Installation ============ External Dependencies --------------------- Zuul interacts with several other systems described below. Nodepool ~~~~~~~~ In order to run all but the simplest jobs, Zuul uses a companion program `Nodepool `__ to supply the nodes (whether dynamic cloud instances or static hardware) used by jobs. Before starting Zuul, ensure you have Nodepool installed and any images you require built. Zuul must be able to log into the nodes provisioned by Nodepool with a given username and SSH private key. Executors should also be able to talk to nodes on TCP port 19885 for log streaming; see :ref:`nodepool_console_streaming`. ZooKeeper ~~~~~~~~~ .. TODO: SpamapS any zookeeper config recommendations? Zuul and Nodepool use ZooKeeper to communicate internally among their components, and also to communicate with each other. You can run a simple single-node ZooKeeper instance, or a multi-node cluster. Ensure that all Zuul and Nodepool hosts have access to the cluster. .. _ansible-installation-options: Executor Deployment ------------------- The Zuul executor requires Ansible to run jobs. There are two approaches that can be used to install Ansible for Zuul. First you may set ``manage_ansible`` to True in the executor config. If you do this Zuul will install all supported Ansible versions on zuul-executor startup. These installations end up in Zuul's state dir, ``/var/lib/zuul/ansible-bin`` if unchanged. The second option is to use ``zuul-manage-ansible`` to install the supported Ansible versions. By default this will install Ansible to ``zuul_install_prefix/lib/zuul/ansible``. This method is preferable to the first because it speeds up zuul-executor start time and allows you to preinstall ansible in containers (avoids problems with bind mounted zuul state dirs). .. program-output:: zuul-manage-ansible -h In both cases if using a non default path you will want to set ``ansible_root`` in the executor config file. .. _web-deployment-options: Web Deployment -------------- The ``zuul-web`` service provides a web dashboard, a REST API and a websocket log streaming service as a single holistic web application. For production use it is recommended to run it behind a reverse proxy, such as Apache or Nginx. The ``zuul-web`` service is entirely self-contained and can be run with minimal configuration, however, more advanced users may desire to do one or more of the following: White Label Serve the dashboard of an individual tenant at the root of its own domain. https://zuul.openstack.org is an example of a Zuul dashboard that has been white labeled for the ``openstack`` tenant of its Zuul. Static Offload Shift the duties of serving static files, such as HTML, Javascript, CSS or images to the reverse proxy server. Static External Serve the static files from a completely separate location that does not support programmatic rewrite rules such as a Swift Object Store. Sub-URL Serve a Zuul dashboard from a location below the root URL as part of presenting integration with other application. https://softwarefactory-project.io/zuul/ is an example of a Zuul dashboard that is being served from a Sub-URL. Most deployments shouldn't need these, so the following discussion will assume that the ``zuul-web`` service is exposed via a reverse proxy. Where rewrite rule examples are given, they will be given with Apache syntax, but any other reverse proxy should work just fine. Reverse Proxy ~~~~~~~~~~~~~ Using Apache as the reverse proxy requires the ``mod_proxy``, ``mod_proxy_http`` and ``mod_proxy_wstunnel`` modules to be installed and enabled. All of the cases require a rewrite rule for the websocket streaming, so the simplest reverse-proxy case is:: RewriteEngine on RewriteRule ^/api/tenant/(.*)/console-stream ws://localhost:9000/api/tenant/$1/console-stream [P] RewriteRule ^/(.*)$ http://localhost:9000/$1 [P] This is the recommended configuration unless one of the following features is required. Static Offload ~~~~~~~~~~~~~~ To have the reverse proxy serve the static html/javascript assets instead of proxying them to the REST layer, enable the ``mod_rewrite`` Apache module, register the location where you unpacked the web application as the document root and add rewrite rules:: Require all granted Alias / /usr/share/zuul/ RewriteEngine on RewriteBase / # Rewrite api to the zuul-web endpoint RewriteRule api/tenant/(.*)/console-stream ws://localhost:9000/api/tenant/$1/console-stream [P,L] RewriteRule api/(.*)$ http://localhost:9000/api/$1 [P,L] # Backward compatible rewrite RewriteRule t/(.*)/(.*).html(.*) /t/$1/$2$3 [R=301,L,NE] # Don't rewrite files or directories RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.html [L] Sub directory serving ~~~~~~~~~~~~~~~~~~~~~ The web application needs to be rebuilt to update the internal location of the static files. Set the homepage setting in the package.json to an absolute path or url. For example, to deploy the web interface through a '/zuul/' sub directory: .. note:: The web dashboard source code and package.json are located in the ``web`` directory. All the yarn commands need to be executed from the ``web`` directory. .. code-block:: bash sed -e 's#"homepage": "/"#"homepage": "/zuul/"#' -i package.json yarn build Then assuming the web application is unpacked in /usr/share/zuul, enable the ``mod_rewrite`` Apache module and add the following rewrite rules:: Require all granted Alias /zuul /usr/share/zuul/ RewriteEngine on RewriteBase /zuul # Rewrite api to the zuul-web endpoint RewriteRule api/tenant/(.*)/console-stream ws://localhost:9000/api/tenant/$1/console-stream [P,L] RewriteRule api/(.*)$ http://localhost:9000/api/$1 [P,L] # Backward compatible rewrite RewriteRule t/(.*)/(.*).html(.*) /t/$1/$2$3 [R=301,L,NE] # Don't rewrite files or directories RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /zuul/index.html [L] White Labeled Tenant ~~~~~~~~~~~~~~~~~~~~ Running a white-labeled tenant is similar to the offload case, but adds a rule to ensure connection webhooks don't try to get put into the tenant scope. .. note:: It's possible to do white-labeling without static offload, but it is more complex with no benefit. Enable the ``mod_rewrite`` Apache module, and assuming the Zuul tenant name is ``example``, the rewrite rules are:: Require all granted Alias / /usr/share/zuul/ RewriteEngine on RewriteBase / # Rewrite api to the zuul-web endpoint RewriteRule api/connection/(.*)$ http://localhost:9000/api/connection/$1 [P,L] RewriteRule api/console-stream ws://localhost:9000/api/tenant/example/console-stream [P,L] RewriteRule api/(.*)$ http://localhost:9000/api/tenant/example/$1 [P,L] # Backward compatible rewrite RewriteRule t/(.*)/(.*).html(.*) /t/$1/$2$3 [R=301,L,NE] # Don't rewrite files or directories RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.html [L] Static External ~~~~~~~~~~~~~~~ .. note:: Hosting the Zuul dashboard on an external static location that does not support dynamic url rewrite rules only works for white-labeled deployments. In order to serve the zuul dashboard code from an external static location, ``REACT_APP_ZUUL_API`` must be set at javascript build time: .. code-block:: bash REACT_APP_ZUUL_API='http://zuul-web.example.com' yarn build