A build manifest is a YAML file that describes how to perform a build. Here's an example:

image: archlinux
packages:
  - cmake
  - wlc-git
  - xorg-server-xwayland
  - xcb-util-image
  - json-c
  - pango
  - cairo
  - wayland
  - gdk-pixbuf2
  - asciidoc
sources:
  - https://github.com/SirCmpwn/sway
tasks:
  - setup: |
      cd sway
      mkdir build
      cd build
      cmake ..
  - build: |
      cd sway
      cd build
      make

The minimum build manifest has an image and at least one task. The various properties available are described here:

#image

string

Which OS image to build in. A list of available build images can be found here.

#packages

list (of string)

A list of package names to install on the image.

• Alpine installs these packages with apk
• Arch Linux installs these packages with yay
• Debian installs these packages with apt-get install
• FreeBSD installs these packages with pkg

#repositories

dictionary (of string: string)

A list of extra repositories to enable with the image's package manager. The format is name: url, and the syntax of url varies between images.

• Alpine uses repo-url key-url key-name, where repo-url is the URL of the package repository and key-url is a URL from where the signing key may be downloaded, and key-name is the name of the file written to /etc/apk/keys/. If the name of the repo is prefixed with an @, it will use that prefix in apk.
• Arch Linux uses url#key-id, where url is the URL of the package repository and key-id is the ID of the published PGP key the packages are signed with.
• Debian uses url distro component key-id, where url is the URL of the package repository, distro is e.g. jessie or stretch, component is e.g. main or non-free, and key-id is an optional PGP key ID to add to apt-key.
• FreeBSD images do not support extra package repositories.

#sources

list (of string)

A list of git repositories to clone into the home directory of the build user in the build environment.

#tasks

list (of string)

A list of scripts to execute in the build environment. These scripts are run with the following preamble:

#!/usr/bin/env bash
. ~/.buildenv
set -x
set -e

~/.buildenv contains environment variables specified by the environment directive.

Task names must use only lowercase alphanumeric characters or underscores and must be <=128 characters in length. Tasks are executed in the order specified.

Each task is run in a separate login session, so if you modify the groups of the build user they will be effective starting from the subsequent task.

#triggers

list (of trigger)

A list of triggers to execute post-build, which can be used to send emails or do other post-build tasks.

See also: Build triggers

#environment

dictionary (of string: string OR string: list)

A list of key/value pairs for options to set in the build environment via ~/.buildenv.

#secrets

list (of string)

List of secret UUIDs to be added to the guest during the build. See also: secrets.