kuberneteskubernetes-helmranchergo-templatessprig-template-functions

helm chart / go-template | Translate environment variables from string


I have a general helm chart in my Kubernetes cluster taking a multiline text field with environment variables (identified by KEY=VALUE), translating them into the deployment.yaml like this:

Inside the Rancher dialog: enter image description here

In the deployment.yaml:

{{- if .Values.envAsMultiline }}
{{- range (split "\n" .Values.envAsMultiline) }}
            - name: "{{ (split "=" .)._0 }}"
              value: "{{ (split "=" .)._1 }}"
{{- end }}
{{- end }}

This works fine so far. But the problem now is: If I have a "=" in my environment variable (Like in the JAVA_OPTS above), it splits the environment variable value at the second "=" of the line:

JAVA_OPTS=-Xms1024m -Xmx2048m -XX:MetaspaceSize=256M -XX:MaxMetaspaceSize=512m

is translated to

-Xms1024m -Xmx2048m -XX:MetaspaceSize

The "=256M -XX:MaxMetaspaceSize=512m" is missing here.

How do I correct my deployment.yaml template accordingly?


Solution

  • Plan 1:

    One of the simplest implementation methods

    You can directly use the yaml file injection method, put the env part here as it is, so you can write the kv form value and the ref form value in the values in the required format.

    As follows:

    values.yaml

    env:
      - name: ENVIRONMENT1
        value: "testABC"
      - name: JAVA_OPTS
        value: "-Xms1024m -Xmx2048m -XX:MetaspaceSize=256M -XX:MaxMetaspaceSize=512M"
      - name: TZ
        value: "Europe/Berlin"
    

    deployment.yaml

    containers:
      - name: {{ .Chart.Name }}
        env:
          {{ toYaml .Values.env | nindent xxx }}
    

    (ps: xxx --> actual indent)

    Plan 2:

    Env is defined in the form of kv, which is rendered in an iterative manner

    values.yaml

    env:
      ENVIRONMENT1: "testABC"
      JAVA_OPTS: "-Xms1024m -Xmx2048m -XX:MetaspaceSize=256M -XX:MaxMetaspaceSize=512M"
      TZ: "Europe/Berlin"
    

    deployment.yaml

    containers:
    - name: {{ .Chart.Name }}
      env: 
        {{- range $k, $v := .Values.env }}
        - name: {{ $k | quote }}
          value: {{ $v | quote }}
        {{- end }}
    

    Plan 3:

    If you still need to follow your previous writing, then you can do this

    values.yaml

    env: |
      ENVIRONMENT1=testABC
      JAVA_OPTS=-Xms1024m -Xmx2048m -XX:MetaspaceSize=256M -XX:MaxMetaspaceSize=512M
      TZ=Europe/Berlin
    

    deployment.yaml

    containers:
    - name: {{ .Chart.Name }}
      {{- if .Values.env }}
      env:
      {{- range (split "\n" .Values.env) }}
      - name: {{ (split "=" .)._0 }}
        value: {{ . | trimPrefix (split "=" .)._0 | trimPrefix "=" | quote }}
      {{- end }}
      {{- end }}
    

    output:

    env:
    - name: ENVIRONMENT1
      value: "testABC"
    - name: JAVA_OPTS
      value: "-Xms1024m -Xmx2048m -XX:MetaspaceSize=256M -XX:MaxMetaspaceSize=512M"
    - name: TZ
      value: "Europe/Berlin"