introducing env to git pipeline resource

Along with type and params, we can specify env. now for git resources.
Env. takes a list of envionment variable names and their values and
sets those variables in a container where git CLI is being executed

e.g.:

```
  inputs:
    resources:
      - name: skaffold
        resourceSpec:
          type: git
          params:
            - name: revision
              value: master
            - name: url
              value: https://github.com/GoogleContainerTools/skaffold
          env:
            - name: HTTPS_PROXY
              value: "myproxy.com"
```

docs/resources.md

@@ -377,6 +377,22 @@ spec:
       value: refs/pull/52525/head
 ```
 
+#### Setting Env. Variables
+
+`Env` section can be used to set common proxy environment variables or any arbitrary variables in a container where
+`git` commands are executed:
+
+```yaml
+spec:
+  type: git
+  params:
+    - name: url
+      value: https://github.com/bobcatfish/wizzbang.git
+  env:
+    - name: HTTPS_PROXY
+      value: "myproxy.com"
+```
+
 ### Pull Request Resource
 
 The `pullRequest` resource represents a pull request event from a source control

examples/v1alpha1/taskruns/git-resource.yaml

@@ -69,3 +69,59 @@ spec:
             value: pull/2932/head
           - name: url
             value: https://github.com/GoogleContainerTools/skaffold
+
+---
+apiVersion: tekton.dev/v1alpha1
+kind: TaskRun
+metadata:
+  generateName: git-resource-sslverify-
+spec:
+  taskSpec:
+    inputs:
+      resources:
+        - name: skaffold
+          type: git
+    steps:
+      - image: ubuntu
+        script: cat skaffold/README.md
+  inputs:
+    resources:
+      - name: skaffold
+        resourceSpec:
+          type: git
+          params:
+            - name: revision
+              value: master
+            - name: url
+              value: https://github.com/GoogleContainerTools/skaffold
+            - name: sslverify
+              value: "false"
+---
+
+apiVersion: tekton.dev/v1alpha1
+kind: TaskRun
+metadata:
+  generateName: git-resource-no-proxy-
+spec:
+  taskSpec:
+    inputs:
+      resources:
+        - name: skaffold
+          type: git
+    steps:
+      - image: ubuntu
+        script: cat skaffold/README.md
+  inputs:
+    resources:
+      - name: skaffold
+        resourceSpec:
+          type: git
+          params:
+            - name: revision
+              value: master
+            - name: url
+              value: https://github.com/GoogleContainerTools/skaffold
+          env:
+            - name: NO_PROXY
+              value: "google.com"
+---

pkg/apis/resource/v1alpha1/git/git_resource.go

@@ -28,6 +28,10 @@ import (
 	corev1 "k8s.io/api/core/v1"
 )
 
+const (
+	TektonResourceName = "TEKTON_RESOURCE_NAME"
+)
+
 var (
 	gitSource = "git-source"
 )
@@ -44,9 +48,10 @@ type Resource struct {
 	Revision   string `json:"revision"`
 	Submodules bool   `json:"submodules"`
 
-	Depth     uint   `json:"depth"`
-	SSLVerify bool   `json:"sslVerify"`
-	GitImage  string `json:"-"`
+	Depth     uint            `json:"depth"`
+	SSLVerify bool            `json:"sslVerify"`
+	GitImage  string          `json:"-"`
+	Env       []corev1.EnvVar `json:"-"`
 }
 
 // NewResource creates a new git resource to pass to a Task
@@ -61,6 +66,7 @@ func NewResource(gitImage string, r *resource.PipelineResource) (*Resource, erro
 		Submodules: true,
 		Depth:      1,
 		SSLVerify:  true,
+		Env:        r.Spec.Env,
 	}
 	for _, param := range r.Spec.Params {
 		switch {
@@ -147,6 +153,13 @@ func (s *Resource) GetInputTaskModifier(_ *v1alpha1.TaskSpec, path string) (v1al
 		args = append(args, "-sslVerify=false")
 	}
 
+	if !s.isTektonResourceName() {
+		s.Env = append(s.Env, corev1.EnvVar{
+			Name:  TektonResourceName,
+			Value: s.Name,
+		})
+	}
+
 	step := v1alpha1.Step{
 		Container: corev1.Container{
 			Name:       names.SimpleNameGenerator.RestrictLengthWithRandomSuffix(gitSource + "-" + s.Name),
@@ -155,10 +168,7 @@ func (s *Resource) GetInputTaskModifier(_ *v1alpha1.TaskSpec, path string) (v1al
 			Args:       args,
 			WorkingDir: pipeline.WorkspaceDir,
 			// This is used to populate the ResourceResult status.
-			Env: []corev1.EnvVar{{
-				Name:  "TEKTON_RESOURCE_NAME",
-				Value: s.Name,
-			}},
+			Env: s.Env,
 		},
 	}
 
@@ -171,3 +181,12 @@ func (s *Resource) GetInputTaskModifier(_ *v1alpha1.TaskSpec, path string) (v1al
 func (s *Resource) GetOutputTaskModifier(_ *v1alpha1.TaskSpec, _ string) (v1alpha1.TaskModifier, error) {
 	return &v1alpha1.InternalTaskModifier{}, nil
 }
+
+func (s *Resource) isTektonResourceName() bool {
+	for _, e := range s.Env {
+		if e.Name == TektonResourceName {
+			return true
+		}
+	}
+	return false
+}

pkg/apis/resource/v1alpha1/git/git_resource_test.go

@@ -329,6 +329,45 @@ func TestGitResource_GetDownloadTaskModifier(t *testing.T) {
 			WorkingDir: "/workspace",
 			Env:        []corev1.EnvVar{{Name: "TEKTON_RESOURCE_NAME", Value: "git-resource"}},
 		},
+	}, {
+		desc: "With Env",
+		gitResource: &git.Resource{
+			Name:       "git-resource",
+			Type:       resourcev1alpha1.PipelineResourceTypeGit,
+			URL:        "[email protected]:test/test.git",
+			Revision:   "master",
+			GitImage:   "override-with-git:latest",
+			Submodules: false,
+			Depth:      1,
+			SSLVerify:  false,
+			Env: []corev1.EnvVar{{
+				Name:      "FOO",
+				Value:     "foo",
+				ValueFrom: nil,
+			}, {
+				Name:      "BAR",
+				Value:     "bar",
+				ValueFrom: nil,
+			}},
+		},
+		want: corev1.Container{
+			Name:    "git-source-git-resource-6nl7g",
+			Image:   "override-with-git:latest",
+			Command: []string{"/ko-app/git-init"},
+			Args: []string{
+				"-url",
+				"[email protected]:test/test.git",
+				"-revision",
+				"master",
+				"-path",
+				"/test/test",
+				"-submodules=false",
+				"-sslVerify=false",
+			},
+			WorkingDir: "/workspace",
+			Env: []corev1.EnvVar{{Name: "FOO", Value: "foo"}, {Name: "BAR", Value: "bar"},
+				{Name: "TEKTON_RESOURCE_NAME", Value: "git-resource"}},
+		},
 	}} {
 		t.Run(tc.desc, func(t *testing.T) {
 			ts := pipelinev1alpha1.TaskSpec{}

pkg/apis/resource/v1alpha1/pipeline_resource_types.go

@@ -17,6 +17,7 @@ limitations under the License.
 package v1alpha1
 
 import (
+	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
@@ -102,6 +103,7 @@ type PipelineResourceSpec struct {
 	// Secrets to fetch to populate some of resource fields
 	// +optional
 	SecretParams []SecretParam `json:"secrets,omitempty"`
+	Env          []v1.EnvVar   `json:"env,omitempty"`
 }
 
 // SecretParam indicates which secret can be used to populate a field of the resource

pkg/reconciler/pipelinerun/resources/input_output_steps.go

@@ -79,6 +79,11 @@ func GetInputSteps(inputs map[string]*v1alpha1.PipelineResource, inputResources
 			}
 		}
 
+		// set Env. when resource is of type Git
+		if inputResource.Spec.Type == v1alpha1.PipelineResourceTypeGit {
+			taskInputResource.ResourceSpec.Env = inputResource.Spec.Env
+		}
+
 		// Determine if the value is meant to come `from` a previous Task - if so, add the path to the pvc
 		// that contains the data as the `path` the resulting TaskRun should get the data from.
 		var stepSourceNames []string

pkg/reconciler/pipelinerun/resources/input_output_steps_test.go

@@ -19,6 +19,8 @@ import (
 	"sort"
 	"testing"
 
+	v1 "k8s.io/api/core/v1"
+
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/tektoncd/pipeline/pkg/apis/pipeline/v1alpha1"
@@ -147,6 +149,17 @@ func TestGetInputSteps(t *testing.T) {
 			SecretParams: nil,
 		},
 	}
+	r3 := &v1alpha1.PipelineResource{
+		Spec: v1alpha1.PipelineResourceSpec{
+			Type: v1alpha1.PipelineResourceTypeGit,
+			Params: []v1alpha1.ResourceParam{{
+				Name:  "url",
+				Value: "https://github.com/tektoncd/pipeline.git",
+			}},
+			SecretParams: nil,
+			Env:          []v1.EnvVar{{Name: "FOO", Value: "foo"}},
+		},
+	}
 	tcs := []struct {
 		name                       string
 		inputs                     map[string]*v1alpha1.PipelineResource
@@ -259,6 +272,23 @@ func TestGetInputSteps(t *testing.T) {
 				},
 				Paths: []string{"/pvc/prev-task-1/test-input", "/pvc/prev-task-2/test-input"},
 			}},
+		}, {
+			name:   "task-with-git-input-resource-with-env",
+			inputs: map[string]*v1alpha1.PipelineResource{"test-input": r3},
+			expectedtaskInputResources: []v1alpha1.TaskResourceBinding{{
+				PipelineResourceBinding: v1alpha1.PipelineResourceBinding{
+					ResourceSpec: &r3.Spec,
+					Name:         "test-input",
+				},
+			}},
+			pipelineTask: &v1alpha1.PipelineTask{
+				Name: "sample-test-task",
+				Resources: &v1alpha1.PipelineTaskResources{
+					Inputs: []v1alpha1.PipelineTaskInputResource{{
+						Name: "test-input",
+					}},
+				},
+			},
 		},
 	}
 	for _, tc := range tcs {

test/builder/pipeline.go

@@ -541,6 +541,13 @@ func PipelineResourceSpecParam(name, value string) PipelineResourceSpecOp {
 	}
 }
 
+// PipelineResourceSpecEnv adds a ResourceEnv, with specified name and value, to the PipelineResourceSpec.
+func PipelineResourceSpecEnv(env []corev1.EnvVar) PipelineResourceSpecOp {
+	return func(spec *v1alpha1.PipelineResourceSpec) {
+		spec.Env = append(spec.Env, env...)
+	}
+}
+
 // PipelineResourceSpecSecretParam adds a SecretParam, with specified fieldname, secretKey and secretName, to the PipelineResourceSpec.
 func PipelineResourceSpecSecretParam(fieldname, secretName, secretKey string) PipelineResourceSpecOp {
 	return func(spec *v1alpha1.PipelineResourceSpec) {