Add Tep for adding taskruntemplate in pipelinerun

Tep aims to resolve setting common configration for all taskrun
in pipelinerun.

Signed-off-by: yuzhipeng <yuzp1996@qq.com>

teps/0119-add-taskrun-template-in-pipelinerun.md

@@ -0,0 +1,179 @@
+---
+status: proposed
+title: Add taskRun template in PipelineRun
+creation-date: '2022-08-12'
+last-updated: '2022-08-12'
+authors:
+- '@yuzp1996'
+---
+
+# TEP-0119: Add taskRun template in PipelineRun
+
+<!-- toc -->
+- [Summary](#summary)
+  - [Use Cases](#use-cases)
+- [Proposal](#proposal)
+- [Design Details](#design-details)
+  - [taskRunTemplate](#implement)
+  - [Test Plan](#test-plan)
+<!-- /toc -->
+
+## Summary
+It is now supported for users to specify spec for a specific taskRun when creating a pipelineRun, but it is not supported for users to set spec for all taskRun.
+
+If you want to specify common configurations for all taskRun, you must specify them individually.
+
+This Tep attempts to provide a convenient way to specify the run specification of all tasks in pipelineRun.
+
+### Use Cases
+Pipeline and Task User:
+
+I would like to use the same service account for all of my pipeline tasks except one.
+
+I want to specify compute resources that each TaskRun in my PipelineRun should run with, and don't want to have to specify them individually for each TaskRun.
+
+## Proposal
+Add filed taskRunTemplate to PipelineRun.Spec then users can specify common configuration in taskRunTemplate and the configuration will apply to all the TaskRun. 
+
+If user specify taskRun spec in pipelineRun with TaskRunSpec then it will be the highest priority.
+
+For example you have a pipeline which contains three tasks clone、unit-test and image-build. Now you want to create pipelineRun which unit-test and image-build use 
+same serviceAccount while clone use a different serviceAccount.
+```yaml
+apiVersion: tekton.dev/v1beta1
+kind: Pipeline
+metadata:
+  name: clone-test-build
+spec:
+  tasks:
+  - name: clone
+    taskRef:
+      name: git-clone
+    workspaces:
+    - name: output
+      workspace: git-source
+  - name: unit-test
+    runAfter:
+    - clone
+    taskRef:
+      name: junit
+  - name: image-build
+    runAfter:
+    - unit-test
+    taskRef:
+      name: buildah
+
+```
+
+In this case, when you create pipelineRun you need to specify serviceAccount for every task.
+```yaml
+apiVersion: tekton.dev/v1beta1
+kind: PipelineRun
+metadata:
+  generateName: clone-test-build-
+spec:
+  pipelineRef:
+    name: clone-test-build
+  taskRunSpecs:
+    - pipelineTaskName: clone
+      taskServiceAccountName: git
+    - pipelineTaskName: unit-test
+      taskServiceAccountName: build
+    - pipelineTaskName: image-build
+      taskServiceAccountName: build
+```
+
+With the help of taskRunTemplate you will save a lot of work.
+```yaml
+apiVersion: tekton.dev/v1beta1
+kind: PipelineRun
+metadata:
+  generateName: clone-test-build-
+spec:
+  pipelineRef:
+    name: clone-test-build
+  taskRunSpecs:
+    - pipelineTaskName: clone
+      taskServiceAccountName: git
+  taskRunSpecTemplate:
+    taskServiceAccountName: build
+
+```
+
+Not only serviceAccount, but also data like computeResources metadata that you can specify for all tasks instead of specify them individually.
+
+## Design Details
+### taskRunTemplate
+Add taskRunSpecTemplate to PipelineRun.Spec so that user can specify configuration.
+```go
+// Add struct PipelineTaskRunTemplate
+type PipelineTaskRunTemplate struct {
+  TaskServiceAccountName string       `json:"taskServiceAccountName,omitempty"`
+  TaskPodTemplate        *PodTemplate `json:"taskPodTemplate,omitempty"`
+  // +listType=atomic
+  StepOverrides []TaskRunStepOverride `json:"stepOverrides,omitempty"`
+  // +listType=atomic
+  SidecarOverrides []TaskRunSidecarOverride `json:"sidecarOverrides,omitempty"`
+
+  // +optional
+  Metadata *PipelineTaskMetadata `json:"metadata,omitempty"`
+
+  // Compute resources to use for this TaskRun
+  ComputeResources *corev1.ResourceRequirements `json:"computeResources,omitempty"`
+}
+
+// Reference PipelineTaskRunTemplate in PipelineRunSpec as filed TaskRunSpecTemplate
+type PipelineRunSpec struct {
+	// +optional
+	PipelineRef *PipelineRef `json:"pipelineRef,omitempty"`
+	// +optional
+	PipelineSpec *PipelineSpec `json:"pipelineSpec,omitempty"`
+    .....
+    // TaskRunTemplate represent template of taskrun
++	// +optional
++	TaskRunTemplate PipelineTaskRunTemplate `json:"taskRunTemplate,omitempty"`
+}
+
+```
+
+Then, if you want to set a common configuration for all taskRun in pipelineRun, you can do so.
+```yaml
+apiVersion: tekton.dev/v1beta1
+kind: PipelineRun
+metadata:
+  generateName: clone-test-build-
+spec:
+  pipelineRef:
+    name: clone-test-build
+  taskRunSpecs:
+    - pipelineTaskName: clone
+      taskServiceAccountName: git
+  taskRunTemplate:
+    taskServiceAccountName: build
+    metadata:
+      annotations:
+        vault.hashicorp.com/agent-inject-secret-foo: "/path/to/foo"
+        vault.hashicorp.com/role: role-name
+    taskPodTemplate:
+      nodeSelector:
+        disktype: ssd
+    computeResources:
+      requests:
+        cpu: 2
+    stepOverrides:
+    - name: build
+      resources:
+        requests:
+          memory: 1Gi
+    sidecarOverrides:
+    - name: logging
+      resources:
+        requests:
+          cpu: 100m
+        limits:
+          cpu: 500m
+```
+
+
+### Test Plan
+Unit tests are necessary, we can add some integration or e2e tests as appropriate.

teps/README.md

@@ -263,3 +263,4 @@ This is the complete list of Tekton teps:
 |[TEP-0114](0114-custom-tasks-beta.md) | Custom Tasks Beta | implementable | 2022-07-12 |
 |[TEP-0116](0116-referencing-finally-task-results-in-pipeline-results.md) | Referencing Finally Task Results in Pipeline Results | implemented | 2022-08-11 |
 |[TEP-0118](0118-matrix-with-explicit-combinations-of-parameters.md) | Matrix with Explicit Combinations of Parameters | implementable | 2022-08-08 |
+|[TEP-0119](0119-add-taskrun-template-in-pipelinerun.md) | Add taskRun template in PipelineRun | proposed | 2022-08-12 |