Add kubernetes startup probe (#139)

* Add kubernetes startup probe

Signed-off-by: Brett Wright <[email protected]>

* Update charts/backstage/templates/backstage-deployment.yaml

Co-authored-by: Vincenzo Scamporlino <[email protected]>
Signed-off-by: Brett Wright <[email protected]>

* Fixed linting issue

Signed-off-by: Brett Wright <[email protected]>

---------

Signed-off-by: Brett Wright <[email protected]>
Co-authored-by: Vincenzo Scamporlino <[email protected]>

Author: wrighbr

Diff for: charts/backstage/Chart.yaml

@@ -38,4 +38,4 @@ sources:
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: 1.3.0
+version: 1.4.0

Diff for: charts/backstage/README.md

@@ -2,7 +2,7 @@
 # Backstage Helm Chart
 
 [![Artifact Hub](https://img.shields.io/endpoint?url=https://artifacthub.io/badge/repository/backstage)](https://artifacthub.io/packages/search?repo=backstage)
-![Version: 1.3.0](https://img.shields.io/badge/Version-1.3.0-informational?style=flat-square)
+![Version: 1.4.0](https://img.shields.io/badge/Version-1.4.0-informational?style=flat-square)
 ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square)
 
 A Helm chart for deploying a Backstage application
@@ -143,6 +143,7 @@ Kubernetes: `>= 1.19.0-0`
 | backstage.replicas | Number of deployment replicas | int | `1` |
 | backstage.resources | Resource requests/limits <br /> Ref: https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#resource-requests-and-limits-of-pod-and-container <!-- E.g. resources:   limits:     memory: 1Gi     cpu: 1000m   requests:     memory: 250Mi     cpu: 100m --> | object | `{}` |
 | backstage.revisionHistoryLimit | Define the [count of deployment revisions](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#clean-up-policy) to be kept. May be set to 0 in case of GitOps deployment approach. | int | `10` |
+| backstage.startupProbe | Startup Probe Backstage doesn't provide any health endpoints by default. A simple one can be added like this: https://backstage.io/docs/plugins/observability/#health-checks <br /> Ref: https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes <!-- E.g. startupProbe:   failureThreshold: 3   httpGet:     path: /healthcheck     port: 7007     scheme: HTTP   initialDelaySeconds: 60   periodSeconds: 10   successThreshold: 1   timeoutSeconds: 2 | object | `{}` |
 | backstage.tolerations | Node tolerations for server scheduling to nodes with taints <br /> Ref: https://kubernetes.io/docs/concepts/scheduling-eviction/taint-and-toleration/ | list | `[]` |
 | clusterDomain | Default Kubernetes cluster domain | string | `"cluster.local"` |
 | commonAnnotations | Annotations to add to all deployed objects | object | `{}` |

Diff for: charts/backstage/ci/probes-values.yaml

@@ -19,3 +19,13 @@ backstage:
     periodSeconds: 10
     successThreshold: 1
     timeoutSeconds: 2
+  startupProbe:
+    failureThreshold: 3
+    httpGet:
+      path: /healthcheck
+      port: 7007
+      scheme: HTTP
+    initialDelaySeconds: 60
+    periodSeconds: 10
+    successThreshold: 1
+    timeoutSeconds: 2

Diff for: charts/backstage/templates/backstage-deployment.yaml

@@ -113,6 +113,9 @@ spec:
           {{- if .Values.backstage.livenessProbe }}
           livenessProbe: {{- include "common.tplvalues.render" (dict "value" .Values.backstage.livenessProbe "context" $) | nindent 12 }}
           {{- end }}
+          {{- if .Values.backstage.startupProbe }}
+          startupProbe: {{- include "common.tplvalues.render" (dict "value" .Values.backstage.startupProbe "context" $) | nindent 12 }}
+          {{- end }}
           {{- if .Values.backstage.extraEnvVarsSecrets }}
           envFrom:
             {{- range .Values.backstage.extraEnvVarsSecrets }}

Diff for: charts/backstage/values.schema.json

@@ -408,6 +408,26 @@
                         }
                     ]
                 },
+                "startupProbe": {
+                    "title": "Startup probe",
+                    "description": "Ref: https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/",
+                    "$ref": "https://kubernetesjsonschema.dev/master/_definitions.json#/definitions/io.k8s.api.core.v1.Probe",
+                    "default": {},
+                    "examples": [
+                        {
+                            "failureThreshold": 3,
+                            "httpGet": {
+                                "path": "/healthcheck",
+                                "port": 7007,
+                                "scheme": "HTTP"
+                            },
+                            "initialDelaySeconds": 60,
+                            "periodSeconds": 10,
+                            "successThreshold": 1,
+                            "timeoutSeconds": 2
+                        }
+                    ]
+                },
                 "podSecurityContext": {
                     "title": "Security settings for a Pod.",
                     "description": "The security settings that you specify for a Pod apply to all Containers in the Pod. Ref: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/#set-the-security-context-for-a-pod",

Diff for: charts/backstage/values.yaml

@@ -190,6 +190,22 @@ backstage:
   #   timeoutSeconds: 2
   livenessProbe: {}
 
+    # -- Startup Probe
+  # Backstage doesn't provide any health endpoints by default. A simple one can be added like this: https://backstage.io/docs/plugins/observability/#health-checks
+  # <br /> Ref: https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes
+  # <!-- E.g.
+  # startupProbe:
+  #   failureThreshold: 3
+  #   httpGet:
+  #     path: /healthcheck
+  #     port: 7007
+  #     scheme: HTTP
+  #   initialDelaySeconds: 60
+  #   periodSeconds: 10
+  #   successThreshold: 1
+  #   timeoutSeconds: 2
+  startupProbe: {}
+
   # -- Security settings for a Pod.
   #  The security settings that you specify for a Pod apply to all Containers in the Pod.
   # <br /> Ref: https://kubernetes.io/docs/tasks/configure-pod-container/security-context/#set-the-security-context-for-a-pod