Problem: I want to inject a service environment variable into my app spec from a Github secret, _instead_ of using an encrypted environment variable stored in the app spec itself. Proposal: Add a "vars" section to the app spec for defining input variables, similar to terraform's input variables. Input variables could be passed as command line parameters to the doctl CLI using the --var my-variable=some-value option. Define values in the app spec using a ${{var.my-variable}} placeholder, which will be replaced when the app spec is read. I suggest the double curly bracket enclosure to indicate yaml substitutions, as opposed to the single curly bracket enclosure used for build/deploy-time bindable variables. Also, adding the var. prefix inside the enclosure leaves room for other sources of substitution in the future. Example: vars: - key: my-variable type: string default: some-default-value services: - name: foo envs: - key: MY_RUNTIME_VAR scope: RUN_TIME value: ${{var.my-variable}} Deploy the spec: doctl app create --spec app.yaml --var my-variable=some-value Alternative: Currently I'm using sed to do a string replacement in the app spec yaml file just before upserting the app using doctl .
