The main building blocks of a snap are parts. They are used to declare pieces of code that will be pulled into your snap package. The parts keys and values in snapcraft.yaml detail how parts are configured and built by the snapcraft command.
See Snapcraft top-level metadata and Snapcraft apps and services metadata for details on how apps and parts are configured within snapcraft.yaml.
parts
Type: dict
A set of independent building blocks.
These independent building blocks are known as parts, and consist of either code or pre-built packages.
parts.<part-name>
Type: dict
The name of the part building block.
<part-name> represents the specific name of a building block which can be then referenced by the command-line tool (i.e. snapcraft).
Keys for parts
The following are keys that can be used within parts. (for example, parts.<part-name>.plugin):
after
Type: list[string]
Ensures that all the <part-names> listed in after are staged before this part begins its lifecycle.
build-attributesâ
Type: enum
A list of named attributes to modify the behaviour of plugins.
Supported attributes:
debug: Plugins that support the concept of build types build in Release mode by default. Setting the âdebugâ attribute requests that they instead build in debug mode.keep-execstack: Do not remove the âexecutable stackâ bit from ELF files.no-patchelf: Do not patch ELF files, even when Snapcraft believes it is required (e.g. for classic snaps)enable-patchelf: Do patch ELF files, even when Snapcraft does not believe itâs required (e.g. for strict snaps)no-install: Do not run the install target provided by the pluginâs build system.
(Only supported by the kbuild plugin)
For more information, refer to the output of snapcraft help plugins.
build-environmentâ
Type: Array
A list of environment variable assignments that are applied during the build step, it is exported in order which allows for later values to override (or modify) earlier values.
This entry supports additional syntax, for more information refer to Advanced grammar.
parts:
_part_name_:
build-environment:
- LANG: C.UTF-8
- LC_ALL: C.UTF-8
build-packages
Type: list[string]
A list of packages required to build a snap.
Packages are installed using the hostâs package manager, such as apt or dnf, and are required for <part-name> to build correctly. This entry supports additional syntax, for more information refer to Advanced grammar.
Example: [ libssl-dev, libssh-dev, libncursesw5-dev]
build-snapsâ
Type: list[string]
A list of snap names to install that are necessary to build <part-name>.
If a specific channel is required, the syntax is of the form <snap-name>/<channel>. This entry supports additional syntax, for more information refer to Advanced grammar
Example: build-snaps: [go/1.13/stable]
disable-parallel â
Type: boolean
Whether to disable parallelism for the build plugins.
filesets
Type: list[string]
A key to represent a group of files or a single file.
Filesets do not currently work when building snaps with core22 base snaps and Snapcraft 7.x .
See Snapcraft filesets for further details.
organize
Type: dict
A map of files to rename.
In the key/value pair, the key represents the path of a file inside the part and the value represents how the file is going to be staged.
Example: bin/snapcraftctl: bin/scriptlet-bin/snapcraftctl
override-buildâ
Type: multiline string
Replaces a pluginâs default build process with a script.
The shell script defined here replaces the build step of the plugin, defined in parts.<part-name>.plugin. The working directory is the base build directory for the given part. The defined script is run with /bin/sh and set -e. A set of Environment Variables will be available to the script.
To run Snapcraftâs original build implementation from within override-build, run snapcraftctl build. This can be run before or after any custom script or omitted entirely.
override-primeâ
Type: multiline string
Replaces a pluginâs default prime process with a script.
The shell script defined here replaces the prime step of the plugin, defined in parts.<part-name>.plugin. The working directory is the base prime directory for the given part. The defined script is run with /bin/sh and set -e. A set of Environment Variables will be available to the script.
To run Snapcraftâs original prime step implementation from within override-prime, run snapcraftctl prime. This can be run before or after any custom script or omitted entirely.
override-pullâ
Type: multiline string
Replaces a pluginâs default pull process with a script.
The shell script defined here replaces the pull step of the plugin, defined in parts.<part-name>.plugin. The working directory is the base pull directory for the given part. The defined script is run with /bin/sh and set -e. A set of Environment Variables will be available to the script.
To run Snapcraftâs original pull stage implementation from within override-pull, run snapcraftctl pull. This can be run before or after any custom script or omitted entirely.
override-stageâ
Type: multiline string
Replaces a pluginâs default stage process with a script.
The shell script defined here replaces the stage step of the plugin, defined in parts.<part-name>.plugin. The working directory is the base stage directory for the given part. The defined script is run with /bin/sh and set -e. A set of Environment Variables will be available to the script.
To run Snapcraftâs original stage implementation from within override-stage, run snapcraftctl stage. This can be run before or after any custom script or omitted entirely.
parse-info
Type: list[string]
Defines content to adopt when using external metadata.
Each entry is a relative path to a supported metadata file from the part source, build or install directory (SNAPCRAFT_PART_SRC, SNAPCRAFT_PART_BUILD, SNAPCRAFT_PART_INSTALL).
See Using external metadata for more details.
plugin
Type: string
The plugin to drive the build process.
Every part drives its build through a plugin, this entry declares the plugin that will drive the build process for <part-name>. Refer to snapcraft plugins for more information on the available plugins and the specific attributes they add to the parts.<part-name>. namespace.
prime
Type: list[string]
A list of files from <part-name> to prime.
Rules applying to the list here are the same as those of filesets. Referencing of fileset keys is done with a $ prefixing the fileset key, which will expand with the value of such key.
sourceâ
Type: string
A URL or path to a source tree to build.
This can be a local path or remote and can refer to a directory tree, a compressed archive, or a revision control repository. This entry supports additional syntax, for more information refer to Advanced grammar
source-branch
Type: string
Work on a specific branch for source repositories under version control.
source-checksum
Type: string
Used when source represents a file.
Takes the syntax <algorithm>/<digest>, where <algorithm> can be any of: md5, sha1, sha224, sha256, sha384, sha512, sha3_256, sha3_384 or sha3_512. When set, the source is cached for multiple uses in different snapcraft projects.
source-commit
Type: string
Work on a specific commit for source repositories under version control.
Cannot be an abbreviation. Requires the full 40-character SHA-1 hash for the commit.
source-depth
Type: integer
Depth of history for sources using version control.
Source repositories under version control are cloned or checked out with full history. Specifying a depth will truncate the history to the specified number of commits.
source-subdir
Type: string
A path within the source to set as the working directory when building. The build will not be able to access files outside of this location, such as one level up.
source-submodules
Type: dict
Configure which submodules to fetch from the source tree in snapcraft.yaml with source-submodules: <list-of-submodules>
When source-submodules is defined, only the listed submodules are fetched:
parts:
git-test:
plugin: dump
source-type: git
source: git@github.com...
source-submodules:
- submodule_1
- dir1/submodule_2
If source-submodules is defined and the list is empty, no submodules are fetched:
parts:
git-test:
plugin: dump
source-type: git
source: git@github.com...
source-submodules: []
If source-submodules is not defined, all submodules are fetched (default behaviour).
source-tag
Type: string
Work on a specific tag for source repositories under version control.
source-type
Type: enum
Used when the type of source entry cannot be detected.
Can be one of the following: [bzr|deb|git|hg|local|mercurial|rpm|subversion|svn|tar|zip|7z]
stageâ
Type: list[string]
A list of files from <part-name> to stage.
Rules applying to the list here are the same as those of filesets. Referencing of fileset keys is done with a $ prefixing the fileset key, which will expand with the value of such key.
stage-packages
Type: list[string]
A list of packages required at runtime by a snap.
Packages are required by <part-name> to run. They are fetched using the hostâs package manager, such as apt or dnf, and are unpacked into the snap being built. This entry supports additional syntax, for more information refer to Advanced grammar.
Example: [python-zope.interface, python-bcrypt]
stage-snaps
Type: list[string]
A list of snaps required at runtime by a snap.
Snaps are required by <part-name> to run. They are fetched using snap download, and are unpacked into the snap being built. This entry supports additional syntax, for more information refer to Advanced grammar.
Example: [hello, black/latest/edge]
