A generic worker for Taskcluster, written in Go.
For documentation of the worker from a user's perspective, see the online documentation.
$ generic-worker --help
generic-worker is a taskcluster worker that can run on any platform that supports go (golang).
See http://taskcluster.github.io/generic-worker/ for more details. Essentially, the worker is
the taskcluster component that executes tasks. It requests tasks from the taskcluster queue,
and reports back results to the queue.
Usage:
generic-worker run [--config CONFIG-FILE]
[--with-worker-runner]
[--worker-runner-protocol-pipe PIPE]
generic-worker show-payload-schema
generic-worker new-ed25519-keypair --file ED25519-PRIVATE-KEY-FILE
generic-worker --help
generic-worker --version
Targets:
run Runs the generic-worker. Pass --with-worker-runner if
running under that service, otherwise generic-worker will
not communicate with worker-runner.
show-payload-schema Each taskcluster task defines a payload to be
interpreted by the worker that executes it. This
payload is validated against a json schema baked
into the release. This option outputs the json
schema used in this version of the generic
worker.
new-ed25519-keypair This will generate a fresh, new ed25519
compliant private/public key pair. The public
key will be written to stdout and the private
key will be written to the specified file.
Options:
--config CONFIG-FILE Json configuration file to use. See
configuration section below to see what this
file should contain. When calling the install
target, this is the config file that the
installation should use, rather than the config
to use during install.
[default: generic-worker.config]
--worker-runner-protocol-pipe PIPE Use this option when running generic-worker under
worker-runner, passing the same value as given for
'worker.protocolPipe' in the runner configuration.
This specifies a named pipe that is used for
communication between the two processes.
--file PRIVATE-KEY-FILE The path to the file to write the private key
to. The parent directory must already exist.
If the file exists it will be overwritten,
otherwise it will be created.
--help Display this help text.
--version The release version of the generic-worker.
Configuring the generic worker:
The configuration file for the generic worker is specified with -c|--config CONFIG-FILE
as described above. Its format is a json dictionary of name/value pairs.
** REQUIRED ** properties
=========================
accessToken Taskcluster access token used by generic worker
to talk to taskcluster queue.
clientId Taskcluster client ID used by generic worker to
talk to taskcluster queue.
ed25519SigningKeyLocation The ed25519 signing key for signing artifacts with.
rootURL The root URL of the taskcluster deployment to which
clientId and accessToken grant access. For example,
'https://community-tc.services.mozilla.com/'.
workerId A name to uniquely identify your worker.
workerType This should match a worker_type managed by the
provisioner you have specified.
** OPTIONAL ** properties
=========================
availabilityZone The EC2 availability zone of the worker.
cachesDir The directory where task caches should be stored on
the worker. The directory will be created if it does
not exist. This may be a relative path to the
current directory, or an absolute path.
[default: "caches"]
certificate Taskcluster certificate, when using temporary
credentials only.
checkForNewDeploymentEverySecs The number of seconds between consecutive calls
to the provisioner, to check if there has been a
new deployment of the current worker type. If a
new deployment is discovered, worker will shut
down. See deploymentId property. [default: 1800]
cleanUpTaskDirs Whether to delete the home directories of the task
users after the task completes. Normally you would
want to do this to avoid filling up disk space,
but for one-off troubleshooting, it can be useful
to (temporarily) leave home directories in place.
Accepted values: true or false. [default: true]
deploymentId If running with --configure-for-aws, then between
tasks, at a chosen maximum frequency (see
checkForNewDeploymentEverySecs property), the
worker will query the provisioner to get the
updated worker type definition. If the deploymentId
in the config of the worker type definition is
different to the worker's current deploymentId, the
worker will shut itself down. See
https://bugzil.la/1298010
disableReboots If true, no system reboot will be initiated by
generic-worker program, but it will still return
with exit code 67 if the system needs rebooting.
This allows custom logic to be executed before
rebooting, by patching run-generic-worker.bat
script to check for exit code 67, perform steps
(such as formatting a hard drive) and then
rebooting in the run-generic-worker.bat script.
[default: false]
downloadsDir The directory to cache downloaded files for
populating preloaded caches and readonly mounts. The
directory will be created if it does not exist. This
may be a relative path to the current directory, or
an absolute path. [default: "downloads"]
idleTimeoutSecs How many seconds to wait without getting a new
task to perform, before the worker process exits.
An integer, >= 0. A value of 0 means "never reach
the idle state" - i.e. continue running
indefinitely. See also shutdownMachineOnIdle.
[default: 0]
instanceID The EC2 instance ID of the worker. Used by chain of trust.
instanceType The EC2 instance Type of the worker. Used by chain of trust.
livelogExecutable Filepath of LiveLog executable to use; see
https://github.com/taskcluster/livelog
[default: "livelog"]
livelogPortBase Set the base port number for livelog. Livelog requires two
ports: livelogPortBase & livelogPortBase + 1 are used.
[default: 60098]
numberOfTasksToRun If zero, run tasks indefinitely. Otherwise, after
this many tasks, exit. [default: 0]
privateIP The private IP of the worker, used by chain of trust.
provisionerId The taskcluster provisioner which is taking care
of provisioning environments with generic-worker
running on them. [default: "test-provisioner"]
publicIP The IP address for VNC access. Also used by chain of
trust when present.
region The EC2 region of the worker. Used by chain of trust.
requiredDiskSpaceMegabytes The garbage collector will ensure at least this
number of megabytes of disk space are available
when each task starts. If it cannot free enough
disk space, the worker will shut itself down.
[default: 10240]
runAfterUserCreation A string, that if non-empty, will be treated as a
command to be executed as the newly generated task
user, after the user has been created, the machine
has rebooted and the user has logged in, but before
a task is run as that user. This is a way to
provide generic user initialisation logic that
should apply to all generated users (and thus all
tasks) and be run as the task user itself. This
option does *not* support running a command as
Administrator. Furthermore, even if
runTasksAsCurrentUser is true, the script will still
be executed as the task user, rather than the
current user (that runs the generic-worker process).
runTasksAsCurrentUser If true, users will still be created for tasks, but
tasks will be executed as the current OS user. [default: false]
sentryProject The project name used in https://sentry.io for
reporting worker crashes. Permission to publish
crash reports is granted via the scope
auth:sentry:<sentryProject>. If the taskcluster
client (see clientId property above) does not
posses this scope, no crash reports will be sent.
Similarly, if this property is not specified or
is the empty string, no reports will be sent.
[default: "generic-worker"]
shutdownMachineOnIdle If true, when the worker is deemed to have been
idle for enough time (see idleTimeoutSecs) the
worker will issue an OS shutdown command. If false,
the worker process will simply terminate, but the
machine will not be shut down. [default: false]
shutdownMachineOnInternalError If true, if the worker encounters an unrecoverable
error (such as not being able to write to a
required file) it will shutdown the host
computer. Note this is generally only desired
for machines running in production, such as on AWS
EC2 spot instances. Use with caution!
[default: false]
taskclusterProxyExecutable Filepath of taskcluster-proxy executable to use; see
https://github.com/taskcluster/taskcluster/tree/main/tools/taskcluster-proxy
[default: "taskcluster-proxy"]
taskclusterProxyPort Port number for taskcluster-proxy HTTP requests.
[default: 80]
tasksDir The location where task directories should be
created on the worker.
[default varies by platform]
workerGroup Typically this would be an aws region - an
identifier to uniquely identify which pool of
workers this worker logically belongs to.
[default: "test-worker-group"]
workerLocation If a non-empty string, task commands will have environment variable
TASKCLUSTER_WORKER_LOCATION set to the value provided.
Otherwise TASKCLUSTER_WORKER_LOCATION environment
variable will not be implicitly set in task commands.
[default: ""]
workerTypeMetaData This arbitrary json blob will be included at the
top of each task log. Providing information here,
such as a URL to the code/config used to set up the
worker type will mean that people running tasks on
the worker type will have more information about how
it was set up (for example what has been installed on
the machine).
wstAudience The audience value for which to request websocktunnel
credentials, identifying a set of WST servers this
worker could connect to. Optional if not using websocktunnel
to expose live logs.
wstServerURL The URL of the websocktunnel server with which to expose
live logs. Optional if not using websocktunnel to expose
live logs.
If an optional config setting is not provided in the json configuration file, the
default will be taken (defaults documented above).
If no value can be determined for a required config setting, the generic-worker will
exit with a failure message.
Exit Codes:
0 Tasks completed successfully; no more tasks to run (see config setting
numberOfTasksToRun).
64 Not able to load generic-worker config. This could be a problem reading the
generic-worker config file on the filesystem, a problem talking to AWS/GCP
metadata service, or a problem retrieving config/files from the taskcluster
secrets service.
67 A task user has been created, and the generic-worker needs to reboot in order
to log on as the new task user. Note, the reboot happens automatically unless
config setting disableReboots is set to true - in either code this exit code will
be issued.
68 The generic-worker hit its idle timeout limit (see config settings idleTimeoutSecs
and shutdownMachineOnIdle).
69 Worker panic - either a worker bug, or the environment is not suitable for running
a task, e.g. a file cannot be written to the file system, or something else did
not work that was required in order to execute a task. See config setting
shutdownMachineOnInternalError.
70 A new deploymentId has been issued in the AWS worker type configuration, meaning
this worker environment is no longer up-to-date. Typcially workers should
terminate.
71 The worker was terminated via an interrupt signal (e.g. Ctrl-C pressed).
72 The worker is running on spot infrastructure in AWS EC2 and has been served a
spot termination notice, and therefore has shut down.
73 The config provided to the worker is invalid.
75 Not able to create an ed25519 key pair.
77 Not able to apply required file access permissions to the generic-worker config
file so that task users can't read from or write to it.
78 Not able to connect to --worker-runner-protocol-pipe.
Simply run:
generic-worker run --config <config file>
where <config file> is the generic worker config file you created above.
See the 
Set up to build Taskcluster in general. See development process.
- Run
go get github.com/taskcluster/livelogRungo get github.com/taskcluster/taskcluster/v30/tools/taskcluster-proxy
In the workers/generic-worker directory, run ./build.sh to check go version, generate code, build binaries, compile (but not run) tests, perform linting, and ensure there are no ineffective assignments in go code.
./build.sh takes optional arguments, -a to build all platforms, and -t to run tests. By default tests are not run and only the current platform is built.
All being well, the binaries will be built in the directory you executed the build.sh script from.
For this you need to have the source files (you cannot run the tests from the binary package).
Then cd into the source directory, and run:
./build.sh -t
Note that this will require sudo access on Linux, unless you set GW_TESTS_RUN_AS_CURRENT_USER (see below).
Most tests run without needing credentials, but some will skip or fail in that circumstance. To run all tests, you will need to provide Taskcluster credentials. To run the tests against the Community-TC deployment of Taskcluster, you will need the project:taskcluster:generic-worker-tester role. Consult a member of the Taskcluster team on the #taskcluster channel to get this set up.
There are a few environment variables that you can set to influence the tests:
Set to a non-empty string if you wish to skip all tests that require python to be installed.
Set to a non-empty string if you wish to skip all tests that require mozilla-build to be installed.
Only used in a single Windows-specific test - if you don't have a Z: drive setup on your computer, or you do but you also run tests from the Z: drive, you can set this env var to a non-empty string to skip this test.
This environment variable applies only to the multiuser engine.
If GW_TESTS_RUN_AS_CURRENT_USER is not set, generic-worker will be tested
running in its normal operational mode, i.e. running tasks as task users
(config setting runTasksAsCurrentUser will be false).
If GW_TESTS_RUN_AS_CURRENT_USER is a non-empty string, generic-worker will be
tested running tasks as the same user that runs go test (config setting
runTasksAsCurrentUser will be true). This is how the CI multiuser workers
are configured, in order that the generic-worker under test has the required
privileges to function correctly. Set this environment variable to ensure that
the generic-worker under test will function correctly as a generic-worker CI
worker.
Before version 25, this project was released from a dedicated GitHub repository. See the release history in that repository.
Please see:
Useful information on win32 APIs: