Merge pull request #704 from deschmih/master

feature "reload-on-delete" documented in README.md

README.md

@@ -327,6 +327,7 @@ helm uninstall {{RELEASE_NAME}} -n {{NAMESPACE}}
 | `reloader.ignoreSecrets`          | To ignore secrets. Valid value are either `true` or `false`. Either `ignoreSecrets` or `ignoreConfigMaps` can be ignored, not both at the same time | boolean     | `false`   |
 | `reloader.ignoreConfigMaps`       | To ignore configMaps. Valid value are either `true` or `false`                                                                                      | boolean     | `false`   |
 | `reloader.reloadOnCreate`         | Enable reload on create events. Valid value are either `true` or `false`                                                                            | boolean     | `false`   |
+| `reloader.reloadOnDelete`         | Enable reload on delete events. Valid value are either `true` or `false`                                                                            | boolean     | `false`   |
 | `reloader.syncAfterRestart`       | Enable sync after Reloader restarts for **Add** events, works only when reloadOnCreate is `true`. Valid value are either `true` or `false`          | boolean     | `false`   |
 | `reloader.reloadStrategy`         | Strategy to trigger resource restart, set to either `default`, `env-vars` or `annotations`                                                          | enumeration | `default` |
 | `reloader.ignoreNamespaces`       | List of comma separated namespaces to ignore, if multiple are provided, they are combined with the AND operator                                     | string      | `""`      |
@@ -338,6 +339,7 @@ helm uninstall {{RELEASE_NAME}} -n {{NAMESPACE}}
 | `reloader.readOnlyRootFileSystem` | Enforce readOnlyRootFilesystem                                                                                                                      | boolean     | `false`   |
 | `reloader.legacy.rbac`            |                                                                                                                                                     | boolean     | `false`   |
 | `reloader.matchLabels`            | Pod labels to match                                                                                                                                 | map         | `{}`      |
+| `reloader.enableMetricsByNamespace`            | Expose an additional Prometheus counter of reloads by namespace (this metric may have high cardinality in clusters with many namespaces) | boolean         | `false`      |
 
 #### Deployment Reloader Parameters
 
@@ -384,14 +386,18 @@ helm uninstall {{RELEASE_NAME}} -n {{NAMESPACE}}
 - Reloading of OpenShift (DeploymentConfig) and/or Argo `Rollouts` has to be enabled explicitly because it might not be always possible to use it on a cluster with restricted permissions
 - `isOpenShift` Recent versions of OpenShift (tested on 4.13.3) require the specified user to be in an `uid` range which is dynamically assigned by the namespace. The solution is to unset the runAsUser variable via ``deployment.securityContext.runAsUser=null`` and let OpenShift assign it at install
 - `reloadOnCreate` controls how Reloader handles secrets being added to the cache for the first time. If `reloadOnCreate` is set to true:
-  1. Configmaps/secrets being added to the cache will cause Reloader to perform a rolling update of the associated workload
-  1. When applications are deployed for the first time, Reloader will perform a rolling update of the associated workload
-  1. If you are running Reloader in HA mode all workloads will have a rolling update performed when a new leader is elected
+    1. Configmaps/secrets being added to the cache will cause Reloader to perform a rolling update of the associated workload
+    1. When applications are deployed for the first time, Reloader will perform a rolling update of the associated workload
+    1. If you are running Reloader in HA mode all workloads will have a rolling update performed when a new leader is elected
+- `reloadOnDelete` controls how Reloader handles secrets being deleted. If `reloadOnDelete` is set to true:
+    1. Configmaps/secrets being deleted will cause Reloader to perform a rolling update of the associated workload
 - `serviceMonitor` will be removed in future releases of Reloader in favour of Pod monitor
 - If `reloadOnCreate` is set to false:
-  1. Updates to configmaps/secrets that occur while there is no leader will not be picked up by the new leader until a subsequent update of the configmap/secret occurs
-  1. In the worst case the window in which there can be no leader is 15s as this is the LeaseDuration
-- By default, `reloadOnCreate` and `syncAfterRestart` are both set to false. Both need to be enabled explicitly
+    1. Updates to configmaps/secrets that occur while there is no leader will not be picked up by the new leader until a subsequent update of the configmap/secret occurs
+    1. In the worst case the window in which there can be no leader is 15s as this is the LeaseDuration
+- If `reloadOnDelete` is set to false:
+    1. Deleting of configmaps/secrets has no effect to pods that references these resources.
+- By default, `reloadOnCreate`, `reloadOnDelete` and `syncAfterRestart` are all set to false. All need to be enabled explicitly
 
 ## Help
 

deployments/kubernetes/chart/reloader/Chart.yaml

@@ -3,8 +3,8 @@
 apiVersion: v1
 name: reloader
 description: Reloader chart that runs on kubernetes
-version: 1.0.108
-appVersion: v1.0.108
+version: 1.0.116
+appVersion: v1.0.116
 keywords:
   - Reloader
   - kubernetes

deployments/kubernetes/chart/reloader/templates/_helpers.tpl

@@ -22,7 +22,7 @@ We truncate at 63 chars because some Kubernetes name fields are limited to this
 
 {{- define "reloader-labels.chart" -}}
 app: {{ template "reloader-fullname" . }}
-chart: "{{ .Chart.Name }}-{{ .Chart.Version }}"
+chart: "{{ .Chart.Name }}-{{ .Chart.Version | replace "+" "_" }}"
 release: {{ .Release.Name | quote }}
 heritage: {{ .Release.Service | quote }}
 app.kubernetes.io/managed-by: {{ .Release.Service | quote }}

deployments/kubernetes/chart/reloader/templates/deployment.yaml

@@ -76,7 +76,7 @@ spec:
       - image: "{{ .Values.reloader.deployment.image.name }}:{{ .Values.reloader.deployment.image.tag }}"
         imagePullPolicy: {{ .Values.reloader.deployment.image.pullPolicy }}
         name: {{ template "reloader-fullname" . }}
-      {{- if or (.Values.reloader.deployment.env.open) (.Values.reloader.deployment.env.secret) (.Values.reloader.deployment.env.field) (.Values.reloader.deployment.env.existing) (eq .Values.reloader.watchGlobally false) (.Values.reloader.enableHA)}}
+      {{- if or (.Values.reloader.deployment.env.open) (.Values.reloader.deployment.env.secret) (.Values.reloader.deployment.env.field) (.Values.reloader.deployment.env.existing) (eq .Values.reloader.watchGlobally false) (.Values.reloader.enableHA) (.Values.reloader.enableMetricsByNamespace)}}
         env:
       {{- range $name, $value := .Values.reloader.deployment.env.open }}
       {{- if not (empty $value) }}
@@ -129,6 +129,10 @@ spec:
             fieldRef:
               fieldPath: metadata.namespace
       {{- end }}
+      {{- if .Values.reloader.enableMetricsByNamespace }}
+        - name: METRICS_COUNT_BY_NAMESPACE
+          value: enabled
+      {{- end }}
       {{- end }}
 
         ports:
@@ -171,7 +175,7 @@ spec:
           {{- . | toYaml | nindent 10 }}
           {{- end }}
       {{- end }}
-      {{- if or (.Values.reloader.logFormat) (.Values.reloader.ignoreSecrets) (.Values.reloader.ignoreNamespaces) (.Values.reloader.namespaceSelector) (.Values.reloader.resourceLabelSelector) (.Values.reloader.ignoreConfigMaps) (.Values.reloader.custom_annotations) (eq .Values.reloader.isArgoRollouts true) (eq .Values.reloader.reloadOnCreate true) (ne .Values.reloader.reloadStrategy "default") (.Values.reloader.enableHA) (.Values.reloader.autoReloadAll)}}
+      {{- if or (.Values.reloader.logFormat) (.Values.reloader.ignoreSecrets) (.Values.reloader.ignoreNamespaces) (.Values.reloader.namespaceSelector) (.Values.reloader.resourceLabelSelector) (.Values.reloader.ignoreConfigMaps) (.Values.reloader.custom_annotations) (eq .Values.reloader.isArgoRollouts true) (eq .Values.reloader.reloadOnCreate true) (eq .Values.reloader.reloadOnDelete true) (ne .Values.reloader.reloadStrategy "default") (.Values.reloader.enableHA) (.Values.reloader.autoReloadAll)}}
         args:
           {{- if .Values.reloader.logFormat }}
           - "--log-format={{ .Values.reloader.logFormat }}"
@@ -231,6 +235,9 @@ spec:
           {{- if eq .Values.reloader.reloadOnCreate true }}
           - "--reload-on-create={{ .Values.reloader.reloadOnCreate }}"
           {{- end }}
+          {{- if eq .Values.reloader.reloadOnDelete true }}
+          - "--reload-on-delete={{ .Values.reloader.reloadOnDelete }}"
+          {{- end }}
           {{- if eq .Values.reloader.syncAfterRestart true }}
           - "--sync-after-restart={{ .Values.reloader.syncAfterRestart }}"
           {{- end }}

deployments/kubernetes/chart/reloader/values.yaml

@@ -18,6 +18,7 @@ reloader:
   ignoreSecrets: false
   ignoreConfigMaps: false
   reloadOnCreate: false
+  reloadOnDelete: false
   syncAfterRestart: false
   reloadStrategy: default # Set to default, env-vars or annotations
   ignoreNamespaces: "" # Comma separated list of namespaces to ignore
@@ -32,6 +33,8 @@ reloader:
   legacy:
     rbac: false
   matchLabels: {}
+  # Set to true to expose a prometheus counter of reloads by namespace (this metric may have high cardinality in clusters with many namespaces)
+  enableMetricsByNamespace: false
   deployment:
     # If you wish to run multiple replicas set reloader.enableHA = true
     replicas: 1
@@ -89,10 +92,10 @@ reloader:
     labels:
       provider: stakater
       group: com.stakater.platform
-      version: v1.0.108
+      version: v1.0.116
     image:
       name: ghcr.io/stakater/reloader
-      tag: v1.0.108
+      tag: v1.0.116
       pullPolicy: IfNotPresent
     # Support for extra environment variables.
     env:

deployments/kubernetes/manifests/deployment.yaml

@@ -17,7 +17,7 @@ spec:
         app: reloader-reloader
     spec:
       containers:
-        - image: "ghcr.io/stakater/reloader:v1.0.108"
+        - image: "ghcr.io/stakater/reloader:v1.0.116"
           imagePullPolicy: IfNotPresent
           name: reloader-reloader
           ports:

deployments/kubernetes/reloader.yaml

@@ -8,7 +8,7 @@ metadata:
     meta.helm.sh/release-name: "reloader"
   labels:
     app: reloader-reloader
-    chart: "reloader-1.0.108"
+    chart: "reloader-1.0.116"
     release: "reloader"
     heritage: "Helm"
     app.kubernetes.io/managed-by: "Helm"
@@ -25,7 +25,7 @@ metadata:
     meta.helm.sh/release-name: "reloader"
   labels:
     app: reloader-reloader
-    chart: "reloader-1.0.108"
+    chart: "reloader-1.0.116"
     release: "reloader"
     heritage: "Helm"
     app.kubernetes.io/managed-by: "Helm"
@@ -92,7 +92,7 @@ metadata:
     meta.helm.sh/release-name: "reloader"
   labels:
     app: reloader-reloader
-    chart: "reloader-1.0.108"
+    chart: "reloader-1.0.116"
     release: "reloader"
     heritage: "Helm"
     app.kubernetes.io/managed-by: "Helm"
@@ -115,13 +115,13 @@ metadata:
     meta.helm.sh/release-name: "reloader"
   labels:
     app: reloader-reloader
-    chart: "reloader-1.0.108"
+    chart: "reloader-1.0.116"
     release: "reloader"
     heritage: "Helm"
     app.kubernetes.io/managed-by: "Helm"
     group: com.stakater.platform
     provider: stakater
-    version: v1.0.108
+    version: v1.0.116
   name: reloader-reloader
   namespace: default
 spec:
@@ -135,16 +135,16 @@ spec:
     metadata:
       labels:
         app: reloader-reloader
-        chart: "reloader-1.0.108"
+        chart: "reloader-1.0.116"
         release: "reloader"
         heritage: "Helm"
         app.kubernetes.io/managed-by: "Helm"
         group: com.stakater.platform
         provider: stakater
-        version: v1.0.108
+        version: v1.0.116
     spec:
       containers:
-      - image: "ghcr.io/stakater/reloader:v1.0.108"
+      - image: "ghcr.io/stakater/reloader:v1.0.116"
         imagePullPolicy: IfNotPresent
         name: reloader-reloader
 
@@ -172,6 +172,13 @@ spec:
 
         securityContext:
           {}
+        resources:
+          limits:
+            cpu: 150m
+            memory: 512Mi
+          requests:
+            cpu: 10m
+            memory: 128Mi
       securityContext: 
         runAsNonRoot: true
         runAsUser: 65534

deployments/kubernetes/templates/chart/values.yaml.tmpl

@@ -23,6 +23,8 @@ reloader:
   legacy:
     rbac: false
   matchLabels: {}
+  # Set to true to expose a prometheus counter of reloads by namespace (this metric may have high cardinality in clusters with many namespaces)
+  enableMetricsByNamespace: false
   deployment:
     replicas: 1
     nodeSelector:

docs/Verify-Reloader-Working.md

@@ -60,3 +60,16 @@ When Reloader is unable to reload, `reloader_reload_executed_total{success="fals
 reloader_reload_executed_total{success="false"} 15
 reloader_reload_executed_total{success="true"} 12
 ```
+
+### Reloads by Namespace
+
+Reloader can also export a metric to show the number of reloads by namespace. This feature is disabled by default, as it can lead to high cardinality in clusters with many namespaces.
+
+The metric will have both `success` and `namespace` as attributes:
+
+```text
+reloader_reload_executed_total{success="false", namespace="some-namespace"} 2
+reloader_reload_executed_total{success="true", namespace="some-namespace"} 1
+```
+
+To opt in, set the environment variable `METRICS_COUNT_BY_NAMESPACE` to `enabled` or set the Helm value `reloader.enableMetricsByNamespace` to `true`.

go.mod

@@ -3,7 +3,7 @@ module github.com/stakater/Reloader
 go 1.21
 
 require (
-	github.com/argoproj/argo-rollouts v1.7.0
+	github.com/argoproj/argo-rollouts v1.7.1
 	github.com/openshift/api v3.9.0+incompatible
 	github.com/openshift/client-go v0.0.0-20231110140829-a6ca51f6d5ba
 	github.com/parnurzeal/gorequest v0.2.16

go.sum

@@ -2,6 +2,8 @@ github.com/argoproj/argo-rollouts v1.6.6 h1:JCJ0cGAwWkh2xCAHZ1OQmrobysRjCatmG9IZ
 github.com/argoproj/argo-rollouts v1.6.6/go.mod h1:X2kTiBaYCSounmw1kmONdIZTwJNzNQYC0SrXUgSw9UI=
 github.com/argoproj/argo-rollouts v1.7.0 h1:3Hv8MUwGIWuZe50+yyS/4X21t4jT4shdGvgDe0lG6aw=
 github.com/argoproj/argo-rollouts v1.7.0/go.mod h1:Te4HrUELxKiBpK8lgk77o4gTa3mv8pXCd8xdPprKrbs=
+github.com/argoproj/argo-rollouts v1.7.1 h1:KWStvHPRrNTbDTclogiYC/s4eKbdS45KkgXiorDzKG0=
+github.com/argoproj/argo-rollouts v1.7.1/go.mod h1:Te4HrUELxKiBpK8lgk77o4gTa3mv8pXCd8xdPprKrbs=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=

internal/pkg/cmd/reloader.go

@@ -51,6 +51,7 @@ func NewReloaderCommand() *cobra.Command {
 	cmd.PersistentFlags().StringVar(&options.IsArgoRollouts, "is-Argo-Rollouts", "false", "Add support for argo rollouts")
 	cmd.PersistentFlags().StringVar(&options.ReloadStrategy, constants.ReloadStrategyFlag, constants.EnvVarsReloadStrategy, "Specifies the desired reload strategy")
 	cmd.PersistentFlags().StringVar(&options.ReloadOnCreate, "reload-on-create", "false", "Add support to watch create events")
+	cmd.PersistentFlags().StringVar(&options.ReloadOnDelete, "reload-on-delete", "false", "Add support to watch delete events")
 	cmd.PersistentFlags().BoolVar(&options.EnableHA, "enable-ha", false, "Adds support for running multiple replicas via leadership election")
 	cmd.PersistentFlags().BoolVar(&options.SyncAfterRestart, "sync-after-restart", false, "Sync add events after reloader restarts")
 

internal/pkg/controller/controller.go

@@ -178,13 +178,22 @@ func (c *Controller) Update(old interface{}, new interface{}) {
 
 // Delete function to add an object to the queue in case of deleting a resource
 func (c *Controller) Delete(old interface{}) {
+
+	if options.ReloadOnDelete == "true" {
+		if !c.resourceInIgnoredNamespace(old) && c.resourceInSelectedNamespaces(old) && secretControllerInitialized && configmapControllerInitialized {
+			c.queue.Add(handler.ResourceDeleteHandler{
+				Resource:   old,
+				Collectors: c.collectors,
+				Recorder:   c.recorder,
+			})
+		}
+	}
+
 	switch object := old.(type) {
 	case *v1.Namespace:
 		c.removeSelectedNamespaceFromCache(*object)
 		return
 	}
-
-	// Todo: Any future delete event can be handled here
 }
 
 // Run function for controller which handles the queue

internal/pkg/handler/create.go

@@ -27,7 +27,7 @@ func (r ResourceCreatedHandler) Handle() error {
 			return sendUpgradeWebhook(config, options.WebhookUrl)
 		}
 		// process resource based on its type
-		return doRollingUpgrade(config, r.Collectors, r.Recorder)
+		return doRollingUpgrade(config, r.Collectors, r.Recorder, invokeReloadStrategy)
 	}
 	return nil
 }

internal/pkg/handler/delete.go

@@ -0,0 +1,92 @@
+package handler
+
+import (
+	"github.com/sirupsen/logrus"
+	"github.com/stakater/Reloader/internal/pkg/callbacks"
+	"github.com/stakater/Reloader/internal/pkg/constants"
+	"github.com/stakater/Reloader/internal/pkg/metrics"
+	"github.com/stakater/Reloader/internal/pkg/options"
+	"github.com/stakater/Reloader/internal/pkg/testutil"
+	"github.com/stakater/Reloader/internal/pkg/util"
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/tools/record"
+)
+
+// ResourceDeleteHandler contains new objects
+type ResourceDeleteHandler struct {
+	Resource   interface{}
+	Collectors metrics.Collectors
+	Recorder   record.EventRecorder
+}
+
+// Handle processes resources being deleted
+func (r ResourceDeleteHandler) Handle() error {
+	if r.Resource == nil {
+		logrus.Errorf("Resource delete handler received nil resource")
+	} else {
+		config, _ := r.GetConfig()
+		// Send webhook
+		if options.WebhookUrl != "" {
+			return sendUpgradeWebhook(config, options.WebhookUrl)
+		}
+		// process resource based on its type
+		return doRollingUpgrade(config, r.Collectors, r.Recorder, invokeDeleteStrategy)
+	}
+	return nil
+}
+
+// GetConfig gets configurations containing SHA, annotations, namespace and resource name
+func (r ResourceDeleteHandler) GetConfig() (util.Config, string) {
+	var oldSHAData string
+	var config util.Config
+	if _, ok := r.Resource.(*v1.ConfigMap); ok {
+		config = util.GetConfigmapConfig(r.Resource.(*v1.ConfigMap))
+	} else if _, ok := r.Resource.(*v1.Secret); ok {
+		config = util.GetSecretConfig(r.Resource.(*v1.Secret))
+	} else {
+		logrus.Warnf("Invalid resource: Resource should be 'Secret' or 'Configmap' but found, %v", r.Resource)
+	}
+	return config, oldSHAData
+}
+
+func invokeDeleteStrategy(upgradeFuncs callbacks.RollingUpgradeFuncs, item runtime.Object, config util.Config, autoReload bool) constants.Result {
+	if options.ReloadStrategy == constants.AnnotationsReloadStrategy {
+		return removePodAnnotations(upgradeFuncs, item, config, autoReload)
+	}
+
+	return removeContainerEnvVars(upgradeFuncs, item, config, autoReload)
+}
+
+func removePodAnnotations(upgradeFuncs callbacks.RollingUpgradeFuncs, item runtime.Object, config util.Config, autoReload bool) constants.Result {
+	config.SHAValue = testutil.GetSHAfromEmptyData()
+	return updatePodAnnotations(upgradeFuncs, item, config, autoReload)
+}
+
+func removeContainerEnvVars(upgradeFuncs callbacks.RollingUpgradeFuncs, item runtime.Object, config util.Config, autoReload bool) constants.Result {
+	envVar := getEnvVarName(config.ResourceName, config.Type)
+	container := getContainerUsingResource(upgradeFuncs, item, config, autoReload)
+
+	if container == nil {
+		return constants.NoContainerFound
+	}
+
+	//remove if env var exists
+	containers := upgradeFuncs.ContainersFunc(item)
+	for i := range containers {
+		envs := containers[i].Env
+		index := -1
+		for j := range envs {
+			if envs[j].Name == envVar {
+				index = j
+				break
+			}
+		}
+		if index != -1 {
+			containers[i].Env = append(containers[i].Env[:index], containers[i].Env[index+1:]...)
+			return constants.Updated
+		}
+	}
+
+	return constants.NotUpdated
+}

internal/pkg/handler/update.go

@@ -29,7 +29,7 @@ func (r ResourceUpdatedHandler) Handle() error {
 				return sendUpgradeWebhook(config, options.WebhookUrl)
 			}
 			// process resource based on its type
-			return doRollingUpgrade(config, r.Collectors, r.Recorder)
+			return doRollingUpgrade(config, r.Collectors, r.Recorder, invokeReloadStrategy)
 		}
 	}
 	return nil

internal/pkg/handler/upgrade.go

@@ -142,35 +142,35 @@ func sendWebhook(url string) (string, []error) {
 	return buffer.String(), nil
 }
 
-func doRollingUpgrade(config util.Config, collectors metrics.Collectors, recorder record.EventRecorder) error {
+func doRollingUpgrade(config util.Config, collectors metrics.Collectors, recorder record.EventRecorder, invoke invokeStrategy) error {
 	clients := kube.GetClients()
 
-	err := rollingUpgrade(clients, config, GetDeploymentRollingUpgradeFuncs(), collectors, recorder)
+	err := rollingUpgrade(clients, config, GetDeploymentRollingUpgradeFuncs(), collectors, recorder, invoke)
 	if err != nil {
 		return err
 	}
-	err = rollingUpgrade(clients, config, GetCronJobCreateJobFuncs(), collectors, recorder)
+	err = rollingUpgrade(clients, config, GetCronJobCreateJobFuncs(), collectors, recorder, invoke)
 	if err != nil {
 		return err
 	}
-	err = rollingUpgrade(clients, config, GetDaemonSetRollingUpgradeFuncs(), collectors, recorder)
+	err = rollingUpgrade(clients, config, GetDaemonSetRollingUpgradeFuncs(), collectors, recorder, invoke)
 	if err != nil {
 		return err
 	}
-	err = rollingUpgrade(clients, config, GetStatefulSetRollingUpgradeFuncs(), collectors, recorder)
+	err = rollingUpgrade(clients, config, GetStatefulSetRollingUpgradeFuncs(), collectors, recorder, invoke)
 	if err != nil {
 		return err
 	}
 
 	if kube.IsOpenshift {
-		err = rollingUpgrade(clients, config, GetDeploymentConfigRollingUpgradeFuncs(), collectors, recorder)
+		err = rollingUpgrade(clients, config, GetDeploymentConfigRollingUpgradeFuncs(), collectors, recorder, invoke)
 		if err != nil {
 			return err
 		}
 	}
 
 	if options.IsArgoRollouts == "true" {
-		err = rollingUpgrade(clients, config, GetArgoRolloutRollingUpgradeFuncs(), collectors, recorder)
+		err = rollingUpgrade(clients, config, GetArgoRolloutRollingUpgradeFuncs(), collectors, recorder, invoke)
 		if err != nil {
 			return err
 		}
@@ -179,17 +179,17 @@ func doRollingUpgrade(config util.Config, collectors metrics.Collectors, recorde
 	return nil
 }
 
-func rollingUpgrade(clients kube.Clients, config util.Config, upgradeFuncs callbacks.RollingUpgradeFuncs, collectors metrics.Collectors, recorder record.EventRecorder) error {
+func rollingUpgrade(clients kube.Clients, config util.Config, upgradeFuncs callbacks.RollingUpgradeFuncs, collectors metrics.Collectors, recorder record.EventRecorder, strategy invokeStrategy) error {
 
-	err := PerformRollingUpgrade(clients, config, upgradeFuncs, collectors, recorder)
+	err := PerformAction(clients, config, upgradeFuncs, collectors, recorder, strategy)
 	if err != nil {
 		logrus.Errorf("Rolling upgrade for '%s' failed with error = %v", config.ResourceName, err)
 	}
 	return err
 }
 
-// PerformRollingUpgrade upgrades the deployment if there is any change in configmap or secret data
-func PerformRollingUpgrade(clients kube.Clients, config util.Config, upgradeFuncs callbacks.RollingUpgradeFuncs, collectors metrics.Collectors, recorder record.EventRecorder) error {
+// PerformAction invokes the deployment if there is any change in configmap or secret data
+func PerformAction(clients kube.Clients, config util.Config, upgradeFuncs callbacks.RollingUpgradeFuncs, collectors metrics.Collectors, recorder record.EventRecorder, strategy invokeStrategy) error {
 	items := upgradeFuncs.ItemsFunc(clients, config.Namespace)
 
 	for _, i := range items {
@@ -210,7 +210,7 @@ func PerformRollingUpgrade(clients kube.Clients, config util.Config, upgradeFunc
 		reloaderEnabled, _ := strconv.ParseBool(reloaderEnabledValue)
 		typedAutoAnnotationEnabled, _ := strconv.ParseBool(typedAutoAnnotationEnabledValue)
 		if reloaderEnabled || typedAutoAnnotationEnabled || reloaderEnabledValue == "" && typedAutoAnnotationEnabledValue == "" && options.AutoReloadAll {
-			result = invokeReloadStrategy(upgradeFuncs, i, config, true)
+			result = strategy(upgradeFuncs, i, config, true)
 		}
 
 		if result != constants.Updated && annotationValue != "" {
@@ -219,7 +219,7 @@ func PerformRollingUpgrade(clients kube.Clients, config util.Config, upgradeFunc
 				value = strings.TrimSpace(value)
 				re := regexp.MustCompile("^" + value + "$")
 				if re.Match([]byte(config.ResourceName)) {
-					result = invokeReloadStrategy(upgradeFuncs, i, config, false)
+					result = strategy(upgradeFuncs, i, config, false)
 					if result == constants.Updated {
 						break
 					}
@@ -230,7 +230,7 @@ func PerformRollingUpgrade(clients kube.Clients, config util.Config, upgradeFunc
 		if result != constants.Updated && searchAnnotationValue == "true" {
 			matchAnnotationValue := config.ResourceAnnotations[options.SearchMatchAnnotation]
 			if matchAnnotationValue == "true" {
-				result = invokeReloadStrategy(upgradeFuncs, i, config, true)
+				result = strategy(upgradeFuncs, i, config, true)
 			}
 		}
 
@@ -245,6 +245,7 @@ func PerformRollingUpgrade(clients kube.Clients, config util.Config, upgradeFunc
 				message := fmt.Sprintf("Update for '%s' of type '%s' in namespace '%s' failed with error %v", resourceName, upgradeFuncs.ResourceType, config.Namespace, err)
 				logrus.Errorf(message)
 				collectors.Reloaded.With(prometheus.Labels{"success": "false"}).Inc()
+				collectors.ReloadedByNamespace.With(prometheus.Labels{"success": "false", "namespace": config.Namespace}).Inc()
 				if recorder != nil {
 					recorder.Event(i, v1.EventTypeWarning, "ReloadFail", message)
 				}
@@ -254,6 +255,7 @@ func PerformRollingUpgrade(clients kube.Clients, config util.Config, upgradeFunc
 				message += fmt.Sprintf(", Updated '%s' of type '%s' in namespace '%s'", resourceName, upgradeFuncs.ResourceType, config.Namespace)
 				logrus.Infof(message)
 				collectors.Reloaded.With(prometheus.Labels{"success": "true"}).Inc()
+				collectors.ReloadedByNamespace.With(prometheus.Labels{"success": "true", "namespace": config.Namespace}).Inc()
 				alert_on_reload, ok := os.LookupEnv("ALERT_ON_RELOAD")
 				if recorder != nil {
 					recorder.Event(i, v1.EventTypeNormal, "Reloaded", message)
@@ -380,6 +382,8 @@ func getContainerUsingResource(upgradeFuncs callbacks.RollingUpgradeFuncs, item
 	return container
 }
 
+type invokeStrategy func(upgradeFuncs callbacks.RollingUpgradeFuncs, item runtime.Object, config util.Config, autoReload bool) constants.Result
+
 func invokeReloadStrategy(upgradeFuncs callbacks.RollingUpgradeFuncs, item runtime.Object, config util.Config, autoReload bool) constants.Result {
 	if options.ReloadStrategy == constants.AnnotationsReloadStrategy {
 		return updatePodAnnotations(upgradeFuncs, item, config, autoReload)
@@ -416,6 +420,13 @@ func updatePodAnnotations(upgradeFuncs callbacks.RollingUpgradeFuncs, item runti
 	return constants.Updated
 }
 
+func getReloaderAnnotationKey() string {
+	return fmt.Sprintf("%s/%s",
+		constants.ReloaderAnnotationPrefix,
+		constants.LastReloadedFromAnnotation,
+	)
+}
+
 func createReloadedAnnotations(target *util.ReloadSource) (map[string]string, error) {
 	if target == nil {
 		return nil, errors.New("target is required")
@@ -426,10 +437,7 @@ func createReloadedAnnotations(target *util.ReloadSource) (map[string]string, er
 	// Intentionally only storing the last item in order to keep
 	// the generated annotations as small as possible.
 	annotations := make(map[string]string)
-	lastReloadedResourceName := fmt.Sprintf("%s/%s",
-		constants.ReloaderAnnotationPrefix,
-		constants.LastReloadedFromAnnotation,
-	)
+	lastReloadedResourceName := getReloaderAnnotationKey()
 
 	lastReloadedResource, err := json.Marshal(target)
 	if err != nil {
@@ -440,9 +448,13 @@ func createReloadedAnnotations(target *util.ReloadSource) (map[string]string, er
 	return annotations, nil
 }
 
+func getEnvVarName(resourceName string, typeName string) string {
+	return constants.EnvVarPrefix + util.ConvertToEnvVarName(resourceName) + "_" + typeName
+}
+
 func updateContainerEnvVars(upgradeFuncs callbacks.RollingUpgradeFuncs, item runtime.Object, config util.Config, autoReload bool) constants.Result {
 	var result constants.Result
-	envVar := constants.EnvVarPrefix + util.ConvertToEnvVarName(config.ResourceName) + "_" + config.Type
+	envVar := getEnvVarName(config.ResourceName, config.Type)
 	container := getContainerUsingResource(upgradeFuncs, item, config, autoReload)
 
 	if container == nil {

internal/pkg/metrics/prometheus.go

@@ -1,13 +1,16 @@
 package metrics
 
 import (
+	"net/http"
+	"os"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"net/http"
 )
 
 type Collectors struct {
-	Reloaded *prometheus.CounterVec
+	Reloaded            *prometheus.CounterVec
+	ReloadedByNamespace *prometheus.CounterVec
 }
 
 func NewCollectors() Collectors {
@@ -17,21 +20,40 @@ func NewCollectors() Collectors {
 			Name:      "reload_executed_total",
 			Help:      "Counter of reloads executed by Reloader.",
 		},
-		[]string{"success"},
+		[]string{
+			"success",
+		},
 	)
 
 	//set 0 as default value
 	reloaded.With(prometheus.Labels{"success": "true"}).Add(0)
 	reloaded.With(prometheus.Labels{"success": "false"}).Add(0)
 
+	reloaded_by_namespace := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "reloader",
+			Name:      "reload_executed_total_by_namespace",
+			Help:      "Counter of reloads executed by Reloader by namespace.",
+		},
+		[]string{
+			"success",
+			"namespace",
+		},
+	)
 	return Collectors{
-		Reloaded: reloaded,
+		Reloaded:            reloaded,
+		ReloadedByNamespace: reloaded_by_namespace,
 	}
 }
 
 func SetupPrometheusEndpoint() Collectors {
 	collectors := NewCollectors()
 	prometheus.MustRegister(collectors.Reloaded)
+
+	if os.Getenv("METRICS_COUNT_BY_NAMESPACE") == "enabled" {
+		prometheus.MustRegister(collectors.ReloadedByNamespace)
+	}
+
 	http.Handle("/metrics", promhttp.Handler())
 
 	return collectors

internal/pkg/options/flags.go

@@ -32,7 +32,9 @@ var (
 	// ReloadStrategy Specify the update strategy
 	ReloadStrategy = constants.EnvVarsReloadStrategy
 	// ReloadOnCreate Adds support to watch create events
-	ReloadOnCreate   = "false"
+	ReloadOnCreate = "false"
+	// ReloadOnDelete Adds support to watch delete events
+	ReloadOnDelete   = "false"
 	SyncAfterRestart = false
 	// EnableHA adds support for running multiple replicas via leadership election
 	EnableHA = false

internal/pkg/testutil/kube.go

@@ -934,6 +934,55 @@ func VerifyResourceEnvVarUpdate(clients kube.Clients, config util.Config, envVar
 	return false
 }
 
+// VerifyResourceEnvVarRemoved verifies whether the rolling upgrade happened or not and all Envvars SKAKATER_name_CONFIGMAP/SECRET are removed
+func VerifyResourceEnvVarRemoved(clients kube.Clients, config util.Config, envVarPostfix string, upgradeFuncs callbacks.RollingUpgradeFuncs) bool {
+	items := upgradeFuncs.ItemsFunc(clients, config.Namespace)
+	for _, i := range items {
+		containers := upgradeFuncs.ContainersFunc(i)
+		accessor, err := meta.Accessor(i)
+		if err != nil {
+			return false
+		}
+
+		annotations := accessor.GetAnnotations()
+		// match statefulsets with the correct annotation
+
+		annotationValue := annotations[config.Annotation]
+		searchAnnotationValue := annotations[options.AutoSearchAnnotation]
+		reloaderEnabledValue := annotations[options.ReloaderAutoAnnotation]
+		typedAutoAnnotationEnabledValue := annotations[config.TypedAutoAnnotation]
+		reloaderEnabled, err := strconv.ParseBool(reloaderEnabledValue)
+		typedAutoAnnotationEnabled, errTyped := strconv.ParseBool(typedAutoAnnotationEnabledValue)
+
+		matches := false
+		if err == nil && reloaderEnabled || errTyped == nil && typedAutoAnnotationEnabled {
+			matches = true
+		} else if annotationValue != "" {
+			values := strings.Split(annotationValue, ",")
+			for _, value := range values {
+				value = strings.Trim(value, " ")
+				if value == config.ResourceName {
+					matches = true
+					break
+				}
+			}
+		} else if searchAnnotationValue == "true" {
+			if config.ResourceAnnotations[options.SearchMatchAnnotation] == "true" {
+				matches = true
+			}
+		}
+
+		if matches {
+			envName := constants.EnvVarPrefix + util.ConvertToEnvVarName(config.ResourceName) + "_" + envVarPostfix
+			value := GetResourceSHAFromEnvVar(containers, envName)
+			if value == "" {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // VerifyResourceAnnotationUpdate verifies whether the rolling upgrade happened or not
 func VerifyResourceAnnotationUpdate(clients kube.Clients, config util.Config, upgradeFuncs callbacks.RollingUpgradeFuncs) bool {
 	items := upgradeFuncs.ItemsFunc(clients, config.Namespace)
@@ -978,3 +1027,7 @@ func VerifyResourceAnnotationUpdate(clients kube.Clients, config util.Config, up
 	}
 	return false
 }
+
+func GetSHAfromEmptyData() string {
+	return crypto.GenerateSHA("")
+}