Changelog commands

There are two commands that Bumper relies on for working with changelogs. Each release group must configure these:

[[groups]]
name = "my-package"
display_name = "my-package"

changelog_cmd = ["..."]
cat_cmd = ["..."]
current_cmd = ["..."]
next_cmd = ["..."]

changelog_cmd

This command is used for updating the changelog it will be called with two environment variables set:

• BUMPER_GROUP: The group that needs a changelog update
• BUMPER_GROUP_NEXT_VERSION: The next version for the group

Additionally, the command will receive a repeating number of command-line flags representing entries in the changelog:

• --patch <entry>
• --minor <entry>
• --major <entry>

So if your changelog_cmd is ["./update-changelog"] and there are two patch entries and one minor entry, the command will be called like this:

BUMPER_GROUP="my-package" BUMPER_GROUP_NEXT_VERSION="1.2.0" ./update-changelog --patch "Fixed bug A" --patch "Fixed bug B" --minor "Added feature C"

This command will be called once per release group when running bumper commit. For example, if there are three release groups, the command will be called three times, once for each group.

cat_cmd

The cat command is used by Bumper to read the contents of a changelog release section. It powers bumper cat which is useful for powering various types of automations like release tools that can create GitHub Releases. It is called with the following environment variables set:

• BUMPER_GROUP: The release group whose changelog entry is being requested
• BUMPER_GROUP_VERSION: The version of the release group whose changelog entry is being requested

So if your cat_cmd is ["./cat-changelog"] the user runs bumper cat --group my-package --version 1.2.0, the command will be called like this:

BUMPER_GROUP="my-package" BUMPER_GROUP_VERSION="1.2.0" ./cat-changelog

This command is expected to output the changelog entry for that release to standard output (STDOUT). Direct any logging or error reporting to standard error (STDERR) so that Bumper can correctly parse the changelog entry from stdout.

Built-in commands

bumper builtins amendlog:default

This is the default changelog command (changelog_cmd) used by Bumper. It maintains a CHANGELOG.md file, writing entries into it using markdown.

bumper builtins cat:default

This is the default cat command (cat_cmd) used by Bumper. It pairs with bumper builtins amendlog:default to read release entries from a CHANGELOG.md file. It expects each release to be delineate by a level two heading in the form of ## [RELEASE_GROUP_NAME] [VERSION]. It will capture everything from after that line until the next level two heading or the end of the file. Whatever it captures it prints to STDOUT.