Update examples and docs to use path templates

docs/tasks.md

@@ -211,7 +211,8 @@ Input resources, like source code (git) or artifacts, are dumped at path
 `/workspace/task_resource_name` within a mounted
 [volume](https://kubernetes.io/docs/concepts/storage/volumes/) and is available
 to all [`steps`](#steps) of your `Task`. The path that the resources are mounted
-at can be overridden with the `targetPath` value.
+at can be overridden with the `targetPath` value. Steps can use the `path`
+ [template](#Templating) key to refer to the local path to the mounted resource.
 
 ### Outputs
 
@@ -372,6 +373,13 @@ Or for an output resource:
 ${outputs.resources.<name>.<key>}
 ```
 
+The local path to a resource on the mounted volume can be accessed using the
+`path` key:
+
+```shell
+${inputs.resouces.<name>.path}
+```
+
 To access an input parameter, replace `resources` with `params`.
 
 ```shell

examples/taskruns/task-output-image.yaml

@@ -60,7 +60,7 @@ spec:
     - -ce
     - |
       set -e
-      cat <<EOF > /workspace/sourcerepo/index.json
+      cat <<EOF > ${inputs.resources.sourcerepo.path}/index.json
       {
         "schemaVersion": 2,
         "manifests": [
@@ -80,7 +80,7 @@ spec:
     - -ce
     - |
       set -e
-      cat /workspace/sourcerepo/index.json
+      cat ${inputs.resources.sourcerepo.path}/index.json
 ---
 apiVersion: tekton.dev/v1alpha1
 kind: TaskRun

examples/taskruns/taskrun-git-source.yaml

@@ -48,7 +48,7 @@ spec:
   - name: dump-workspace
     image: ubuntu
     command: ["cat"]
-    args: ["/workspace/gitspace/WORKSPACE"]
+    args: ["${inputs.resources.gitspace.path}/WORKSPACE"]
 ---
 apiVersion: tekton.dev/v1alpha1
 kind: TaskRun

examples/taskruns/taskrun-targetpath-gotest.yaml

@@ -35,7 +35,7 @@ spec:
       - '-v'
       - '-count=1'
       - './...'
-      workingDir: "/workspace/go/src/github.com/tektoncd/pipeline"
+      workingDir: "${inputs.resources.gitspace.path}"
       env:
       - name: GOPATH
         value: /workspace/go