exec improvements, extra messages for when agent can't start

Author: petethepig

pkg/agent/session.go

@@ -201,18 +201,3 @@ func findAllSubprocesses(pid int) []int {
 
 	return res
 }
-
-// TODO: add this check back
-
-// func isRoot() bool {
-// 	u, err := user.Current()
-// 	return err == nil && u.Username == "root"
-// }
-
-// func printDarwinMessage() {
-// 	if runtime.GOOS == "darwin" {
-// 		if !isRoot() {
-// 			log.Error("on macOS it is required to run the agent with sudo")
-// 		}
-// 	}
-// }

pkg/cli/cli_test.go

@@ -18,6 +18,7 @@ type FlagsStruct struct {
 	Foos   []string
 	Bar    int
 	Baz    time.Duration
+	FooBar string
 }
 
 var _ = Describe("config package", func() {
@@ -41,13 +42,15 @@ var _ = Describe("config package", func() {
 					"-foos", "test-val-3",
 					"-bar", "123",
 					"-baz", "10h",
+					"-foo-bar", "test-val-4",
 				})
 
 				Expect(err).ToNot(HaveOccurred())
 				Expect(cfg.Foo).To(Equal("test-val-1"))
 				Expect(cfg.Foos).To(Equal([]string{"test-val-2", "test-val-3"}))
 				Expect(cfg.Bar).To(Equal(123))
 				Expect(cfg.Baz).To(Equal(10 * time.Hour))
+				Expect(cfg.FooBar).To(Equal("test-val-4"))
 			})
 		})
 
@@ -77,6 +80,7 @@ var _ = Describe("config package", func() {
 				Expect(cfg.Foos).To(Equal([]string{"test-val-2", "test-val-3"}))
 				Expect(cfg.Bar).To(Equal(123))
 				Expect(cfg.Baz).To(Equal(10 * time.Hour))
+				Expect(cfg.FooBar).To(Equal("test-val-4"))
 			})
 
 			It("arguments take precendence", func() {

pkg/cli/example.yml

@@ -5,3 +5,4 @@ foos:
   - "test-val-3"
 bar: 123
 baz: "10h"
+foo-bar: "test-val-4"

pkg/exec/cli.go

@@ -6,7 +6,9 @@ import (
 	"os"
 	"os/exec"
 	"os/signal"
+	"os/user"
 	"path"
+	"runtime"
 	"strings"
 	"syscall"
 	"time"
@@ -33,20 +35,21 @@ func Cli(cfg *config.Config, args []string) error {
 			supportedSpies := supportedSpiesWithoutGospy()
 			suggestedCommand := fmt.Sprintf("pyroscope exec -spy-name %s %s", supportedSpies[0], strings.Join(args, " "))
 			return fmt.Errorf(
-				"could not automatically find a spy for program \"%s\". Pass spy name via %s argument, for example: \n  %s\n\nAvailable spies are: %s\n\nIf you believe this is a mistake, please submit an issue at %s",
+				"could not automatically find a spy for program \"%s\". Pass spy name via %s argument, for example: \n  %s\n\nAvailable spies are: %s\n%s\nIf you believe this is a mistake, please submit an issue at %s",
 				baseName,
 				color.YellowString("-spy-name"),
 				color.YellowString(suggestedCommand),
 				strings.Join(supportedSpies, ","),
+				armMessage(),
 				color.BlueString("https://github.com/pyroscope-io/pyroscope/issues"),
 			)
 		}
 	}
 
 	logrus.Info("to disable logging from pyroscope, pass " + color.YellowString("-no-logging") + " argument to pyroscope exec")
 
-	if spyName == "gospy" {
-		return fmt.Errorf("gospy can not profile other processes. See our documentation on using gospy: %s", color.BlueString("https://pyroscope.io/docs/"))
+	if err := performChecks(spyName); err != nil {
+		return err
 	}
 
 	signal.Ignore(syscall.SIGCHLD)
@@ -97,3 +100,48 @@ func supportedSpiesWithoutGospy() []string {
 
 	return supportedSpies
 }
+
+func performChecks(spyName string) error {
+	if spyName == "gospy" {
+		return fmt.Errorf("gospy can not profile other processes. See our documentation on using gospy: %s", color.BlueString("https://pyroscope.io/docs/"))
+	}
+
+	if runtime.GOOS == "darwin" {
+		if !isRoot() {
+			logrus.Error("on macOS you're required to run the agent with sudo")
+		}
+	}
+
+	if stringsContains(spy.SupportedSpies, spyName) {
+		supportedSpies := supportedSpiesWithoutGospy()
+		return fmt.Errorf(
+			"Spy \"%s\" is not supported. Available spies are: %s\n%s",
+			color.BlueString("spyName"),
+			strings.Join(supportedSpies, ","),
+			armMessage(),
+		)
+	}
+
+	return nil
+}
+
+func stringsContains(arr []string, element string) bool {
+	for _, v := range arr {
+		if v == element {
+			return true
+		}
+	}
+	return false
+}
+
+func isRoot() bool {
+	u, err := user.Current()
+	return err == nil && u.Username == "root"
+}
+
+func armMessage() string {
+	if runtime.GOARCH == "arm64" {
+		return "Note that rbspy is not available on arm64 platform"
+	}
+	return ""
+}