Add a --filename parameter to 'tkn tasks start'.

This parameter lets users specify a local task definition. tkn will then
inline that definition in the generated TaskRun, without creating it first.
This is useful for "as-code" scenarios and development.

docs/cmd/tkn_task_start.md

@@ -20,13 +20,17 @@ Start tasks
 # start task foo by creating a taskrun named "foo-run-xyz123" from the namespace "bar"
 tkn task start foo -s ServiceAccountName -n bar
 
+The task can either be specified by reference in a cluster using the positional argument
+or in a file using the --filename argument.
+
 For params value, if you want to provide multiple values, provide them comma separated
 like cat,foo,bar
 
 
 ### Options
 
 ```
+  -f, --filename string          filename containing a task definition
   -h, --help                     help for start
   -i, --inputresource strings    pass the input resource name and ref as name=ref
   -l, --labels strings           pass labels as label=value.

docs/man/man1/tkn-task-start.1

@@ -19,6 +19,10 @@ Start tasks
 
 
 .SH OPTIONS
+.PP
+\fB\-f\fP, \fB\-\-filename\fP=""
+    filename containing a task definition
+
 .PP
 \fB\-h\fP, \fB\-\-help\fP[=false]
     help for start
@@ -72,6 +76,10 @@ Start tasks
 .PP
 tkn task start foo \-s ServiceAccountName \-n bar
 
+.PP
+The task can either be specified by reference in a cluster using the positional argument
+or in a file using the \-\-filename argument.
+
 .PP
 For params value, if you want to provide multiple values, provide them comma separated
 like cat,foo,bar

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/cpuguy83/go-md2man v1.0.10
 	github.com/evanphx/json-patch v4.1.0+incompatible // indirect
 	github.com/fatih/color v1.7.0
+	github.com/ghodss/yaml v1.0.0
 	github.com/google/go-cmp v0.3.1
 	github.com/google/go-containerregistry v0.0.0-20190320210540-8d4083db9aa0 // indirect
 	github.com/google/gofuzz v0.0.0-20161122191042-44d81051d367 // indirect

pkg/cmd/task/start.go

@@ -17,8 +17,11 @@ package task
 import (
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"strings"
 
+	"github.com/ghodss/yaml"
+
 	"github.com/spf13/cobra"
 	"github.com/tektoncd/cli/pkg/cli"
 	"github.com/tektoncd/cli/pkg/cmd/taskrun"
@@ -48,6 +51,7 @@ type startOptions struct {
 	Last               bool
 	Labels             []string
 	ShowLog            bool
+	Filename           string
 }
 
 // NameArg validates that the first argument is a valid task name
@@ -90,6 +94,9 @@ func startCommand(p cli.Params) *cobra.Command {
 # start task foo by creating a taskrun named "foo-run-xyz123" from the namespace "bar"
 tkn task start foo -s ServiceAccountName -n bar
 
+The task can either be specified by reference in a cluster using the positional argument
+or in a file using the --filename argument.
+
 For params value, if you want to provide multiple values, provide them comma separated
 like cat,foo,bar
 `,
@@ -98,15 +105,21 @@ like cat,foo,bar
 			if err := flags.InitParams(p, cmd); err != nil {
 				return err
 			}
-			return NameArg(args, p)
+			if len(args) != 0 {
+				return NameArg(args, p)
+			}
+			if opt.Filename == "" {
+				return errors.New("Either a task name or a --filename parameter must be supplied")
+			}
+			return nil
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
 			opt.stream = &cli.Stream{
 				Out: cmd.OutOrStdout(),
 				Err: cmd.OutOrStderr(),
 			}
 
-			return startTask(opt, args[0])
+			return startTask(opt, args)
 		},
 	}
 
@@ -118,22 +131,50 @@ like cat,foo,bar
 	c.Flags().BoolVarP(&opt.Last, "last", "L", false, "re-run the task using last taskrun values")
 	c.Flags().StringSliceVarP(&opt.Labels, "labels", "l", []string{}, "pass labels as label=value.")
 	c.Flags().BoolVarP(&opt.ShowLog, "showlog", "", true, "show logs right after starting the task")
+	c.Flags().StringVarP(&opt.Filename, "filename", "f", "", "filename containing a task definition")
 
 	_ = c.MarkZshCompPositionalArgumentCustom(1, "__tkn_get_task")
 
 	return c
 }
 
-func startTask(opt startOptions, tname string) error {
+// Setting as var for stubbing in tests
+var parseTask = func(p string) (*v1alpha1.Task, error) {
+	b, err := ioutil.ReadFile(p)
+	if err != nil {
+		return nil, err
+	}
+	task := v1alpha1.Task{}
+	if err := yaml.Unmarshal(b, &task); err != nil {
+		return nil, err
+	}
+	return &task, nil
+}
+
+func startTask(opt startOptions, args []string) error {
 	tr := &v1alpha1.TaskRun{
 		ObjectMeta: metav1.ObjectMeta{
-			Namespace:    opt.cliparams.Namespace(),
-			GenerateName: tname + "-run-",
+			Namespace: opt.cliparams.Namespace(),
 		},
-		Spec: v1alpha1.TaskRunSpec{
+	}
+
+	var tname string
+	if len(args) > 0 {
+		tname = args[0]
+		tr.Spec = v1alpha1.TaskRunSpec{
 			TaskRef: &v1alpha1.TaskRef{Name: tname},
-		},
+		}
+	} else {
+		task, err := parseTask(opt.Filename)
+		if err != nil {
+			return err
+		}
+		tname = task.ObjectMeta.Name
+		tr.Spec = v1alpha1.TaskRunSpec{
+			TaskSpec: &task.Spec,
+		}
 	}
+	tr.ObjectMeta.GenerateName = tname + "-run-"
 
 	cs, err := opt.cliparams.Clients()
 	if err != nil {

pkg/cmd/task/start_test.go

@@ -94,11 +94,34 @@ func Test_start_has_task_arg(t *testing.T) {
 	c := Command(&test.Params{})
 
 	_, err := test.ExecuteCommand(c, "start", "-n", "ns")
-
 	if err == nil {
 		t.Error("Expecting an error but it's empty")
 	}
-	test.AssertOutput(t, "missing task name", err.Error())
+	test.AssertOutput(t, "Either a task name or a --filename parameter must be supplied", err.Error())
+}
+
+func Test_start_has_task_filename(t *testing.T) {
+	ns := []*corev1.Namespace{
+		{
+			ObjectMeta: metav1.ObjectMeta{
+				Name: "ns",
+			},
+		},
+	}
+	cs, _ := test.SeedTestData(t, pipelinetest.Data{Namespaces: ns})
+	c := Command(&test.Params{Tekton: cs.Pipeline, Kube: cs.Kube})
+
+	oldParseTask := parseTask
+	defer func() {
+		parseTask = oldParseTask
+	}()
+	parseTask = func(p string) (*v1alpha1.Task, error) {
+		return tb.Task("task", "ns"), nil
+	}
+	_, err := test.ExecuteCommand(c, "start", "-n", "ns", "--filename=foo", "--showlog=false")
+	if err != nil {
+		t.Errorf("Not expecting an error, but got %s", err)
+	}
 }
 
 func Test_start_task_not_found(t *testing.T) {

test/resources/task-volume.yaml

@@ -46,4 +46,4 @@ metadata:
   namespace: tektoncd
 spec:
   taskRef:
-    name: task-volume
+    name: task-volume