9.9 KiB
Installation
External Dependencies
Zuul interacts with several other systems described below.
Gearman
Gearman is a job distribution system that Zuul uses to communicate with its distributed components. The Zuul scheduler distributes work to Zuul mergers and executors using Gearman. You may supply your own gearman server, but the Zuul scheduler includes a built-in server which is recommended. Ensure that all Zuul hosts can communicate with the gearman server.
Zuul distributes secrets to executors via gearman, so be sure to secure it with TLS and certificate authentication. Obtain (or generate) a certificate for both the server and the clients (they may use the same certificate or have individual certificates). They must be signed by a CA, but it can be your own CA.
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 only makes one requirement of these nodes: that it be able to log in given a username and ssh private key.
ZooKeeper
Nodepool uses ZooKeeper to communicate internally among its
components, and also to communicate with Zuul. You can run a simple
single-node ZooKeeper instance, or a multi-node cluster. Ensure that the
host running the Zuul scheduler has access to the cluster. See howto-zookeeper
for
recommendations for operating a small ZooKeeper cluster.
Zuul stores private keys for each project it knows about in ZooKeeper. It is recommended that you periodically back up the private keys in case the ZooKeeper data store is lost or damaged. The Zuul Client provides two sub-commands for use in this case: export-keys and import-keys. Each takes an argument to a filesystem path and will write the keys to, or read the keys from that path. The data in the exported files are still secured with the keystore passphrase, so be sure to retain it as well.
Database
Zuul requires an SQL database; either MariaDB, MySQL, or PostgreSQL.
Installation from PyPI
Zuul is a Python application which can be installed from the Python Package Index (PyPI).
To install a Zuul release from PyPI, run:
pip install zuul
Or from a git checkout, run:
pip install .
That will also install Zuul's python dependencies. To minimize interaction with other python packages installed on a system, you may wish to install Zuul within a Python virtualenv.
Zuul has several system-level dependencies as well. You can find a
list of operating system packages in bindep.txt
in Zuul's
source directory.
It is also required to run zuul-manage-ansible
on the
zuul-executor in order to install all supported Ansible versions so Zuul
can use them. See ansible-installation-options
for details.
Installation from Containers
The Zuul project also builds and releases container images on DockerHub. These are available at: https://hub.docker.com/u/zuul
There is a container image for each of the Zuul components <components>
.
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).
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
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:
<Directory /usr/share/zuul>
Require all granted
</Directory>
Alias / /usr/share/zuul/
<Location />
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]
</Location>
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.
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:
<Directory /usr/share/zuul>
Require all granted
</Directory>
Alias /zuul /usr/share/zuul/
<Location /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$3 [R=301,L,NE]
# Don't rewrite files or directories
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /zuul/index.html [L]
</Location>
White Labeled Tenant
Running a white-labeled tenant is similar to the offload case, but adds a rule to ensure connection webhooks don't try to get put into the tenant scope.
Note
It's possible to do white-labeling without static offload, but it is more complex with no benefit.
Enable the mod_rewrite
Apache module, and assuming the
Zuul tenant name is example
, the rewrite rules are:
<Directory /usr/share/zuul>
Require all granted
</Directory>
Alias / /usr/share/zuul/
<Location />
RewriteEngine on
RewriteBase /
# Rewrite api to the zuul-web endpoint
RewriteRule api/connection/(.*)$ 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]
</Location>
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:
REACT_APP_ZUUL_API='http://zuul-web.example.com' yarn build