Variable Interpolation

furyctl allows to specify interpolated strings inside a furyctl.yaml configuration file.

Path interpolation

Intended for fields where you should specify a path to a folder or a file (e.g.: spec.kubernetes.ssh.keyPath). It will be replaced by the absolute path as computed from the current working directory.

Format: "{path://<relative-path>}"

Example:

...
spec:
  kubernetes:
    ssh:
      keyPath: "{path://./ssh-key}"
...

Assuming you are running furyctl from /home/user/projects/test, the "{path://./ssh-key}" string will be replaced with /home/user/projects/test/ssh-key.

File interpolation

Replaces the interpolation string with the contents of a specified file. Useful for fields where you could have a file in your local filesystem that holds the required data, for example spec.distribution.modules.ingress.nginx.tls.secret.cert. To locate the file, furyctl will first convert the specified path to an absolute one (if needed).

Format: "{file://<path-to-file>}"

Example:

...
spec:
  distribution:
    modules:
      ingress:
        nginx:
          tls:
            secret:
              cert: "{file://relative/path/to/ssl.crt}"
              key: "{file://relative/path/to/ssl.key}"
              ca: "{file://relative/path/to/ssl.ca}"
...

Assuming you are running furyctl from /home/user/projects/test, the cert, key and ca values will be replaced with /home/user/projects/test/relative/path/to/ssl.{crt|key|ca}.

warning

Be mindful about newlines at the end of the interpolated files: they will be part of the interpolation and can cause issues.

This is especially true for random strings generated with the commandline. For example, if your command uses echo to print a string, use echo -n to avoid printing a newline.

Environment interpolation

Replaces the interpolation string with the value of the specified environment variable. Useful to specify secrets that you may not want to store inside plaintext files.

Format: "{env://<env-variable-name>}"

Example:

...
spec:
  distribution:
    modules:
      auth:
        pomerium:
          secrets:
            COOKIE_SECRET: "{env://POMERIUM_COOKIE_SECRET}"
            IDP_CLIENT_SECRET: "{env://POMERIUM_IDP_CLIENT_SECRET}"
            SHARED_SECRET: "{env://POMERIUM_IDP_CLIENT_SECRET}"
            SIGNING_KEY: "{env://POMERIUM_IDP_CLIENT_SECRET}"
...

The strings in the above example will be replaced with the value of the specified environment variables.