Configuration

All Zuul processes read the /etc/zuul/zuul.conf file (an alternate location may be supplied on the command line) which uses an INI file syntax. Each component may have its own configuration file, though you may find it simpler to use the same file for all components.

Zuul will interpolate environment variables starting with the ZUUL_ prefix given in the config file escaped as python string expansion. foo=%(ZUUL_HOME)s will set the value of foo to the same value as the environment variable named ZUUL_HOME.

An example zuul.conf:

[zookeeper]
hosts=zk1.example.com,zk2.example.com,zk3.example.com

[database]
dburi=<URI>

[keystore]
password=MY_SECRET_PASSWORD

[web]
root=https://zuul.example.com/

[scheduler]
log_config=/etc/zuul/scheduler-logging.yaml

Common Options

The following sections of zuul.conf are used by all Zuul components:

Statsd

statsd

Information about the optional statsd server. If the statsd python module is installed and this section is configured, statistics will be reported to statsd. See Statsd reporting for more information.

statsd.server: Hostname or IP address of the statsd server.

statsd.port Default: 8125: The UDP port on which the statsd server is listening.

statsd.prefix: If present, this will be prefixed to all of the keys before transmitting to the statsd server.

Tracing

tracing

Information about the optional OpenTelemetry tracing configuration. See Tracing for more information.

tracing.enabled (required): To enable tracing, set this value to true. This is the only required parameter in order to export to a collector running locally.

tracing.protocol Default: grpc

The OTLP wire protocol to use.

grpc: Use gRPC (the default).

http/protobuf: Use HTTP with protobuf encoding.

tracing.endpoint: The endpoint to use. The default is protocol specific, but defaults to localhost in all cases.

tracing.service_name Default: zuul: The service name may be specified here. Multiple Zuul installations should use different values.

tracing.tls_cert: The path to the PEM encoded certificate file. Used only by grpc.

tracing.tls_key: The path to the PEM encoded key file. Used only by grpc.

tracing.tls_ca: The path to the PEM encoded CA certificate file. Used only by grpc.

tracing.certificate_file: The path to the PEM encoded certificate file used to verify the endpoint. Used only by http/protobuf.

tracing.insecure: Whether to allow an insecure connection. Used only by grpc.

tracing.timeout Default: 10000: The timeout for outgoing data in milliseconds.

tracing.compression: The compression algorithm to use. Available values depend on the protocol and endpoint. The only universally supported value is gzip.

ZooKeeper

zookeeper

Client connection information for ZooKeeper. TLS is required.

zookeeper.hosts (required): A list of zookeeper hosts for Zuul to use when communicating with Nodepool.

zookeeper.tls_cert (required): The path to the PEM encoded certificate file.

zookeeper.tls_key (required): The path to the PEM encoded key file.

zookeeper.tls_ca (required): The path to the PEM encoded CA certificate file.

zookeeper.session_timeout Default: 10.0: The ZooKeeper session timeout, in seconds.

Database

database

database.dburi (required)

Database connection information in the form of a URI understood by SQLAlchemy. See The SQLAlchemy manual for more information.

The driver will automatically set up the database creating and managing the necessary tables. Therefore the provided user should have sufficient permissions to manage the database. For example:

GRANT ALL ON my_database TO 'my_user'@'%';

database.pool_recycle Default: 1: Tune the pool_recycle value. See The SQLAlchemy manual on pooling for more information.

database.table_prefix Default: '': The string to prefix the table names. This makes it possible to run several zuul deployments against the same database. This can be useful if you rely on external databases which are not under your control. The default is to have no prefix.

Scheduler

The scheduler is the primary component of Zuul. The scheduler is a scalable component; one or more schedulers must be running at all times for Zuul to be operational. It receives events from any connections to remote systems which have been configured, enqueues items into pipelines, distributes jobs to executors, and reports results.

The scheduler must be able to connect to the ZooKeeper cluster shared by Zuul and Nodepool in order to request nodes. It does not need to connect directly to the nodes themselves, however – that function is handled by the Executors.

It must also be able to connect to any services for which connections are configured (Gerrit, GitHub, etc).

The following sections of zuul.conf are used by the scheduler:

web

web.root (required)

The root URL of the web service (e.g., https://zuul.example.com/).

See tenant.web-root for additional options for whitelabeled tenant configuration.

web.status_url: Warning

This is deprecate and only used for the also deprecated status_url replacement field available in pipeline reporter messages.

URL that will be posted in Zuul comments made to changes when starting jobs for a change.

keystore

keystore.password (required): Encryption password for private data stored in Zookeeper.

scheduler

scheduler.command_socket Default: /var/lib/zuul/scheduler.socket: Path to command socket file for the scheduler process.

scheduler.tenant_config: Path to Tenant Configuration file. This attribute is exclusive with scheduler.tenant_config_script.

scheduler.tenant_config_script: Path to a script to execute and load the tenant config from. This attribute is exclusive with scheduler.tenant_config.

scheduler.default_ansible_version: Default ansible version to use for jobs that doesn’t specify a version. See job.ansible-version for details.

scheduler.log_config: Path to log config file.

scheduler.pidfile Default: /var/run/zuul/scheduler.pid: Path to PID lock file.

scheduler.relative_priority Default: False

A boolean which indicates whether the scheduler should supply relative priority information for node requests.

In all cases, each pipeline may specify a precedence value which is used by Nodepool to satisfy requests from higher-precedence pipelines first. If relative_priority is set to True, then Zuul will additionally group items in the same pipeline by pipeline queue and weight each request by its position in that project’s group. A request for the first change in a given queue will have the highest relative priority, and the second change a lower relative priority. The first change of each queue in a pipeline has the same relative priority, regardless of the order of submission or how many other changes are in the pipeline. This can be used to make node allocations complete faster for projects with fewer changes in a system dominated by projects with more changes.

After the first 10 changes, the relative priority becomes more coarse (batching groups of 10 changes at the same priority). Likewise, after 100 changes they are batchen in groups of 100. This is to avoid causing additional load with unecessary priority changes if queues are long.

If this value is False (the default), then node requests are sorted by pipeline precedence followed by the order in which they were submitted. If this is True, they are sorted by pipeline precedence, followed by relative priority, and finally the order in which they were submitted.

scheduler.default_hold_expiration Default: max_hold_expiration: The default value for held node expiration if not supplied. This will default to the value of max_hold_expiration if not changed, or if it is set to a higher value than the max.

scheduler.max_hold_expiration Default: 0: Maximum number of seconds any nodes held for an autohold request will remain available. A value of 0 disables this, and the nodes will remain held until the autohold request is manually deleted. If a value higher than max_hold_expiration is supplied during hold request creation, it will be lowered to this value.

scheduler.prometheus_port: Set a TCP port to start the prometheus metrics client.

scheduler.prometheus_addr Default: 0.0.0.0: The IPv4 addr to listen for prometheus metrics poll. To use IPv6, python>3.8 is required issue24209.

Merger

Mergers are an optional Zuul service; they are not required for Zuul to operate, but some high volume sites may benefit from running them. Zuul performs quite a lot of git operations in the course of its work. Each change that is to be tested must be speculatively merged with the current state of its target branch to ensure that it can merge, and to ensure that the tests that Zuul perform accurately represent the outcome of merging the change. Because Zuul’s configuration is stored in the git repos it interacts with, and is dynamically evaluated, Zuul often needs to perform a speculative merge in order to determine whether it needs to perform any further actions.

All of these git operations add up, and while Zuul executors can also perform them, large numbers may impact their ability to run jobs. Therefore, administrators may wish to run standalone mergers in order to reduce the load on executors.

Mergers need to be able to connect to the ZooKeeper cluster as well as any services for which connections are configured (Gerrit, GitHub, etc).

The following section of zuul.conf is used by the merger:

merger

merger.command_socket Default: /var/lib/zuul/merger.socket: Path to command socket file for the merger process.

merger.git_dir Default: /var/lib/zuul/merger-git: Directory in which Zuul should clone git repositories.

merger.git_http_low_speed_limit Default: 1000

If the HTTP transfer speed is less then git_http_low_speed_limit for longer then git_http_low_speed_time, the transfer is aborted.

Value in bytes, setting to 0 will disable.

merger.git_http_low_speed_time Default: 30

If the HTTP transfer speed is less then git_http_low_speed_limit for longer then git_http_low_speed_time, the transfer is aborted.

Value in seconds, setting to 0 will disable.

merger.git_timeout Default: 300

Timeout for git clone and fetch operations. This can be useful when dealing with large repos. Note that large timeouts can increase startup and reconfiguration times if repos are not cached so be cautious when increasing this value.

Value in seconds.

merger.git_user_email: Value to pass to git config user.email.

merger.git_user_name: Value to pass to git config user.name.

merger.log_config: Path to log config file for the merger process.

merger.pidfile Default: /var/run/zuul/merger.pid: Path to PID lock file for the merger process.

merger.prometheus_port: Set a TCP port to start the prometheus metrics client.

merger.prometheus_addr Default: 0.0.0.0: The IPv4 addr to listen for prometheus metrics poll. To use IPv6, python>3.8 is required issue24209.

Executor

Executors are responsible for running jobs. At the start of each job, an executor prepares an environment in which to run Ansible which contains all of the git repositories specified by the job with all dependent changes merged into their appropriate branches. The branch corresponding to the proposed change will be checked out (in all projects, if it exists). Any roles specified by the job will also be present (also with dependent changes merged, if appropriate) and added to the Ansible role path. The executor also prepares an Ansible inventory file with all of the nodes requested by the job.

The executor also contains a merger. This is used by the executor to prepare the git repositories used by jobs, but is also available to perform any tasks normally performed by standalone mergers. Because the executor performs both roles, small Zuul installations may not need to run standalone mergers.

Executors need to be able to connect to the ZooKeeper cluster, any services for which connections are configured (Gerrit, GitHub, etc), as well as directly to the hosts which Nodepool provides.

Trusted and Untrusted Playbooks

The executor runs playbooks in one of two execution contexts depending on whether the project containing the playbook is a config-project or an untrusted-project. If the playbook is in a config project, the executor runs the playbook in the trusted execution context, otherwise, it is run in the untrusted execution context.

Both execution contexts use bubblewrap to create a namespace to ensure that playbook executions are isolated and are unable to access files outside of a restricted environment. The administrator may configure additional local directories on the executor to be made available to the restricted environment.

Security Considerations

Bubblewrap restricts access to files outside of the build environment in both execution contexts. Operators may allow either read-only or read-write access to additional paths in either the trusted context or both contexts with additional options described below. Be careful when adding additional paths, and consider that any trusted or untrusted (as appropriate) playbook will have access to these paths.

If executors are configured to use WinRM certificates, these must be made available to the bubblewrap environment in order for Ansible to use them. This invariably makes them accessible to any playbook in that execution context. Operators may want to consider only supplying WinRM credentials to trusted playbooks and installing per-build certificates in a pre-playbook; or using Ansible’s experimental SSH support instead of WinRM.

Local code execution is permitted on the executor, so if a vulnerability in bubblewrap or the kernel allows for an escape from the restricted environment, users may be able to escalate their privileges and obtain access to any data or secrets available to the executor.

Playbooks which run on the executor will have the same network access as the executor itself. This should be kept in mind when considering IP-based network access control within an organization. Zuul’s internal communication is via ZooKeeper which is authenticated and secured by TLS certificates, so as long as these certificates are not made available to jobs, users should not be able to access or disrupt Zuul’s internal communications. However, statsd is an unauthenticated protocol, so a malicious user could emit false statsd information.

If the Zuul executor is running in a cloud environment with a network metadata service, users may be able to access that service. If it supplies credentials, they may be able to obtain those credentials and access cloud resources. Operators should ensure that in these environments, the executors are configured with appropriately restricted IAM profiles.

Configuration

The following sections of zuul.conf are used by the executor:

executor

executor.command_socket Default: /var/lib/zuul/executor.socket: Path to command socket file for the executor process.

executor.finger_port Default: 7900: Port to use for finger log streamer.

executor.state_dir Default: /var/lib/zuul: Path to directory in which Zuul should save its state.

executor.git_dir Default: /var/lib/zuul/executor-git

Directory that Zuul should clone local git repositories to. The executor keeps a local copy of every git repository it works with to speed operations and perform speculative merging.

This should be on the same filesystem as executor.job_dir so that when git repos are cloned into the job workspaces, they can be hard-linked to the local git cache.

executor.job_dir Default: /var/lib/zuul/builds

Directory that Zuul should use to hold temporary job directories. When each job is run, a new entry will be created under this directory to hold the configuration and scratch workspace for that job. It will be deleted at the end of the job (unless the –keep-jobdir command line option is specified).

This should be on the same filesystem as executor.git_dir so that when git repos are cloned into the job workspaces, they can be hard-linked to the local git cache.

executor.log_config: Path to log config file for the executor process.

executor.pidfile Default: /var/run/zuul/executor.pid: Path to PID lock file for the executor process.

executor.private_key_file Default: ~/.ssh/id_rsa: SSH private key file to be used when logging into worker nodes.

Note

If you use an RSA key, ensure it is encoded in the PEM format (use the -t rsa -m PEM arguments to ssh-keygen).

executor.default_username Default: zuul: Username to use when logging into worker nodes, if none is supplied by Nodepool.

executor.winrm_cert_key_file Default: ~/.winrm/winrm_client_cert.key: The private key file of the client certificate to use for winrm connections to Windows nodes.

executor.winrm_cert_pem_file Default: ~/.winrm/winrm_client_cert.pem: The certificate file of the client certificate to use for winrm connections to Windows nodes.

Note

Currently certificate verification is disabled when connecting to Windows nodes via winrm.

executor.winrm_operation_timeout_sec Default: None. The Ansible default of 20 is used in this case.: The timeout for WinRM operations.

executor.winrm_read_timeout_sec Default: None. The Ansible default of 30 is used in this case.: The timeout for WinRM read. Increase this if there are intermittent network issues and read timeout errors keep occurring.

executor.variables: Path to an Ansible variables file to supply site-wide variables. This should be a YAML-formatted file consisting of a single dictionary. The contents will be made available to all jobs as Ansible variables. These variables take precedence over all other forms (job variables and secrets). Care should be taken when naming these variables to avoid potential collisions with those used by jobs. Prefixing variable names with a site-specific identifier is recommended. The default is not to add any site-wide variables. See the User’s Guide for more information.

executor.manage_ansible Default: True

Specifies wether the zuul-executor should install the supported ansible versions during startup or not. If this is True the zuul-executor will install the ansible versions into executor.ansible_root.

It is recommended to set this to False and manually install Ansible after the Zuul installation by running zuul-manage-ansible. This has the advantage that possible errors during Ansible installation can be spotted earlier. Further especially containerized deployments of Zuul will have the advantage of predictable versions.

executor.ansible_root Default: <state_dir>/ansible-bin

Specifies where the zuul-executor should look for its supported ansible installations. By default it looks in the following directories and uses the first which it can find.

<zuul_install_dir>/lib/zuul/ansible
<ansible_root>

The ansible_root setting allows you to override the second location which is also used for installation if manage_ansible is True.

executor.ansible_setup_timeout Default: 60: Timeout of the ansible setup playbook in seconds that runs before the first playbook of the job.

executor.disk_limit_per_job Default: 250: This integer is the maximum number of megabytes that any one job is allowed to consume on disk while it is running. If a job’s scratch space has more than this much space consumed, it will be aborted. Set to -1 to disable the limit.

executor.trusted_ro_paths: List of paths, separated by : to read-only bind mount into trusted bubblewrap contexts.

executor.trusted_rw_paths: List of paths, separated by : to read-write bind mount into trusted bubblewrap contexts.

executor.untrusted_ro_paths: List of paths, separated by : to read-only bind mount into untrusted bubblewrap contexts.

executor.untrusted_rw_paths: List of paths, separated by : to read-write bind mount into untrusted bubblewrap contexts.

executor.load_multiplier Default: 2.5

When an executor host gets too busy, the system may suffer timeouts and other ill effects. The executor will stop accepting more than 1 job at a time until load has lowered below a safe level. This level is determined by multiplying the number of CPU’s by load_multiplier.

So for example, if the system has 2 CPUs, and load_multiplier is 2.5, the safe load for the system is 5.00. Any time the system load average is over 5.00, the executor will quit accepting multiple jobs at one time.

The executor will observe system load and determine whether to accept more jobs every 30 seconds.

executor.max_starting_builds Default: None

An executor is accepting up to as many starting builds as defined by the executor.load_multiplier on systems with more than four CPU cores, and up to twice as many on systems with four or less CPU cores. For example, on a system with two CPUs: 2 * 2.5 * 2 - up to ten starting builds may run on such executor; on systems with eight CPUs: 2.5 * 8 - up to twenty starting builds may run on such executor.

On systems with high CPU/vCPU count an executor may accept too many starting builds. This can be overwritten using this option providing a fixed number of maximum starting builds on an executor.

executor.min_avail_hdd Default: 5.0: This is the minimum percentage of HDD storage available for the executor.state_dir directory. The executor will stop accepting more than 1 job at a time until more HDD storage is available. The available HDD percentage is calculated from the total available disk space divided by the total real storage capacity multiplied by 100.

executor.min_avail_inodes Default: 5.0: This is the minimum percentage of HDD inodes available for the executor.state_dir directory. The executor will stop accepting more than 1 job at a time until more inodes are available. The available inode percentage is calculated from the total available inodes divided by the total real inode capacity multiplied by 100.

executor.min_avail_mem Default: 5.0: This is the minimum percentage of system RAM available. The executor will stop accepting more than 1 job at a time until more memory is available. The available memory percentage is calculated from the total available memory divided by the total real memory multiplied by 100. Buffers and cache are considered available in the calculation.

executor.hostname Default: hostname of the server: The executor needs to know its hostname under which it is reachable by zuul-web. Otherwise live console log streaming doesn’t work. In most cases This is automatically detected correctly. But when running in environments where it cannot determine its hostname correctly this can be overridden here.

executor.paused_on_start Default: false: Whether the executor should start in a paused mode. Such executor will not accept tasks until it is unpaused.

executor.zone Default: None

Name of the nodepool executor-zone to exclusively execute all jobs that have nodes with the specified executor-zone attribute. As an example, it is possible for nodepool nodes to exist in a cloud without public accessable IP address. By adding an executor to a zone nodepool nodes could be configured to use private ip addresses.

To enable this in nodepool, you’ll use the node-attributes setting in a provider pool. For example:

pools:
  - name: main
    node-attributes:
      executor-zone: vpn

executor.allow_unzoned Default: False: If executor.zone is set it by default only processes jobs with nodes of that specific zone even if the nodes have no zone at all. Enabling allow_unzoned lets the executor also take jobs with nodes without zone.

executor.merge_jobs Default: True: To disable global merge job, set it to false. This is useful for zoned executors that are running on slow network where you don’t want them to perform merge operations for any events. The executor will still perform the merge operations required for the build they are executing.

executor.sigterm_method Default: graceful

Determines how the executor responds to a SIGTERM signal.

graceful: Stop accepting new jobs and wait for all running jobs to complete before exiting.

stop: Abort all running jobs and exit as soon as possible.

executor.prometheus_port: Set a TCP port to start the prometheus metrics client.

executor.prometheus_addr Default: 0.0.0.0: The IPv4 addr to listen for prometheus metrics poll. To use IPv6, python>3.8 is required issue24209.

keystore

keystore.password (required): Encryption password for private data stored in Zookeeper.

merger

merger.git_user_email: Value to pass to git config user.email.

merger.git_user_name: Value to pass to git config user.name.

merger.prometheus_port: Set a TCP port to start the prometheus metrics client.

merger.prometheus_addr Default: 0.0.0.0: The IPv4 addr to listen for prometheus metrics poll. To use IPv6, python>3.8 is required issue24209.

ansible_callback "<name>""" title="Link to this definition">

To whitelist ansible callback <name>. Any attributes found is this section will be added to the callback_<name> section in ansible.cfg.

An example of what configuring the builtin mail callback would look like. The configuration in zuul.conf.

[ansible_callback "mail"]
to = user@example.org
sender = zuul@example.org

Would generate the following in ansible.cfg:

[defaults]
callback_whitelist = mail

[callback_mail]
to = user@example.org
sender = zuul@example.org

Web Server

The Zuul web server serves as the single process handling all HTTP interactions with Zuul. This includes the websocket interface for live log streaming, the REST API and the html/javascript dashboard. All three are served as a holistic web application. For information on additional supported deployment schemes, see Web Deployment.

Web servers need to be able to connect to the ZooKeeper cluster and the SQL database. If a GitHub, Gitlab, or Pagure connection is configured, they need to be reachable so they may receive notifications.

In addition to the common configuration sections, the following sections of zuul.conf are used by the web server:

web

web.command_socket Default: /var/lib/zuul/web.socket: Path to command socket file for the web process.

web.listen_address Default: 127.0.0.1: IP address or domain name on which to listen.

web.log_config: Path to log config file for the web server process.

web.pidfile Default: /var/run/zuul/web.pid: Path to PID lock file for the web server process.

web.port Default: 9000: Port to use for web server process.

web.websocket_url: Base URL on which the websocket service is exposed, if different than the base URL of the web app.

web.stats_url: Base URL from which statistics emitted via statsd can be queried.

web.stats_type Default: graphite: Type of server hosting the statistics information. Currently only ‘graphite’ is supported by the dashboard.

web.static_path Default: zuul/web/static: Path containing the static web assets.

web.static_cache_expiry Default: 3600: The Cache-Control max-age response header value for static files served by the zuul-web. Set to 0 during development to disable Cache-Control.

web.zone

The zone in which zuul-web is deployed. This is only needed if there are executors with different zones in the environment and not all executors are directly addressable from zuul-web. The parameter specifies the zone where the executors are directly adressable. Live log streaming will go directly to the executors of the same zone and be routed to a finger gateway of the target zone if the zones are different.

In a mixed system (with zoned and unzoned executors) there may also be zoned and unzoned zuul-web services. Omit the zone parameter for any unzoned zuul-web servers.

If this is used the finger gateways should be configured accordingly.

keystore

keystore.password (required): Encryption password for private data stored in Zookeeper.

Authentication

A user can be granted access to protected REST API endpoints by providing a valid JWT (JSON Web Token) as a bearer token when querying the API endpoints.

JWTs are signed and therefore Zuul must be configured so that signatures can be verified. More information about the JWT standard can be found on the IETF’s RFC page.

This optional section of zuul.conf, if present, will activate the protected endpoints and configure JWT validation:

auth <authenticator name>

auth <authenticator name>.driver: The signing algorithm to use. Accepted values are HS256, RS256, RS256withJWKS or OpenIDConnect. See below for driver-specific configuration options.

auth <authenticator name>.allow_authz_override Default: false: Allow a JWT to override predefined access rules. See the section on JWT contents for more details on how to grant access to tenants with a JWT.

auth <authenticator name>.realm: The authentication realm.

auth <authenticator name>.default Default: false: If set to true, use this realm as the default authentication realm when handling HTTP authentication errors.

auth <authenticator name>.client_id: The expected value of the “aud” claim in the JWT. This is required for validation.

auth <authenticator name>.issuer_id: The expected value of the “iss” claim in the JWT. This is required for validation.

auth <authenticator name>.uid_claim Default: sub: The JWT claim that Zuul will use as a unique identifier for the bearer of a token. This is “sub” by default, as it is usually the purpose of this claim in a JWT. This identifier is used in audit logs.

auth <authenticator name>.max_validity_time: Optional value to ensure a JWT cannot be valid for more than this amount of time in seconds. This is useful if the Zuul operator has no control over the service issueing JWTs, and the tokens are too long-lived.

auth <authenticator name>.skew Default: 0: Optional integer value to compensate for skew between Zuul’s and the JWT emitter’s respective clocks. Use a negative value if Zuul’s clock is running behind.

This section can be repeated as needed with different authenticators, allowing access to privileged API actions from several JWT issuers.

Driver-specific attributes

HS256

This is a symmetrical encryption algorithm that only requires a shared secret between the JWT issuer and the JWT consumer (ie Zuul). This driver should be used in test deployments, or in deployments where JWTs may be issued manually to users.

Note

At least one HS256 authenticator should be configured in order to use admin commands with the Zuul command line interface.

secret: The shared secret used to sign JWTs and validate signatures.

RS256

This is an asymmetrical encryption algorithm that requires an RSA key pair. Only the public key is needed by Zuul for signature validation.

public_key: The path to the public key of the RSA key pair. It must be readable by Zuul.

private_key: Optional. The path to the private key of the RSA key pair. It must be readable by Zuul.

RS256withJWKS

Warning

This driver is deprecated, use OpenIDConnect instead.

Some Identity Providers use key sets (also known as JWKS), therefore the key to use when verifying the Authentication Token’s signatures cannot be known in advance; the key’s id is stored in the JWT’s header and the key must then be found in the remote key set. The key set is usually available at a specific URL that can be found in the “well-known” configuration of an OpenID Connect Identity Provider.

keys_url: The URL where the Identity Provider’s key set can be found. For example, for Google’s OAuth service: https://www.googleapis.com/oauth2/v3/certs

OpenIDConnect

Use a third-party Identity Provider implementing the OpenID Connect protocol. The issuer ID should be an URI, from which the “well-known” configuration URI of the Identity Provider can be inferred. This is intended to be used for authentication on Zuul’s web user interface.

scope Default: openid profile: The scope(s) to use when requesting access to a user’s details. This attribute can be multivalued (values must be separated by a space). Most OpenID Connect Identity Providers support the default scopes “openid profile”. A full list of supported scopes can be found in the well-known configuration of the Identity Provider under the key “scopes_supported”.

keys_url: Optional. The URL where the Identity Provider’s key set can be found. For example, for Google’s OAuth service: https://www.googleapis.com/oauth2/v3/certs The well-known configuration of the Identity Provider should provide this URL under the key “jwks_uri”, therefore this attribute is usually not necessary.

Some providers may not conform to the JWT specification and further configuration may be necessary. In these cases, the following additional values may be used:

authority Default: issuer_id: If the authority in the token response is not the same as the issuer_id in the request, it may be explicitly set here.

audience Default: client_id: If the audience in the token response is not the same as the issuer_id in the request, it may be explicitly set here.

load_user_info Default: true: If the web UI should skip accessing the “UserInfo” endpoint and instead rely only on the information returned in the token, set this to false.

Client

Zuul’s command line client may be configured to make calls to Zuul’s web server. The client will then look for a zuul.conf file with a webclient section to set up the connection over HTTP.

Note

At least one authenticator must be configured in Zuul for admin commands to be enabled in the client.

webclient

webclient.url: The root URL of Zuul’s web server.

webclient.verify_ssl Default: true: Enforce SSL verification when sending requests over to Zuul’s web server. This should only be disabled when working with test servers.

Finger Gateway

The Zuul finger gateway listens on the standard finger port (79) for finger requests specifying a build UUID for which it should stream log results. The gateway will determine which executor is currently running that build and query that executor for the log stream.

This is intended to be used with the standard finger command line client. For example:

finger UUID@zuul.example.com

The above would stream the logs for the build identified by UUID.

Finger gateway servers need to be able to connect to the ZooKeeper cluster, as well as the console streaming port on the executors (usually 7900).

Finger gateways are optional. They may be run for either or both of the following purposes:

Allowing end-users to connect to the finger port to stream logs.
Providing an accessible log streaming port for remote zoned executors which are otherwise inacessible.

In this case, log streaming requests from finger gateways or zuul-web will route to the executors via finger gateways in the same zone.

In addition to the common configuration sections, the following sections of zuul.conf are used by the finger gateway:

fingergw

fingergw.command_socket
Default: /var/lib/zuul/fingergw.socket

Path to command socket file for the executor process.

fingergw.listen_address
Default: all addresses

IP address or domain name on which to listen.

fingergw.log_config

Path to log config file for the finger gateway process.

fingergw.pidfile
Default: /var/run/zuul/fingergw.pid

Path to PID lock file for the finger gateway process.

fingergw.port
Default: 79

Port to use for the finger gateway. Note that since command line finger clients cannot usually specify the port, leaving this set to the default value is highly recommended.

fingergw.user

User ID for the zuul-fingergw process. In normal operation as a daemon, the finger gateway should be started as the root user, but if this option is set, it will drop privileges to this user during startup. It is recommended to set this option to an unprivileged user.

fingergw.hostname
Default: hostname of the server

When running finger gateways in a multi-zone configuration, the gateway needs to know its hostname under which it is reachable by zuul-web. Otherwise live console log streaming doesn’t work. In most cases This is automatically detected correctly. But when running in environments where it cannot determine its hostname correctly this can be overridden here.

fingergw.zone

The zone where the finger gateway is located. This is only needed for live log streaming if the zuul deployment is spread over multiple zones without the ability to directly connect to all executors from zuul-web. See executor.zone for further information.

In a mixed system (with zoned and unzoned executors) there may also be zoned and unzoned finger gateway services. Omit the zone parameter for any unzoned finger gateway servers.

If the Zuul installation spans an untrusted network (for example, if there are remote executor zones), it may be necessary to use TLS between the components that handle log streaming (zuul-executor, zuul-fingergw, and zuul-web). If so, set the following options.

Note that this section is also read by zuul-web in order to load a client certificate to use when connecting to a finger gateway which requires TLS, and it is also read by zuul-executor to load a server certificate for its console streaming port.

If any of these are present, all three certificate options must be provided.

fingergw.tls_cert

The path to the PEM encoded certificate file.

fingergw.tls_key

The path to the PEM encoded key file.

fingergw.tls_ca

The path to the PEM encoded CA certificate file.

fingergw.tls_verify_hostnames
Default: true

In the case of a private CA it may be both safe and convenient to disable hostname checks. However, if the certificates are issued by a public CA, hostname verification should be enabled.

fingergw.tls_client_only
Default: false

In order to provide a finger gateway which can reach remote finger gateways and executors which use TLS, but does not itself serve end-users via TLS (i.e., it runs within a protected network and users access it directly via the finger port), set this to true and the finger gateway will not listen on TLS, but will still use the supplied certificate to make remote TLS connections.

Connections

Most of Zuul’s configuration is contained in the git repositories upon which Zuul operates, however, some configuration outside of git repositories is still required to bootstrap the system. This includes information on connections between Zuul and other systems, as well as identifying the projects Zuul uses.

In order to interact with external systems, Zuul must have a connection to that system configured. Zuul includes a number of drivers, each of which implements the functionality necessary to connect to a system. Each connection in Zuul is associated with a driver.

To configure a connection in Zuul, select a unique name for the connection and add a section to zuul.conf with the form [connection NAME]. For example, a connection to a gerrit server may appear as:

[connection mygerritserver]
driver=gerrit
server=review.example.com

Zuul needs to use a single connection to look up information about changes hosted by a given system. When it looks up changes, it will do so using the first connection it finds that matches the server name it’s looking for. It’s generally best to use only a single connection for a given server, however, if you need more than one (for example, to satisfy unique reporting requirements) be sure to list the primary connection first as that is what Zuul will use to look up all changes for that server.