During the Linux startup process, ylem is intended to sequentially execute arbitrary "user scripts" (alphabetically sorted). Moreover ylem provides logging which facilitates startup debugging.

Startup scripts executed through ylem SHOULD be aimed to:

• create required files and directories
• setup users and permissions
• prepare the system to run deamons

For example, ylem COULD start supervisor, to manage daemons, as soon as the system is sufficiently ready.

Create an /etc/ylem/scripts directory and put your bootstraping scripts. Then scripts are executed alphabetically sorted.

In a Dockerfile:

ENTRYPOINT ["dumb-init", "-c", "--", "ylem", "start", "--"]
CMD ["sleep", "infinity"]

The configuration uses a YAML syntax and remains in /etc/#{progname}/config.yml, where progname is ylem. Furthermore configuration filepath can be set on the CLI.

Available configuration keys are:

• scripts.path
  where bootstraping scripts are stored
  default value is: /etc/#{progname}/scripts
• logger.file
  default value is: /var/log/#{progname}.log
• logger.level
  default value is: INFO (see: Logger::Severity)
• environment.file
  default value is: /etc/environment (System-wide environment variables)

Missing configuration keys use default values. Configuration file can be: complete, partial or empty.