kustomize/releasing/README.md

# Releasing

[release page]: /../../releases
[`cloud-build-local`]: https://github.com/GoogleCloudPlatform/cloud-build-local
[Google Cloud Build]: https://cloud.google.com/cloud-build
[semver]: https://semver.org
[Go modules]: https://github.com/golang/go/wiki/Modules
[multi-module repo]: https://github.com/go-modules-by-example/index/blob/master/009_submodules/README.md
[semver review]: #semver-review
[semver release]: #semver-review
[`cloudbuild.yaml`]: cloudbuild.yaml
[kustomize repo release page]: https://github.com/kubernetes-sigs/kustomize/releases

This document describes how to perform a [semver release]
of one of the several [Go modules] in this repository.

### Release sequence

The dependencies determine the release order:

| module | depends on |
| ---    | ---        |
| `sigs.k8s.io/kustomize/kyaml`      | no local dependencies |
| `sigs.k8s.io/cli-utils`            | `kyaml`               |
| `sigs.k8s.io/kustomize/cmd/config` | `kyaml`, `cli-utils`  |
| `sigs.k8s.io/kustomize/api`        | `kyaml`               |
| `sigs.k8s.io/kustomize/kustomize`  | `cmd/config`, `api`   |

Thus, do `kyaml` first, then `cli-utils`, etc.

#### Establish clean state

```
cd ~/gopath/src/sigs.k8s.io/kustomize
git fetch upstream
git co master
git rebase upstream/master
make prow-presubmit-check
```

#### Release `kyaml`

```
gorepomod release kyaml
```
Undraft the release on the [kustomize repo release page].


#### Release `cli-utils`

```
cd ../cli-utils

# Pin to the most recent kyaml.
gorepomod pin kyaml

# Merge these changes to upstream (make a PR, merge it)

# Release cli-utils
gorepomod release {top}
```

#### Release `cmd/config`

```
cd ../kustomize

# Pin to the most recent kyaml.
gorepomod pin kyaml

# Pin cmd/config/go.mod to the new cli-utils, e.g.
(cd cmd/config; go mod edit -require=sigs.k8s.io/cli-utils@v0.20.2)

# Merge these changes to upstream (make a PR, etc.)

# Release it.
gorepomod release cmd/config
```

Undraft the release on the [kustomize repo release page].

#### Release `api` (the kustomize API, used by the CLI)

```
gorepomod pin cmd/config
# Merge these changes.

gorepomod release api
```

Undraft the release on the [kustomize repo release page].

#### Release the kustomize CLI

```
gorepomod pin api
# Merge these changes.

gorepomod release kustomize
```

Undraft the release on the [kustomize repo release page].

#### Unpin everything

Go back into development mode, so current code in-repo
depends on current code in-repo.

```
gorepomod unpin api
gorepomod unpin cmd/config
gorepomod unpin kyaml
# Merge these changes.
```

Visit the [release page] and edit the release notes as desired;
this should be automated, and descriptions in PR's should
be standardized to make automation possible.
See kubebuilder project.


## Public Modules

[`sigs.k8s.io/cli-utils`]: #sigsk8siocli-utils
[`sigs.k8s.io/kustomize/api`]: #sigsk8siokustomizeapi
[`sigs.k8s.io/kustomize/kustomize`]: #sigsk8siokustomizekustomize
[`sigs.k8s.io/kustomize/kyaml`]: #sigsk8siokustomizekyaml
[`sigs.k8s.io/kustomize/cmd/config`]: #sigsk8siokustomizecmdconfig

[kustomize/v3.2.1]: /../../releases/tag/kustomize%2Fv3.2.1
[pluginator/v1.0.0]: /../../releases/tag/pluginator%2Fv1.0.0

| Module Name                          | Module Description         | Example Tag         | Example Branch Name         |
| ------                               | ---                        | ---                 | ---                         |
| [`sigs.k8s.io/cli-utils`]            | General cli-utils          | _cli-utils/v0.20.2_ | _release-cli-utils-v0.20.2_ |
| [`sigs.k8s.io/kustomize/kustomize`]  | kustomize executable       | _kustomize/v3.2.2_  | _release-kustomize-v3.2.2_  |
| [`sigs.k8s.io/kustomize/api`]        | kustomize API              | _api/v0.1.0_        | _release-api-v0.1_          |
| [`sigs.k8s.io/kustomize/kyaml`]      | k8s-specific yaml editting | _kyaml/v0.3.3_      | _release-kyaml-v0.2_        |
| [`sigs.k8s.io/kustomize/cmd/config`] | kyaml related commands     | _cmd/config/v0.3.3_ | _release-cmd/config-v0.3_   |

### sigs.k8s.io/kustomize/kustomize

The `kustomize` program, a CLI for performing
structured edits to Kubernetes Resource Model (KRM) YAML.

There's only one public package in this module.
It's called `main`, it's therefore unimportable.
It holds the `kustomize` executable.

See the [installation instructions](../docs/INSTALL.md)
to perform an install.


### sigs.k8s.io/kustomize/api

The [kustomize Go API](https://github.com/kubernetes-sigs/kustomize/tree/master/api).

The packages in this module are used by API clients,
like the `kustomize` program itself, and programs in
other repositories, e.g. `kubectl`.  They include
methods to read, edit and emit modified YAML.

Release notes should appear on the [release page].

The package has a toy executable called `api`, which,
if run, prints the API release version, but has no
other use.

### sigs.k8s.io/kustomize/kyaml

The [kyaml module](https://github.com/kubernetes-sigs/kustomize/tree/master/kyaml).

Low level packages for transforming YAML associated
with KRM objects.

These are used to build _kyaml filters_, computational units
that accept and emit KRM YAML, editing or simply validating it.

The kustomize `api` and the `cmd/config` packages are built on this.

### sigs.k8s.io/kustomize/cmd/config

The [cmd/config module](https://github.com/kubernetes-sigs/kustomize/tree/master/cmd/config).

A collection od CLI commands that correspond to
kyaml filters.

### sigs.k8s.io/kustomize/pluginator

The `pluginator` program, a code generator that
converts Go plugins to conventional statically
linkable library code.

Only holds a `main`, and therefore unimportable.
It holds the _pluginator_ executable.

This binary is only of
interest to someone writing a new builtin
transformer or generator.  See the [plugin
documentation](../docs/plugins).
Its dependence on the API is  for
plugin-related constants, not logic.

## Manual process

In this repo, releasing a module is accomplished by applying
a tag to the repo and pushing it upstream.  A minor release
branch is also created as necessary to track patch releases.

A properly formatted tag (described below) contains
the module name and version.

Pushing the tag upstream will trigger [Google Cloud Build] to build a release
and make it available on the  [release page].

Cloud build reads its instructions from the
[`cloudbuild.yaml`] file in this directory.

We use a Go program to make the tagging and branch
creation process less error prone.

See this [multi-module repo] tagging discussion
for an explanation of the path-like portion of these tags.

### Get up to date

It's assumed that whatever is already commited to the latest
commit is passing all tests and appropriate for release.


```
git fetch upstream
git checkout master
git rebase upstream/master
make prow-presubmit-check
```

### Select a module to release

E.g.
```
module=kustomize   # The kustomize executable
module=api         # The API
```

### Review tags to help determine new tag

Local:
```
git tag -l | grep $module
```

Remote:
```
git ls-remote --tags upstream | grep $module
```

Set the version you want:

```
major=0; minor=1; patch=0
```

#### semver review

Go's [semver]-compatible version tags take the form `v{major}.{minor}.{patch}`:

| major | minor | patch |
| :---:   | :---:  | :---: |
| API change | enhancements | bug fixes |
| manual update | maybe auto-update | auto-update encouraged |

 - If there are only bug fixes or refactors, increment `patch` from whatever it is now.
 - If there are new features, increment  `minor`.
 - If there's an API change (either the Go API or the CLI behavior
   with respect to CLI arguments and flags), increment `major`.



### Create the release branch

Every module release occurs on it's own git branch.

The branch name doesn't include the patch number,
since the branch accumulates patch releases.

> TODO: define procedure for doing a cherrypick (committing a patch) to a
> release branch that already exists.

Name the branch:

```
branch="release-${module}-v${major}.${minor}"
echo "branch=$branch"
```

Create it:
```
git checkout -b $branch
```

### Define the release tag

```
tag="${module}/v${major}.${minor}.${patch}"
echo "tag=$tag"
```

### Pin the executable to a particular API version

Only do this if releasing one of the
executables (kustomize or pluginator).

In this repository, an executable in development
on the master branch typically depends on the API
also in development on the master branch.  This is
achieved via a `replace` directive in the
executable's `go.mod` file.

A _released_ executable, however, must depend on a
specific release of the API.  For this reason,
it's typical, but not required, to release an
executable immediately after releasing the API,
updating the API version that the executable
requires.

```
# Update the following as needed, obviously.

# git checkout -b pinTheRelease
# go mod edit -dropreplace=sigs.k8s.io/kustomize/api    $module/go.mod
# go mod edit -require=sigs.k8s.io/kustomize/api@v0.1.1 $module/go.mod
# git commit -a -m "Drop API module replacement"

```

### Push the release branch

```
git push -f upstream $branch
```

#### if replacing a release...

Must delete the tag before re-pushing it.
Dangerous - only do this if you're sure nothing
has already pulled the release.

Delete the tag locally:

```
git tag --delete $tag
```

Delete it upstream:
```
# Disable push protection:
git remote set-url --push upstream git@github.com:kubernetes-sigs/kustomize.git

# The empty space before the colon effectively means delete the tag.
git push upstream :refs/tags/$tag

# Enable push protection:
git remote set-url --push upstream no_push
```

Optionally visit the [release page] and delete
(what has now become) the _draft_ release for that
version.

### Tag the local repository

```
git tag -a $tag -m "Release $tag on branch $branch"
```

Move the `latest_kustomize` tag:
```
git tag -d latest_kustomize
git push upstream :latest_kustomize
git tag -a latest_kustomize
```

### Optionally build a release locally

[localbuild.sh]: localbuild.sh

Install [`cloud-build-local`], then run [localbuild.sh]:

```
./releasing/localbuild.sh $module
```

This should create release artifacts in a local directory.

### Trigger the cloud build by pushing the tag

Push the tag:

```
git remote set-url --push upstream git@github.com:kubernetes-sigs/kustomize.git
git push upstream $tag
git push upstream latest_kustomize
git remote set-url --push upstream no_push
```

This triggers [Google Cloud Build].

###  Update release notes

Visit the [release page] and edit the release notes as desired.