Motivation

When automating tasks often the requirement comes up to retry commands, for example when network connections are involved and commands do not return successfully immediately or if resources are temporarily not available. Sometimes a simple for-loop in bash is sufficient. Sometimes it is necessary to use additional waiting between retries, sometimes timeouts are desired. Getting all those combinations right can be tedious and error-prone so a generic "retry" command should be available in usual environments so we should provide a retry command to openSUSE distributions.

Goals

G1: A "retry" command is submitted to openSUSE:Factory as part of a package

Execution

Research existing approaches and distributions
Package existing solution or develop alternative on your own
Submit package to a devel repository and then openSUSE:Factory and work on feedback

Results

2022-06-11: Couldn't wait until hackweek so made it a small weekend project :D Based on what I had in https://github.com/okurz/scripts/tree/master/retry I created https://github.com/okurz/retry including proper README, license, tests, CI, spec file for a package. An according package in OBS https://build.opensuse.org/package/show/home:okurz:retry/retry setup to be triggered from github following https://linuxkamarada.com/en/2019/03/19/integrating-the-open-build-service-with-github/
2022-06-13: After some fixes to get the package to build preparing submission to openSUSE:Factory so created https://build.opensuse.org/package/show/home:okurz:retry_submission/retry. To my knowledge the best approach to automate submission is still something like https://github.com/os-autoinst/scripts/blob/master/os-autoinst-obs-auto-submit but in this case I did it manually, something like getting the tarball, actually obscpio, obsinfo, spec-file and replacing the services in _service and submitting all, then creating a submission to Base:System https://build.opensuse.org/request/show/982215
2022-06-14: The package is already in openSUSE:Factory so usable in openSUSE Tumbleweed. openSUSE Leap does not currently accept submissions to any version
2022-06-16: The project already received a contribution from a second person \o/ https://github.com/okurz/retry/pull/1
2022-06-27: Created new submission https://build.opensuse.org/request/show/985315 including the exponential backoff feature added by jbaier. Created https://github.com/os-autoinst/os-autoinst-distri-openQA/pull/92 to use the retry feature within the openQA-in-openQA tests. Created lightning talk presentation https://v.gd/okurz_retry

Further details

There are some "best practices" like https://stackoverflow.com/questions/7449772/how-to-retry-a-command-in-bash and https://unix.stackexchange.com/questions/82598/how-do-i-write-a-retry-logic-in-script-to-keep-retrying-to-run-it-upto-5-times . There are also existing commands, like https://github.com/minfrin/retry but it seems to unmaintained and even fails to build so maybe https://github.com/okurz/scripts/blob/master/retry is a better start.

Looking for hackers with the skills:

linux retry bash github coreutils packaging

This project is part of:

Hack Week 21

Activity

over 2 years ago: cdywan liked this project.

over 2 years ago: fbonazzi liked this project.

over 2 years ago: maritawerner liked this project.

over 2 years ago: ph03nix liked this project.

over 2 years ago: okurz added keyword "bash" to this project.

over 2 years ago: okurz added keyword "github" to this project.

over 2 years ago: okurz added keyword "coreutils" to this project.

over 2 years ago: okurz added keyword "packaging" to this project.

over 2 years ago: okurz added keyword "linux" to this project.

over 2 years ago: okurz added keyword "retry" to this project.

over 2 years ago: okurz started this project.

over 2 years ago: okurz originated this project.

Comments

over 2 years ago by okurz | Reply

Couldn't wait until hackweek so made it a small weekend project :D Based on what I had in https://github.com/okurz/scripts/tree/master/retry I created https://github.com/okurz/retry including proper README, license, tests, CI, spec file for a package. An according package in OBS https://build.opensuse.org/package/show/home:okurz:retry/retry setup to be triggered from github following https://linuxkamarada.com/en/2019/03/19/integrating-the-open-build-service-with-github/

almost 2 years ago by minfrin | Reply

While alternative implementations are great, please be careful with naming. The “retry” tool is already out the box in Debian, Ubuntu, and Nix, and in the queue for EPEL. It is currently available for Suse via copr. If you create a different tool with the same name but different command line options into opensuse it creates chaos for everyone.
- almost 2 years ago by okurz | Reply
  
  Thanks for the comment. I researched earlier if I could find existing solutions in various distributions and I had not found the applications you mentioned at that time. Regarding copr, do you mean https://software.opensuse.org/package/python-copr ?