Wrap an OS process in a GenServer so that it can be supervised.

For example, in your children list add MuonTrap.Daemon like this:

children = [
  {MuonTrap.Daemon, ["my_server", ["--options", "foo"]], [cd: "/some_directory"]]}
]

opts = [strategy: :one_for_one, name: MyApplication.Supervisor]
Supervisor.start_link(children, opts)

In the child_spec tuple, the second element is a list that corresponds to the MuonTrap.cmd/3 parameters. I.e., The first item in the list is the program to run, the second is a list of commandline arguments, and the third is a list of options. The same options as MuonTrap.cmd/3 are available with the following additions:

• :name - Name the Daemon GenServer
• :log_output - When set, send output from the command to the Logger. Specify the log level (e.g., :debug)
• :log_prefix - Prefix each log message with this string (defaults to the program's path)
• :log_transform - Pass a function that takes a string and returns a string to format output from the command. Defaults to String.replace_invalid/1 on Elixir 1.16+ to avoid crashing the logger on non-UTF8 output.
• :logger_metadata - A keyword list to merge into the process's logger metadata. The :muontrap_cmd and :muontrap_args keys are automatically added and cannot be overridden.
• :stderr_to_stdout - When set to true, redirect stderr to stdout. Defaults to false.
• :exit_status_to_reason - Optional function to convert the exit status (a number) to stop reason for the Daemon GenServer. Use if error exit codes carry information or aren't errors.

If you want to run multiple MuonTrap.Daemons under one supervisor, they'll all need unique IDs. Use Supervisor.child_spec/2 like this:

Supervisor.child_spec({MuonTrap.Daemon, ["my_server", []]}, id: :server1)