Zot Developer Guide¶

Revised: 2022-08-10

Getting Started¶

Supported Developer Platforms¶

Development is officially supported on Linux and Apple MacOS platforms. However, development should be possible on any platform that supports the golang toolchain.

Supported platforms and architectures

Prerequisites¶

Install golang (1.17+)¶

The zot project requires golang 1.17 or newer. You can follow these instructions to install the golang toolchain. After installation, make sure that the path environment variable or your IDE can find the toolchain.

Cloning zot¶

The zot registry code base is hosted on GitHub at https://github.com/project-zot/zot.

To clone the zot project, use this command:

$ git clone https://github.com/project-zot/zot.git

Building zot¶

To build zot, execute the make command in the zot directory using the following general syntax:

$ make OS=os ARCH=architecture {binary | binary-minimal}

• The operating system and architecture options are listed in the Supported platforms and architectures table. If an option is not specified, the defaults are linux and amd64.

• The binary option builds the full zot binary image with all extensions.

• The binary-minimal option builds the minimal distribution-spec conformant zot binary image without extensions, reducing the attack surface.

For example, to build a zot image with extensions for an Intel-based linux server, use the following command:

make OS=linux ARCH=amd64 binary

The make command builds an executable image in the zot/bin directory. The original filename of the zot executable image will indicate the build options. For example, the filename of an Intel-based linux minimal image is zot-linux-amd64-minimal.

Running zot¶

The behavior of zot is controlled via configuration only. To launch the zot server, execute the following command:

$  bin/zot-linux-amd64 serve examples/config-example.json

Debugging zot¶

To produce a zot binary that includes extensive debugging information, build zot with the binary-debug option, as shown in this example:

make OS=linux ARCH=amd64 binary-debug

You can then attach and run a debugging tool such as Delve to the running zot process.

Delve is a powerful open-source debugger for the Go programming language. Downloads and documentation for Delve are available on GitHub at https://github.com/go-delve/delve.

Code Organization¶

The zot project codebase is organized as follows:

/
- pkg/              # Source code for all libraries
  - api/            # Source code for HTTP APIs
    - config/       # Global configuration model
  - storage/        # Source code for storage backends
  - cli/            # Source code for command line interface (cli)
  - common/         # Source code for common utility routines
  - compliance/     # Source code for dist-spec conformance tests
  - log/            # Source code for logging framework
  - test/           # Internal test scripts/data
  - extensions/     # Source code for all extensions
    - config/
    - sync/
    - monitoring/
    - sync/
  - exporter/       # Source code for metrics exporter
- cmd/              # Source code for binary main()s
  - zot/            # Source code for zot binary
  - zli/            # Source code for zot cli
  - zb/             # Source code for zb, the dist-spec benchmarking tool
- errors/           # Source code for error codes
- examples/         # Configuration examples
- swagger/          # Swagger integration
- docs/             # Documentation

Contributor Guidelines¶

License¶

zot is released under the Apache License 2.0. All contributions must adhere to this license.

Developer Certificate of Origin (DCO)¶

All commits require a Developer Certificate of Origin via the "Signed-off-by:" commit message and commit signatures using GPG keys.

Submitting a Pull Request (PR)¶

First, fork the zot project on GitHub and submit a commit to your fork. Then open a new pull request (PR) to the zot project.

PR Requirements¶

Any new PR requires a form to be filled out with details about the PR. Appropriate code owners are automatically identified, and they will be notified of the new PR.

CI/CD Checks¶

We take code quality very very seriously. All PRs must pass various CI/CD checks which cover enforce code quality such as code coverage, security scanning, performance regressions, distribution spec conformance, ecosystem client tool compatibility, etc.

Reporting Issues¶

Issues are broadly classified as functional bugs and security issues. The latter is treated a little differently due to the sensitive nature.

Filing an Issue¶

No software is perfect, and we expect users to find issues with the zot code base. First, check whether your issue has already been filed by someone else by doing an issue search. If the issue not found, file a new issue by clicking the New issue button on the zot/issues page and answering the questions. The more information that you can provide, the easier it becomes to triage the issue.

Security Issues¶

Security issues are best filed by sending an email to security@zotregistry.io. After 45 days, we will make the issue public and give credit to the original filer of the issue.

Code of Conduct¶

The zot project follows the CNCF Code of Conduct.

Reporting¶

For incidents occurring on the zot project, contact the zot project conduct committee at conduct@zotproject.io. You can expect a response within three business days.