Document steps to create a release

hack/README.md

@@ -3,10 +3,110 @@
 This directory contains several scripts useful in the development process of
 Knative Eventing.
 
-- `boilerplate/add-boilerplate.sh` Adds license boilerplate to _txt_ or _go_
-  files in a directory, recursively.
-- `release.sh` Creates a new [release](release.md) of Knative Eventing.
-- `update-codegen.sh` Updates auto-generated client libraries.
-- `update-deps.sh` Updates Go dependencies.
-- `verify-codegen.sh` Verifies that auto-generated client libraries are
-  up-to-date.
+-   `boilerplate/add-boilerplate.sh` Adds license boilerplate to _txt_ or _go_
+    files in a directory, recursively.
+-   `release.sh` Creates a new [release](#creating-a-release) of Knative Eventing.
+-   `update-codegen.sh` Updates auto-generated client libraries.
+-   `update-deps.sh` Updates Go dependencies.
+-   `verify-codegen.sh` Verifies that auto-generated client libraries are
+    up-to-date.
+
+## Creating a release
+
+_Note: only Knative leads can create versioned releases._
+
+See https://github.com/knative/test-infra/blob/master/ci for more information on
+creating releases.
+
+### Creating a major version release
+
+#### GitHub UI
+
+1. Click the Branch dropdown.
+1. Type the desired `release-X.Y` branch name into the search box.
+1. Click the `Create branch: release-X.Y from 'master'` button. _You must have write permissions to the repo to create a branch._
+
+    Prow will detect the new release branch and run the `release.sh` script. If
+    the build succeeds, a new tag `vX.Y.0` will be created and a GitHub release
+    published. If the build fails, logs can be retrieved from
+    https://testgrid.knative.dev/eventing#auto-release.
+
+1.  Write release notes and add them to
+    [the release](https://github.com/knative/eventing/releases).
+
+#### Git CLI
+
+1.  Fetch the upstream remote.
+
+    ```sh
+    git fetch upstream
+    ```
+
+1.  Create a `release-X.Y` branch from `upstream/master`.
+
+    ```sh
+    git branch --no-track release-X.Y upstream/master
+    ```
+
+1.  Push the branch to upstream.
+
+    ```sh
+    git push upstream release-X.Y
+    ```
+
+    _You must have write permissions to the repo to create a branch._
+
+    Prow will detect the new release branch and run the `release.sh` script. If
+    the build succeeds, a new tag `vX.Y.0` will be created and a GitHub release
+    published. If the build fails, logs can be retrieved from
+    https://testgrid.knative.dev/eventing#auto-release.
+
+1.  Write release notes and add them to
+    [the release](https://github.com/knative/eventing/releases).
+
+The major version release job is currently called
+`ci-knative-eventing-auto-release` and runs
+[every alternate hour](https://github.com/knative/test-infra/blob/957032b0badbf4409384995f3c34350f24f5f5ae/ci/prow/config.yaml).
+
+### Creating a minor version release
+
+1.  Fetch the upstream remote.
+
+    ```sh
+    git fetch upstream
+    ```
+
+1.  Create a branch based on the desired `release-X.Y` branch.
+
+    ```sh
+    git co -b my-backport-branch upstream/release-X.Y
+    ```
+
+1.  Cherry-pick desired commits from master into the new branch.
+
+    ```sh
+    git cherry-pick <commitid>
+    ```
+
+1.  Push the branch to your fork.
+
+    ```sh
+    git push origin
+    ```
+
+1.  Create a PR for your branch based on the `release-X.Y` branch.
+
+    Once the PR is merged, Prow will detect the new commits in the release
+    branch and run the `release.sh` script. If the build succeeds, a new tag
+    `vX.Y.Z` will be created (where `Z` is the current minor version number + 1)
+    and a
+    [GitHub release published](https://github.com/knative/eventing/releases). If
+    the build fails, logs can be retrieved from
+    https://testgrid.knative.dev/eventing#dot-release.
+
+1.  Write release notes and add them to
+    [the release](https://github.com/knative/eventing/releases).
+
+The minor version release job is currently called
+`ci-knative-eventing-dot-release` and runs
+[every Tuesday at 09:56 Pacific time](https://github.com/knative/test-infra/blob/957032b0badbf4409384995f3c34350f24f5f5ae/ci/prow/config.yaml#L2209).