feat: add ability to deploy extra k8s yamls with helm chart (#5942)

helm/templates/_helpers.tpl

@@ -177,3 +177,16 @@ Deprecated value coder.tls.secretName must not be used.
 {{ fail "coder.tls.secretName is deprecated, use coder.tls.secretNames instead." }}
 {{- end }}
 {{- end }}
+
+{{/*
+Renders a value that contains a template.
+Usage:
+{{ include "coder.renderTemplate" ( dict "value" .Values.path.to.the.Value "context" $) }}
+*/}}
+{{- define "coder.renderTemplate" -}}
+    {{- if typeIs "string" .value }}
+        {{- tpl .value .context }}
+    {{- else }}
+        {{- tpl (.value | toYaml) .context }}
+    {{- end }}
+{{- end -}}

helm/templates/extra-templates.yaml

@@ -0,0 +1,4 @@
+{{- range .Values.extraTemplates }}
+---
+{{ include "coder.renderTemplate" (dict "value" . "context" $) }}
+{{- end }}

helm/values.yaml

@@ -198,3 +198,15 @@ coder:
       # coder.ingress.tls.wildcardSecretName -- The name of the TLS secret to
       # use for the wildcard host.
       wildcardSecretName: ""
+
+# extraTemplates -- Array of extra objects to deploy with the release. Strings
+# are evaluated as a template and can use template expansions and functions. All
+# other objects are used as yaml.
+extraTemplates:
+  #- |
+  #    apiVersion: v1
+  #    kind: ConfigMap
+  #    metadata:
+  #      name: my-configmap
+  #    data:
+  #      key: {{ .Values.myCustomValue | quote }}