Add environment variables on container specs

Signed-off-by: Ed Doh <[email protected]>

Author: edwarddoh

charts/coredns/README.md

@@ -103,6 +103,7 @@ The command removes all the Kubernetes components associated with the chart and
 | `extraVolumes`                                 | Optional array of volumes to create                                                                                                       | []                                                           |
 | `extraVolumeMounts`                            | Optional array of volumes to mount inside the CoreDNS container                                                                           | []                                                           |
 | `extraSecrets`                                 | Optional array of secrets to mount inside the CoreDNS container                                                                           | []                                                           |
+| `env`                                          | Optional array of environment variables for CoreDNS container                                                                           | []                                                           |
 | `customLabels`                                 | Optional labels for Deployment(s), Pod, Service, ServiceMonitor objects                                                                   | {}                                                           |
 | `customAnnotations`                            | Optional annotations for Deployment(s), Pod, Service, ServiceMonitor objects                                                              |
 | `rollingUpdate.maxUnavailable`                 | Maximum number of unavailable replicas during rolling update                                                                              | `1`                                                          |

charts/coredns/templates/deployment.yaml

@@ -107,6 +107,10 @@ spec:
 {{- end }}
 {{- if .Values.extraVolumeMounts }}
 {{- toYaml .Values.extraVolumeMounts | nindent 8}}
+{{- end }}
+{{- if .Values.env }}
+        env:
+{{- toYaml .Values.env | nindent 10}}
 {{- end }}
         resources:
 {{ toYaml .Values.resources | indent 10 }}

charts/coredns/values.yaml

@@ -259,6 +259,17 @@ extraSecrets: []
 #   mountPath: /etc/wherever
 #   defaultMode: 440
 
+# optional array of environment variables for coredns container
+# possible usecase: provides username and password for etcd user authentications
+env: []
+# - name: WHATEVER_ENV
+#   value: whatever
+# - name: SOME_SECRET_ENV
+#   valueFrom:
+#     secretKeyRef:
+#       name: some-secret-name
+#       key: secret-key
+
 # To support legacy deployments using CoreDNS with the "k8s-app: kube-dns" label selectors.
 # See https://github.com/coredns/helm/blob/master/charts/coredns/README.md#adopting-existing-coredns-resources
 # k8sAppLabelOverride: "kube-dns"