Provided by: kas_4.8.1-2_all 
NAME
kas - a setup tool for bitbake based projects
SYNOPSIS
kas [-h] [--version] [-l {debug,info,warning,error,critical}]
{build,checkout,clean,cleansstate,cleanall,purge,diff,dump,for-all-repos,lock,menu,shell} ...
DESCRIPTION
kas - setup tool for bitbake based project
This tool provides an easy mechanism to setup bitbake based projects.
The OpenEmbedded tooling support starts at step 2 with bitbake. The downloading of sources and then
configuration has to be done by hand. Usually, this is explained in a README. Instead kas is using a
project configuration file and does the download and configuration phase.
Key features provided by the build tool:
• clone and checkout bitbake layers
• create default bitbake settings (machine, arch, ...)
• launch minimal build environment, reducing risk of host contamination
• initiate bitbake build process
OPTIONS
Positional Arguments
cmd sub command help
Possible choices: build, checkout, clean, cleansstate, cleanall, purge, diff, dump, for-all-repos,
lock, menu, shell
Named Arguments
--version
show program's version number and exit
-l='info', --log-level='info'
Set log level (default: info)
Possible choices: debug, info, warning, error, critical
SUB-COMMANDS
kas build [-h] [--skip STEP] [--force-checkout] [--update] [-k]
[--target TARGET] [-c TASK] [--provenance {true,mode=min,mode=max}]
[config] [extra_bitbake_args ...] Checks out all necessary repositories and builds
using bitbake as specified in the configuration file.
kas checkout [-h] [--skip STEP] [--force-checkout] [--update] [config]
Checks out all necessary repositories and sets up the build directory as specified in the
configuration file.
kas clean [-h] [--dry-run] [--isar] [config]
Clean build artifacts, keep sstate cache and downloads.
kas cleansstate [-h] [--dry-run] [--isar] [config]
Clean build artifacts and sstate cache.
kas cleanall [-h] [--dry-run] [--isar] [config]
Clean build artifacts, sstate-cache and downloads.
kas purge [-h] [--dry-run] [--isar] [--preserve-repo-refs] [config]
Purge all data managed by kas, including managed repos.
kas diff [-h] [--skip STEP] [--force-checkout] [--update]
[--format {json,text}] [--oneline] [--no-color] [--commit-only]
[--content-only]
config1 config2 Compare two KAS configurations.
kas dump [-h] [--skip STEP] [--force-checkout] [--update] [--indent INDENT]
[--sort] [--format {yaml,json}] [--resolve-refs] [--resolve-local]
[--resolve-env | --lock]
[config] Expand and dump the final config to stdout. When resolving branches, this is
done before patches are applied.
kas for-all-repos [-h] [--skip STEP] [--force-checkout] [--update] [-E] [-k]
[config] command Runs a specified command in all checked out repositories.
kas lock [-h] [--skip STEP] [--force-checkout] [--update] [--indent INDENT]
[--sort]
[config] Create and update kas project lockfiles.
kas menu [-h] [kconfig]
Provides a configuration menu and triggers the build of the choices.
kas shell [-h] [--skip STEP] [--force-checkout] [--update] [-E] [-k]
[-c COMMAND]
[config] Run a shell in the build environment.
PROJECT CONFIGURATION
The project configuration file describes the build environment and the layers to be used. It is the main
input to kas. For details, see kas-project-config(1)
BUILD ATTESTATION
Kas supports to generate build attestation. For details, see kas-build-attestation(1).
CREDENTIAL HANDLING
kas provides various mechanisms to inject credentials into the build. For details, see
kas-credentials(1).
ENVIRONMENT VARIABLES
kas uses a number of environment variables to configure its behavior. The Variables Glossary provides an
overview, wherein the tuple (C,K,E) denotes the scope of the variable.
All directories that are passed to kas by setting the corresponding environment variables (e.g.
KAS_WORK_DIR, KAS_BUILD_DIR, ...) must not overlap with each other, except for overlapping with
KAS_WORK_DIR (i.e. the build|sstate|downloads|repo-ref dirs can be below the work dir). Environment
variables that reference a file or directory must have a valid path that is accessible and readable.
Variable Scope
kas-container (C)
The variable is processed or forwarded by the kas-container script. For some variables, the variable is
re-written to the container's directory layout.
NOTE:
The env section of the project configuration can be used to make arbitrary environment variables
available to the build environment. When invoking the build via kas-container, make sure to also
forward the corresponding environment variables into the container.
kas (K)
The variable is processed by kas itself. Some variables (e.g. the credentials for the awscli) are
re-written to configuration files to also support older versions of the tooling.
build environment (E)
The variable is exported into the build environment. In this environment, the bitbake command is
executed.
config-file (c)
The variable can be set in the env section of the Project Configuration. Note, that a value provided by
the calling environment takes precedence over the value in the configuration file.
Variables Glossary
These environment variables are processed before the configuration file is read (except if stated
otherwise). By that, they cannot be defined or overwritten using the env section of the config file.
┌───────────────────────────────────────┬─────────────────────────────────────────────┐
│ Environment variables │ Description │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_WORK_DIR (C, K) │ The path of the kas work directory, │
│ │ current work directory is the │
│ │ default. This directory must exist if │
│ │ set. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_BUILD_DIR (C, K) │ The path of the build directory, │
│ │ ${KAS_WORK_DIR}/build is the default. │
│ │ The parent directory must exist if │
│ │ set. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_REPO_REF_DIR (C, K) │ The path to the repository reference │
│ │ directory. Repositories in this │
│ │ directory are used as references when │
│ │ cloning. In order for kas to find │
│ │ those repositories, they have to be │
│ │ named in a specific way. The repo │
│ │ URLs are translated like this: │
│ │ https://github.com/siemens/meta-iot2000.git │
│ │ resolves to the name │
│ │ github.com.siemens.meta-iot2000.git. │
│ │ Repositories that are not found will │
│ │ be cloned below this directory. │
│ │ Multiple instances of kas can │
│ │ simultaneously work on the same │
│ │ directory, as long as the underlying │
│ │ filesystem is POSIX compatible. This │
│ │ directory must exist if set. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_DISTRO KAS_MACHINE KAS_TARGET │ This overwrites the respective setting in │
│ KAS_TASK (C, K) │ the configuration file. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_PREMIRRORS (C, K) │ Specifies alternatives for repo URLs. Just │
│ │ like bitbake PREMIRRORS, this variable │
│ │ consists of new-line separated entries. │
│ │ Each entry defines a regular expression to │
│ │ match a URL and, space-separated, its │
│ │ replacement. E.g.: http://.*\.someurl\.io/ │
│ │ http://localmirror.net/ │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ DISTRO_APT_PREMIRRORS (C,c) │ Specifies alternatives for apt URLs. Just │
│ │ like KAS_PREMIRRORS. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_CLONE_DEPTH (C, K) │ Perform shallow git clone/fetch using │
│ │ --depth=N specified by this variable. This │
│ │ is useful in case CI always starts with │
│ │ empty work directory and this directory is │
│ │ always discarded after the CI run. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ SSH_PRIVATE_KEY (K) │ Variable containing the private key that │
│ │ should be added to an internal ssh-agent. │
│ │ This key cannot be password protected. This │
│ │ setting is useful for CI build servers. On │
│ │ desktop machines, an ssh-agent running │
│ │ outside the kas environment is more useful. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ SSH_PRIVATE_KEY_FILE (K) │ Path to the private key file that should be │
│ │ added to an internal ssh-agent. This key │
│ │ cannot be password protected. This setting │
│ │ is useful for CI build servers. On desktop │
│ │ machines, an ssh-agent running outside the │
│ │ kas environment is more useful. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ SSH_AUTH_SOCK (C,K,E) │ SSH authentication socket. Used for cloning │
│ │ over SSH (alternative to SSH_PRIVATE_KEY or │
│ │ SSH_PRIVATE_KEY_FILE). │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ DL_DIR SSTATE_DIR SSTATE_MIRRORS │ Environment variables that are transferred │
│ (C,K,E,c) │ to the bitbake environment. The DL_DIR and │
│ │ SSTATE_DIR directories are created along │
│ │ with their parents, if set. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ TMPDIR (K,E,c) │ Directory for temporary files. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ http_proxy https_proxy ftp_proxy │ These variables define the proxy │
│ no_proxy (C,K,E) │ configuration bitbake should use. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ GIT_PROXY_COMMAND (E) NO_PROXY │ Set proxy for native git fetches. NO_PROXY │
│ (C,K,E) │ is evaluated by OpenEmbedded's oe-git-proxy │
│ │ script. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ SHELL (C,K,E) │ The shell to start when using the shell │
│ │ plugin. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ TERM (C,K,E) │ The terminal options used in the shell │
│ │ plugin. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ TZ (C) │ Timezone settings. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ AWS_CONFIG_FILE AWS_ROLE_ARN │ Path to the awscli configuration and │
│ AWS_SHARED_CREDENTIALS_FILE │ credentials files that are copied to the │
│ AWS_WEB_IDENTITY_TOKEN_FILE (K,C) │ kas home dir. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ GIT_CREDENTIAL_HELPER │ Allows one to set and configure the git │
│ GIT_CREDENTIAL_USEHTTPPATH (K,C) │ credential helper in the .gitconfig of the │
│ │ kas user. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ GITCONFIG_FILE (K,C) │ Path to a .gitconfig file which will be │
│ │ copied to the kas home dir as .gitconfig. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ NETRC_FILE (K,C) │ Path to a .netrc file which will be copied │
│ │ to the kas home dir as .netrc. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ NPMRC_FILE (K,C) │ Path to a .npmrc file which will be copied │
│ │ to the kas home dir as .npmrc. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ REGISTRY_AUTH_FILE (K,C) │ Path to a container registry authentication │
│ │ file. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ CI_SERVER_HOST CI_SERVER_PORT │ Environment variables from GitLab CI, if │
│ CI_SERVER_PROTOCOL │ set .netrc is configured to allow fetching │
│ CI_SERVER_SHELL_SSH_HOST │ from the GitLab instance. An entry will be │
│ CI_SERVER_SHELL_SSH_PORT CI_JOB_TOKEN │ appended in case NETRC_FILE was given as │
│ CI_JOB_URL CI_REGISTRY │ well. Note that if the file already │
│ CI_REGISTRY_USER (K) │ contains an entry for that host most tools │
│ │ would probably take that first one. The job │
│ │ URL is added to the provenance attestation │
│ │ (if enabled). If CI_REGISTRY and │
│ │ CI_REGISTRY_USER is also set, a container │
│ │ registry login file is created, which is │
│ │ used by docker, podman and skopeo. In case │
│ │ REGISTRY_AUTH_FILE was given as well, the │
│ │ CI login data will be appended to that │
│ │ file. The required base64 encoded login │
│ │ data is generated by kas. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ GITHUB_ACTIONS GITLAB_CI (K) │ Environment variables from GitHub actions │
│ │ or GitLab CI. If set to true, .gitconfig is │
│ │ automatically imported. For details, see │
│ │ GITCONFIG_FILE. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ REMOTE_CONTAINERS (K) │ Environment variables related to VSCode │
│ REMOTE_CONTAINERS_<x> (K,E) │ Remote Containers. If running in this │
│ │ environment, .gitconfig is automatically │
│ │ imported. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ BB_NUMBER_THREADS PARALLEL_MAKE │ Environment variables to control the │
│ (C,K,E) │ concurrency. │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_IMAGE_VERSION (C) │ Select the version of the (official) kas │
│ │ container (e.g. 4.5). │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_CONTAINER_IMAGE (C) │ Select the container image (full OCI path │
│ │ including tag). │
├───────────────────────────────────────┼─────────────────────────────────────────────┤
│ KAS_CONTAINER_ENGINE (C) │ Explicitly set the container engine (either │
│ │ docker or podman). If not set, this is │
│ │ auto-detected (preference: docker). │
└───────────────────────────────────────┴─────────────────────────────────────────────┘
SEE ALSO
kas-project-config(1), kas-build(1), kas-credentials(1)
KAS
Part of the kas(1) suite.
AUTHOR
Daniel Wagner, Jan Kiszka, Claudius Heine
COPYRIGHT
Siemens and contributors, 2017-2025
4.8.1 Jun 17, 2025 KAS(1)