| |
| |
| .. _cache_servers: |
| |
| Configuring Cache Servers |
| ========================= |
| BuildStream caches the results of builds in a local artifact cache, and will |
| avoid building an element if there is a suitable build already present in the |
| local artifact cache. Similarly it will cache sources and avoid pulling them if |
| present in the local cache. See :ref:`caches <caches>` for more details. |
| |
| In addition to the local caches, you can configure one or more remote caches and |
| BuildStream will then try to pull a suitable object from one of the remotes, |
| falling back to performing a local build or fetching a source if needed. |
| |
| Configuring BuildStream to use remote caches |
| -------------------------------------------- |
| A project will often set up continuous build infrastructure that pushes |
| cached objects to a shared cache, so developers working on the project can |
| make use of these pre-made objects instead of having to each build the whole |
| project locally. The project can declare this cache in its |
| project configuration file for :ref:`artifacts <project_essentials_artifacts>` |
| and :ref:`sources <project_source_cache>`. |
| |
| Users can declare additional remote caches in the :ref:`user configuration |
| <config_artifacts>`. There are several use cases for this: your project may not |
| define its own cache, it may be useful to have a local mirror of its cache, or |
| you may have a reason to share artifacts privately. |
| |
| Remote caches are identified by their URL. There are currently two supported |
| protocols: |
| |
| * ``http``: Pull and push access, without transport-layer security |
| * ``https``: Pull and push access, with transport-layer security |
| |
| BuildStream allows you to configure as many caches as you like, and will query |
| them in a specific order: |
| |
| 1. Project-specific overrides in the user config |
| 2. Project configuration |
| 3. User configuration |
| |
| When an an object is created locally, BuildStream will try to push it to all the |
| caches which have the ``push: true`` flag set. You can also manually push |
| artifacts to a specific cache using the :ref:`bst artifact push command |
| <invoking_artifact_push>`. |
| |
| Objects are identified using the element or sources :ref:`cache key <cachekeys>` |
| so the objects provided by a cache should be interchangable with those provided |
| by any other cache. |
| |
| |
| Setting up a remote cache |
| ------------------------- |
| The rest of this page outlines how to set up a shared cache. |
| |
| Setting up the user |
| ~~~~~~~~~~~~~~~~~~~ |
| A specific user is not needed, however, a dedicated user to own the cache is |
| recommended. |
| |
| .. code:: bash |
| |
| useradd artifacts |
| |
| The recommended approach is to run two instances on different ports. |
| One instance has push disabled and doesn't require client authentication. |
| The other instance has push enabled and requires client authentication. |
| |
| Alternatively, you can set up a reverse proxy and handle authentication |
| and authorization there. |
| |
| |
| Installing the server |
| ~~~~~~~~~~~~~~~~~~~~~ |
| You will also need to install BuildStream on the cache server in order |
| to receive uploaded artifacts over ssh. Follow the instructions for installing |
| BuildStream `here <https://buildstream.build/install.html>`_. |
| |
| When installing BuildStream on the cache server, it must be installed |
| in a system wide location, with ``pip3 install .`` in the BuildStream |
| checkout directory. |
| |
| Otherwise, some tinkering is required to ensure BuildStream is available |
| in ``PATH`` when its companion ``bst-artifact-server`` program is run |
| remotely. |
| |
| You can install only the artifact server companion program without |
| requiring BuildStream's more exigent dependencies by setting the |
| ``BST_ARTIFACTS_ONLY`` environment variable at install time, like so: |
| |
| .. code:: |
| |
| BST_ARTIFACTS_ONLY=1 pip3 install . |
| |
| |
| .. _artifact_command_reference: |
| |
| Command reference |
| ~~~~~~~~~~~~~~~~~ |
| |
| .. click:: buildstream._cas.casserver:server_main |
| :prog: bst-artifact-server |
| |
| |
| .. _server_authentication: |
| |
| Key pair for the server |
| ~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| For TLS you need a key pair for the server. The following example creates |
| a self-signed key, which requires clients to have a copy of the server certificate |
| (e.g., in the project directory). |
| You can also use a key pair obtained from a trusted certificate authority instead. |
| |
| .. code:: bash |
| |
| openssl req -new -newkey rsa:4096 -x509 -sha256 -days 3650 -nodes -batch -subj "/CN=artifacts.com" -out server.crt -keyout server.key |
| |
| .. note:: |
| |
| Note that in the ``-subj "/CN=<foo>"`` argument, ``/CN`` is the *certificate common name*, |
| and as such ``<foo>`` should be the public hostname of the server. IP addresses will |
| **not** provide you with working authentication. |
| |
| In addition to this, ensure that the host server is recognised by the client. |
| You may need to add the line: ``<ip address>`` ``<hostname>`` to |
| your ``/etc/hosts`` file. |
| |
| Authenticating users |
| ~~~~~~~~~~~~~~~~~~~~ |
| In order to give permission to a given user to upload |
| artifacts, create a TLS key pair on the client. |
| |
| .. code:: bash |
| |
| openssl req -new -newkey rsa:4096 -x509 -sha256 -days 3650 -nodes -batch -subj "/CN=client" -out client.crt -keyout client.key |
| |
| Copy the public client certificate ``client.crt`` to the server and then add it |
| to the authorized keys, like so: |
| |
| .. code:: bash |
| |
| cat client.crt >> /home/artifacts/authorized.crt |
| |
| |
| Serve the cache over https |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| Public instance without push: |
| |
| .. code:: bash |
| |
| bst-artifact-server --port 11001 --server-key server.key --server-cert server.crt /home/artifacts/artifacts |
| |
| Instance with push and requiring client authentication: |
| |
| .. code:: bash |
| |
| bst-artifact-server --port 11002 --server-key server.key --server-cert server.crt --client-certs authorized.crt --enable-push /home/artifacts/artifacts |
| |
| .. note:: |
| |
| BuildStream's artifact cache is an extension of `Google's Remote |
| Execution CAS server |
| <https://github.com/bazelbuild/remote-apis/>`_. |
| |
| Sometimes, when using Remote Execution, it is useful to run |
| BuildStream with just a basic CAS server, without using the |
| artifact extensions, but BuildStream still needs to store these to |
| work correctly. |
| |
| For this scenario, you can add the `--index-only` flag to the above |
| commands, and configure BuildStream to store artifact metadata and |
| files in a separate caches (e.g. bst-artifact-server and Buildbarn) |
| using :ref:`"types" <project_essentials_split_artifacts>`. |
| |
| Managing the cache with systemd |
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| We recommend running the cache as a systemd service, especially if it is running |
| on a dedicated server, as this will allow systemd to manage the cache, in case |
| the server encounters any issues. |
| |
| Below are two examples of how to run the cache server as a systemd service. The |
| first, is for pull only and the other is configured for push & pull. Notice that |
| the two configurations use different ports. |
| |
| ``bst-artifact-serve.service``: |
| |
| .. code:: ini |
| |
| # |
| # Pull |
| # |
| [Unit] |
| Description=Buildstream Artifact pull server |
| After=remote-fs.target network-online.target |
| |
| [Service] |
| Environment="LC_ALL=C.UTF-8" |
| ExecStart=/usr/local/bin/bst-artifact-server --port 11001 --server-key {{certs_path}}/server.key --server-cert {{certs_path}}/server.crt {{artifacts_path}} |
| User=artifacts |
| |
| [Install] |
| WantedBy=multi-user.target |
| |
| |
| ``bst-artifact-serve-receive.service``: |
| |
| .. code:: ini |
| |
| # |
| # Pull/Push |
| # |
| [Unit] |
| Description=Buildstream Artifact pull/push server |
| After=remote-fs.target network-online.target |
| |
| [Service] |
| Environment="LC_ALL=C.UTF-8" |
| ExecStart=/usr/local/bin/bst-artifact-server --port 11002 --server-key {{certs_path}}/server.key --server-cert {{certs_path}}/server.crt --client-certs {{certs_path}}/authorized.crt --enable-push {{artifacts_path}} |
| User=artifacts |
| |
| [Install] |
| WantedBy=multi-user.target |
| |
| |
| Here we define when systemd should start the service, which is after the networking |
| stack has been started, we then define how to run the cache with the desired |
| configuration, under the artifacts user. The {{ }} are there to denote where you |
| should change these files to point to your desired locations. |
| |
| .. note:: |
| |
| You may need to run some of the following commands as the superuser. |
| |
| These files should be copied to ``/etc/systemd/system/``. We can then start these services |
| with: |
| |
| .. code:: bash |
| |
| systemctl enable bst-artifact-serve.service |
| systemctl enable bst-artifact-serve-receive.service |
| |
| Then, to start these services: |
| |
| .. code:: bash |
| |
| systemctl start bst-artifact-serve.service |
| systemctl start bst-artifact-serve-receive.service |
| |
| We can then check if the services are successfully running with: |
| |
| .. code:: bash |
| |
| journalctl -u bst-artifact-serve.service |
| journalctl -u bst-artifact-serve-receive.service |
| |
| For more information on systemd services see: |
| `Creating Systemd Service Files <https://www.devdungeon.com/content/creating-systemd-service-files>`_. |
| |
| Declaring remote caches |
| ~~~~~~~~~~~~~~~~~~~~~~~ |
| Remote caches can be declared within either: |
| |
| 1. The project configuration for :ref:`artifact <project_essentials_artifacts>` |
| and :ref:`sources <project_source_cache>`, or |
| 2. The user configuration for :ref:`artifacts <config_artifacts>` and |
| :ref:`sources <config_sources>`. |
| |
| Please follow the above links to see examples showing how we declare remote |
| caches in both the project configuration and the user configuration, respectively. |