Command dependencies

[luetge]

Hi,

the following is an idea to allow dependence of processes on unix commands: instead of the keyword "require" to list a number of immortal processes as dependencies one could introduce a keyword "require_cmd", which specifies a list of unix commands that are executed and have to return without errors (exit code 0) in order for the immortal process to start. Immortal would then automatically check this periodically, and as soon as these dynamic conditions are fulfilled, the process would be spawned.

Use case: spawn a process when a certain file exists/does not exist anymore.

Thank you!

[nbari]

@luetge please check latest release 0.20.0 it has implemented this feature 👍

For testing in mac:

 $ brew install immortal

create a supervisor dir:

 mkdir /tmp/immortal

set the enviroment IMMORTAL_SDIR to that directory:

 export IMMORTAL_SDIR=/tmp/immortal

add this environment in all terminals you use in case want to use immortaldir so that immortalctl can read/know where are the sockets for the processes

Create a dir to scan (in where your run.yml files will be):

mkdir $HOME/tmp/services

Start immortaldir on that directory:

immortaldir $HOME/tmp/services

Create a test run.yml file in $HOME/tmp/services, something like:

cmd: iostat 3
log:
    file: /tmp/iostat.log
require_cmd: test -f /tmp/foo

It should not start until you create the file /tmp/foo, so you could test immortalctl should not print any process, later do touch /tmp/foo and it should start the process.

Please give a try and let me know how it goes.

[luetge]

That works perfectly, thank you! (Tested on MacOS)