The Rig

The Rig runs commands from preset files in parallel, presenting the aggregated output in different ways.

Usage

Create a “preset.yaml” file.

Say, for example, that you want to have a look at how much space is being wasted by logs on some remote hosts you manage.

label: "du {{.host}}:{{.path}}"
command: ["ssh", "{{.host}}", "du", "-sh", "{{.path}}" ]
arguments:
- { host: "example.com", path: /var/log }
- { host: "example.org", path: /var/log }

If a preset file defines one or more argument dictionaries, the command line and the label will be treated as a templates, and one instance of the command is run for each argument dictionary, after placeholders have been replaced with the actual named arguments values.

Order of execution

• commands from different preset files given as positional arguments to the Rig are run in parallel.
• commands generated by interpolating arguments from a single preset are run serially (eg.: one starts only after the previous has finished but irregardless of failure or success).
  • they can be forced to run in parallel using the --fearless option.

Run the Rig

rig report log-size.yaml

The output will look like this, except for colors

du example.com:/var/log/* | PID 83508: ssh example.com du -sh /var/log/*
du example.com:/var/log/* | du: /var/log/secret: Permission denied
du example.com:/var/log/* |  16K	/var/log/auth.log
du example.com:/var/log/* |  12K	/var/log/cron
du example.com:/var/log/* | 152K	/var/log/messages
du example.com:/var/log/* | finished after 0.75s with error: exit status 1
du example.org:/var/log/* | PID 83508: ssh example.org du -sh /var/log/*
du example.org:/var/log/* | du: /var/log/secret: Permission denied
du example.org:/var/log/* |  22K	/var/log/auth.log
du example.org:/var/log/* |   3K	/var/log/cron
du example.org:/var/log/* | 200K	/var/log/messages
du example.org:/var/log/* | finished after 1.48s with error: exit status 1
all commands failed

The report subcommand will buffer the commands output and print it only when the command finishes. Who finishes first gets it’s output printed first.

The stream subcommand instead print each commands output as it comes in, without any buffering or ordering, and is more suitable for running commands like tail.