Git tips & tricks

Pre-commit hooks

Ksconf is setup to work as a pre-commit plugin. To use ksconf in this manner, simply configure the ksconf repo in your pre-commit configuration file. If you haven’t done any of this before, it’s not difficult to setup but is beyond the scope of this guide. We suggest that you read the pre-commit docs and review this section when you are ready to setup the hooks.

Hooks provided by ksconf

Three hooks are currently defined by the ksconf repository:

ksconf-check
Runs ksconf check to perform basic validation tests against all files in your repo that end with .conf or .meta. Any errors will be reported by the UI at commit time and you’ll be able to correct mistakes before bogus files are committed into your repo. If you’re not sure why you’d need this, check out Why validate my conf files?
ksconf-sort
Runs ksconf sort to normalize any of your .conf or .meta files which will make diffs more readable and merging more predictable. As with any hook, you can customize the filename pattern of which files this applies to. For example, to manually organize props.conf files, simply add the exclude setting. See Example below.
ksconf-xml-format:
Runs ksconf xml-format to apply consistency to your XML representations of Simple XML dashboards and navigation files. Formatting includes appropriate indention and the automatic addition of <![CDATA[ ... ]]> blocks, as needed, to reduce the need for XML escaping, resulting in more readable source file. By default, this hook looks at standard locations where XML views and navigation typically live. So if you use Advanced XML, proceed with caution, as they share the same path and haven’t been tested.

Configuring pre-commit hooks in you repo

To add ksconf pre-commit hooks to your repository, add the following content to your .pre-commit-config.yaml file:

repos:
- repo: https://github.com/Kintyre/ksconf
  rev: v0.7.7
  hooks:
    - id: ksconf-check
    - id: ksconf-sort
    - id: ksconf-xml-format

For general reference, here’s a copy of what we frequently use for our repos.

- repo: https://github.com/pre-commit/pre-commit-hooks
  rev: v2.0.0
  hooks:
    - id: trailing-whitespace
      exclude: README.md
    - id: end-of-file-fixer
      exclude: README.md$
    - id: check-json
    - id: check-xml
    - id: check-ast
    - id: check-added-large-files
      args: [ '--maxkb=50' ]
    - id: check-merge-conflict
    - id: detect-private-key
    - id: mixed-line-ending
      args: [ '--fix=lf' ]
- repo: https://github.com/Kintyre/ksconf
  rev: v0.7.7
  hooks:
    - id: ksconf-check
    - id: ksconf-sort
      exclude: (props|logging)\.conf
    - id: ksconf-xml-format

Tip

You should update rev to the most currently released stable version. Upgrading this frequently isn’t typically necessary since these two operations are pretty basic and stable. However, it’s still a good idea to review the change log to see what, if any, pre-commit functionality was updated.

Note

Sometimes pre-commit can get in the way.

Instead of disabling it entirely, it’s often better to disable the specific rule that’s causing an issue using the SKIP environmental variable. So for example, if intentionally adding a file over 50 Kb, a command like this will allow all the other rules to still run.

SKIP=check-added-large-file git commit -m "Refresh lookup files for bogus TA"

This and other tricks are fully documented in the pre-commit docs. However, this comes up frequently enough that it’s worth repeating here.

Should my version of ksconf and pre-commit plugins be the same?

If you’re running both ksconf locally as well as the ksconf pre-commit plugin, then technically you have ksconf installed twice. That may sound less than ideal, but practically, this isn’t a problem. As long as the version of the ksconf CLI tool is close to the rev listed in .pre-commit-config.yaml, then everything should work fine.

Our suggestion:

  1. Keep versions in the same major.minor release range or bump the version every 6-12 months.
  2. Check the changelog for any pre-commit related changes or compatibility concerns.

While keeping ksconf CLI versions in sync across your environment is recommended, it doesn’t matter as much for the pre-commit plugin. Why?

  1. The pre-commit plugin offers a small subset of overall ksconf functionality.
  2. The exposed functionality is stable and changes infrequently.
  3. Updating pre-commit too frequently may cause unnecessary delays if you have a large team or high number of git clones throughout your environment, as each one will have to wait and upgrade the next time pre-commit is kicked off.

Git configuration tweaks

Ksconf as external difftool

Use ksconf diff as an external difftool provider for git. Edit ~/.gitconfig and add the following entries:

[difftool "ksconf"]
    cmd = "ksconf --force-color diff \"$LOCAL\" \"$REMOTE\" | less -R"
[difftool]
    prompt = false
[alias]
    ksdiff = "difftool --tool=ksconf"

Now you can run this new git alias to compare files in your directory using the ksconf diff feature instead of the default textual diff that git provides. This is especially helpful if the ksconf-sort pre-commit hook hasn’t been enabled.

git ksdiff props.conf

Tip

Wonky version of git?

If you find yourself in the situation where git-difftool hasn’t been fully installed correctly (or the Perl extensions are missing), then here’s a workaround option for you.

ksconf diff <(git show HEAD:./props.conf) props.conf

Take note of the relative path prefix ./. In practice, this can be problematic.

Stanza aware textual diffs

Make git diff show the ‘stanza’ on the @@ output lines.

Note

How does git know that?

Ever wonder how git diff is able to show you the name of the function or method where changes were made? This works for many programming languages out of the box. If you’ve ever spent much time looking at diffs, that additional context is invaluable. As it turns out, this is customizable by adding a stanza matching regular expression with a file pattern match.

Simply add the following settings to your git configuration:

[diff "conf"]
    xfuncname = "^(\\[.*\\])$"

Then register this new ability with specific file patterns using git’s attributes feature. Edit ~/.config/git/attributes and add:

*.conf diff=conf
*.meta diff=conf

Note

Didn’t work as expected?

Be aware that the location for your global-level attributes may be different. Use the following command to test if the settings have been applied.
git check-attr -a -- *.conf

Test to make sure the xfuncname attribute was set as expected:

git config diff.conf.xfuncname