As requirements change, you'll inevitably need to evolve your Protobuf APIs, and potentially update your dependencies.
As much as buf
's breaking change detection gives you confidence that you'll be evolving your module in a backwards
compatible way, there can still be situations in which you want to validate a change locally before pushing a new
version to the BSR.
This guide assumes that you've familiarized yourself with these topics:
1. Edit and push
The typical buf
workflow involves editing your .proto
files, and verifying the changes continue to conform to the
configured lint rules.
Once you've made your edits, you can manually verify your changes with the buf
CLI, or by
configuring your editor to automatically report errors on save.
On the command line, that should look like this:
$ buf lint
$ buf generate
Once you're satisfied with the changes, save the change in your VCS (such as a Git repository) like you would with regular code. If the module is published to the BSR, you can push a new version using this command:
$ buf push --tag "$(git rev-parse HEAD)"
The --tag
flag isn't required, but we recommend tagging BSR commits with version control references as a way to track
corresponding revisions.
All of these steps (and more) ought to be configured in CI/CD. If you're a GitHub Actions user, make sure to check out the GitHub Actions guide to learn more.
2. Update dependencies
If your module has any dependencies, you can update your dependencies to their latest versions with the buf mod update
command. This command resolves the latest commit on the repository and updates the contents of your module's
buf.lock
.
For example, if a buf.yaml
is in the current directory, you can update your
dependencies with this command:
$ buf mod update
When your dependencies conform to buf
's default lint and breaking rules,
updating is straightforward. Despite buf
's best efforts, however, dependencies sometimes undergo changes that can
break compatibility, so you might encounter errors when you try to buf push
a new version of your module to the BSR.
We encourage you to validate compatibility with buf build
after any call to buf mod update
:
# Update dependencies
$ buf mod update
# Verify that nothing has broken
$ buf build
3. Edit multiple modules
As you develop buf
modules, you might find yourself in a situation where you own multiple modules that depend on each
other. When you want to make a change to one of your modules, you normally need to push the update up to the BSR so that
the other module can update its dependency and use it locally. This workflow imposes a frustrating feedback loop and
invites more opportunities for mistakes in each pushed module commit.
The buf
module workspace was created to solve exactly this problem (and more).
For example, if you have two modules checked out in sibling directories:
.
├── paymentapis
│ ├── acme
│ │ └── payment
│ │ └── v2
│ │ └── payment.proto
│ ├── buf.lock
│ └── buf.yaml
└── petapis
├── acme
│ └── pet
│ └── v1
│ └── pet.proto
├── buf.lock
└── buf.yaml
version: v1
name: buf.build/acme/petapis
deps:
- buf.build/acme/paymentapis
version: v1
name: buf.build/acme/paymentapis
You can add a buf.work.yaml
file in the parent directory. Here's an example
directory structure:
.
├── buf.work.yaml
├── paymentapis
│ ├── acme
│ │ └── payment
│ │ └── v2
│ │ └── payment.proto
│ ├── buf.lock
│ └── buf.yaml
└── petapis
├── acme
│ └── pet
│ └── v1
│ └── pet.proto
├── buf.lock
└── buf.yaml
version: v1
directories:
- paymentapis
- petapis
Now when running buf build petapis
the existence of the buf.work.yaml
file causes buf
to resolve the imports of
buf.build/acme/paymentapis
with the module defined in the paymentapis
directory, rather than by using the version
fetched from the BSR according to the buf.lock
specified in the petapis
directory.
Thus, you can make edits across both modules and immediately see the changes reflected between each module. It's
important to note that workspaces only apply to local operations. When you are ready to push updates you've made in
a local workspace, you'll need to push each module independently, starting with the upstream modules first
(buf.build/acme/paymentapis
in this case). Once the upstream module's changes are published, you can run the
buf mod update
command in the downstream module to fetch the latest version, and continue to push each of your modules
until all of your local changes are published to the BSR.
For more on workspaces, see the workspace documentation.
buf
provides a variety of powerful tools that help you develop your APIs and iterate on one or more modules at a time.
Make sure to check out more of the how-to guides to learn more!