TaskRuns
- Overview
- Configuring a
TaskRun
- Specifying the target
Task
- Specifying
Parameters
- Specifying
Resource
limits - Specifying Task-level
ComputeResources
- Specifying a
Pod
template - Specifying
Workspaces
- Specifying
Sidecars
- Configuring
Task
Steps
andSidecars
in a TaskRun - Specifying
LimitRange
values - Specifying
Retries
- Configuring the failure timeout
- Specifying
ServiceAccount
credentials
- Specifying the target
TaskRun
status- Monitoring execution status
- Cancelling a
TaskRun
- Debugging a
TaskRun
- Events
- Running a TaskRun Hermetically
- Code examples
Overview
A TaskRun
allows you to instantiate and execute a Task
on-cluster. A Task
specifies one or more
Steps
that execute container images and each container image performs a specific piece of build work. A TaskRun
executes the
Steps
in the Task
in the order they are specified until all Steps
have executed successfully or a failure occurs.
Configuring a TaskRun
A TaskRun
definition supports the following fields:
- Required:
apiVersion
- Specifies the API version, for exampletekton.dev/v1beta1
.kind
- Identifies this resource object as aTaskRun
object.metadata
- Specifies the metadata that uniquely identifies theTaskRun
, such as aname
.spec
- Specifies the configuration for theTaskRun
.taskRef
ortaskSpec
- Specifies theTasks
that theTaskRun
will execute.
- Optional:
serviceAccountName
- Specifies aServiceAccount
object that provides custom credentials for executing theTaskRun
.params
- Specifies the desired execution parameters for theTask
.timeout
- Specifies the timeout before theTaskRun
fails.podTemplate
- Specifies aPod
template to use as the starting point for configuring thePods
for theTask
.workspaces
- Specifies the physical volumes to use for theWorkspaces
declared by aTask
.debug
- Specifies any breakpoints and debugging configuration for theTask
execution.stepOverrides
- Specifies configuration to use to override theTask
’sStep
s.sidecarOverrides
- Specifies configuration to use to override theTask
’sSidecar
s.
Specifying the target Task
To specify the Task
you want to execute in your TaskRun
, use the taskRef
field as shown below:
spec:
taskRef:
name: read-task
You can also embed the desired Task
definition directly in the TaskRun
using the taskSpec
field:
spec:
taskSpec:
workspaces:
- name: source
steps:
- name: build-and-push
image: gcr.io/kaniko-project/executor:v0.17.1
# specifying DOCKER_CONFIG is required to allow kaniko to detect docker credential
workingDir: $(workspaces.source.path)
env:
- name: "DOCKER_CONFIG"
value: "/tekton/home/.docker/"
command:
- /kaniko/executor
args:
- --destination=gcr.io/my-project/gohelloworld
Tekton Bundles
A Tekton Bundle
is an OCI artifact that contains Tekton resources like Tasks
which can be referenced within a taskRef
.
You can reference a Tekton bundle
in a TaskRef
in both v1
and v1beta1
using remote resolution. The example syntax shown below for v1
uses remote resolution and requires enabling beta features.
spec:
taskRef:
resolver: bundles
params:
- name: bundle
value: docker.io/myrepo/mycatalog
- name: name
value: echo-task
- name: kind
value: Task
You may also specify a tag
as you would with a Docker image which will give you a repeatable reference to a Task
.
spec:
taskRef:
resolver: bundles
params:
- name: bundle
value: docker.io/myrepo/mycatalog:v1.0.1
- name: name
value: echo-task
- name: kind
value: Task
You may also specify a fixed digest instead of a tag which ensures the referenced task is constant.
spec:
taskRef:
resolver: bundles
params:
- name: bundle
value: docker.io/myrepo/mycatalog@sha256:abc123
- name: name
value: echo-task
- name: kind
value: Task
A working example can be found here.
Any of the above options will fetch the image using the ImagePullSecrets
attached to the
ServiceAccount
specified in the TaskRun
. See the Service Account
section for details on how to configure a ServiceAccount
on a TaskRun
. The TaskRun
will then run that Task
without registering it in the cluster allowing multiple versions
of the same named Task
to be run at once.
Tekton Bundles
may be constructed with any toolsets that produces valid OCI image artifacts so long as
the artifact adheres to the contract. Additionally, you may also use the tkn
cli (coming soon).
Remote Tasks
A taskRef
field may specify a Task in a remote location such as git.
Support for specific types of remote will depend on the Resolvers your
cluster’s operator has installed. For more information including a tutorial, please check resolution docs. The below example demonstrates referencing a Task in git:
spec:
taskRef:
resolver: git
params:
- name: url
value: https://github.com/tektoncd/catalog.git
- name: revision
value: abc123
- name: pathInRepo
value: /task/golang-build/0.3/golang-build.yaml
Specifying Parameters
If a Task
has parameters
, you can use the params
field to specify their values:
spec:
params:
- name: flags
value: -someflag
Note: If a parameter does not have an implicit default value, you must explicitly set its value.
Propagated Parameters
When using an inlined taskSpec
, parameters from the parent TaskRun
will be
available to the Task
without needing to be explicitly defined.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
generateName: hello-
spec:
params:
- name: message
value: "hello world!"
taskSpec:
# There are no explicit params defined here.
# They are derived from the TaskRun params above.
steps:
- name: default
image: ubuntu
script: |
echo $(params.message)
On executing the task run, the parameters will be interpolated during resolution. The specifications are not mutated before storage and so it remains the same. The status is updated.
kind: TaskRun
metadata:
name: hello-dlqm9
...
spec:
params:
- name: message
value: hello world!
serviceAccountName: default
taskSpec:
steps:
- image: ubuntu
name: default
script: |
echo $(params.message)
status:
conditions:
- lastTransitionTime: "2022-05-20T15:24:41Z"
message: All Steps have completed executing
reason: Succeeded
status: "True"
type: Succeeded
...
steps:
- container: step-default
...
taskSpec:
steps:
- image: ubuntu
name: default
script: |
echo "hello world!"
Propagated Object Parameters
When using an inlined taskSpec
, object parameters from the parent TaskRun
will be
available to the Task
without needing to be explicitly defined.
Note: If an object parameter is being defined explicitly then you must define the spec of the object in Properties
.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
generateName: object-param-result-
spec:
params:
- name: gitrepo
value:
commit: sha123
url: xyz.com
taskSpec:
steps:
- name: echo-object-params
image: bash
args:
- echo
- --url=$(params.gitrepo.url)
- --commit=$(params.gitrepo.commit)
On executing the task run, the object parameters will be interpolated during resolution. The specifications are not mutated before storage and so it remains the same. The status is updated.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: object-param-result-vlnmb
...
spec:
params:
- name: gitrepo
value:
commit: sha123
url: xyz.com
serviceAccountName: default
taskSpec:
steps:
- args:
- echo
- --url=$(params.gitrepo.url)
- --commit=$(params.gitrepo.commit)
image: bash
name: echo-object-params
status:
completionTime: "2022-09-08T17:09:37Z"
conditions:
- lastTransitionTime: "2022-09-08T17:09:37Z"
message: All Steps have completed executing
reason: Succeeded
status: "True"
type: Succeeded
...
steps:
- container: step-echo-object-params
...
taskSpec:
steps:
- args:
- echo
- --url=xyz.com
- --commit=sha123
image: bash
name: echo-object-params
Extra Parameters
You can pass in extra Parameters
if needed depending on your use cases. An example use
case is when your CI system autogenerates TaskRuns
and it has Parameters
it wants to
provide to all TaskRuns
. Because you can pass in extra Parameters
, you don’t have to
go through the complexity of checking each Task
and providing only the required params.
Parameter Enums
🌱
enum
is an alpha feature. Theenable-param-enum
feature flag must be set to"true"
to enable this feature.
If a Parameter
is guarded by Enum
in the Task
, you can only provide Parameter
values in the TaskRun
that are predefined in the Param.Enum
in the Task
. The TaskRun
will fail with reason InvalidParamValue
otherwise.
You can also specify Enum
for TaskRun
with an embedded Task
. The same param validation will be executed in this scenario.
See more details in Param.Enum.
Specifying Resource
limits
Each Step in a Task can specify its resource requirements. See
Defining Steps
. Resource requirements defined in Steps and Sidecars
may be overridden by a TaskRun’s StepSpecs and SidecarSpecs.
Specifying Task-level ComputeResources
Task-level compute resources can be configured in TaskRun.ComputeResources
, or PipelineRun.TaskRunSpecs.ComputeResources
.
e.g.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: Task
metadata:
name: task
spec:
steps:
- name: foo
---
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: taskrun
spec:
taskRef:
name: task
computeResources:
requests:
cpu: 1
limits:
cpu: 2
Further details and examples could be found in Compute Resources in Tekton.
Specifying a Pod
template
You can specify a Pod
template configuration that will serve as the configuration starting
point for the Pod
in which the container images specified in your Task
will execute. This allows you to
customize the Pod
configuration specifically for that TaskRun
.
In the following example, the Task
specifies a volumeMount
(my-cache
) object, also provided by the TaskRun
,
using a PersistentVolumeClaim
volume. A specific scheduler is also configured in the SchedulerName
field.
The Pod
executes with regular (non-root) user permissions.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: Task
metadata:
name: mytask
namespace: default
spec:
steps:
- name: writesomething
image: ubuntu
command: ["bash", "-c"]
args: ["echo 'foo' > /my-cache/bar"]
volumeMounts:
- name: my-cache
mountPath: /my-cache
---
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: mytaskrun
namespace: default
spec:
taskRef:
name: mytask
podTemplate:
schedulerName: volcano
securityContext:
runAsNonRoot: true
runAsUser: 1001
volumes:
- name: my-cache
persistentVolumeClaim:
claimName: my-volume-claim
Specifying Workspaces
If a Task
specifies one or more Workspaces
, you must map those Workspaces
to
the corresponding physical volumes in your TaskRun
definition. For example, you
can map a PersistentVolumeClaim
volume to a Workspace
as follows:
workspaces:
- name: myworkspace # must match workspace name in the Task
persistentVolumeClaim:
claimName: mypvc # this PVC must already exist
subPath: my-subdir
For more information, see the following topics:
- For information on mapping
Workspaces
toVolumes
, see UsingWorkspace
variables inTaskRuns
. - For a list of supported
Volume
types, see SpecifyingVolumeSources
inWorkspaces
. - For an end-to-end example, see
Workspaces
in aTaskRun
.
Propagated Workspaces
When using an embedded spec, workspaces from the parent TaskRun
will be
propagated to any inlined specs without needing to be explicitly defined. This
allows authors to simplify specs by automatically propagating top-level
workspaces down to other inlined resources.
Workspace substutions will only be made for commands
, args
and script
fields of steps
, stepTemplates
, and sidecars
.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
generateName: propagating-workspaces-
spec:
taskSpec:
steps:
- name: simple-step
image: ubuntu
command:
- echo
args:
- $(workspaces.tr-workspace.path)
workspaces:
- emptyDir: {}
name: tr-workspace
Upon execution, the workspaces will be interpolated during resolution through to the taskSpec
.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: propagating-workspaces-ndxnc
...
spec:
...
status:
...
taskSpec:
steps:
...
workspaces:
- name: tr-workspace
Propagating Workspaces to Referenced Tasks
Workspaces can only be propagated to embedded
task specs, not referenced
Tasks.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: Task
metadata:
name: workspace-propagation
spec:
steps:
- name: simple-step
image: ubuntu
command:
- echo
args:
- $(workspaces.tr-workspace.path)
---
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
generateName: propagating-workspaces-
spec:
taskRef:
name: workspace-propagation
workspaces:
- emptyDir: {}
name: tr-workspace
Upon execution, the above TaskRun
will fail because the Task
is referenced and workspace is not propagated. It must be explicitly defined in the spec
of the defined Task
.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
...
spec:
taskRef:
kind: Task
name: workspace-propagation
workspaces:
- emptyDir: {}
name: tr-workspace
status:
conditions:
- lastTransitionTime: "2022-09-13T15:12:35Z"
message: workspace binding "tr-workspace" does not match any declared workspace
reason: TaskRunValidationFailed
status: "False"
type: Succeeded
...
Specifying Sidecars
A Sidecar
is a container that runs alongside the containers specified
in the Steps
of a task to provide auxiliary support to the execution of
those Steps
. For example, a Sidecar
can run a logging daemon, a service
that updates files on a shared volume, or a network proxy.
Tekton supports the injection of Sidecars
into a Pod
belonging to
a TaskRun
with the condition that each Sidecar
running inside the
Pod
are terminated as soon as all Steps
in the Task
complete execution.
This might result in the Pod
including each affected Sidecar
with a
retry count of 1 and a different container image than expected.
We are aware of the following issues affecting Tekton’s implementation of Sidecars
:
-
The configured
nop
image must not provide the command that theSidecar
is expected to run, otherwise it will not exit, resulting in theSidecar
running forever and the Task eventually timing out. For more information, see the associated issue. -
The
kubectl get pods
command returns the status of thePod
as “Completed” if aSidecar
exits successfully and as “Error” if aSidecar
exits with an error, disregarding the exit codes of the container images that actually executed theSteps
inside thePod
. Only the above command is affected. ThePod's
description correctly denotes a “Failed” status and the container statuses correctly denote their exit codes and reasons.
Configuring Task Steps and Sidecars in a TaskRun
A TaskRun can specify StepSpecs
or SidecarSpecs
to configure Step or Sidecar
specified in a Task. Only named Steps and Sidecars may be configured.
For example, given the following Task definition:
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: Task
metadata:
name: image-build-task
spec:
steps:
- name: build
image: gcr.io/kaniko-project/executor:latest
sidecars:
- name: logging
image: my-logging-image
An example TaskRun definition could look like:
apiVersion: tekton.dev/v1
kind: TaskRun
metadata:
name: image-build-taskrun
spec:
taskRef:
name: image-build-task
stepSpecs:
- name: build
computeResources:
requests:
memory: 1Gi
sidecarSpecs:
- name: logging
computeResources:
requests:
cpu: 100m
limits:
cpu: 500m
apiVersion: tekton.dev/v1beta1
kind: TaskRun
metadata:
name: image-build-taskrun
spec:
taskRef:
name: image-build-task
stepOverrides:
- name: build
resources:
requests:
memory: 1Gi
sidecarOverrides:
- name: logging
resources:
requests:
cpu: 100m
limits:
cpu: 500m
StepSpecs
and SidecarSpecs
must include the name
field and may include resources
.
No other fields can be overridden.
If the overridden Task
uses a StepTemplate
, configuration on
Step
will take precedence over configuration in StepTemplate
, and configuration in StepSpec
will
take precedence over both.
When merging resource requirements, different resource types are considered independently.
For example, if a Step
configures both CPU and memory, and a StepSpec
configures only memory,
the CPU values from the Step
will be preserved. Requests and limits are also considered independently.
For example, if a Step
configures a memory request and limit, and a StepSpec
configures only a
memory request, the memory limit from the Step
will be preserved.
Specifying LimitRange
values
In order to only consume the bare minimum amount of resources needed to execute one Step
at a
time from the invoked Task
, Tekton will request the compute values for CPU, memory, and ephemeral
storage for each Step
based on the LimitRange
object(s), if present. Any Request
or Limit
specified by the user (on Task
for example) will be left unchanged.
For more information, see the LimitRange
support in Pipeline.
Specifying Retries
You can use the retries
field to set how many times you want to retry on a failed TaskRun.
All TaskRun failures are retriable except for Cancellation
.
For a retriable TaskRun
, when an error occurs:
- The error status is archived in
status.RetriesStatus
- The
Succeeded
condition instatus
is updated:
Type: Succeeded
Status: Unknown
Reason: ToBeRetried
status.StartTime
,status.PodName
andstatus.Results
are unset to trigger another retry attempt.
Configuring the failure timeout
You can use the timeout
field to set the TaskRun's
desired timeout value for each retry attempt. If you do
not specify this value, the global default timeout value applies (the same, to each retry attempt
). If you set the timeout to 0,
the TaskRun
will have no timeout and will run until it completes successfully or fails from an error.
The timeout
value is a duration
conforming to Go’s
ParseDuration
format. For example, valid
values are 1h30m
, 1h
, 1m
, 60s
, and 0
.
If a TaskRun
runs longer than its timeout value, the pod associated with the TaskRun
will be deleted. This
means that the logs of the TaskRun
are not preserved. The deletion of the TaskRun
pod is necessary in order to
stop TaskRun
step containers from running.
The global default timeout is set to 60 minutes when you first install Tekton. You can set
a different global default timeout value using the default-timeout-minutes
field in
config/config-defaults.yaml
. If you set the global timeout to 0,
all TaskRuns
that do not have a timeout set will have no timeout and will run until it completes successfully
or fails from an error.
:note: An internal detail of the
PipelineRun
andTaskRun
reconcilers in the Tekton controller is that it will requeue aPipelineRun
orTaskRun
for re-evaluation, versus waiting for the next update, under certain conditions. The wait time for that re-queueing is the elapsed time subtracted from the timeout; however, if the timeout is set to ‘0’, that calculation produces a negative number, and the new reconciliation event will fire immediately, which can impact overall performance, which is counter to the intent of wait time calculation. So instead, the reconcilers will use the configured global timeout as the wait time when the associated timeout has been set to ‘0’.
Specifying ServiceAccount
credentials
You can execute the Task
in your TaskRun
with a specific set of credentials by
specifying a ServiceAccount
object name in the serviceAccountName
field in your TaskRun
definition. If you do not explicitly specify this, the TaskRun
executes with the credentials
specified in the configmap-defaults
ConfigMap
. If this default is not specified, TaskRuns
will execute with the default
service account
set for the target namespace
.
For more information, see ServiceAccount
.
TaskRun
status
The status
field defines the observed state of TaskRun
The status
field
-
Required:
status
- The most relevant information about the TaskRun’s state. This field includes:
status.conditions
, which contains the latest observations of theTaskRun
’s state. See here for information on typical status properties.podName
- Name of the pod containing the containers responsible for executing thistask
’sstep
s.startTime
- The time at which theTaskRun
began executing, conforms to RFC3339 format.completionTime
- The time at which theTaskRun
finished executing, conforms to RFC3339 format.taskSpec
-TaskSpec
defines the desired state of theTask
executed via theTaskRun
.
-
Optional:
-
results
- List of results written out by thetask
’s containers. -
provenance
- Provenance contains metadata about resources used in theTaskRun
such as the source from where a remotetask
definition was fetched. It carries minimum amount of metadata inTaskRun
status
so thatTekton Chains
can utilize it for provenance, its two subfields are:refSource
: the source from where a remoteTask
definition was fetched.featureFlags
: Identifies the feature flags used during theTaskRun
.
-
steps
- Contains thestate
of eachstep
container.steps[].terminationReason
- When the step is terminated, it stores the step’s final state.
-
retriesStatus
- Contains the history ofTaskRun
’sstatus
in case of a retry in order to keep record of failures. Nostatus
stored withinretriesStatus
will have anydate
within as it is redundant. -
sidecars
- This field is a list. The list has one entry persidecar
in the manifest. Each entry represents the imageid of the corresponding sidecar. -
spanContext
- Contains tracing span context fields.
-
Monitoring execution status
As your TaskRun
executes, its status
field accumulates information on the execution of each Step
as well as the TaskRun
as a whole. This information includes start and stop times, exit codes, the
fully-qualified name of the container image, and the corresponding digest.
Note: If any Pods
have been OOMKilled
by Kubernetes, the TaskRun
is marked as failed even if its exit code is 0.
The following example shows the status
field of a TaskRun
that has executed successfully:
completionTime: "2019-08-12T18:22:57Z"
conditions:
- lastTransitionTime: "2019-08-12T18:22:57Z"
message: All Steps have completed executing
reason: Succeeded
status: "True"
type: Succeeded
podName: status-taskrun-pod
startTime: "2019-08-12T18:22:51Z"
steps:
- container: step-hello
imageID: docker-pullable://busybox@sha256:895ab622e92e18d6b461d671081757af7dbaa3b00e3e28e12505af7817f73649
name: hello
terminationReason: Completed
terminated:
containerID: docker://d5a54f5bbb8e7a6fd3bc7761b78410403244cf4c9c5822087fb0209bf59e3621
exitCode: 0
finishedAt: "2019-08-12T18:22:56Z"
reason: Completed
startedAt: "2019-08-12T18:22:54Z"
The following tables shows how to read the overall status of a TaskRun
:
status |
reason |
message |
completionTime is set |
Description |
---|---|---|---|---|
Unknown | Started | n/a | No | The TaskRun has just been picked up by the controller. |
Unknown | Pending | n/a | No | The TaskRun is waiting on a Pod in status Pending. |
Unknown | Running | n/a | No | The TaskRun has been validated and started to perform its work. |
Unknown | TaskRunCancelled | n/a | No | The user requested the TaskRun to be cancelled. Cancellation has not been done yet. |
True | Succeeded | n/a | Yes | The TaskRun completed successfully. |
False | Failed | n/a | Yes | The TaskRun failed because one of the steps failed. |
False | [Error message] | n/a | No | The TaskRun encountered a non-permanent error, and it’s still running. It may ultimately succeed. |
False | [Error message] | n/a | Yes | The TaskRun failed with a permanent error (usually validation). |
False | TaskRunCancelled | n/a | Yes | The TaskRun was cancelled successfully. |
False | TaskRunCancelled | TaskRun cancelled as the PipelineRun it belongs to has timed out. | Yes | The TaskRun was cancelled because the PipelineRun timed out. |
False | TaskRunTimeout | n/a | Yes | The TaskRun timed out. |
False | TaskRunImagePullFailed | n/a | Yes | The TaskRun failed due to one of its steps not being able to pull the image. |
When a TaskRun
changes status, events are triggered accordingly.
The name of the Pod
owned by a TaskRun
is univocally associated to the owning resource.
If a TaskRun
resource is deleted and created with the same name, the child Pod
will be created with the same name
as before. The base format of the name is <taskrun-name>-pod
. The name may vary according to the logic of
kmeta.ChildName
. In case of retries of a TaskRun
triggered by the PipelineRun
controller, the base format of the name is <taskrun-name>-pod-retry<N>
starting from
the first retry.
Some examples:
TaskRun Name |
Pod Name |
---|---|
task-run | task-run-pod |
task-run-0123456789-0123456789-0123456789-0123456789-0123456789-0123456789 | task-run-0123456789-01234560d38957287bb0283c59440df14069f59-pod |
Monitoring Steps
If multiple Steps
are defined in the Task
invoked by the TaskRun
, you can monitor their execution
status in the status.steps
field using the following command, where <name>
is the name of the target
TaskRun
:
kubectl get taskrun <name> -o yaml
The exact Task Spec used to instantiate the TaskRun is also included in the Status for full auditability.
Steps
The corresponding statuses appear in the status.steps
list in the order in which the Steps
have been
specified in the Task
definition.
Monitoring Results
If one or more results
fields have been specified in the invoked Task
, the TaskRun's
execution
status will include a Task Results
section, in which the Results
appear verbatim, including original
line returns and whitespace. For example:
Status:
# […]
Steps:
# […]
Task Results:
Name: current-date-human-readable
Value: Thu Jan 23 16:29:06 UTC 2020
Name: current-date-unix-timestamp
Value: 1579796946
Cancelling a TaskRun
To cancel a TaskRun
that’s currently executing, update its status to mark it as cancelled.
When you cancel a TaskRun, the running pod associated with that TaskRun
is deleted. This
means that the logs of the TaskRun
are not preserved. The deletion of the TaskRun
pod is necessary
in order to stop TaskRun
step containers from running.
Note: if keep-pod-on-cancel
is set to
"true"
in the feature-flags
, the pod associated with that TaskRun
will not be deleted
Example of cancelling a TaskRun
:
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: go-example-git
spec:
# […]
status: "TaskRunCancelled"
Debugging a TaskRun
Breakpoint on Failure
TaskRuns can be halted on failure for troubleshooting by providing the following spec patch as seen below.
spec:
debug:
breakpoints:
onFailure: "enabled"
Upon failure of a step, the TaskRun Pod execution is halted. If this TaskRun Pod continues to run without any lifecycle change done by the user (running the debug-continue or debug-fail-continue script) the TaskRun would be subject to TaskRunTimeout. During this time, the user/client can get remote shell access to the step container with a command such as the following.
kubectl exec -it print-date-d7tj5-pod -c step-print-date-human-readable sh
Debug Environment
After the user/client has access to the container environment, they can scour for any missing parts because of which their step might have failed.
To control the lifecycle of the step to mark it as a success or a failure or close the breakpoint, there are scripts
provided in the /tekton/debug/scripts
directory in the container. The following are the scripts and the tasks they
perform :-
debug-continue
: Mark the step as a success and exit the breakpoint.
debug-fail-continue
: Mark the step as a failure and exit the breakpoint.
More information on the inner workings of debug can be found in the Debug documentation
Code examples
To better understand TaskRuns
, study the following code examples:
- Example
TaskRun
with a referencedTask
- Example
TaskRun
with an embeddedTask
- Example of reusing a
Task
- Example of Using custom
ServiceAccount
credentials - Example of Running Step Containers as a Non Root User
Example TaskRun
with a referenced Task
In this example, a TaskRun
named read-repo-run
invokes and executes an existing
Task
named read-task
. This Task
reads the repository from the
“input” workspace
.
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: Task
metadata:
name: read-task
spec:
workspaces:
- name: input
steps:
- name: readme
image: ubuntu
script: cat $(workspaces.input.path)/README.md
---
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: read-repo-run
spec:
taskRef:
name: read-task
workspaces:
- name: input
persistentVolumeClaim:
claimName: mypvc
subPath: my-subdir
Example TaskRun
with an embedded Task
In this example, a TaskRun
named build-push-task-run-2
directly executes
a Task
from its definition embedded in the TaskRun's
taskSpec
field:
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: build-push-task-run-2
spec:
workspaces:
- name: source
persistentVolumeClaim:
claimName: my-pvc
taskSpec:
workspaces:
- name: source
steps:
- name: build-and-push
image: gcr.io/kaniko-project/executor:v0.17.1
workingDir: $(workspaces.source.path)
# specifying DOCKER_CONFIG is required to allow kaniko to detect docker credential
env:
- name: "DOCKER_CONFIG"
value: "/tekton/home/.docker/"
command:
- /kaniko/executor
args:
- --destination=gcr.io/my-project/gohelloworld
Example of Using custom ServiceAccount
credentials
The example below illustrates how to specify a ServiceAccount
to access a private git
repository:
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
name: test-task-with-serviceaccount-git-ssh
spec:
serviceAccountName: test-task-robot-git-ssh
workspaces:
- name: source
persistentVolumeClaim:
claimName: repo-pvc
- name: ssh-creds
secret:
secretName: test-git-ssh
params:
- name: url
value: https://github.com/tektoncd/pipeline.git
taskRef:
name: git-clone
In the above code snippet, serviceAccountName: test-build-robot-git-ssh
references the following
ServiceAccount
:
apiVersion: v1
kind: ServiceAccount
metadata:
name: test-task-robot-git-ssh
secrets:
- name: test-git-ssh
And secretName: test-git-ssh
references the following Secret
:
apiVersion: v1
kind: Secret
metadata:
name: test-git-ssh
annotations:
tekton.dev/git-0: github.com
type: kubernetes.io/ssh-auth
data:
# Generated by:
# cat id_rsa | base64 -w 0
ssh-privatekey: LS0tLS1CRUdJTiBSU0EgUFJJVk.....[example]
# Generated by:
# ssh-keyscan github.com | base64 -w 0
known_hosts: Z2l0aHViLmNvbSBzc2g.....[example]
Example of Running Step Containers as a Non Root User
All steps that do not require to be run as a root user should make use of TaskRun features to designate the container for a step runs as a user without root permissions. As a best practice, running containers as non root should be built into the container image to avoid any possibility of the container being run as root. However, as a further measure of enforcing this practice, TaskRun pod templates can be used to specify how containers should be run within a TaskRun pod.
An example of using a TaskRun pod template is shown below to specify that containers running via this TaskRun’s pod should run as non root and run as user 1001 if the container itself does not specify what user to run as:
apiVersion: tekton.dev/v1 # or tekton.dev/v1beta1
kind: TaskRun
metadata:
generateName: show-non-root-steps-run-
spec:
taskRef:
name: show-non-root-steps
podTemplate:
securityContext:
runAsNonRoot: true
runAsUser: 1001
If a Task step specifies that it is to run as a different user than what is specified in the pod template,
the step’s securityContext
will be applied instead of what is specified at the pod level. An example of
this is available as a TaskRun example.
More information about Pod and Container Security Contexts can be found via the Kubernetes website.
Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License.
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