comment-monitor: Added flag support; added built-in help command.

Implements first phase of prometheus/proposals#41

Signed-off-by: bwplotka <bwplotka@gmail.com>

tools/comment-monitor/internal/command.go

@@ -54,6 +54,10 @@ func parseConfigContent(content []byte) (_ *Config, err error) {
 			if c.Name == "" && c.ArgsRegex == "" {
 				return nil, fmt.Errorf("/%v bad config; default commands cannot have empty args_regex (no required arguments)", p.Prefix)
 			}
+			if strings.ToLower(c.Name) == "help" {
+				return nil, fmt.Errorf("/%v bad config; 'help' command name is reserved", p.Prefix)
+
+			}
 			if strings.HasPrefix(c.ArgsRegex, "^") {
 				return nil, fmt.Errorf("/%v bad config; args_regex has to be front open, got %v", p.Prefix, c.ArgsRegex)
 			}
@@ -144,6 +148,16 @@ func ParseCommand(cfg *Config, comment string) (_ *Command, ok bool, err *Comman
 	cmdLine := comment[:i]
 	rest := cmdLine[len(prefix.Prefix):]
 
+	// Is it help?
+	if hasExactPrefix(rest, " help") {
+		return &Command{
+			Args:                   map[string]string{},
+			Prefix:                 prefix.Prefix,
+			SuccessCommentTemplate: prefix.Help,
+			DebugCMDLine:           cmdLine,
+		}, true, nil
+	}
+
 	// Find the command.
 	var cmdConfig *CommandConfig
 	var defaultCmdConfig *CommandConfig

tools/comment-monitor/internal/command_test.go

@@ -28,11 +28,11 @@ const (
 	eventTypeStop    = "prombench_stop"
 )
 
-func testCommand(evenType, release string) *Command {
+func testCommand(eventType, release string) *Command {
 	c := &Command{
 		Prefix:           "/prombench",
 		Args:             map[string]string{},
-		EventType:        evenType,
+		EventType:        eventType,
 		ShouldVerifyUser: true,
 	}
 	if release != "" {
@@ -41,6 +41,13 @@ func testCommand(evenType, release string) *Command {
 	return c
 }
 
+func helpCommand() *Command {
+	return &Command{
+		Prefix: "/prombench",
+		Args:   map[string]string{},
+	}
+}
+
 type parseCommandCase struct {
 	comment                string
 	expect                 *Command
@@ -99,9 +106,8 @@ func testParseCommand(t *testing.T, c *Config, cases []parseCommandCase) {
 }
 
 func TestParseCommand(t *testing.T) {
-	const testConfigFile = "./testconfig.yaml"
 
-	c, err := ParseConfig(testConfigFile)
+	c, err := ParseConfig("./testconfig.yaml")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -122,6 +128,10 @@ func TestParseCommand(t *testing.T) {
 			comment: "/prombench cancel",
 			expect:  testCommand(eventTypeStop, ""),
 		},
+		{
+			comment: "/prombench help",
+			expect:  helpCommand(),
+		},
 		// Different versions based on the provided  args_regex: ^\s+(?P<RELEASE>master|main|v[0-9]+\.[0-9]+\.[0-9]+\S*)\s*$
 		{
 			comment: "/prombench main",

tools/comment-monitor/main.go

@@ -236,12 +236,14 @@ func (d *dispatcher) HandleIssue(w http.ResponseWriter, r *http.Request) {
 			}
 			return
 		}
+	}
 
+	allArgs := cmd.Args
+	if cmd.EventType != "" {
 		logger = logger.With("cmdLine", cmd.DebugCMDLine)
 		logger.Info("dispatching a new command and updating issue")
 
 		// Combine all arguments for both dispatch and the comment update.
-		allArgs := cmd.Args
 		allArgs["PR_NUMBER"] = strconv.Itoa(eventDetails.PR)
 		allArgs["LAST_COMMIT_SHA"], err = ghClient.GetLastCommitSHA()
 		if err != nil {
@@ -257,26 +259,27 @@ func (d *dispatcher) HandleIssue(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 		logger.Info("dispatched repository GitHub payload")
+	}
 
-		// Update the issue.
-		comment, err := executeCommentTemplate(cmd.SuccessCommentTemplate, allArgs)
-		if err != nil {
-			handleErr(w, logger, "failed to execute template", http.StatusInternalServerError, err)
-			return
-		}
+	// Update the issue.
+	comment, err := executeCommentTemplate(cmd.SuccessCommentTemplate, allArgs)
+	if err != nil {
+		handleErr(w, logger, "failed to execute template", http.StatusInternalServerError, err)
+		return
+	}
 
-		if err = ghClient.PostComment(comment); err != nil {
-			handleErr(w, logger, "dispatch successful; but could not post comment to GitHub", http.StatusInternalServerError, err)
-			return
-		}
+	if err = ghClient.PostComment(comment); err != nil {
+		handleErr(w, logger, "dispatch successful; but could not post comment to GitHub", http.StatusInternalServerError, err)
+		return
+	}
 
-		if cmd.SuccessLabel != "" {
-			if err = ghClient.PostLabel(cmd.SuccessLabel); err != nil {
-				handleErr(w, logger, "dispatch successful; but could not post label to GitHub", http.StatusInternalServerError, err)
-				return
-			}
+	if cmd.SuccessLabel != "" {
+		if err = ghClient.PostLabel(cmd.SuccessLabel); err != nil {
+			handleErr(w, logger, "dispatch successful; but could not post label to GitHub", http.StatusInternalServerError, err)
+			return
 		}
 	}
+
 }
 
 func executeCommentTemplate(commentTemplate string, args map[string]string) (string, error) {