Processes

Starting with a simple example:

devenv.nix

{ pkgs, ... }:

{
  processes = {
    silly-example.exec = "while true; do echo hello && sleep 1; done";
    ping.exec = "ping localhost";
  };
}

To start the processes in the foreground, run:

$ devenv up
Starting processes ...

20:37:44 system          | ping.1 started (pid=4094686)
20:37:44 system          | silly-example.1 started (pid=4094688)
20:37:44 silly-example.1 | hello
20:37:44 ping.1          | PING localhost (127.0.0.1) 56 bytes of data.
20:37:44 ping.1          | 64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.127 ms
20:37:45 silly-example.1 | hello
20:37:45 ping.1          | 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.257 ms
20:37:46 silly-example.1 | hello
20:37:46 ping.1          | 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.242 ms
20:37:47 silly-example.1 | hello
20:37:47 ping.1          | 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.249 ms
...

A set of common services are also available, such as services.postgres.enable for setting up a PostgreSQL process.

Running tasks before/after the process

Processes are automatically available as tasks, allowing you to define pre and post hooks. See the Processes as tasks section for details on how to run tasks before a process starts or after it stops.