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Environment Variables

Environment variables may be used in your configuration YAML files to provide certain values dynamically. This is especially useful in certain environments, such as Kubernetes. Secrets serve a similar purpose, however those still require you to modify a file to provide the values.

Version Requirement

Environment variables support was introduced in v4.3.0.

The following rules apply:

  • Environment variables may only be used in configuration YAML files.
  • You may only substitute single (scalar) values in YAML; not complex, multi-line data.
  • Environment variable names are case-sensitive.

Syntax​

!env_var MY_ENV_VAR my_default_value

Where:

  • MY_ENV_VAR is the name of the environment variable to substitute the value of.
  • my_default_value is an optional default value to use if the specified environment variable is either not defined, a blank string, or contains only whitespace characters.
caution

If an environment variable cannot be found or does not have a value as defined above, and no default value is provided, an exception is thrown and configuration loading will fail for that specific instance.

Default Value Parsing Behavior​

Special notes about parsing and the default value.

  • Spaces are allowed in the default value. Example:

    !env_var FUBAR my default value

    The default value will be my default value.

  • If either single (') or double (") quotation marks surround the default value, they are stripped. Example:

    !env_var FUBAR "my default value"

    The default value will be my default value (without quotes).

    info

    Quotation marks are not required for default values that contain spaces!

Example​

Suppose you have the following recyclarr.yml file and you want to move your base_url and api_key to environment variables:

radarr:
  radarr4k:
    base_url: http://localhost:7878
    api_key: bf99da49d0b0488ea34e4464aa63a0e5

Using Linux OS as an example, define some environment variables with the above API key and base URL values:

export RADARR_BASE_URL="http://localhost:7878"
export RADARR_API_KEY="bf99da49d0b0488ea34e4464aa63a0e5"

Then, simply replace those properties in your configuration YAML with the environment variables syntax:

radarr:
  radarr4k:
    base_url: !env_var RADARR_BASE_URL
    api_key: !env_var RADARR_API_KEY

Note that, above, no default values are specified for either environment variable. So if those end up being empty or are deleted later, you'll get failures when loading this config.