Add postStart lifecycle hook (#315)

* Add postStart lifecycle hook

* Update values.yaml

Co-authored-by: Theron Voran <tvoran@users.noreply.github.com>

Co-authored-by: Theron Voran <tvoran@users.noreply.github.com>

templates/server-statefulset.yaml

@@ -159,6 +159,14 @@ spec:
                   # to this pod while it's terminating
                   "sleep {{ .Values.server.preStopSleepSeconds }} && kill -SIGTERM $(pidof vault)",
                 ]
+            {{- if .Values.server.postStart }}
+            postStart:
+              exec:
+                command:
+                {{- range (.Values.server.postStart) }}
+                - {{ . | quote }}
+                {{- end }}
+            {{- end }}
         {{- if .Values.server.extraContainers }}
           {{ toYaml .Values.server.extraContainers | nindent 8}}
         {{- end }}

test/unit/server-statefulset.bats

@@ -1048,3 +1048,24 @@ load _helpers
       yq '.spec.template.spec | .priorityClassName == "armaggeddon"' | tee /dev/stderr)
   [ "${actual}" = "true" ]
 }
+
+#--------------------------------------------------------------------
+# postStart
+@test "server/standalone-StatefulSet: postStart disabled by default" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      --show-only templates/server-statefulset.yaml  \
+      . | tee /dev/stderr |
+      yq -r '.spec.template.spec.containers[0].lifecycle.postStart' | tee /dev/stderr)
+  [ "${actual}" = "null" ]
+}
+
+@test "server/standalone-StatefulSet: postStart can be set" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      --show-only templates/server-statefulset.yaml  \
+      --set='server.postStart={/bin/sh,-c,sleep}' \
+      . | tee /dev/stderr |
+      yq -r '.spec.template.spec.containers[0].lifecycle.postStart.exec.command[0]' | tee /dev/stderr)
+  [ "${actual}" = "/bin/sh" ]
+}

values.yaml

@@ -188,6 +188,14 @@ server:
   # Used to set the sleep time during the preStop step
   preStopSleepSeconds: 5
 
+  # Used to define commands to run after the pod is ready.
+  # This can be used to automate processes such as initialization
+  # or boostrapping auth methods.
+  postStart: []
+  # - /bin/sh
+  # - -c
+  # - /vault/userconfig/myscript/run.sh
+
   # extraEnvironmentVars is a list of extra enviroment variables to set with the stateful set. These could be
   # used to include variables required for auto-unseal.
   extraEnvironmentVars: {}