Rum

Rum is a simple tool to easily run and manage long processes in the background.

It is particularly useful for running code via SSH without dealing with the bloat, complexity and terminal reemulation of tools such as Screen or Tmux -- if you disconnect, your code will continue running in the background, and nothing is lost.

Installation

You can install Rum via Cargo, Rust's package manager:

cargo install --git https://github.com/dccsillag/rum.git

Alternatively, precompiled binaries for various platforms can be found in the releases page.

Overview

To start a new run, simply prefix your command with 'rum'. For example, to start a run of sleep 10:

$ rum sleep 10
Started run d00ba0ab-bfad-43b2-a0d6-9aee1eda6e1f

Note that this does not interpret shell syntax. So, if you want to, say, execute seq 10 | wc -l, then you should use:

$ rum sh -c 'seq 10 | wc -l'
Started run 740fbf4a-dca2-4144-bade-9188bfb71d22

To list runs which were started with rum, you can use the --list subcommand:

$ rum --list  # or just `rum -l`
d00ba0ab [done] sleep 10
         Started Fri Feb 18 22:36:44 2022, Finished Fri Feb 18 22:36:54 2022
740fbf4a [done] sh -c 'seq 10 | wc -l'
         Started Fri Feb 18 22:37:34 2022, Finished Fri Feb 18 22:37:34 2022

Each run has an ID which identifies it -- it is printed right after it is initialized, and is also shown (leftmost) in the output of rum --list. This ID is used to manage runs.

To see more information about a run, use the --info subcommand:

$ rum --info d00ba0ab  # or just `rum -i d00ba0ab`
Command:   sleep 10
Status:    finished
Exit code: 0 (success)
Started:   Fri Feb 18 22:36:44 2022
Finished:  Fri Feb 18 22:36:54 2022

Note how the identifier shown when we started the run is much longer than the one we passed to the --info subcommand, yet it still worked; that's because Rum allows for a very handy shorthand: if there is only one ID which starts with the characters you passed it, it will use that ID. So we could actually have run the command above as follows:

$ rum --info d0  # or just `rum -i d0`
Command:   sleep 10
Status:    finished
Exit code: 0 (success)
Started:   Fri Feb 18 22:36:44 2022
Finished:  Fri Feb 18 22:36:54 2022

Using the first two characters of an ID is practical and almost always uniquely identifies an ID (when it doesn't, an extra character will do the trick).

Let's start a new run, which will take a very long time:

$ rum python -c 'import time; time.sleep(1000)'
Started run 5d7473cd-5ad5-45b8-a0f6-c01c4b3687c2

If we do rum --list now, we see that it is running:

$ rum -l
5d7473cd [running] python -c 'import time; time.sleep(1000)'
         Started Fri Feb 18 22:47:10 2022
d00ba0ab [done] sleep 10
         Started Fri Feb 18 22:36:44 2022, Finished Fri Feb 18 22:36:54 2022
740fbf4a [done] sh -c 'seq 10 | wc -l'
         Started Fri Feb 18 22:37:34 2022, Finished Fri Feb 18 22:37:34 2022

We might want to interrupt this run. Rum provides three ways to interrupt a run: --interrupt, --terminate and --kill. --interrupt (or -c) is the equivalent of hitting Ctrl+C (i.e., a SIGINT signal); --terminate (or -t) is the equivalent of killing the process' group (akin kill <PID>, i.e., SIGTERM); --kill (or -K) is the equivalent of killing the process' group with signal 9 (akin kill -9 <PID>, i.e., SIGKILL). Rule of thumb: prefer -c. If it doesn't work, fallback to -t. Use -K only if you must, as it absolutely doesn't allow the process to clean itself up.

So let's use --interrupt (-c) on the Python run:

$ rum --interrupt 5d  # or `rum -c 5d`

Now, if we look at the output of rum --list:

d00ba0ab [done] sleep 10
         Started Fri Feb 18 22:36:44 2022, Finished Fri Feb 18 22:36:54 2022
740fbf4a [done] sh -c 'seq 10 | wc -l'
         Started Fri Feb 18 22:37:34 2022, Finished Fri Feb 18 22:37:34 2022
5d7473cd [killed] python -c 'import time; time.sleep(1000)'
         Started Fri Feb 18 22:47:10 2022, Finished Fri Feb 18 22:56:34 2022

Note how Rum now displays the Python process, run 5d7473cd, as [killed] (instead of [running] or [done]). This indicates that the run was killed by a signal, which is indeed what we just did.

If we were to have a run which exited with non-zero exit code (i.e., it errored out):

$ rum python -c 'print(not_in_scope)'
Started run 605abbc1-dc36-4a90-bebf-94bc756100e0
$ rum --list  # or `rum -l`
d00ba0ab [done] sleep 10
         Started Fri Feb 18 22:36:44 2022, Finished Fri Feb 18 22:36:54 2022
740fbf4a [done] sh -c 'seq 10 | wc -l'
         Started Fri Feb 18 22:37:34 2022, Finished Fri Feb 18 22:37:34 2022
5d7473cd [killed] python -c 'import time; time.sleep(1000)'
         Started Fri Feb 18 22:47:10 2022, Finished Fri Feb 18 22:56:34 2022
605abbc1 [failed:1] python -c 'print(not_in_scope)'
         Started Fri Feb 18 23:00:40 2022, Finished Fri Feb 18 23:00:40 2022

See how this new run is shown with [failed:1] -- this indicates that it exited with a non-zero exit code of 1.

You can also view the output of a run with the --view (-v) subcommand:

$ rum --view <RUN_ID>
 # or
$ rum -v <RUN_ID>

For example, if we were to run

$ rum -v 605abbc1

We'd be shown the following output:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
NameError: name 'not_in_scope' is not defined

The --view subcommand also works for runs which are still running, and automatically follows output.

Finally, after some time, the output of rum --list will begin to be a bit cluttered with runs which are no longer of importance. To aid this, there is the --remove (or -r) subcommand:

$ rum --remove 74
Command:   sh -c 'seq 10 | wc -l'
Status:    finished
Exit code: 0 (success)
Started:   Fri Feb 18 22:37:34 2022
Finished:  Fri Feb 18 22:37:34 2022
 
✔ Are you sure you want to delete this run? · yes
Deleted.

It prints information about the given run and asks for confirmation before removing it.

You can also pass it multiple runs at once:

$ rum --remove 5d 60
Command:   python -c 'import time; time.sleep(1000)'
Status:    finished
Exit code: none (killed)
Started:   Fri Feb 18 22:47:10 2022
Finished:  Fri Feb 18 22:56:34 2022
 
✔ Are you sure you want to delete this run? · yes
Deleted.
Command:   python -c 'print(not_in_scope)'
Status:    finished
Exit code: 1 (failed)
Started:   Fri Feb 18 23:00:40 2022
Finished:  Fri Feb 18 23:00:40 2022
 
✔ Are you sure you want to delete this run? · yes
Deleted.

And, if we were to run rum --list now, we are left with only our first sleep 10 run.

$ rum --list
d00ba0ab [done] sleep 10
         Started Fri Feb 18 22:36:44 2022, Finished Fri Feb 18 22:36:54 2022