Document the KubeOne release process (#493)

* Document the KubeOne release process

Signed-off-by: Marko Mudrinić <[email protected]>

* Fix git merge command

Co-Authored-By: Artiom Diomin <[email protected]>

docs/release_process.md

@@ -0,0 +1,149 @@
+# KubeOne Release Process
+
+This document explains how to release a new version of KubeOne.
+
+## Prerequisites
+
+Please follow these steps to prepare your environment for releasing
+a new version of KubeOne.
+
+* Make sure your Go version is up-to-date
+  * On your computer, run `go version` to find out what
+  Go version you're using
+  * If you're not using the latest Go version, go to
+  [the official Go website][1] to grab the latest binaries
+* Install [GoReleaser][2]
+* [Generate GitHub Token][3] with the `repo` permissions
+and export the token as the `GITHUB_TOKEN` environment variable
+  * The GitHub Token is needed to create a GitHub Release and
+  upload KubeOne binaries
+
+## Preparing the release
+
+Before releasing a new version, you need to update the documentation
+to reference to the upcoming version and generate a changelog.
+
+### Updating documentation
+
+You need to update the following documents to point to the new release:
+
+* `README.md`
+  * Links and binary name should point to the upcoming version in the
+  [Installing KubeOne section][4]
+  * [Kubernetes versions compatibility section][5] if there are changes
+  in supported Kubernetes versions, Terraform versions and/or providers
+* [Optional] Update [the quickstart guides][6] to require/recommend
+the latest version
+
+### Generating the changelog
+
+Add a new entry for the upcoming release to the [CHANGELOG.md][7] file.
+
+The changelog file contains only changes that are directly affecting
+the end-users, such as a new feature, a bug or security fix, a new
+version of a dependency and more. Changes such as changes to tests,
+refactors (as long as there are no behavior changes) are not documented.
+
+**Note:** Currently, we're generating the changelog manually.
+To find what changes have been made since a previous release
+you can use the GitHub Compare feature. Grab the latest
+commit from the previous release and put it in the
+following link:
+```
+https://github.com/kubermatic/kubeone/compare/<commit>...master
+```
+
+### Creating a PR
+
+**Warning:** This part is still work in progress!
+
+Once you have finished updating the documentation and the
+changelog, go ahead and create a PR with all changes.
+
+We're using this PR to run all tests and ensure that
+the upcoming version works correctly on all providers.
+
+Once the PR is created, hold it so it's not merged by
+Prow/Tide as soon as the required tests pass:
+```
+/hold
+```
+
+Then, run optional tests that tests KubeOne on providers
+other than AWS:
+```
+TBD
+```
+
+Finally, go to the Prow Dashboard to monitor the progress.
+Once all tests are green, unhold the PR:
+```
+/hold cancel
+```
+
+At this point, the documentation is updated and we ensured that
+KubeOne works correctly on all providers. You're ready
+to create a new KubeOne release.
+
+## Releasing KubeOne
+
+Before running the release process, ensure your
+`master` branch is up-to-date:
+
+```
+git checkout master
+git fetch origin
+git reset --hard origin/master
+```
+
+Create a release branch and push it:
+
+```
+git checkout -b release/v0.x
+git push origin release/v0.x
+```
+
+**Note:** Currently there's a bug with branch-protector that
+requires a new protection to be created for each release branch.
+
+Create a tag for the new version and push it:
+
+```
+git tag -a v0.x.y -m "KubeOne version 0.x.y"
+git push origin --tags
+```
+
+Once the tag is in the place, run GoReleaser from the KubeOne
+root directory which will create a GitHub Release and generate
+and upload binaries:
+
+```
+goreleaser
+```
+
+As GoReleaser generates the release notes based on the list of
+all commits since the last release, we're going to change it
+to the changelog we generated earlier.
+
+At the top, add the following links:
+
+```
+Check out the [documentation](https://github.com/kubermatic/kubeone/tree/v0.x.y/docs) for this release to find out how to get started with KubeOne.
+```
+
+Then, add the changelog and after the changelog add information
+about checksums:
+
+```
+### Checksums
+
+SHA256 checksums can be found in the `kubeone_0.x.y_checksums.txt` file.
+```
+
+[1]: https://golang.org/dl/
+[2]: https://goreleaser.com/install/
+[3]: https://help.github.com/en/articles/creating-a-personal-access-token-for-the-command-line
+[4]: https://github.com/kubermatic/kubeone#installing-kubeone
+[5]: https://github.com/kubermatic/kubeone#kubernetes-versions-compatibility
+[6]: https://github.com/kubermatic/kubeone/tree/master/docs
+[7]: https://github.com/kubermatic/kubeone/blob/master/CHANGELOG.md