KAS(1)

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 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-privileged | --isar-rootless] [config]
        Clean build artifacts, keep sstate cache and downloads.

    kas cleansstate [-h] [--dry-run] [--isar-privileged | --isar-rootless]
                        [config] Clean build artifacts and sstate cache.

    kas cleanall [-h] [--dry-run] [--isar-privileged | --isar-rootless] [config]
        Clean build artifacts, sstate-cache and downloads.

    kas purge [-h] [--dry-run] [--isar-privileged | --isar-rootless]
                  [--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.

By default, kas does not inherit the full host shell environment into the build environment. Instead, kas constructs a controlled environment to improve reproducibility and reduce host contamination.

How additional environment variables are handled depends on their scope and on the selected sub-command. Where supported, variables can be defined in the kas configuration or preserved explicitly from the host environment, for example with -E/--preserve-env.

When using kas-container, this is more limited, especially for variables that contain file or directory paths, because the container may use a different directory layout.

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 <#project-configuration-label>. 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 adds a CACHEDIR.TAG.
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 KAS_TASK (C, K) | This overwrites the respective setting in 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 (C,K,E,c) | Environment variables that are transferred 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 no_proxy (C,K,E) | These variables define the proxy configuration bitbake should use.
GIT_PROXY_COMMAND (E) NO_PROXY (C,K,E) | Set proxy for native git fetches. NO_PROXY is evaluated by OpenEmbedded's oe-git-proxy script.
SHELL (C,K,E) | The shell to start when using the shell plugin and in the bitbake environment.
TERM (C,K,E) | The terminal options used in the shell plugin and in the bitbake environment.
TZ (C) | Timezone settings.
AWS_CONFIG_FILE AWS_ROLE_ARN AWS_SHARED_CREDENTIALS_FILE AWS_WEB_IDENTITY_TOKEN_FILE (K,C) | Path to the awscli configuration and credentials files that are copied to the kas home dir.
GIT_CREDENTIAL_HELPER GIT_CREDENTIAL_USEHTTPPATH (K,C) | Allows one to set and configure the git credential helper in the .gitconfig of the kas user.
KAS_GIT_CREDENTIAL_STORE (C) | Path to a git credential store file on the host. When set, the file is bind-mounted into the container (read-only) and the git credential store helper is configured to use it. Equivalent to --git-credential-store.
KAS_GIT_CREDENTIAL_SOCKET (C) | Path to the git credential cache daemon socket on the host. When set, the socket is bind-mounted into the container and the git credential cache helper is configured to use it. Equivalent to --git-credential-socket.
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 CI_SERVER_PROTOCOL CI_SERVER_SHELL_SSH_HOST CI_SERVER_SHELL_SSH_PORT CI_JOB_TOKEN CI_JOB_URL CI_REGISTRY CI_REGISTRY_USER (K) | Environment variables from GitLab CI, if set .netrc is configured to allow fetching from the GitLab instance. An entry will be appended in case NETRC_FILE was given as well. Note that if the file already 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) REMOTE_CONTAINERS_<x> (K,E) | Environment variables related to VSCode Remote Containers. If running in this environment, .gitconfig is automatically imported.
BB_NUMBER_THREADS PARALLEL_MAKE (C,K,E) | Environment variables to control the concurrency.
KAS_IMAGE_VERSION (C) | Select the version of the (official) kas container (e.g. 4.5).
KAS_CONTAINER_IMAGE_DISTRO (C) | Select the base distro and its release of the container image (e.g. debian-bookworm). If not specified, the default (most-recent supported) distro version is used.
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).
KAS_SUDO_CMD (C) | Explicitly set the sudo command (either sudo or run0) for operations that require higher privileges. If not set, this is auto-detected (preference: sudo). Note, that run0 does not preserve the environment and cannot setup loopback devices.
KAS_BUILDTOOLS_DIR (C,K) | Explicitly set the path where kas will download and install buildtools. If not set, kas will use KAS_BUILD_DIR/buildtools as the default path.

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