Debugging LAVA test definitions

Debugging LAVA test definitions

Convert Multi-Node jobs to single node

The scripts available in the MultiNode API are not installed for test jobs which are not part of a MultiNode group, so the job will simply fail that test as a command not found.

Therefore, by reversing the Changes to submission JSON, a MultiNode JSON file can be converted to singlenode.

Other calls which may require communication with other devices may need to be removed from your YAML. This can be extended to retain a set of singlenode YAML files in which new wrapper scripts and new builds are tested.

The Job Definition of one job within a MultiNode group may be a good starting point for creating a singlenode equivalent.

Always use set -x in wrapper scripts

By viewing the complete log, the complete processing of the wrapper script becomes obvious.

set -e
set -x

Avoid using shell operators in YAML lines

Pipes, redirects and nested sub shells will not work reliably when put directly into the YAML. Use a wrapper script (with set -x).


set -e
set -x
ifconfig|grep "inet addr"|grep -v ""|cut -d: -f2|cut -d' ' -f1

Un-nested sub-shells do work:

- lava-test-case multinode-send-network --shell lava-send network hostname=$(hostname) fqdn=$(hostname -f)

Check that your message ID labels are consistent

A lava-wait must be preceded by a lava-send from at least one other device in the group or the waiting device will timeout

This can be a particular problem if you remove test definitions from the JSON or edit a YAML file without checking other uses of the same file.

# can be used as a comment in YAML but JSON does not support comments, so take care.

Test your result parsers

If the YAML uses a custom result parser, configure one of your YAML files to output the entire test result output to stdout so that you can reliably capture a representative block of output. Test your proposed result parser against the block using your favourite language.

Comment out the parser from the YAML if there are particular problems, just to see what the default LAVA parsers can provide.

Be obsessive about paths and scripts

  • If you use cd in your YAML, always store where you were and where you end up using pwd.
  • Output your location prior to calling local wrapper scripts.
  • Ensure that all wrapper scripts are executable in your VCS
  • Ensure that the relevant interpreter is installed. e.g. python is not necessarily part of the test image.
  • Consider installing realpath and use that to debug your directory structure. * Avoid the temptation of using absolute paths - LAVA may need to change the absolute locations.

A failed test is not necessarily a bug in the test

Always check whether the test result came back as failed due to some cause other than the test definition itself. Particularly with MultiNode, a test result can fail due to some problem on a different board within the group.

Check your JSON files

Syntax problems will be picked up by LAVA when you submit but also check that the URLs listed in the JSON are correct. Keep your YAML descriptions, names and filenames unique so that it is easier to pick up if the JSON simply calls the wrong YAML test definition.