Configuration

Tunnel's settings can be configured in any of the following methods, which will apply in the following precedence:

1. CLI flags (overrides all other settings)
2. Environment variables (overrides config file settings)
3. Configuration file

CLI Flags

You can view the list of available flags by adding the --help flag to a Tunnel command, or by exploring the CLI reference.

Environment Variables

Any CLI option can be set as an environment variable. The environment variable name are similar to the CLI option name, with the following augmentations:

• Add TUNNEL_ prefix
• All uppercase letters
• Replace - with _

For example:

• --debug => TUNNEL_DEBUG
• --cache-dir => TUNNEL_CACHE_DIR

$ TUNNEL_DEBUG=true TUNNEL_SEVERITY=CRITICAL tunnel image alpine:3.15

Configuration File

Any setting can be set in a YAML file. By default, config file named tunnel.yaml is read from the current directory where Tunnel is run. To load configuration from a different file, use the --config flag and specify the config path to load: tunnel --config /etc/tunnel/myconfig.yaml.

The structure and settings of the YAML config file is documented in the Config file document.