Job

A job is a unit of work performed by Zuul on an item enqueued into a pipeline. Items may run any number of jobs (which may depend on each other). Each job is an invocation of an Ansible playbook with a specific inventory of hosts. The actual tasks that are run by the job appear in the playbook for that job while the attributes that appear in the Zuul configuration specify information about when, where, and how the job should be run.

Jobs in Zuul support inheritance. Any job may specify a single parent job, and any attributes not set on the child job are collected from the parent job. In this way, a configuration structure may be built starting with very basic jobs which describe characteristics that all jobs on the system should have, progressing through stages of specialization before arriving at a particular job. A job may inherit from any other job in any project (however, if the other job is marked as job.final, jobs may not inherit from it). Generally, attributes on child jobs will override (or completely replace) attributes on the parent, however some attributes are combined. See the documentation for individual attributes for these exceptions.

A job with no parent is called a base job and may only be defined in a config-project. Every other job must have a parent, and so ultimately, all jobs must have an inheritance path which terminates at a base job. Each tenant has a default parent job which will be used if no explicit parent is specified.

Multiple job definitions with the same name are called variants. These may have different selection criteria which indicate to Zuul that, for instance, the job should behave differently on a different git branch. Unlike inheritance, all job variants must be defined in the same project. Some attributes of jobs marked job.final may not be overridden.

When Zuul decides to run a job, it performs a process known as freezing the job. Because any number of job variants may be applicable, Zuul collects all of the matching variants and applies them in the order they appeared in the configuration. The resulting frozen job is built from attributes gathered from all of the matching variants. In this way, exactly what is run is dependent on the pipeline, project, branch, and content of the item.

In addition to the job’s main playbook, each job may specify one or more pre- and post-playbooks. These are run, in order, before and after (respectively) the main playbook. They may be used to set up and tear down resources needed by the main playbook. When combined with inheritance, they provide powerful tools for job construction. A job only has a single main playbook, and when inheriting from a parent, the child’s main playbook overrides (or replaces) the parent’s. However, the pre- and post-playbooks are appended and prepended in a nesting fashion. So if a parent job and child job both specified pre and post playbooks, the sequence of playbooks run would be:

• parent pre-run playbook

• child pre-run playbook

• child playbook

• child post-run playbook

• parent post-run playbook

• parent cleanup-run playbook

Further inheritance would nest even deeper.

Here is an example of two job definitions:

- job:
    name: base
    pre-run: copy-git-repos
    post-run: copy-logs

- job:
    name: run-tests
    parent: base
    nodeset:
      nodes:
        - name: test-node
          label: fedora

job

The following attributes are available on a job; all are optional unless otherwise specified:

job.name (required)

The name of the job. By default, Zuul looks for a playbook with this name to use as the main playbook for the job. This name is also referenced later in a project pipeline configuration.

job.parent
Default: Tenant default-parent

Specifies a job to inherit from. The parent job can be defined in this or any other project. Any attributes not specified on a job will be collected from its parent. If no value is supplied here, the job specified by tenant.default-parent will be used. If parent is set to null (which is only valid in a config-project), this is a base job.

job.description

A textual description of the job. Not currently used directly by Zuul, but it is used by the zuul-sphinx extension to Sphinx to auto-document Zuul jobs (in which case it is interpreted as ReStructuredText.

job.final
Default: false

To prevent other jobs from inheriting from this job, and also to prevent changing execution-related attributes when this job is specified in a project’s pipeline, set this attribute to true.

Warning

It is possible to circumvent the use of final in an untrusted-project by creating a change which Depends-On a change which alters final. This limitation does not apply to jobs in a config-project.

job.protected
Default: false

When set to true only jobs defined in the same project may inherit from this job. This includes changing execution-related attributes when this job is specified in a project’s pipeline. Once this is set to true it cannot be reset to false.

Warning

It is possible to circumvent the use of protected in an untrusted-project by creating a change which Depends-On a change which alters protected. This limitation does not apply to jobs in a config-project.

job.abstract
Default: false

To indicate a job is not intended to be run directly, but instead must be inherited from, set this attribute to true.

Once this is set to true in a job it cannot be reset to false within the same job by other variants; however jobs which inherit from it can (and by default do) reset it to false.

Warning

It is possible to circumvent the use of abstract in an untrusted-project by creating a change which Depends-On a change which alters abstract. This limitation does not apply to jobs in a config-project.

job.intermediate
Default: false

An intermediate job must be inherited by an abstract job; it can not be inherited by a final job. All intermediate jobs must also be abstract; a configuration error will be raised if not.

Once this is set to true in a job it cannot be reset to false within the same job by other variants; however jobs which inherit from it can (and by default do) reset it to false.

For example, you may define a base abstract job foo and create two abstract jobs that inherit from foo called foo-production and foo-development. If it would be an error to accidentally inherit from the base job foo instead of choosing one of the two variants, foo could be marked as intermediate.

job.success-message
Default: SUCCESS

Normally when a job succeeds, the string SUCCESS is reported as the result for the job. If set, this option may be used to supply a different string.

job.failure-message
Default: FAILURE

Normally when a job fails, the string FAILURE is reported as the result for the job. If set, this option may be used to supply a different string.

job.hold-following-changes
Default: false

In a dependent pipeline, this option may be used to indicate that no jobs should start on any items which depend on the current item until this job has completed successfully. This may be used to conserve build resources, at the expense of inhibiting the parallelization which speeds the processing of items in a dependent pipeline.

job.voting
Default: true

Indicates whether the result of this job should be used in determining the overall result of the item.

job.semaphore

A deprecated alias of job.semaphores.

job.semaphores

The name of a Semaphore (or list of them) or Global Semaphore which should be acquired and released when the job begins and ends. If the semaphore is at maximum capacity, then Zuul will wait until it can be acquired before starting the job. The format is either a string, a dictionary, or a list of either of those in the case of multiple semaphores. If it’s a string it references a semaphore using the default value for job.semaphores.resources-first.

If multiple semaphores are requested, the job will not start until all have been acquired, and Zuul will wait until all are available before acquiring any.

When inheriting jobs or applying variants, the list of semaphores is extended (semaphores specified in a job definition are added to any supplied by their parents).

job.semaphores.name (required)

The name of the referenced semaphore

job.semaphores.resources-first
Default: False

By default a semaphore is acquired before the resources are requested. However in some cases the user may want to run cheap jobs as quickly as possible in a consecutive manner. In this case resources-first can be enabled to request the resources before locking the semaphore. This can lead to some amount of blocked resources while waiting for the semaphore so this should be used with caution.

job.tags

Metadata about this job. Tags are units of information attached to the job; they do not affect Zuul’s behavior, but they can be used within the job to characterize the job. For example, a job which tests a certain subsystem could be tagged with the name of that subsystem, and if the job’s results are reported into a database, then the results of all jobs affecting that subsystem could be queried. This attribute is specified as a list of strings, and when inheriting jobs or applying variants, tags accumulate in a set, so the result is always a set of all the tags from all the jobs and variants used in constructing the frozen job, with no duplication.

job.provides

A list of free-form strings which identifies resources provided by this job which may be used by other jobs for other changes using the job.requires attribute.

When inheriting jobs or applying variants, the list of provides is extended (provides specified in a job definition are added to any supplied by their parents).

job.requires

A list of free-form strings which identify resources which may be provided by other jobs for other changes (via the job.provides attribute) that are used by this job.

When Zuul encounters a job with a requires attribute, it searches for those values in the provides attributes of any jobs associated with any queue items ahead of the current change. In this way, if a change uses either git dependencies or a Depends-On header to indicate a dependency on another change, Zuul will be able to determine that the parent change affects the run-time environment of the child change. If such a relationship is found, the job with requires will not start until all of the jobs with matching provides have completed or paused. Additionally, the artifacts returned by the provides jobs will be made available to the requires job.

When inheriting jobs or applying variants, the list of requires is extended (requires specified in a job definition are added to any supplied by their parents).

For example, a job which produces a builder container image in one project that is then consumed by a container image build job in another project might look like this:

- job:
    name: build-builder-image
    provides: images

- job:
    name: build-final-image
    requires: images

- project:
    name: builder-project
    check:
      jobs:
        - build-builder-image

- project:
    name: final-project
    check:
      jobs:
        - build-final-image

job.secrets

A list of secrets which may be used by the job. A Secret is a named collection of private information defined separately in the configuration. The secrets that appear here must be defined in the same project as this job definition.

Each item in the list may may be supplied either as a string, in which case it references the name of a Secret definition, or as a dict. If an element in this list is given as a dict, it may have the following fields:

job.secrets.name (required)

The name to use for the Ansible variable into which the secret content will be placed.

job.secrets.secret (required)

The name to use to find the secret’s definition in the configuration.

job.secrets.pass-to-parent
Default: false

A boolean indicating that this secret should be made available to playbooks in parent jobs. Use caution when setting this value – parent jobs may be in different projects with different security standards. Setting this to true makes the secret available to those playbooks and therefore subject to intentional or accidental exposure.

For example:

- secret:
    name: important-secret
    data:
      key: encrypted-secret-key-data

- job:
    name: amazing-job
    secrets:
      - name: ssh_key
        secret: important-secret

will result in the following being passed as a variable to the playbooks in amazing-job:

ssh_key:
  key: decrypted-secret-key-data

job.nodeset

The nodes which should be supplied to the job. This parameter may be supplied either as a string, in which case it references a Nodeset definition which appears elsewhere in the configuration, or a dictionary, in which case it is interpreted in the same way as a Nodeset definition, though the top-level nodeset name attribute should be omitted (in essence, it is an anonymous Nodeset definition unique to this job; the nodes themselves still require names). See the Nodeset reference for the syntax to use in that case.

If a job has an empty (or no) Nodeset definition, it will still run and is able to perform limited actions within the Zuul executor sandbox. Note so-called “executor-only” jobs run with an empty inventory, and hence Ansible’s implicit localhost. This means an executor-only playbook must be written to match localhost directly; i.e.

- hosts: localhost
  tasks:
   ...

not with hosts: all (as this does not match the implicit localhost and the playbook will not run). There are also caveats around things like enumerating the magic variable hostvars in this situation. For more information see the Ansible implicit localhost documentation.

A useful example of executor-only jobs is saving resources by directly utilising the prior results from testing a committed change. For example, a review which updates documentation source files would generally test validity by building a documentation tree. When this change is committed, the pre-built output can be copied in an executor-only job directly to the publishing location in a post-commit promote pipeline; avoiding having to use a node to rebuild the documentation for final publishing.

job.override-checkout

When Zuul runs jobs for a proposed change, it normally checks out the branch associated with that change on every project present in the job. If jobs are running on a ref (such as a branch tip or tag), then that ref is normally checked out. This attribute is used to override that behavior and indicate that this job should, regardless of the branch for the queue item, use the indicated ref (i.e., branch or tag) instead. This can be used, for example, to run a previous version of the software (from a stable maintenance branch) under test even if the change being tested applies to a different branch (this is only likely to be useful if there is some cross-branch interaction with some component of the system being tested). See also the project-specific job.required-projects.override-checkout attribute to apply this behavior to a subset of a job’s projects.

This value is also used to help select which variants of a job to run. If override-checkout is set, then Zuul will use this value instead of the branch of the item being tested when collecting jobs to run.

job.timeout

The time in seconds that the job should be allowed to run before it is automatically aborted and failure is reported. If no timeout is supplied, the job may run indefinitely. Supplying a timeout is highly recommended.

This timeout only applies to the pre-run and run playbooks in a job.

job.post-timeout

The time in seconds that each post playbook should be allowed to run before it is automatically aborted and failure is reported. If no post-timeout is supplied, the job may run indefinitely. Supplying a post-timeout is highly recommended.

The post-timeout is handled separately from the above timeout because the post playbooks are typically where you will copy jobs logs. In the event of the pre-run or run playbooks timing out we want to do our best to copy the job logs in the post-run playbooks.

job.attempts
Default: 3

When Zuul encounters an error running a job’s pre-run playbook, Zuul will stop and restart the job. Errors during the main or post-run -playbook phase of a job are not affected by this parameter (they are reported immediately). This parameter controls the number of attempts to make before an error is reported.

job.pre-run

The name of a playbook or list of playbooks to run before the main body of a job. The full path to the playbook in the repo where the job is defined is expected.

When a job inherits from a parent, the child’s pre-run playbooks are run after the parent’s. See Job for more information.

job.post-run

The name of a playbook or list of playbooks to run after the main body of a job. The full path to the playbook in the repo where the job is defined is expected.

When a job inherits from a parent, the child’s post-run playbooks are run before the parent’s. See Job for more information.

job.cleanup-run

The name of a playbook or list of playbooks to run after a job execution. The full path to the playbook in the repo where the job is defined is expected.

The cleanup phase is performed unconditionally of the job’s result, even when the job is canceled. Cleanup results are not taken into account.

When a job inherits from a parent, the child’s cleanup-run playbooks are run before the parent’s. See Job for more information.

job.run

The name of a playbook or list of playbooks for this job. If it is not supplied, the parent’s playbook will be used (and likewise up the inheritance chain). The full path within the repo is required. Example:

run: playbooks/job-playbook.yaml

job.ansible-version

The ansible version to use for all playbooks of the job. This can be defined at the following layers of configuration where the first match takes precedence:

• job.ansible-version

• tenant.default-ansible-version

• scheduler.default_ansible_version

• Zuul default version

The supported ansible versions are:

5 (default)
6

job.roles

- job:
    name: myjob
    roles:
      - zuul: myorg/our-roles-project
      - zuul: myorg/ansible-role-foo
        name: foo

A list of Ansible roles to prepare for the job. Because a job runs an Ansible playbook, any roles which are used by the job must be prepared and installed by Zuul before the job begins. This value is a list of dictionaries, each of which indicates one of two types of roles: a Galaxy role, which is simply a role that is installed from Ansible Galaxy, or a Zuul role, which is a role provided by a project managed by Zuul. Zuul roles are able to benefit from speculative merging and cross-project dependencies when used by playbooks in untrusted projects. Roles are added to the Ansible role path in the order they appear on the job – roles earlier in the list will take precedence over those which follow.

This attribute is not overridden on inheritance or variance; instead roles are added with each new job or variant. In the case of job inheritance or variance, the roles used for each of the playbooks run by the job will be only those which were cumulatively defined up to that point in the inheritance hierarchy where that playbook was added. If a child job inherits from a parent which defines a pre and post playbook, then the pre and post playbooks it inherits from the parent job will run only with the roles that were defined on the parent. If the child adds its own pre and post playbooks, then any roles added by the child will be available to the child’s playbooks. This is so that a job which inherits from a parent does not inadvertently alter the behavior of the parent’s playbooks by the addition of conflicting roles. Roles added by a child will appear before those it inherits from its parent.

If a project used for a Zuul role has branches, the usual process of selecting which branch should be checked out applies. See job.override-checkout for a description of that process and how to override it. As a special case, if the role project is the project in which this job definition appears, then the branch in which this definition appears will be used. In other words, a playbook may not use a role from a different branch of the same project.

If the job is run on a ref (for example, a branch tip or a tag) then a different form of the branch selection process is used. There is no single branch context available for selecting an appropriate branch of the role’s repo to check out, so only the following are considered: First the ref specified by job.required-projects.override-checkout, or job.override-checkout. Then if the role repo is the playbook repo, that branch is used; otherwise the project’s default branch is selected.

Warning

Keep this behavior difference in mind when designing jobs that run on both branches and tags. If the same job must be used in both circumstances, ensure that any roles from other repos used by playbooks in the job originate only in un-branched repositories. Otherwise different branches of the role repo may be checked out.

A project which supplies a role may be structured in one of two configurations: a bare role (in which the role exists at the root of the project), or a contained role (in which the role exists within the roles/ directory of the project, perhaps along with other roles). In the case of a contained role, the roles/ directory of the project is added to the role search path. In the case of a bare role, the project itself is added to the role search path. In case the name of the project is not the name under which the role should be installed (and therefore referenced from Ansible), the name attribute may be used to specify an alternate.

A job automatically has the project in which it is defined added to the roles path if that project appears to contain a role or roles/ directory. By default, the project is added to the path under its own name, however, that may be changed by explicitly listing the project in the roles list in the usual way.

job.roles.galaxy

Warning

Galaxy roles are not yet implemented.

The name of the role in Ansible Galaxy. If this attribute is supplied, Zuul will search Ansible Galaxy for a role by this name and install it. Mutually exclusive with zuul; either galaxy or zuul must be supplied.

job.roles.zuul

The name of a Zuul project which supplies the role. Mutually exclusive with galaxy; either galaxy or zuul must be supplied.

job.roles.name

The installation name of the role. In the case of a bare role, the role will be made available under this name. Ignored in the case of a contained role.

job.required-projects

A list of other projects which are used by this job. Any Zuul projects specified here will also be checked out by Zuul into the working directory for the job. Speculative merging and cross-repo dependencies will be honored. If there is not a change for the project ahead in the pipeline, its repo state as of the time the item was enqueued will be frozen and used for all jobs for a given change (see Global Repo State).

This attribute is not overridden by inheritance; instead it is the union of all applicable parents and variants (i.e., jobs can expand but not reduce the set of required projects when they inherit).

The format for this attribute is either a list of strings or dictionaries. Strings are interpreted as project names, dictionaries, if used, may have the following attributes:

job.required-projects.name (required)

The name of the required project.

job.required-projects.override-checkout

When Zuul runs jobs for a proposed change, it normally checks out the branch associated with that change on every project present in the job. If jobs are running on a ref (such as a branch tip or tag), then that ref is normally checked out. This attribute is used to override that behavior and indicate that this job should, regardless of the branch for the queue item, use the indicated ref (i.e., branch or tag) instead, for only this project. See also the job.override-checkout attribute to apply the same behavior to all projects in a job.

This value is also used to help select which variants of a job to run. If override-checkout is set, then Zuul will use this value instead of the branch of the item being tested when collecting any jobs to run which are defined in this project.

job.vars

A dictionary of variables to supply to Ansible. When inheriting from a job (or creating a variant of a job) vars are merged with previous definitions. This means a variable definition with the same name will override a previously defined variable, but new variable names will be added to the set of defined variables.

When running a trusted playbook, the value of variables will be frozen at the start of the job. Therefore if the value of the variable is an Ansible Jinja template, it may only reference values which are known at the start of the job, and its value will not change. Untrusted playbooks dynamically evaluate variables and are not limited by this restriction.

Un-frozen versions of all the original job variables are available tagged with the !unsafe YAML tag under the unsafe_vars variable hierarchy. This tag prevents Ansible from evaluating them as Jinja templates. For example, the job variable myvar would be available under unsafe_vars.myvar. Advanced users may force Ansible to evaluate these values, but it is not recommended to do so except in the most controlled of circumstances. They are almost impossible to render safely.

job.extra-vars

A dictionary of variables to supply to Ansible with higher precedence than job, host, or group vars.

job.host-vars

A dictionary of host variables to supply to Ansible. The keys of this dictionary are node names as defined in a Nodeset, and the values are dictionaries of variables, just as in job.vars.

job.group-vars

A dictionary of group variables to supply to Ansible. The keys of this dictionary are node groups as defined in a Nodeset, and the values are dictionaries of variables, just as in job.vars.

An example of three kinds of variables:

- job:
    name: variable-example
    nodeset:
      nodes:
        - name: controller
          label: fedora-27
        - name: api1
          label: centos-7
        - name: api2
          label: centos-7
      groups:
        - name: api
          nodes:
            - api1
            - api2
   vars:
     foo: "this variable is visible to all nodes"
   host-vars:
     controller:
       bar: "this variable is visible only on the controller node"
   group-vars:
     api:
       baz: "this variable is visible on api1 and api2"

job.dependencies

A list of other jobs upon which this job depends. Zuul will not start executing this job until all of its dependencies have completed successfully, and if one or more of them fail, this job will not be run.

The format for this attribute is either a list of strings or dictionaries. Strings are interpreted as job names, dictionaries, if used, may have the following attributes:

job.dependencies.name (required)

The name of the required job.

job.dependencies.soft
Default: false

A boolean value which indicates whether this job is a hard or soft dependency. A hard dependency will cause an error if the specified job is not run. That is, if job B depends on job A, but job A is not run for any reason (for example, it contains a file matcher which does not match), then Zuul will not run any jobs and report an error. A soft dependency will simply be ignored if the dependent job is not run.

job.allowed-projects

A list of Zuul projects which may use this job. By default, a job may be used by any other project known to Zuul, however, some jobs use resources or perform actions which are not appropriate for other projects. In these cases, a list of projects which are allowed to use this job may be supplied. If this list is not empty, then it must be an exhaustive list of all projects permitted to use the job. The current project (where the job is defined) is not automatically included, so if it should be able to run this job, then it must be explicitly listed. This setting is ignored by config projects – they may add any job to any project’s pipelines. By default, all projects may use the job.

If a job.secrets is used in a job definition in an untrusted-project, allowed-projects is automatically set to the current project only, and can not be overridden. However, a config-project may still add such a job to any project’s pipeline. Apply caution when doing so as other projects may be able to expose the source project’s secrets.

This attribute is not overridden by inheritance; instead it is the intersection of all applicable parents and variants (i.e., jobs can reduce but not expand the set of allowed projects when they inherit).

Warning

It is possible to circumvent the use of allowed-projects in an untrusted-project by creating a change which Depends-On a change which alters allowed-projects. This limitation does not apply to jobs in a config-project, or jobs in an untrusted-project which use a secret.

job.post-review
Default: false

A boolean value which indicates whether this job may only be used in pipelines where pipeline.post-review is true. This is automatically set to true if this job uses a Secret and is defined in a untrusted-project. It may be explicitly set to obtain the same behavior for jobs defined in config projects. Once this is set to true anywhere in the inheritance hierarchy for a job, it will remain set for all child jobs and variants (it can not be set to false).

Warning

It is possible to circumvent the use of post-review in an untrusted-project by creating a change which Depends-On a change which alters post-review. This limitation does not apply to jobs in a config-project, or jobs in an untrusted-project which use a secret.

job.branches

A regular expression (or list of regular expressions) which describe on what branches a job should run (or in the case of variants, to alter the behavior of a job for a certain branch).

This attribute is not inherited in the usual manner. Instead, it is used to determine whether each variant on which it appears will be used when running the job.

If none of the defined job variants contain a branches setting which matches the branch of an item, then that job is not run for the item. Otherwise, all of the job variants which match that branch are used when freezing the job. However, if job.override-checkout or job.required-projects.override-checkout are set for a project, Zuul will attempt to use the job variants which match the values supplied in override-checkout for jobs defined in those projects. This can be used to run a job defined in one project on another project without a matching branch.

If a tag item is enqueued, we look up the branches which contain the commit referenced by the tag. If any of those branches match a branch matcher, the matcher is considered to have matched.

Additionally in the case of a tag item, if the expression matches the full name of the ref (eg, refs/tags/foo) then the job is considered to match. The preceding section still applies, so the definition must appear in a branch containing the commit referenced by the tag to be considered, and then the expression must also match the tag.

This example illustrates a job called run-tests which uses a nodeset based on the current release of an operating system to perform its tests, except when testing changes to the stable/2.0 branch, in which case it uses an older release:

- job:
    name: run-tests
    nodeset: current-release

- job:
    name: run-tests
    branches: stable/2.0
    nodeset: old-release

In some cases, Zuul uses an implied value for the branch specifier if none is supplied:

• For a job definition in a config-project, no implied branch specifier is used. If no branch specifier appears, the job applies to all branches.

• In the case of an untrusted-project, if the project has only one branch, no implied branch specifier is applied to Job definitions. If the project has more than one branch, the branch containing the job definition is used as an implied branch specifier.

This allows for the very simple and expected workflow where if a project defines a job on the master branch with no branch specifier, and then creates a new branch based on master, any changes to that job definition within the new branch only affect that branch, and likewise, changes to the master branch only affect it.

See pragma.implied-branch-matchers for how to override this behavior on a per-file basis.

job.files

This indicates that the job should only run on changes where the specified files are modified. Unlike branches, this value is subject to inheritance and overriding, so only the final value is used to determine if the job should run. This is a regular expression or list of regular expressions.

job.irrelevant-files

This is a negative complement of files. It indicates that the job should run unless all of the files changed match this list. In other words, if the regular expression docs/.* is supplied, then this job will not run if the only files changed are in the docs directory. A regular expression or list of regular expressions.

job.match-on-config-updates
Default: true

If this is set to true (the default), then the job’s file matchers are ignored if a change alters the job’s configuration. This means that changes to jobs with file matchers will be self-testing without requiring that the file matchers include the Zuul configuration file defining the job.

job.deduplicate
Default: auto

In the case of a dependency cycle where multiple changes within the cycle run the same job, this setting indicates whether Zuul should attempt to deduplicate the job. If it is deduplicated, then the job will only run for one queue item within the cycle and other items which run the same job will use the results of that build.

This setting determins whether Zuul will consider deduplication. If it is set to false, Zuul will never attempt to deduplicate the job. If it is set to auto (the default), then Zuul will compare the job with other jobs of other queue items in the dependency cycle, and if they are equivalent and meet certain project criteria, it will deduplicate them.

The project criteria that Zuul considers under the auto setting are either:

• The job must specify job.required-projects.

• Or the queue items must be for the same project.

This is because of the following heuristic: if a job specifies job.required-projects, it is most likely to be one which operates in the same way regardless of which project the change under test belongs to, therefore the result of the same job running on two queue items in the same dependency cycle should be the same. If a job does not specify job.required-projects and runs with two different projects under test, the outcome is likely different for those two items.

If this is not true for a job (e.g., the job ignores the project under test and interacts only with external resources) job.deduplicate may be set to true to ignore the heuristic and deduplicate anyway.

job.workspace-scheme
Default: golang

The scheme to use when placing git repositories in the workspace.

golang

This writes the repository into a directory based on the canonical hostname and the full name of the repository. For example:

src/example.com/organization/project

This is the default and, despite the name, is suitable and recommended for any language.

flat

This writes the repository into a directory based only on the last component of the name. For example:

src/project

In some cases the golang scheme can produce collisions (consider the projects component and component/subcomponent). In this case it may be preferable to use the flat scheme (which would produce repositories at component and subcomponent).

Note, however, that this scheme may produce collisions with component and component/component.

unique

This writes the repository into a directory based on the organization name and the urllib.parse.quote_plus formatted project name. For example:

src/example.com/organization/organization%2Fproject

This scheme will produce unique workspace paths for every repository and won’t cause collisions.