2.5.7. Builder Configuration¶
The builders
configuration key is a list of objects giving configuration for the Builders.
For more information on the function of Builders in Buildbot, see the Concepts chapter.
The class definition for the builder configuration is in buildbot.config
.
However there is a much simpler way to use it, so in the configuration file, its use looks like:
from buildbot.plugins import util
c['builders'] = [
util.BuilderConfig(name='quick', workernames=['bot1', 'bot2'], factory=f_quick),
util.BuilderConfig(name='thorough', workername='bot1', factory=f_thorough),
]
BuilderConfig
takes the following keyword arguments:
name
- This specifies the Builder’s name, which is used in status reports.
workername
workernames
- These arguments specify the worker or workers that will be used by this Builder.
All workers names must appear in the
workers
configuration parameter. Each worker can accommodate multiple builders. Theworkernames
parameter can be a list of names, whileworkername
can specify only one worker. factory
- This is a
buildbot.process.factory.BuildFactory
instance which controls how the build is performed by defining the steps in the build. Full details appear in their own section, Build Factories.
Other optional keys may be set on each BuilderConfig
:
builddir
- Specifies the name of a subdirectory of the master’s basedir in which everything related to this builder will be stored. This holds build status information. If not set, this parameter defaults to the builder name, with some characters escaped. Each builder must have a unique build directory.
workerbuilddir
- Specifies the name of a subdirectory (under the worker’s configured base directory) in which everything related to this builder will be placed on the worker.
This is where checkouts, compiles, and tests are run.
If not set, defaults to
builddir
. If a worker is connected to multiple builders that share the sameworkerbuilddir
, make sure the worker is set to run one build at a time or ensure this is fine to run multiple builds from the same directory simultaneously. tags
- If provided, this is a list of strings that identifies tags for the builder.
Status clients can limit themselves to a subset of the available tags.
A common use for this is to add new builders to your setup (for a new module, or for a new worker) that do not work correctly yet and allow you to integrate them with the active builders.
You can tag these new builders with a
test
tag, make your main status clients ignore them, and have only private status clients pick them up. As soon as they work, you can move them over to the active tag. nextWorker
- If provided, this is a function that controls which worker will be assigned future jobs.
The function is passed three arguments, the
Builder
object which is assigning a new job, a list ofWorkerForBuilder
objects and theBuildRequest
. The function should return one of theWorkerForBuilder
objects, orNone
if none of the available workers should be used. As an example, for eachworker
in the list,worker.worker
will be aWorker
object, andworker.worker.workername
is the worker’s name. The function can optionally return a Deferred, which should fire with the same results. nextBuild
- If provided, this is a function that controls which build request will be handled next.
The function is passed two arguments, the
Builder
object which is assigning a new job, and a list ofBuildRequest
objects of pending builds. The function should return one of theBuildRequest
objects, orNone
if none of the pending builds should be started. This function can optionally return a Deferred which should fire with the same results. canStartBuild
If provided, this is a function that can veto whether a particular worker should be used for a given build request. The function is passed three arguments: the
Builder
, aWorker
, and aBuildRequest
. The function should returnTrue
if the combination is acceptable, orFalse
otherwise. This function can optionally return a Deferred which should fire with the same results.See canStartBuild Functions for a concrete example.
locks
- A list of
Locks
(instances ofbuildbot.locks.WorkerLock
orbuildbot.locks.MasterLock
) that should be acquired before starting aBuild
from thisBuilder
. Alternatively this could be a renderable that returns this list depending on properties of related to a build that is just about to be created. This lets you defer picking the locks to acquire until it is known whichWorker
a build would get assigned to. The properties available to the renderable include all properties that are set to the build before its first step excluding the properties that come from the build itself and thebuilddir
property that comes from worker. TheLocks
will be released when the build is complete. Note that this is a list of actualLock
instances, not names. Also note that all Locks must have unique names. See Interlocks. env
A Builder may be given a dictionary of environment variables in this parameter. The variables are used in
ShellCommand
steps in builds created by this builder. The environment variables will override anything in the worker’s environment. Variables passed directly to aShellCommand
will override variables of the same name passed to the Builder.For example, if you have a pool of identical workers it is often easier to manage variables like
PATH
from Buildbot rather than manually editing it inside of the workers’ environment.f = factory.BuildFactory f.addStep(ShellCommand( command=['bash', './configure'])) f.addStep(Compile()) c['builders'] = [ BuilderConfig(name='test', factory=f, workernames=['worker1', 'worker2', 'worker3', 'worker4'], env={'PATH': '/opt/local/bin:/opt/app/bin:/usr/local/bin:/usr/bin'}), ]
Unlike most builder configuration arguments, this argument can contain renderables.
collapseRequests
- Specifies how build requests for this builder should be collapsed. See Collapsing Build Requests, below.
properties
- A builder may be given a dictionary of Build Properties specific for this builder in this parameter. Those values can be used later on like other properties. Interpolate.
defaultProperties
- Similar to the
properties
parameter. ButdefaultProperties
will only be added to Build Properties if they are not already set by another source. description
- A builder may be given an arbitrary description, which will show up in the web status on the builder’s page.
2.5.7.1. Collapsing Build Requests¶
When more than one build request is available for a builder, Buildbot can “collapse” the requests into a single build. This is desirable when build requests arrive more quickly than the available workers can satisfy them, but has the drawback that separate results for each build are not available.
Requests are only candidated for a merge if both requests have exactly the same codebases.
This behavior can be controlled globally, using the collapseRequests
parameter, and on a per-Builder
basis, using the collapseRequests
argument to the Builder
configuration.
If collapseRequests
is given, it completely overrides the global configuration.
Possible values for both collapseRequests
configurations are:
True
- Requests will be collapsed if their sourcestamp are compatible (see below for definition of compatible).
False
- Requests will never be collapsed.
callable(builder, req1, req2)
- Requests will be collapsed if the callable returns true. See Collapse Request Functions for detailed example.
Sourcestamps are compatible if all of the below conditions are met:
- Their codebase, branch, project, and repository attributes match exactly
- Neither source stamp has a patch (e.g., from a try scheduler)
- Either both source stamps are associated with changes, or neither are associated with changes but they have matching revisions.
2.5.7.2. Prioritizing Builds¶
The BuilderConfig
parameter nextBuild
can be use to prioritize build requests within a builder.
Note that this is orthogonal to Prioritizing Builders, which controls the order in which builders are called on to start their builds.
The details of writing such a function are in Build Priority Functions.
Such a function can be provided to the BuilderConfig as follows:
def pickNextBuild(builder, requests):
...
c['builders'] = [
BuilderConfig(name='test', factory=f,
nextBuild=pickNextBuild,
workernames=['worker1', 'worker2', 'worker3', 'worker4']),
]
2.5.7.3. Virtual Builders¶
Dynamic Trigger is a method which allows to trigger the same builder, with different parameters. This method is used by frameworks which store the build config along side the source code like Buildbot_travis. The drawback of this method is that it is difficult to extract statistics for similar builds. The standard dashboards are not working well due to the fact that all the builds are on the same builder.
In order to overcome those drawbacks, Buildbot has the concept of virtual builder.
If a build has the property virtual_builder_name
, it will automatically attach to that builder instead of the original builder.
That created virtual builder is not attached to any master and is only used for better sorting in the UI and better statistics.
The original builder and worker configuration is still used for all other build behaviors.
The virtual builder metadata is configured with the following properties:
virtual_builder_name
: The name of the virtual builder.virtual_builder_description
: The description of the virtual builder.virtual_builder_tags
: The tags for the virtual builder.