Rework error handling to check context.State

Currently the debos error handling sets an exitcode during the run, then
exits with that code once execution has finished. This paradigm is quite
fragile, so let's switch around the error handling to use context.State
to track errors and check the state of this variable after the run has
completed.

Signed-off-by: Christopher Obbard <[email protected]>

cmd/debos/debos.go

@@ -15,18 +15,18 @@ import (
 	"github.com/jessevdk/go-flags"
 )
 
-func checkError(context *debos.DebosContext, err error, a debos.Action, stage string) int {
+func checkError(context *debos.DebosContext, err error, a debos.Action, stage string) bool {
 	if err == nil {
-		return 0
+		return true
 	}
 
 	context.State = debos.Failed
 	log.Printf("Action `%s` failed at stage %s, error: %s", a, stage, err)
 	debos.DebugShell(*context)
-	return 1
+	return false
 }
 
-func do_run(r actions.Recipe, context *debos.DebosContext) int {
+func do_run(r actions.Recipe, context *debos.DebosContext) bool {
 	for _, a := range r.Actions {
 		err := a.Run(context)
 
@@ -35,12 +35,12 @@ func do_run(r actions.Recipe, context *debos.DebosContext) int {
 		defer a.Cleanup(context)
 
 		// Check the state of Run method
-		if exitcode := checkError(context, err, a, "Run"); exitcode != 0 {
-			return exitcode
+		if !checkError(context, err, a, "Run") {
+			return false
 		}
 	}
 
-	return 0
+	return true
 }
 
 func warnLocalhost(variable string, value string) {
@@ -88,11 +88,12 @@ func main() {
 		"no_proxy",
 	}
 
-	var exitcode int = 0
 	// Allow to run all deferred calls prior to os.Exit()
-	defer func() {
-		os.Exit(exitcode)
-	}()
+	defer func(context debos.DebosContext) {
+		if context.State == debos.Failed {
+			os.Exit(1)
+		}
+	}(context)
 
 	parser := flags.NewParser(&options, flags.Default)
 	fakemachineBackends := parser.FindOptionByLongName("fakemachine-backend")
@@ -104,20 +105,20 @@ func main() {
 		if ok && flagsErr.Type == flags.ErrHelp {
 			return
 		} else {
-			exitcode = 1
+			context.State = debos.Failed
 			return
 		}
 	}
 
 	if len(args) != 1 {
 		log.Println("No recipe given!")
-		exitcode = 1
+		context.State = debos.Failed
 		return
 	}
 
 	if options.DisableFakeMachine && options.Backend != "auto" {
 		log.Println("--disable-fakemachine and --fakemachine-backend are mutually exclusive")
-		exitcode = 1
+		context.State = debos.Failed
 		return
 	}
 
@@ -140,12 +141,12 @@ func main() {
 	r := actions.Recipe{}
 	if _, err := os.Stat(file); os.IsNotExist(err) {
 		log.Println(err)
-		exitcode = 1
+		context.State = debos.Failed
 		return
 	}
 	if err := r.Parse(file, options.PrintRecipe, options.Verbose, options.TemplateVars); err != nil {
 		log.Println(err)
-		exitcode = 1
+		context.State = debos.Failed
 		return
 	}
 
@@ -169,7 +170,7 @@ func main() {
 			if options.Backend == "auto" {
 				runInFakeMachine = false
 			} else {
-				exitcode = 1
+				context.State = debos.Failed
 				return
 			}
 		}
@@ -233,7 +234,7 @@ func main() {
 
 	for _, a := range r.Actions {
 		err = a.Verify(&context)
-		if exitcode = checkError(&context, err, a, "Verify"); exitcode != 0 {
+		if !checkError(&context, err, a, "Verify") {
 			return
 		}
 	}
@@ -253,7 +254,7 @@ func main() {
 		memsize, err := units.RAMInBytes(options.Memory)
 		if err != nil {
 			fmt.Printf("Couldn't parse memory size: %v\n", err)
-			exitcode = 1
+			context.State = debos.Failed
 			return
 		}
 		m.SetMemory(int(memsize / 1024 / 1024))
@@ -268,7 +269,7 @@ func main() {
 			size, err := units.FromHumanSize(options.ScratchSize)
 			if err != nil {
 				fmt.Printf("Couldn't parse scratch size: %v\n", err)
-				exitcode = 1
+				context.State = debos.Failed
 				return
 			}
 			m.SetScratch(size, "")
@@ -310,25 +311,25 @@ func main() {
 			defer a.PostMachineCleanup(&context)
 
 			err = a.PreMachine(&context, m, &args)
-			if exitcode = checkError(&context, err, a, "PreMachine"); exitcode != 0 {
+			if !checkError(&context, err, a, "PreMachine") {
 				return
 			}
 		}
 
-		exitcode, err = m.RunInMachineWithArgs(args)
+		exitcode, err := m.RunInMachineWithArgs(args)
 		if err != nil {
 			fmt.Println(err)
+			context.State = debos.Failed
 			return
 		}
-
 		if exitcode != 0 {
 			context.State = debos.Failed
 			return
 		}
 
 		for _, a := range r.Actions {
 			err = a.PostMachine(&context)
-			if exitcode = checkError(&context, err, a, "Postmachine"); exitcode != 0 {
+			if !checkError(&context, err, a, "Postmachine") {
 				return
 			}
 		}
@@ -343,7 +344,7 @@ func main() {
 			defer a.PostMachineCleanup(&context)
 
 			err = a.PreNoMachine(&context)
-			if exitcode = checkError(&context, err, a, "PreNoMachine"); exitcode != 0 {
+			if !checkError(&context, err, a, "PreNoMachine") {
 				return
 			}
 		}
@@ -353,20 +354,19 @@ func main() {
 	if _, err = os.Stat(context.Rootdir); os.IsNotExist(err) {
 		err = os.Mkdir(context.Rootdir, 0755)
 		if err != nil && os.IsNotExist(err) {
-			exitcode = 1
+			context.State = debos.Failed
 			return
 		}
 	}
 
-	exitcode = do_run(r, &context)
-	if exitcode != 0 {
+	if !do_run(r, &context) {
 		return
 	}
 
 	if !fakemachine.InMachine() {
 		for _, a := range r.Actions {
 			err = a.PostMachine(&context)
-			if exitcode = checkError(&context, err, a, "PostMachine"); exitcode != 0 {
+			if !checkError(&context, err, a, "PostMachine") {
 				return
 			}
 		}