tendermint/RELEASES.md

Releases

Tendermint uses semantic versioning with each release following a vX.Y.Z format. The master branch is used for active development and thus it's advisable not to build against it.

The latest changes are always initially merged into master. Releases are specified using tags and are built from long-lived "backport" branches that are cut from master when the release process begins. Each release "line" (e.g. 0.34 or 0.33) has its own long-lived backport branch, and the backport branches have names like v0.34.x or v0.33.x (literally, x; it is not a placeholder in this case). Tendermint only maintains the last two releases at a time (the oldest release is predominantly just security patches).

Backporting

As non-breaking changes land on master, they should also be backported to these backport branches.

We use Mergify's backport feature to automatically backport to the needed branch. There should be a label for any backport branch that you'll be targeting. To notify the bot to backport a pull request, mark the pull request with the label corresponding to the correct backport branch. For example, to backport to v0.35.x, add the label S:backport-to-v0.35.x. Once the original pull request is merged, the bot will try to cherry-pick the pull request to the backport branch. If the bot fails to backport, it will open a pull request. The author of the original pull request is responsible for solving the conflicts and merging the pull request.

Creating a backport branch

If this is the first release candidate for a major release, you get to have the honor of creating the backport branch!

Note that, after creating the backport branch, you'll also need to update the tags on master so that go mod is able to order the branches correctly. You should tag master with a "dev" tag that is "greater than" the backport branches tags. See #6072 for more context.

In the following example, we'll assume that we're making a backport branch for the 0.35.x line.

1. Start on master

2. Create and push the backport branch:

   git checkout -b v0.35.x
   git push origin v0.35.x
   

3. Create a PR to update the documentation directory for the backport branch.

   We only maintain RFC and ADR documents on master, to avoid confusion. In addition, we rewrite Markdown URLs pointing to master to point to the backport branch, so that generated documentation will link to the correct versions of files elsewhere in the repository. For context on the latter, see https://github.com/tendermint/tendermint/issues/7675.

   To prepare the PR:

   # Remove the RFC and ADR documents from the backport.
   # We only maintain these on master to avoid confusion.
   git rm -r docs/rfc docs/architecture
   
   # Update absolute links to point to the backport.
   go run ./scripts/linkpatch -recur -target v0.35.x -skip-path docs/DOCS_README.md,docs/README.md docs
   
   # Create and push the PR.
   git checkout -b update-docs-v035x
   git commit -m "Update docs for v0.35.x backport branch." docs
   git push -u origin update-docs-v035x
   

   Be sure to merge this PR before making other changes on the newly-created backport branch.

After doing these steps, go back to master and do the following:

1. Tag master as the dev branch for the next major release and push it up to GitHub. For example:

   git tag -a v0.36.0-dev -m "Development base for Tendermint v0.36."
   git push origin v0.36.0-dev
   

2. Create a new workflow to run e2e nightlies for the new backport branch. (See e2e-nightly-master.yml for an example.)

3. Add a new section to the Mergify config (.github/mergify.yml) to enable the backport bot to work on this branch, and add a corresponding S:backport-to-v0.35.x label so the bot can be triggered.

4. Add a new section to the Dependabot config (.github/dependabot.yml) to enable automatic update of Go dependencies on this branch. Copy and edit one of the existing branch configurations to set the correct target-branch.

Release candidates

Before creating an official release, especially a major release, we may want to create a release candidate (RC) for our friends and partners to test out. We use git tags to create RCs, and we build them off of backport branches.

Tags for RCs should follow the "standard" release naming conventions, with -rcX at the end (for example, v0.35.0-rc0).

(Note that branches and tags cannot have the same names, so it's important that these branches have distinct names from the tags/release names.)

If this is the first RC for a major release, you'll have to make a new backport branch (see above). Otherwise:

1. Start from the backport branch (e.g. v0.35.x).
2. Run the integration tests and the e2e nightlies (which can be triggered from the Github UI; e.g., https://github.com/tendermint/tendermint/actions/workflows/e2e-nightly-34x.yml).
3. Prepare the changelog:
   • Move the changes included in CHANGELOG_PENDING.md into CHANGELOG.md. Each RC should have it's own changelog section. These will be squashed when the final candidate is released.
   • Run python ./scripts/linkify_changelog.py CHANGELOG.md to add links for all PRs
   • Ensure that UPGRADING.md is up-to-date and includes notes on any breaking changes or other upgrading flows.
   • Bump TMVersionDefault version in version.go
   • Bump P2P and block protocol versions in version.go, if necessary. Check the changelog for breaking changes in these components.
   • Bump ABCI protocol version in version.go, if necessary
4. Open a PR with these changes against the backport branch.
5. Once these changes have landed on the backport branch, be sure to pull them back down locally.
6. Once you have the changes locally, create the new tag, specifying a name and a tag "message": git tag -a v0.35.0-rc0 -m "Release Candidate v0.35.0-rc0
7. Push the tag back up to origin: git push origin v0.35.0-rc0 Now the tag should be available on the repo's releases page.
8. Future RCs will continue to be built off of this branch.

Note that this process should only be used for "true" RCs-- release candidates that, if successful, will be the next release. For more experimental "RCs," create a new, short-lived branch and tag that instead.

Major release

This major release process assumes that this release was preceded by release candidates. If there were no release candidates, begin by creating a backport branch, as described above.

1. Start on the backport branch (e.g. v0.35.x)
2. Run integration tests (make test_integrations) and the e2e nightlies.
3. Prepare the release:
   • "Squash" changes from the changelog entries for the RCs into a single entry, and add all changes included in CHANGELOG_PENDING.md. (Squashing includes both combining all entries, as well as removing or simplifying any intra-RC changes. It may also help to alphabetize the entries by package name.)
   • Run python ./scripts/linkify_changelog.py CHANGELOG.md to add links for all PRs
   • Ensure that UPGRADING.md is up-to-date and includes notes on any breaking changes or other upgrading flows.
   • Bump TMVersionDefault version in version.go
   • Bump P2P and block protocol versions in version.go, if necessary
   • Bump ABCI protocol version in version.go, if necessary
4. Open a PR with these changes against the backport branch.
5. Once these changes are on the backport branch, push a tag with prepared release details. This will trigger the actual release v0.35.0.
   • git tag -a v0.35.0 -m 'Release v0.35.0'
   • git push origin v0.35.0
6. Make sure that master is updated with the latest CHANGELOG.md, CHANGELOG_PENDING.md, and UPGRADING.md.
7. Add the release to the documentation site generator config (see DOCS_README.md for more details). In summary:
   • Start on branch master.
   • Add a new line at the bottom of docs/versions to ensure the newest release is the default for the landing page.
   • Add a new entry to themeConfig.versions in docs/.vuepress/config.js to include the release in the dropdown versions menu.
   • Commit these changes to master and backport them into the backport branch for this release.

Minor release (point releases)

Minor releases are done differently from major releases: They are built off of long-lived backport branches, rather than from master. As non-breaking changes land on master, they should also be backported into these backport branches.

Minor releases don't have release candidates by default, although any tricky changes may merit a release candidate.

To create a minor release:

1. Checkout the long-lived backport branch: git checkout v0.35.x
2. Run integration tests (make test_integrations) and the nightlies.
3. Check out a new branch and prepare the release:
   • Copy CHANGELOG_PENDING.md to top of CHANGELOG.md
   • Run python ./scripts/linkify_changelog.py CHANGELOG.md to add links for all issues
   • Run bash ./scripts/authors.sh to get a list of authors since the latest release, and add the GitHub aliases of external contributors to the top of the CHANGELOG. To lookup an alias from an email, try bash ./scripts/authors.sh <email>
   • Reset the CHANGELOG_PENDING.md
   • Bump the TMDefaultVersion in version.go
   • Bump the ABCI version number, if necessary. (Note that ABCI follows semver, and that ABCI versions are the only versions which can change during minor releases, and only field additions are valid minor changes.)
4. Open a PR with these changes that will land them back on v0.35.x
5. Once this change has landed on the backport branch, make sure to pull it locally, then push a tag.
   • git tag -a v0.35.1 -m 'Release v0.35.1'
   • git push origin v0.35.1
6. Create a pull request back to master with the CHANGELOG & version changes from the latest release.
   • Remove all R:minor labels from the pull requests that were included in the release.
   • Do not merge the backport branch into master.