Refactor exit behaviour and deprecate Exit()

Shall be replaced by either Exitf() or ExitRaw().

fixes #31

Author: lazyfrosch

README.md

@@ -16,8 +16,6 @@ package main
 
 import (
 	"github.com/NETWAYS/go-check"
-	log "github.com/sirupsen/logrus"
-	"os"
 )
 
 func main() {
@@ -28,14 +26,19 @@ func main() {
 
 	_ = config.FlagSet.StringP("hostname", "H", "localhost", "Hostname to check")
 
-	os.Args = []string{"check_example", "--help"}
-
 	config.ParseArguments()
 
-	log.Info("test")
+	// Some checking should be done here, when --help is not passed
+
+	check.Exitf(check.OK, "Everything is fine - answer=%d", 42)
 }
 ```
 
+```
+OK - Everything is fine - answer=42
+would exit with code 0
+```
+
 See the [documentation on pkg.go.dev](https://pkg.go.dev/github.com/NETWAYS/go-check) for more details and examples.
 
 ## Plugins

cmd/check_example/main.go

@@ -24,10 +24,10 @@ func main() {
 	// time.Sleep(20 * time.Second)
 
 	if *value > *critical {
-		check.Exit(check.Critical, "value is %d", *value)
+		check.Exitf(check.Critical, "value is %d", *value)
 	} else if *value > *warning {
-		check.Exit(check.Warning, "value is %d", *value)
+		check.Exitf(check.Warning, "value is %d", *value)
 	} else {
-		check.Exit(check.OK, "value is %d", *value)
+		check.Exitf(check.OK, "value is %d", *value)
 	}
 }

config_test.go

@@ -1,10 +1,5 @@
 package check
 
-import (
-	log "github.com/sirupsen/logrus"
-	"os"
-)
-
 func ExampleConfig() {
 	config := NewConfig()
 	config.Name = "check_test"
@@ -13,21 +8,12 @@ func ExampleConfig() {
 
 	_ = config.FlagSet.StringP("hostname", "H", "localhost", "Hostname to check")
 
-	os.Args = []string{"check_example", "--help"}
-
 	config.ParseArguments()
 
-	log.Info("test")
-	// Output: Usage of check_test
-	//
-	// Test Plugin
-	//
-	// Arguments:
-	//   -H, --hostname string   Hostname to check (default "localhost")
-	//   -t, --timeout int       Abort the check after n seconds (default 30)
-	//   -d, --debug             Enable debug mode
-	//   -v, --verbose           Enable verbose mode
-	//   -V, --version           Print version and exit
-	// UNKNOWN - pflag: help requested
-	// would exit with code 3
+	// Some checking should be done here
+
+	Exitf(OK, "Everything is fine - answer=%d", 42)
+
+	// Output: OK - Everything is fine - answer=42
+	// would exit with code 0
 }

exit.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"runtime/debug"
+	"strconv"
 
 	"github.com/mitchellh/go-ps"
 )
@@ -16,25 +17,51 @@ var AllowExit = true
 // PrintStack prints the error stack when recovering from a panic with CatchPanic()
 var PrintStack = true
 
+// Exitf prints the plugin output using formatting and exits the program.
+//
+// Output is the formatting string, and the rest of the arguments help adding values.
+//
+// Also see fmt package: https://golang.org/pkg/fmt
+func Exitf(rc int, output string, args ...interface{}) {
+	ExitRaw(rc, fmt.Sprintf(output, args...))
+}
+
+// ExitRaw prints the plugin output with the state prefixed and exits the program.
+//
+// Example:
+//	OK - everything is fine
+func ExitRaw(rc int, output ...string) {
+	text := StatusText(rc) + " -"
+
+	for _, s := range output {
+		text += " " + s
+	}
+
+	text += "\n"
+
+	_, _ = os.Stdout.WriteString(text)
+
+	BaseExit(rc)
+}
+
 // Exit prints the plugin output and exits the program
+//
+// Deprecated, please use Exitf or ExitRaw.
 func Exit(rc int, output string, args ...interface{}) {
-	fmt.Println(StatusText(rc), "-", fmt.Sprintf(output, args...))
-	BaseExit(rc)
+	Exitf(rc, output, args...)
 }
 
 func BaseExit(rc int) {
 	if AllowExit {
 		os.Exit(rc)
 	} else {
-		fmt.Println("would exit with code", rc)
+		_, _ = os.Stdout.WriteString("would exit with code " + strconv.Itoa(rc) + "\n")
 	}
 }
 
 // ExitError exists with an Unknown state while reporting the error
-//
-// TODO: more information about the error
 func ExitError(err error) {
-	Exit(Unknown, err.Error())
+	Exitf(Unknown, "%s (%T)", err.Error(), err)
 }
 
 // CatchPanic is a general function for defer, to capture any panic that occurred during runtime of a check
@@ -56,6 +83,6 @@ func CatchPanic() {
 			output += "\n\n" + string(debug.Stack())
 		}
 
-		Exit(Unknown, output)
+		ExitRaw(Unknown, output)
 	}
 }

exit_test.go

@@ -7,15 +7,27 @@ import (
 )
 
 func ExampleExit() {
-	Exit(OK, "Everything is fine")
+	Exitf(OK, "Everything is fine - value=%d", 42)
+	// Output: OK - Everything is fine - value=42
+	// would exit with code 0
+}
+
+func ExampleExitf() {
+	Exitf(OK, "Everything is fine - value=%d", 42)
+	// Output: OK - Everything is fine - value=42
+	// would exit with code 0
+}
+
+func ExampleExitRaw() {
+	ExitRaw(OK, "Everything is fine")
 	// Output: OK - Everything is fine
 	// would exit with code 0
 }
 
 func ExampleExitError() {
 	err := fmt.Errorf("connection to %s has been timed out", "localhost:12345")
 	ExitError(err)
-	// Output: UNKNOWN - connection to localhost:12345 has been timed out
+	// Output: UNKNOWN - connection to localhost:12345 has been timed out (*errors.errorString)
 	// would exit with code 3
 }
 

timeout.go

@@ -25,16 +25,16 @@ func HandleTimeout(timeout int) {
 	signal.Notify(signals, os.Interrupt, syscall.SIGTERM, syscall.SIGHUP)
 
 	if timeout < 1 {
-		Exit(Unknown, "Invalid timeout: %d", timeout)
+		Exitf(Unknown, "Invalid timeout: %d", timeout)
 	}
 
 	timedOut := time.After(time.Duration(timeout) * time.Second)
 	timeoutEnabled = true
 
 	select {
 	case s := <-signals:
-		Exit(Unknown, "Received signal: %s", s)
+		Exitf(Unknown, "Received signal: %s", s)
 	case <-timedOut:
-		Exit(Unknown, "Timeout reached")
+		ExitRaw(Unknown, "Timeout reached")
 	}
 }