ns: env
preamble: |
  [12-factor]: https://12factor.net
  [Docker Secrets]: https://docs.docker.com/engine/swarm/secrets/#build-support-for-docker-secrets-into-your-images
funcs:
  - name: env.Getenv
    alias: getenv
    released: v0.2.0
    description: |
      Exposes the [os.Getenv](https://pkg.go.dev/os/#Getenv) function.

      Retrieves the value of the environment variable named by the key. If the
      variable is unset, but the same variable ending in `_FILE` is set, the contents
      of the file will be returned. Otherwise the provided default (or an empty
      string) is returned.

      This is a more forgiving alternative to using `.Env`, since missing keys will
      return an empty string, instead of panicking.

      The `_FILE` fallback is especially useful for use with [12-factor][]-style
      applications configurable only by environment variables, and especially in
      conjunction with features like [Docker Secrets][].
    pipeline: false
    arguments:
      - name: var
        required: true
        description: the environment variable name
      - name: default
        required: false
        description: the default
    examples:
      - |
        $ gomplate -i 'Hello, {{env.Getenv "USER"}}'
        Hello, hairyhenderson
        $ gomplate -i 'Hey, {{getenv "FIRSTNAME" "you"}}!'
        Hey, you!
      - |
        $ echo "safe" > /tmp/mysecret
        $ export SECRET_FILE=/tmp/mysecret
        $ gomplate -i 'Your secret is {{getenv "SECRET"}}'
        Your secret is safe
  - name: env.ExpandEnv
    released: v2.5.0
    description: |
      Exposes the [os.ExpandEnv](https://pkg.go.dev/os/#ExpandEnv) function.

      Replaces `${var}` or `$var` in the input string according to the values of the
      current environment variables. References to undefined variables are replaced by the empty string.

      Like [`env.Getenv`](#envgetenv), the `_FILE` variant of a variable is used.
    pipeline: false
    arguments:
      - name: input
        required: true
        description: the input
    examples:
      - |
        $ gomplate -i '{{env.ExpandEnv "Hello $USER"}}'
        Hello, hairyhenderson
        $ gomplate -i 'Hey, {{env.ExpandEnv "Hey, ${FIRSTNAME}!"}}'
        Hey, you!
      - |
        $ echo "safe" > /tmp/mysecret
        $ export SECRET_FILE=/tmp/mysecret
        $ gomplate -i '{{env.ExpandEnv "Your secret is $SECRET"}}'
        Your secret is safe
      - |
        $ gomplate -i '{{env.ExpandEnv (file.Read "foo")}}
        contents of file "foo"...