.. _tutorial-getting-started:

=============================
Getting started with debusine
=============================

In this tutorial you will discover two of debusine's building blocks:
:ref:`work requests <explanation-work-requests>` and :ref:`artifacts
<explanation-artifacts>`. The former lets you schedule the execution of
different kind of :ref:`tasks <explanation-tasks>` on remote workers,
while the latter is a simple way to represent a set of files managed by
debusine.

For the purpose of this tutorial, we will use debusine's command line
interface to:

* create a build chroot
* upload a source package
* build binary packages out of the uploaded source package and in the build
  chroot that got created

Pre-requisites
--------------

You need to have access to a working debusine instance:

* If you are a Debian developer, you can use `debusine.debian.net
  <https://debusine.debian.net>`_. You can login there with your
  salsa.debian.org account, and it will automatically create
  your debusine account.
* Otherwise, please follow the instructions from
  :ref:`tutorial-install-debusine`. Once completed, the debusine instance
  will be available under the ``debusine.internal`` hostname and this is
  the name that we will continue to use here.

Install the client and configure it
-----------------------------------

You should first install the ``debusine-client`` package (if needed
configure APT with one of the :ref:`supported package repositories
<debusine-package-repositories>`):

.. code-block:: console

   $ sudo apt install debusine-client

Now it's time to create yourself a *token* that the client will use to
connect to the server. For this open your web browser and visit the URL
of your debusine instance (i.e. ``http://debusine.internal`` or
https://debusine.debian.net). Then login with your user credentials (or
with the salsa.debian.org authentication) and open the the user menu (in
the top right corner, or behind the "hamburger" menu) and click on the
*Tokens* page.

Click the link *create a new token* and input a comment describing the
token's intended usage (for example "On my laptop") and click the *Create*
button. You are back on the page with your list of tokens: click on the
*Show token* button to display the token and copy it to the clipboard.

Finally, we can create debusine-client's configuration file. It indicates
the server URL and the token to use (please adjuste the DEBUSINE_URL to
to match your specific case and paste the value of the token in the
TOKEN variable):

.. code-block:: console

   $ DEBUSINE_URL="http://debusine.internal" # or DEBUSINE_URL="https://debusine.debian.net"
   $ TOKEN="1e81fb5f00a489344ddfe4e34588c84d202a97ca87cc136d15d17cb3d1eb4e82"
   $ DEBUSINE_FQDN=$(basename $DEBUSINE_URL)
   $ mkdir -p ~/.config/debusine/client
   $ cat >~/.config/debusine/client/config.ini <<END
   [General]
   default-server = $DEBUSINE_FQDN

   [server:$DEBUSINE_FQDN]
   api-url = $DEBUSINE_URL/api
   token = $TOKEN
   END

More information about the debusine command line interface is available
in :ref:`debusine-cli`.

Submit a work request to create a build chroot
----------------------------------------------

Submitting a work request is asking the debusine server to schedule some
specific task on one of its available workers. Debusine can execute
many different :ref:`tasks <task-reference>`.

In order to generate a build chroot, you can rely on the :ref:`mmdebstrap task
<task-mmdebstrap>`. Each task requires a certain numbers of key-value
parameters that are fed to ``debusine create-work-request TASKNAME`` as YAML data
on the standard input. Try this:

.. code-block:: console

  $ debusine create-work-request mmdebstrap << END
  bootstrap_options:
    architecture: amd64
    variant: buildd
  bootstrap_repositories:
    - mirror: http://deb.debian.org/debian
      suite: bookworm
      components:
      - main
      - contrib
      - non-free
      - non-free-firmware
  END

It does output some YAML structured information:

.. code-block:: yaml

  result: success
  message: Work request registered on http://debusine.internal/api with id 314.
  work_request_id: 314

At this point, the task has not been executed yet but it has been accepted
and will be processed as soon as a worker becomes available. You can
follow the status of the work request through the web interface
(click on *Work requests* in the top menu) or with ``debusine
show-work-request WORK_REQUEST_ID``.

.. code-block:: console

    $ debusine show-work-request 314
    id: 314
    created_at: 2024-01-24 17:02:31.855184+00:00
    started_at: 2024-01-24 17:02:31.937001+00:00
    completed_at: null
    duration: null
    status: running
    result: ''
    worker: 1
    task_name: mmdebstrap
    task_data:
    […]
    artifacts: []
    workspace: System

In the above example, the task is currently running. Note that if the
status is ``pending`` it indicates that no ``debusine-worker`` is
currently available to run the task. Check that the ``debusine-worker`` is
connected and has been approved.

Once it has completed (as indicated by ``status: completed``), you will
see different values: the result field will be either ``success``,
``failure`` (task ran but returned a failure) or ``error`` (something
unexpected happened), and more information will be available in the
``artifacts`` key in particular:

.. code-block:: console

    $ debusine show-work-request 314
    id: 314
    created_at: 2024-01-24 17:02:31.855184+00:00
    started_at: 2024-01-24 17:02:31.937001+00:00
    completed_at: 2024-01-24 17:05:48.457239+00:00
    duration: 196
    status: completed
    result: success
    […]
    artifacts:
    - id: 534
      workspace: System
      category: debian:system-tarball
    […]
    - id: 535
      workspace: System
      category: debusine:work-request-debug-logs
    […]

The two artifacts listed correspond to two set of files generated by the
task and each task will typically generate the same kind of files as
output. In the case of the ``mmdebstrap`` task, you will get:

* a :ref:`debian:system-tarball <artifact-system-tarball>` artifact: it
  contains a compressed tarball with the chroot.
* a :ref:`debusine:work-request-debug-logs
  <artifact-work-request-debug-logs>` artifact: it contains various files
  generated by debusine to help troubleshoot issues with the task.
  Here it contains the input that debusine submitted to mmdebstrap, the
  precise command-line, and the output of the command.

The generated artifacts can be browsed and downloaded from the web
interface. But they can also be downloaded from the command line
with the debusine client:

.. code-block:: console

  $ debusine download-artifact 534
  Downloading artifact and uncompressing into /home/debian
  system.tar.xz

Artifacts are thus created by debusine tasks, but they can also be
provided as input to some debusine tasks. Later in this tutorial
we will refer to this artifact ``534`` to schedule a package build
in the build chroot that it contains.

Create an artifact by uploading a source package
------------------------------------------------

The low level ``debusine create-artifact`` command can be used to create
any arbitrary artifact but when it comes to Debian source packages (.dsc)
or Debian uploads (.changes), debusine offers a more convenient
interface with ``debusine import-debian-artifact [FILE|URL]``. You can
refer to a local file or to a remote URL.

For instance, you can create and upload an artifact for the "hello" source
package with:

.. code-block:: console

  $ debusine import-debian-artifact http://deb.debian.org/debian/pool/main/h/hello/hello_2.10-3.dsc
  [...]
  message: New artifact created in http://debusine.internal/api in workspace System with id 536.
  artifact_id: 536

Submit a work request to build binary packages
----------------------------------------------

Among the available tasks, the :ref:`sbuild <task-sbuild>` one can build
binary packages out of a source package (provided through the parameter
``source_artifact_id`` below the ``input`` key) and a build chroot
(provided through the parameter ``environment_id``).

Let's generate the YAML file with the work request specification by taking care
to refer to the IDs of the artifacts that we created in the former steps
(``536`` for the source package, ``534`` for the build chroot):

.. code-block:: console

    $ cat > work-request-hello.debusine << END
    build_components:
    - any
    - all
    host_architecture: amd64
    input:
      source_artifact_id: 536
    environment_id: 534
    END

Then submit the job:

.. code-block:: console

  $ debusine create-work-request sbuild < work-request-hello.debusine

Again you can follow the status of the work request on the web interface
or with the command line, and once completed you will be able to download
the binary packages that have been built.

The sbuild tasks generates :ref:`debian:upload <artifact-upload>`,
:ref:`debian:binary-packages <artifact-binary-packages>` and
:ref:`debian:package-build-log <artifact-package-build-log>` artifacts.

On top of the contained files, the artifact category also defines the
structure of the metadata that is associated to the artifact. You can
inspect those metadata and the file listing on the web interface or on
the command line with ``debusine show-artifact ARTIFACT_ID`` (here ``539``
is the artifact ID of the ``debian:upload`` artifact created by the
task):

.. code-block:: console

    $ debusine show-artifact 539
    id: 539
    workspace: System
    category: debian:upload
    created_at: '2024-01-24T21:07:04.975882+00:00'
    data:
      type: dpkg
      changes_fields:
        Date: Mon, 26 Dec 2022 16:30:00 +0100
    […]
    download_tar_gz_url: http://debusine.internal/artifact/539/?archive=tar.gz
    files_to_upload: []
    expire_at: null
    files:
      hello_2.10-3_amd64.buildinfo:
        size: 5511
        checksums:
          sha256: 422aef340c827d2ed2b38c353f660b70e754509bc0ddb0952975090d9f25caaa
        type: file
        url: http://debusine.internal/artifact/539/hello_2.10-3_amd64.buildinfo
      hello_2.10-3_amd64.changes:
        size: 1889
        checksums:
          sha256: d5d694b42b94587d38a5f883fe1fc5d44368ffe974ac3d506d55bcbef0ab0767
        type: file
        url: http://debusine.internal/artifact/539/hello_2.10-3_amd64.changes
      hello_2.10-3_amd64.deb:
        size: 53084
        checksums:
          sha256: 069754b87d7a546253554813252dacbd7a53e959845cc9f6e8f4c1c8fe3746c5
        type: file
        url: http://debusine.internal/artifact/539/hello_2.10-3_amd64.deb
      hello-dbgsym_2.10-3_amd64.deb:
        size: 35096
        checksums:
          sha256: 1550fcd93105a3cf8fddfc776fda0fbebb51dd7c2d2286eeabc43cb37896ad1e
        type: file
        url: http://debusine.internal/artifact/539/hello-dbgsym_2.10-3_amd64.deb
