Setup from scratch

Install Go.
1. Ensure that your GOBIN directory (by default $(go env GOPATH)/bin) is in your PATH.
2. Check it's working by running go version.
  - If it doesn't work, check the install location, usually /usr/local/go, is on your PATH.
Sign one of the contributor license agreements below.
Clone the repo: git clone https://github.com/googleapis/google-cloud-go
Change into the checked out source: cd google-cloud-go
Fork the repo and add your fork as a secondary remote (this is necessary in order to create PRs).

Which module to release?

The Go client libraries have several modules. Each module does not strictly correspond to a single library - they correspond to trees of directories. If a file needs to be released, you must release the closest ancestor module.

To see all modules:

$ cat `find . -name go.mod` | grep module
module cloud.google.com/go
module cloud.google.com/go/bigtable
module cloud.google.com/go/firestore
module cloud.google.com/go/bigquery
module cloud.google.com/go/storage
module cloud.google.com/go/datastore
module cloud.google.com/go/pubsub
module cloud.google.com/go/spanner
module cloud.google.com/go/logging

The cloud.google.com/go is the repository root module. Each other module is a submodule.

So, if you need to release a change in bigtable/bttest/inmem.go, the closest ancestor module is cloud.google.com/go/bigtable - so you should release a new version of the cloud.google.com/go/bigtable submodule.

If you need to release a change in asset/apiv1/asset_client.go, the closest ancestor module is cloud.google.com/go - so you should release a new version of the cloud.google.com/go repository root module. Note: releasing cloud.google.com/go has no impact on any of the submodules, and vice-versa. They are released entirely independently.

Test failures

If there are any test failures in the Kokoro build, releases are blocked until the failures have been resolved.

How to release `cloud.google.com/go`

Check for failures in the continuous Kokoro build. If there are any failures in the most recent build, address them before proceeding with the release.
Navigate to ~/code/gocloud/ and switch to master.
git pull
Run git tag -l | grep -v beta | grep -v alpha to see all existing releases. The current latest tag $CV is the largest tag. It should look something like vX.Y.Z (note: ignore all LIB/vX.Y.Z tags - these are tags for a specific library, not the module root). We'll call the current version $CV and the new version $NV.
On master, run git log $CV... to list all the changes since the last release. NOTE: You must manually visually parse out changes to submodules [1] (the git log is going to show you things in submodules, which are not going to be part of your release).
Edit CHANGES.md to include a summary of the changes.
cd internal/version && go generate && cd -
Commit the changes, push to your fork, and create a PR.
Wait for the PR to be reviewed and merged. Once it's merged, and without merging any other PRs in the meantime: a. Switch to master. b. git pull c. Tag the repo with the next version: git tag $NV. d. Push the tag to origin: git push origin $NV
Update the releases page with the new release, copying the contents of CHANGES.md.
Run go get cloud.google.com/go@vX.Y.Z then wait for the release to show up on http://pkg.go.dev/cloud.google.com/go (a few minutes).
Go to the doc publishing job and trigger the job with the following environment variables: MODULE=cloud.google.com,VERSION=vX.Y.Z. Replace the version with the value for the module you're releasing. See publish_docs.sh.

How to release a submodule

We have several submodules, including cloud.google.com/go/logging, cloud.google.com/go/datastore, and so on.

To release a submodule:

(these instructions assume we're releasing cloud.google.com/go/datastore - adjust accordingly)

Check for failures in the continuous Kokoro build. If there are any failures in the most recent build, address them before proceeding with the release. (This applies even if the failures are in a different submodule from the one being released.)
Navigate to ~/code/gocloud/ and switch to master.
git pull
Run git tag -l | grep datastore | grep -v beta | grep -v alpha to see all existing releases. The current latest tag $CV is the largest tag. It should look something like datastore/vX.Y.Z. We'll call the current version $CV and the new version $NV.
On master, run git log $CV.. -- datastore/ to list all the changes to the submodule directory since the last release.
Edit datastore/CHANGES.md to include a summary of the changes.
cd internal/version && go generate && cd -
Commit the changes, push to your fork, and create a PR.
Wait for the PR to be reviewed and merged. Once it's merged, and without merging any other PRs in the meantime: a. Switch to master. b. git pull c. Tag the repo with the next version: git tag $NV. d. Push the tag to origin: git push origin $NV
Update the releases page with the new release, copying the contents of datastore/CHANGES.md.
Run go get cloud.google.com/go/datastore@vX.Y.Z then wait for the release to show up on http://pkg.go.dev/cloud.google.com/go/datastore (a few minutes).
Go to the doc publishing job and trigger the job with the following environment variables: MODULE=cloud.google.com/go/datastore,VERSION=vX.Y.Z. Replace the module path and version with the values for the module you're releasing. You can leave all of the other fields blank. See publish_docs.sh.

Appendix