Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/dependabot/dependabot-core

🤖 Dependabot's core logic for creating update PRs.
https://github.com/dependabot/dependabot-core

dependencies docker dotnet elixir elm go java javascript php pnpm python ruby rubygems rust terraform

Last synced: 3 days ago
JSON representation

🤖 Dependabot's core logic for creating update PRs.

Awesome Lists containing this project

README 

        


    

        

        

        Dependabot

    




Welcome to the public home of Dependabot :dependabot:.



# Table of Contents



- [What is Dependabot-Core?](#what-is-dependabot-core)

- [How to run Dependabot](#how-to-run-dependabot)

- [Contributing to Dependabot](#contributing-to-dependabot)

  - [Reporting Issues and Feature Requests](#reporting-issues-and-feature-requests)

  - [Submitting Pull Requests](#submitting-pull-requests)

  - [New Ecosystems](#new-ecosystems)

- [Development Guide](#development-guide)

  - [Getting a Development Environment Running](#getting-a-development-environment-running)

  - [Debugging Problems](#debugging-problems)

  - [Running Tests](#running-tests)

  - [Profiling](#profiling)

- [Architecture and Code Layout](#architecture-and-code-layout)

- [Trademarks](#trademarks)

- [Notes for Project Maintainers](#notes-for-project-maintainers)



---



# What is Dependabot-Core?



Dependabot-Core is the library at the heart of [Dependabot](https://docs.github.com/en/code-security/dependabot) security / version updates.



Use it to generate automated pull requests updating dependencies for projects written in Ruby, JavaScript, Python,

PHP, Dart, Elixir, Elm, Go, Rust, Java and .NET. It can also update git submodules, Docker files, and Terraform files.

Features include:



- Check for the latest version of a dependency *that's resolvable given a project's other dependencies*

- Generate updated manifest and lockfiles for a new dependency version

- Generate PR descriptions that include the updated dependency's changelogs, release notes, and commits



# How to run Dependabot



Most people are familiar with the Dependabot service that runs on GitHub.com and GitHub Enterprise. Enabling that is as

simple as [checking a `dependabot.yml` configuration file in to your repository's `.github` directory](https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuring-dependabot-version-updates).



However, if you want to run a custom version of Dependabot or run it on another platform, you're not left out in the cold.

This repo provides the logic necessary for hosting your own standalone Dependabot. It currently supports opening Pull Requests against repositories hosted on GitHub, Github Enterprise, Azure DevOps, GitLab, BitBucket, and AWS CodeCommit.



Dependabot-Core is a library, so you'll need an entrypoint script of some kind. Here are a few examples to help you get

started.



>**Note:** If you're looking to run Dependabot locally for development/debugging purposes, see the [Development Guide](#development-guide).



## Dependabot-Script



The [dependabot-script](https://github.com/dependabot/dependabot-script) repo provides a collection of example scripts for configuring the Dependabot-Core library.

It is intended as a starting point for advanced users to run a self-hosted version of Dependabot within their own projects.



>**Note:** We recently refactored the monolithic docker image used within the Dependabot Core library into one-image-per-ecosystem. Unfortunately, that broke dependabot-scripts, and we haven't had time to update them yet. We are aware of the problem and hope to provide a solution soon.



## Dependabot CLI



The [Dependabot CLI](https://github.com/dependabot/cli) is a newer tool that may eventually replace [`dependabot-script`](#dependabot-script) for standalone use cases.

While it creates dependency diffs, it's currently missing the logic to turn those diffs into actual PRs. Nevertheless, it

may be useful for advanced users looking for examples of how to hack on Dependabot.



## Dependabot on CI



In an environment such as GitHub where Dependabot is running in a container, if you want to change your build or installation process depending on whether Dependabot is checking, you can determine it by the existence of `DEPENDABOT` environment variable.



# Contributing to Dependabot



## Reporting issues and Feature Requests



👋 Want to give us feedback on Dependabot, or contribute to it? That's great - thank you so much!



### Reproducible Example



Most bug reports should be accompanied by a link to a public repository that reproduces the problem. Bug reports that

cannot be reproduced on a public repo using the [CLI tool](#cli-tool) or [dry-run script](#dry-run-script) may be

closed as "cannot reproduce".



### No "+1" Comments



Our issue tracker is quite active, and as a result there's a good chance someone already filed the same issue. If so,

please upvote that issue, because we use 👍 reactions on issues as one signal to gauge the impact of a feature request or bug.



However, please do not leave comments that contribute nothing new to the discussion. For details, see [https://github.com/golang/go/wiki/NoPlusOne](https://github.com/golang/go/wiki/NoPlusOne). This is open source, if you see something you want fixed, we are happy to coach you through contributing a pull request to fix it.



### Don't file issues about Security Alerts or Dependency Graph



The issue-tracker is meant solely for issues related to Dependabot's updating logic. Issues about [security alerts](https://docs.github.com/en/code-security/dependabot/dependabot-alerts/about-dependabot-alerts) or [Dependency Graph](https://docs.github.com/en/code-security/supply-chain-security/understanding-your-software-supply-chain/about-the-dependency-graph) should instead be filed as a [Code Security discussion](https://github.com/orgs/community/discussions/categories/code-security).



A good rule of thumb is that if you have questions about the _diff_ in a PR, it belongs here.



### Disclosing Security Issues



If you believe you have found a security vulnerability in Dependabot, please review [our security policy](https://github.com/dependabot/dependabot-core/security/policy) for details about disclosing them to the GitHub Bug Bounty program, so we can work to resolve the issue before it is disclosed publicly.



## Submitting Pull Requests



Want to contribute to Dependabot? That's great - thank you so much!



Contribution workflow:

1. Fork the project.

2. Get the [development environment running](#getting-a-development-environment-running).

3. Make your feature addition or bug fix.

4. Add [tests for it](#running-tests). This is important so we don't break it in a future version unintentionally.

5. Send a pull request. The tests will run on it automatically, so don't worry if you couldn't get them running locally.



Please refer to the [CONTRIBUTING](CONTRIBUTING.md) guidelines for more information.



## New Ecosystems

	

If you're interested in contributing support for a new ecosystem, please refer to the [contributing guidelines](CONTRIBUTING.md#contributing-new-ecosystems) for more information.



# Development Guide



## Getting a Development Environment Running



The first step to debugging a problem or writing a new feature is getting a development environment going. We provide a

custom [Docker-based](https://www.docker.com/products/docker-desktop/) developer shell that bakes in all required dependencies.

In most cases this is the best way to work with the project.



The developer shell uses volume mounts to incorporate your local changes to Dependabot's source code. This way you can

edit locally using your favorite editor and the changes are immediately reflected within the docker container for performing

[dry-runs](#debugging-problems) or executing [tests](#running-tests).

Note: See caveat about [editing the native package manager helper scripts](#making-changes-to-native-package-manager-helpers).



### Quickstart



The script to launch the developer shell builds the docker images from scratch if it can't find them locally. This can take a while.



Skip the wait by pulling the pre-built image for the ecosystem you want to work on. The image name uses the [YAML ecosystem name](https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#package-ecosystem)

to specify the ecosystem.  For example, for Go Modules, the YAML name is `gomod`:



```shell

$ docker pull ghcr.io/dependabot/dependabot-updater-gomod

```



>**Note:** Pre-built images are currently only available for AMD64 / Intel architecture. They _will_ run on ARM, but 2x-3x slower than if you [manually build ARM-specific images](#building-images-from-scratch).



Next, run the developer shell, specifying the desired ecosystem _using the top-level directory name of the ecosystem in this project_. For example, for Go Modules, the top-level directory is named `go_modules`:



```shell

$ bin/docker-dev-shell go_modules

=> running docker development shell

[dependabot-core-dev] ~ $ cd go_modules && rspec spec # to run tests for a particular package

```



### Building Images from Scratch



Normally the [Quickstart](#quickstart) is all you need, but occasionally you'll need to rebuild the underlying images.



For example, while we don't yet publish ARM-specific images, if you _are_ working on an ARM-based platform, we recommend

manually building the images because the resulting containers run much faster.



The developer shell runs within a Dependabot Development docker image, which is built on top of an ecosystem image.



```mermaid

flowchart LR

    A["docker-dev-shell script"] --> B("Dependabot Development docker image")

    B --> C("Dependabot Updater Ecosystem docker image (ecosystem specific)")

    C --> D("Dependabot Updater Core docker image")

```



Changes to the docker files for any of these images requires building one or more of the images locally in order to be reflected in the development shell.



The simple but slow way is to delete any existing images and then run `bin/docker-dev-shell` which automatically builds

missing images.



The faster way is to pull all the pre-built images that are dependencies of the image you actually need to build.

To (re)build a specific one:



- The Updater core image:



  ```shell

  $ docker pull ghcr.io/dependabot/dependabot-updater-core # OR

  $ docker build -f Dockerfile.updater-core . # recommended on ARM

  ```



- The Updater ecosystem image:



  ```shell

  $ docker pull ghcr.io/dependabot/dependabot-updater-gomod # OR

  $ script/build go_modules # recommended on ARM

  ```



- The development container using the `--rebuild` flag:



  ```shell

  $ bin/docker-dev-shell go_modules --rebuild

  ```



### Making Changes to native Package Manager helpers



Several Dependabot packages make use of 'native helpers', small executables in their host language.



**Changes to these files are not automatically reflected inside the development container.**



Once you have made any edits to the helper files, run the appropriate build script to update the

installed version with your changes like so:



```bash

$ bin/docker-dev-shell bundler

=> running docker development shell

$ bundler/helpers/v2/build

$ bin/dry-run.rb bundler dependabot/demo --dir="/ruby"

```



To view logs and stdout from the native package manager helpers, see [debugging native helpers](#debugging-native-package-manager-helpers).



# Debugging Problems



The first step to debugging is getting the [development environment running](#getting-a-development-environment-running).



Within the development environment, you have two options for simulating a dependency update job:

You can use the newly-developed [CLI tool](#cli-tool) or the original [Dry-run script](#dry-run-script).



## CLI tool



The [Dependabot CLI](https://github.com/dependabot/cli) is a newly-developed tool that incorporates the [GitHub

Credentials Proxy](#private-registry-credential-management) to more realistically simulate what's happening within

the Dependabot-at-GitHub service when talking to private registries.



It has a [dedicated debugging guide](https://github.com/dependabot/cli#debugging-with-the-cli), including support for dropping into the Ruby debugger.



## Dry-Run Script



>Note: Before running the dry-run script, you'll need to [get the development environment running](#getting-a-development-environment-running).



You can use the `bin/dry-run.rb` script to simulate a dependency update job, printing

the diff that would be generated to the terminal. It takes two positional

arguments: the package manager and the GitHub repo name (including the

account):



```bash

$ bin/docker-dev-shell go_modules

=> running docker development shell

$ bin/dry-run.rb go_modules rsc/quote

=> fetching dependency files

=> parsing dependency files

=> updating 2 dependencies

...

```



### Helpful options to speed up dry-run testing



The [Dry-Run script](#dry-run-script) supports many other options, all of which are documented at the [top of the script's source code](bin/dry-run.rb). For example:



1. `LOCAL_GITHUB_ACCESS_TOKEN="fake-GitHub-PAT"` allows specifying a [GitHub Personal Access Token (PAT)](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/creating-a-personal-access-token) to avoid rate-limiting.

2. `--dir="path/to/subdir/containing/manifest` is required if the manifest file is located in a subdirectory.

3. `--dep="dep-name-that-I-want-to-test"` allows specifying a single dep to try to update and all others are ignored.

4. `--cache=files` allows caching remote dep files locally for faster re-runs when testing local logic changes.

5. `--updater-options=feature_flag_name` allows passing in feature flags.



Here's an example of how to string all these together



```bash

  LOCAL_GITHUB_ACCESS_TOKEN=github_pat_123_fake_string \

  bin/dry-run.rb docker jeffwidman/secrets-store-driver \

  --dir "/manifest_staging/charts/secrets-store-provider" \

  --cache=files \

  --dep="secrets-store" \

  --updater-options=kubernetes_updates

```



### Adding debug breakpoints



You can add a `debugger` statement anywhere in the ruby code, for example:



```ruby

      def latest_resolvable_version

        debugger

        latest_version_finder.latest_version

      end

```



When you execute the job, the Ruby debugger will open. It should look something like this:



```ruby

[11, 20] in ~/go_modules/lib/dependabot/go_modules/update_checker.rb

    11|   module GoModules

    12|     class UpdateChecker < Dependabot::UpdateCheckers::Base

    13|       require_relative "update_checker/latest_version_finder"

    14|

    15|       def latest_resolvable_version

=>  16|         debugger

    17|         latest_version_finder.latest_version

    18|       end

    19|

    20|       # This is currently used to short-circuit latest_resolvable_version,

=>#0    Dependabot::GoModules::UpdateChecker#latest_resolvable_version at ~/go_modules/lib/dependabot/go_modules/update_checker.rb:16

  #1    Dependabot::GoModules::UpdateChecker#latest_version at ~/go_modules/lib/dependabot/go_modules/update_checker.rb:24

  # and 9 frames (use `bt' command for all frames)

(rdbg)

```



At this prompt, you can run [debugger commands](https://github.com/ruby/debug) to navigate around, or enter methods and variables to see what they contain. Try entering `dependency` to see what dependency Dependabot is currently working on.



>**Note** While in the debugger, changes made to the source code will not be picked up. You will have to end your debugging session and restart it.



### Debugging Native Package Manager Helpers



When you're debugging an issue you often need to peek inside these scripts that run in a separate process.



Print all log statements from native helpers using `DEBUG_HELPERS=true`:



```bash

DEBUG_HELPERS=true bin/dry-run.rb bundler dependabot/demo --dir="/ruby"

```



Pause execution to debug a single native helper function using `DEBUG_FUNCTION=`. The function maps to a

native helper function name, for example, one of the functions in `bundler/helpers/v2/lib/functions.rb`.



When this function is being executed a `debugger` is inserted, pausing execution of the `bin/dry-run.rb` script, this leaves the current updates `tmp` directory in place allowing you to `cd` into the directory and run the native helper function directly:



```bash

 DEBUG_FUNCTION=parsed_gemfile bin/dry-run.rb bundler dependabot/demo --dir="/ruby"

=> fetching dependency files

=> dumping fetched dependency files: ./dry-run/dependabot/demo/ruby

=> parsing dependency files

$ cd /home/dependabot/dependabot-core/tmp/dependabot_TEMP/ruby && echo "{\"function\":\"parsed_gemfile\",\"args\":{\"gemfile_name\":\"Gemfile\",\"lockfile_name\":\"Gemfile.lock\",\"dir\":\"/home/dependabot/dependabot-core/tmp/dependabot_TEMP/ruby\"}}" | BUNDLER_VERSION=1.17.3 BUNDLE_GEMFILE=/opt/bundler/v1/Gemfile GEM_HOME=/opt/bundler/v1/.bundle bundle exec ruby /opt/bundler/v1/run.rb

```



Copy and run the `cd...` command:



```bash

cd /home/dependabot/dependabot-core/tmp/dependabot_TEMP/ruby && echo "{\"function\":\"parsed_gemfile\",\"args\":{\"gemfile_name\":\"Gemfile\",\"lockfile_name\":\"Gemfile.lock\",\"dir\":\"/home/dependabot/dependabot-core/tmp/dependabot_TEMP/ruby\"}}" | BUNDLER_VERSION=1.17.3 BUNDLE_GEMFILE=/opt/bundler/v1/Gemfile GEM_HOME=/opt/bundler/v1/.bundle bundle exec ruby /opt/bundler/v1/run.rb

```



This should log out the output of the `parsed_gemfile` function:



```ruby

{"result":[{"name":"business","requirement":"~> 1.0.0","groups":["default"],"source":null,"type":"runtime"},{"name":"uk_phone_numbers","requirement":"~> 0.1.0","groups":["default"],"source":null,"type":"runtime"}]}

```



Keep in mind that unlike changes to the ruby source, changes on your host machine to the native helpers source code are

not synced to the development container. So you have two choices for editing the native helper:



- You can directly edit the temporary copy of the native helper within the development container, for example: `vi /opt/bundler/v1/lib/functions/file_parser.rb`. And then re-run the `cd...` command. This is the fastest way to debug, but any changes won't be saved outside the container.

- You can edit your local copy, and then [rebuild the native helper](#making-changes-to-native-package-manager-helpers). This will require re-running the dry-run script to pickup the change.



### Debugging Ignore Conditions



Most of the ecosystems in Dependabot-Core support `ignore` conditions which allow a user to specify dependency names or

versions to exclude from upgrades. The docs for the Dependabot service at GitHub [describe the feature in more detail](https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#ignore).



The [Dependabot CLI](#cli-tool) supports passing in ignore conditions as part of the job definition. See [the example](https://github.com/dependabot/cli#scenario-file).



The [dry-run script](#dry-run-script) supports passing in one or more ignore conditions via the env var `IGNORE_CONDITIONS`:



```bash

IGNORE_CONDITIONS='[{"dependency-name":"*","update-types": ["version-update:semver-major"]}]' \

bin/dry-run.rb docker test_org/test-dependabot`

```



### Debugging Security Updates



Many of the ecosystems in Dependabot-Core support [security updates](https://docs.github.com/en/code-security/dependabot/dependabot-security-updates/about-dependabot-security-updates). These are a special form of version update where a

dependency name and range of vulnerable versions are passed in. Dependabot-Core will try to upgrade any instance of that

dependency to the _minimum_ non-vulnerable version. This is in contrast to a normal version update which tries to update

to the _latest_ version.



The env var `SECURITY_ADVISORIES` allows passing one or more security alert notifications to the [dry-run script](#dry-run-script) in order to simulate a security update:



```bash

SECURITY_ADVISORIES='[{"dependency-name":"buffer","patched-versions":[],"unaffected-versions":[],"affected-versions":["<= 2.0.0"]}]' \

bin/dry-run.rb pub dart-lang/pub-dev --dir "/app" --cache=files --dep="buffer"

```



### Visual Studio Code and Docker



There's built-in support for leveraging Visual Studio Code's [ability for

debugging](https://code.visualstudio.com/docs/devcontainers/containers) inside a Docker container.

After installing the recommended [`Dev Containers` extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers),

simply press `Ctrl+Shift+P` (`⇧⌘P` on macOS) and select `Dev Containers: Reopen in Container`.

You can also access the dropdown by clicking on the green button in the bottom-left corner of the editor.

If the development Docker image isn't present on your machine, it will be built automatically.

Once that's finished, start the `Debug Dry Run` configuration `(F5)` and you'll be prompted

to select a package manager and a repository to perform a dry run on.

Feel free to place breakpoints on the code.



There is also support to debug individual test runs by running the `Debug Tests` configuration `(F5)`

and you'll be prompted to select an ecosystem and provide an rspec path.



⚠️ The `Clone Repository ...` commands of the Remote Containers extension are currently

missing some functionality and are therefore not supported. You have to clone the

repository manually and use the `Reopen in Container` or `Open Folder in Container...`

command.



## Running Tests



Once you get the [development environment for a particular ecosystem](#getting-a-development-environment-running) going,

execute the tests for that ecosystem by running `rspec spec` inside that ecosystem's folder, e.g.



```bash

$ cd go_modules

$ rspec spec

```



You can also limit the tests to only the file you're working on, or only tests that previously failed, for example:



```bash

$ rspec spec/dependabot/file_updaters/elixir --only-failures

```



Style is enforced by [RuboCop](https://rubocop.org/). To check for style violations, simply run `rubocop` in

each of the packages, e.g.



```bash

$ cd go_modules

$ rubocop

```



## Profiling



You can profile a [dry-run](#dry-run-script) by passing the `--profile` flag when running it, or tag an `rspec` test with `:profile`.

This will generate a `stackprof-.dump` file in the `tmp/` folder, and you can generate a flamegraph from this

by running:



```bash

stackprof --d3-flamegraph tmp/stackprof-.dump > tmp/flamegraph.html

```



# Architecture and Code Layout



Dependabot-Core is a collection of Ruby packages (gems), which contain the logic for updating dependencies in several languages.



### `dependabot-common`



The `common` package contains all general-purpose/shared functionality. For instance, the code for creating pull

requests for the different supported platforms lives here, as does most of the logic for handling Git dependencies (as

most languages support Git dependencies in one way or another). There are also base classes defined for each of the

major concerns required to implement support for a language or package manager.



### `dependabot-{package-manager}`



There is a gem for each package manager or language that Dependabot

supports. At a minimum, each of these gems will implement the following

classes:



| Service          | Description                                                                                   |

|------------------|-----------------------------------------------------------------------------------------------|

| `FileFetcher`    | Fetches the relevant dependency files for a project (e.g., the `Gemfile` and `Gemfile.lock`). See the [README](common/lib/dependabot/file_fetchers/README.md) for more details. |

| `FileParser`     | Parses a dependency file and extracts a list of dependencies for a project. See the [README](common/lib/dependabot/file_parsers/README.md) for more details. |

| `UpdateChecker`  | Checks whether a given dependency is up-to-date. See the [README](common/lib/dependabot/update_checkers/README.md) for more details. |

| `FileUpdater`    | Updates a dependency file to use the latest version of a given dependency. See the [README](common/lib/dependabot/file_updaters/README.md) for more details. |

| `MetadataFinder` | Looks up metadata about a dependency, such as its GitHub URL. See the [README](common/lib/dependabot/metadata_finders/README.md) for more details. |

| `Version`        | Describes the logic for comparing dependency versions. See the [hex Version class](hex/lib/dependabot/hex/version.rb) for an example. |

| `Requirement`    | Describes the format of a dependency requirement (e.g. `>= 1.2.3`). See the [hex Requirement class](hex/lib/dependabot/hex/requirement.rb) for an example. |



The high-level flow looks like this:



![Dependabot high-level architecture diagram](architecture.svg)



### `dependabot-omnibus`



This is a "meta" gem, that simply depends on all the others. If you want to

automatically include support for all languages, you can just include this gem

and you'll get all you need.



## Private Registry Credential Management



For many ecosystems, Dependabot-Core supports private registries. Sometimes this happens by passing the private registry

credentials directly to the native package managers (`npm`, `pip`, `bundler`, etc), other times it happens within the

Dependabot-Core Ruby code.



```mermaid

sequenceDiagram

    Private Registry Credentials->>Dependabot-Core:


    Dependabot-Core->>Native Package Managers:


    Native Package Managers->>Package Registries:


    Dependabot-Core->>Package Registries:


```



While simple and straightforward, this is a security risk for ecosystems that allow running untrusted code within their

manifest files. For example `setup.py` and `.gemspec` allow running native Python and Ruby code. If a package in the

dependency tree gets hacked, an attacker could push a malicious manifest that forces the native package manager to

expose the creds.



To guard against this, for the Dependabot service that Github runs, we wrap Dependabot-Core with a credential proxy so

those private registry secrets are never exposed to Dependabot-Core.



```mermaid

sequenceDiagram

    Dependabot-Core->>Credentials Proxy: All requests are unauthenticated

    Credentials Proxy->>Package Registries: Creds are injected by the Proxy

    Note left of Dependabot-Core: The Dependabot Service
 that GitHub Runs

    Package Registries->>Credentials Proxy: Creds are stripped by the Proxy

    Credentials Proxy->>Dependabot-Core: Dependabot-Core never sees private registry credentials

```



This also means if Dependabot-Core ever has a security vulnerability, those creds are still not at risk of being exposed.



# Trademarks



This project may contain trademarks or logos for projects, products, or services. Authorized use of GitHub trademarks or logos is

subject to and must follow [GitHub Logos and Usage](https://github.com/logos). Use of GitHub trademarks or logos in modified versions of this project must not

cause confusion or imply GitHub sponsorship. Any use of third-party trademarks or logos are subject to those third-party’s policies.



# History



Dependabot and dependabot-core started life as [Bump](https://github.com/gocardless/bump) and

[Bump Core](https://github.com/gocardless/bump-core), back when @hmarr and @greysteil were working at

[GoCardless](https://gocardless.com).



Dependabot became a part of GitHub in 2019!



# Notes for project maintainers



:book: Release guide




Publish a new release to RubyGems by running the [`Gems - Bump Version`](https://github.com/dependabot/dependabot-core/actions/workflows/gems-bump-version.yml) workflow and following the instructions on the job summary.



In a nutshell the process will be:



1. Run the action to generate a version bump PR.

2. Merge the PR.

3. Tag that merge commit as a new release using the format `v1.2.3`. The job summary contains a URL pre-populated with the correct version for the title and tag.

4. Once the release is tagged, another GitHub Action workflow automatically pushes it to RubyGems.