=6h
         - --config.file=/etc/prometheus/prometheus.yml
+        - --log.level=info
         image: prom/prometheus:v2.7.1
         imagePullPolicy: IfNotPresent
         livenessProbe:

cli/cmd/testdata/install_no_init_container.golden

@@ -577,6 +577,7 @@ spec:
         - --storage.tsdb.path=/data
         - --storage.tsdb.retention=6h
         - --config.file=/etc/prometheus/prometheus.yml
+        - --log.level=info
         image: prom/prometheus:v2.7.1
         imagePullPolicy: IfNotPresent
         livenessProbe:

cli/cmd/testdata/install_no_init_container_auto_inject.golden

@@ -634,6 +634,7 @@ spec:
         - --storage.tsdb.path=/data
         - --storage.tsdb.retention=6h
         - --config.file=/etc/prometheus/prometheus.yml
+        - --log.level=info
         image: prom/prometheus:v2.7.1
         imagePullPolicy: IfNotPresent
         livenessProbe:

cli/cmd/testdata/install_output.golden

@@ -630,6 +630,7 @@ spec:
         - --storage.tsdb.path=/data
         - --storage.tsdb.retention=6h
         - --config.file=/etc/prometheus/prometheus.yml
+        - --log.level=PrometheusLogLevel
         image: PrometheusImage
         imagePullPolicy: ImagePullPolicy
         livenessProbe: