Add --step flag for taskrun logs

This will add --step flag for taskrun logs to
show logs of respective tasks only

Rename --only-tasks to --task in pipelinerun
logs

Add tests and docs

Fix #578

docs/cmd/tkn_pipelinerun_logs.md

@@ -30,11 +30,11 @@ Show the logs of PipelineRun named 'microservice-1' for all tasks and steps (inc
 ### Options
 
 ```
-  -a, --all                  show all logs including init steps injected by tekton
-  -f, --follow               stream live logs
-  -h, --help                 help for logs
-      --limit int            lists number of pipelineruns (default 5)
-  -t, --only-tasks strings   show logs for mentioned tasks only
+  -a, --all            show all logs including init steps injected by tekton
+  -f, --follow         stream live logs
+  -h, --help           help for logs
+      --limit int      lists number of pipelineruns (default 5)
+  -t, --task strings   show logs for mentioned tasks only
 ```
 
 ### Options inherited from parent commands

docs/cmd/tkn_taskrun_logs.md

@@ -22,14 +22,19 @@ Show the live logs of TaskRun named 'foo' from namespace 'bar':
 
     tkn taskrun logs -f foo -n bar
 
+Show the logs of TaskRun named 'microservice-1' for step 'build' only from namespace 'bar':
+
+    tkn tr logs microservice-1 -s build -n bar
+
 
 ### Options
 
 ```
-  -a, --all         show all logs including init steps injected by tekton
-  -f, --follow      stream live logs
-  -h, --help        help for logs
-      --limit int   lists number of taskruns (default 5)
+  -a, --all            show all logs including init steps injected by tekton
+  -f, --follow         stream live logs
+  -h, --help           help for logs
+      --limit int      lists number of taskruns (default 5)
+  -s, --step strings   show logs for mentioned steps only
 ```
 
 ### Options inherited from parent commands

docs/man/man1/tkn-pipelinerun-logs.1

@@ -36,7 +36,7 @@ Show the logs of PipelineRun
     lists number of pipelineruns
 
 .PP
-\fB\-t\fP, \fB\-\-only\-tasks\fP=[]
+\fB\-t\fP, \fB\-\-task\fP=[]
     show logs for mentioned tasks only
 
 

docs/man/man1/tkn-taskrun-logs.1

@@ -35,6 +35,10 @@ Show taskruns logs
 \fB\-\-limit\fP=5
     lists number of taskruns
 
+.PP
+\fB\-s\fP, \fB\-\-step\fP=[]
+    show logs for mentioned steps only
+
 
 .SH OPTIONS INHERITED FROM PARENT COMMANDS
 .PP
@@ -79,6 +83,18 @@ tkn taskrun logs \-f foo \-n bar
 .fi
 .RE
 
+.PP
+Show the logs of TaskRun named 'microservice\-1' for step 'build' only from namespace 'bar':
+
+.PP
+.RS
+
+.nf
+tkn tr logs microservice\-1 \-s build \-n bar
+
+.fi
+.RE
+
 
 .SH SEE ALSO
 .PP

pkg/cmd/pipelinerun/log_test.go

@@ -880,7 +880,7 @@ func updatePR(finalRuns []*v1alpha1.PipelineRun, watcher *watch.FakeWatcher) {
 	}()
 }
 
-func logOpts(name string, ns string, cs pipelinetest.Clients, streamer stream.NewStreamerFunc, allSteps bool, follow bool, onlyTasks ...string) *options.LogOptions {
+func logOpts(name string, ns string, cs pipelinetest.Clients, streamer stream.NewStreamerFunc, allSteps bool, follow bool, tasks ...string) *options.LogOptions {
 	p := test.Params{
 		Kube:   cs.Kube,
 		Tekton: cs.Pipeline,
@@ -889,7 +889,7 @@ func logOpts(name string, ns string, cs pipelinetest.Clients, streamer stream.Ne
 
 	logOptions := options.LogOptions{
 		PipelineRunName: name,
-		Tasks:           onlyTasks,
+		Tasks:           tasks,
 		AllSteps:        allSteps,
 		Follow:          follow,
 		Params:          &p,

pkg/cmd/pipelinerun/logs.go

@@ -70,7 +70,7 @@ Show the logs of PipelineRun named 'microservice-1' for all tasks and steps (inc
 
 	c.Flags().BoolVarP(&opts.AllSteps, "all", "a", false, "show all logs including init steps injected by tekton")
 	c.Flags().BoolVarP(&opts.Follow, "follow", "f", false, "stream live logs")
-	c.Flags().StringSliceVarP(&opts.Tasks, "only-tasks", "t", []string{}, "show logs for mentioned tasks only")
+	c.Flags().StringSliceVarP(&opts.Tasks, "task", "t", []string{}, "show logs for mentioned tasks only")
 	c.Flags().IntVarP(&opts.Limit, "limit", "", 5, "lists number of pipelineruns")
 
 	_ = c.MarkZshCompPositionalArgumentCustom(1, "__tkn_get_pipelinerun")

pkg/cmd/taskrun/log_reader.go

@@ -57,6 +57,7 @@ type LogReader struct {
 	Follow   bool
 	AllSteps bool
 	Stream   *cli.Stream
+	Steps    []string
 }
 
 func (lr *LogReader) Read() (<-chan Log, <-chan error, error) {
@@ -113,7 +114,7 @@ func (lr *LogReader) readLiveLogs() (<-chan Log, <-chan error, error) {
 		return nil, nil, errors.New(fmt.Sprintf("task %s failed: %s. Run tkn tr desc %s for more details.", lr.Task, strings.TrimSpace(err.Error()), tr.Name))
 	}
 
-	steps := filterSteps(pod, lr.AllSteps)
+	steps := filterSteps(pod, lr.AllSteps, lr.Steps)
 	logC, errC := lr.readStepsLogs(steps, p, lr.Follow)
 	return logC, errC, err
 }
@@ -143,7 +144,7 @@ func (lr *LogReader) readAvailableLogs(tr *v1alpha1.TaskRun) (<-chan Log, <-chan
 		return nil, nil, errors.New(fmt.Sprintf("task %s failed: %s. Run tkn tr desc %s for more details.", lr.Task, strings.TrimSpace(err.Error()), tr.Name))
 	}
 
-	steps := filterSteps(pod, lr.AllSteps)
+	steps := filterSteps(pod, lr.AllSteps, lr.Steps)
 	logC, errC := lr.readStepsLogs(steps, p, lr.Follow)
 	return logC, errC, nil
 }
@@ -198,14 +199,29 @@ func (lr *LogReader) readStepsLogs(steps []*step, pod *pods.Pod, follow bool) (<
 	return logC, errC
 }
 
-func filterSteps(pod *corev1.Pod, allSteps bool) []*step {
+func filterSteps(pod *corev1.Pod, allSteps bool, stepsGiven []string) []*step {
 	steps := []*step{}
+	stepsInPod := getSteps(pod)
 
 	if allSteps {
 		steps = append(steps, getInitSteps(pod)...)
 	}
 
-	steps = append(steps, getSteps(pod)...)
+	if len(stepsGiven) == 0 {
+		steps = append(steps, stepsInPod...)
+		return steps
+	}
+
+	stepsToAdd := map[string]bool{}
+	for _, s := range stepsGiven {
+		stepsToAdd[s] = true
+	}
+
+	for _, sp := range stepsInPod {
+		if stepsToAdd[sp.name] {
+			steps = append(steps, sp)
+		}
+	}
 
 	return steps
 }

pkg/cmd/taskrun/logs.go

@@ -40,6 +40,10 @@ func logCommand(p cli.Params) *cobra.Command {
 Show the live logs of TaskRun named 'foo' from namespace 'bar':
 
     tkn taskrun logs -f foo -n bar
+
+Show the logs of TaskRun named 'microservice-1' for step 'build' only from namespace 'bar':
+
+    tkn tr logs microservice-1 -s build -n bar
 `
 	c := &cobra.Command{
 		Use:          "logs",
@@ -63,13 +67,18 @@ Show the live logs of TaskRun named 'foo' from namespace 'bar':
 				return err
 			}
 
+			if len(opts.Steps) > 0 && opts.AllSteps {
+				return fmt.Errorf("option --all and option --step are not compatible")
+			}
+
 			return Run(opts)
 		},
 	}
 
 	c.Flags().BoolVarP(&opts.AllSteps, "all", "a", false, "show all logs including init steps injected by tekton")
 	c.Flags().BoolVarP(&opts.Follow, "follow", "f", false, "stream live logs")
 	c.Flags().IntVarP(&opts.Limit, "limit", "", 5, "lists number of taskruns")
+	c.Flags().StringSliceVarP(&opts.Steps, "step", "s", []string{}, "show logs for mentioned steps only")
 
 	_ = c.MarkZshCompPositionalArgumentCustom(1, "__tkn_get_taskrun")
 	return c
@@ -100,6 +109,7 @@ func Run(opts *options.LogOptions) error {
 		Stream:   opts.Stream,
 		Follow:   opts.Follow,
 		AllSteps: opts.AllSteps,
+		Steps:    opts.Steps,
 	}
 
 	logC, errC, err := lr.Read()