don't panick on unix connection failure

main.go

@@ -55,6 +55,11 @@ func main() {
 	}
 
 	if err != nil {
+		if errMessage, known := app.KnownError(err); known {
+			log.Println(errMessage)
+			os.Exit(0)
+		}
+
 		if client.IsErrConnectionFailed(err) {
 			log.Println(app.Tr.ConnectionFailed)
 			os.Exit(0)

pkg/app/app.go

@@ -2,6 +2,7 @@ package app
 
 import (
 	"io"
+	"strings"
 
 	"github.com/jesseduffield/lazydocker/pkg/commands"
 	"github.com/jesseduffield/lazydocker/pkg/config"
@@ -50,7 +51,9 @@ func NewApp(config *config.AppConfig) (*App, error) {
 }
 
 func (app *App) Run() error {
-	return app.Gui.RunWithSubprocesses()
+	err := app.Gui.RunWithSubprocesses()
+
+	return err
 }
 
 // Close closes any resources
@@ -63,3 +66,28 @@ func (app *App) Close() error {
 	}
 	return nil
 }
+
+type errorMapping struct {
+	originalError string
+	newError      string
+}
+
+// KnownError takes an error and tells us whether it's an error that we know about where we can print a nicely formatted version of it rather than panicking with a stack trace
+func (app *App) KnownError(err error) (string, bool) {
+	errorMessage := err.Error()
+
+	mappings := []errorMapping{
+		{
+			originalError: "Got permission denied while trying to connect to the Docker daemon socket",
+			newError:      app.Tr.CannotAccessDockerSocketError,
+		},
+	}
+
+	for _, mapping := range mappings {
+		if strings.Contains(errorMessage, mapping.originalError) {
+			return mapping.newError, true
+		}
+	}
+
+	return "", false
+}

pkg/i18n/english.go

@@ -25,6 +25,7 @@ type TranslationSet struct {
 	ConnectionFailed                           string
 	UnattachableContainerError                 string
 	CannotAttachStoppedContainerError          string
+	CannotAccessDockerSocketError              string
 
 	Donate                     string
 	Cancel                     string
@@ -98,6 +99,7 @@ func englishSet() TranslationSet {
 		ConnectionFailed:                  "connection to docker client failed. You may need to restart the docker client",
 		UnattachableContainerError:        "Container does not support attaching. You must either run the service with the '-it' flag or use `stdin_open: true, tty: true` in the docker-compose.yml file",
 		CannotAttachStoppedContainerError: "You cannot attach to a stopped container, you need to start it first (which you can actually do with the 'r' key) (yes I'm too lazy to do this automatically for you) (pretty cool that I get to communicate one-on-one with you in the form of an error message though)",
+		CannotAccessDockerSocketError:     "Can't access docker socket at: unix:///var/run/docker.sock\nRun lazydocker as root or read https://docs.docker.com/install/linux/linux-postinstall/",
 
 		Donate:  "Donate",
 		Confirm: "Confirm",