Use cobra's RunE wherever possible (#343)

pkg/commands/apply.go

@@ -15,8 +15,8 @@
 package commands
 
 import (
+	"errors"
 	"fmt"
-	"log"
 	"os"
 	"os/exec"
 
@@ -62,22 +62,21 @@ func addApply(topLevel *cobra.Command) {
   # Apply from stdin:
   cat config.yaml | ko apply -f -`,
 		Args: cobra.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			if !isKubectlAvailable() {
-				log.Print("error: kubectl is not available. kubectl must be installed to use ko apply.")
-				return
+				return errors.New("error: kubectl is not available. kubectl must be installed to use ko apply")
 			}
 
 			// Cancel on signals.
 			ctx := createCancellableContext()
 
 			builder, err := makeBuilder(ctx, bo)
 			if err != nil {
-				log.Fatalf("error creating builder: %v", err)
+				return fmt.Errorf("error creating builder: %v", err)
 			}
 			publisher, err := makePublisher(po)
 			if err != nil {
-				log.Fatalf("error creating publisher: %v", err)
+				return fmt.Errorf("error creating publisher: %v", err)
 			}
 			defer publisher.Close()
 			// Create a set of ko-specific flags to ignore when passing through
@@ -110,7 +109,7 @@ func addApply(topLevel *cobra.Command) {
 			// Wire up kubectl stdin to resolveFilesToWriter.
 			stdin, err := kubectlCmd.StdinPipe()
 			if err != nil {
-				log.Fatalf("error piping to 'kubectl apply': %v", err)
+				return fmt.Errorf("error piping to 'kubectl apply': %v", err)
 			}
 
 			// Make sure builds are cancelled if kubectl apply fails.
@@ -138,9 +137,7 @@ func addApply(topLevel *cobra.Command) {
 				return nil
 			})
 
-			if err := g.Wait(); err != nil {
-				log.Fatal(err)
-			}
+			return g.Wait()
 		},
 	}
 	options.AddPublishArg(apply, po)

pkg/commands/create.go

@@ -15,8 +15,8 @@
 package commands
 
 import (
+	"errors"
 	"fmt"
-	"log"
 	"os"
 	"os/exec"
 
@@ -62,22 +62,21 @@ func addCreate(topLevel *cobra.Command) {
   # Create from stdin:
   cat config.yaml | ko create -f -`,
 		Args: cobra.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			if !isKubectlAvailable() {
-				log.Print("error: kubectl is not available. kubectl must be installed to use ko create.")
-				return
+				return errors.New("error: kubectl is not available. kubectl must be installed to use ko create")
 			}
 
 			// Cancel on signals.
 			ctx := createCancellableContext()
 
 			builder, err := makeBuilder(ctx, bo)
 			if err != nil {
-				log.Fatalf("error creating builder: %v", err)
+				return fmt.Errorf("error creating builder: %v", err)
 			}
 			publisher, err := makePublisher(po)
 			if err != nil {
-				log.Fatalf("error creating publisher: %v", err)
+				return fmt.Errorf("error creating publisher: %v", err)
 			}
 			defer publisher.Close()
 			// Create a set of ko-specific flags to ignore when passing through
@@ -110,7 +109,7 @@ func addCreate(topLevel *cobra.Command) {
 			// Wire up kubectl stdin to resolveFilesToWriter.
 			stdin, err := kubectlCmd.StdinPipe()
 			if err != nil {
-				log.Fatalf("error piping to 'kubectl create': %v", err)
+				return fmt.Errorf("error piping to 'kubectl create': %v", err)
 			}
 
 			// Make sure builds are cancelled if kubectl create fails.
@@ -138,9 +137,7 @@ func addCreate(topLevel *cobra.Command) {
 				return nil
 			})
 
-			if err := g.Wait(); err != nil {
-				log.Fatal(err)
-			}
+			return g.Wait()
 		},
 	}
 	options.AddPublishArg(create, po)

pkg/commands/delete.go

@@ -15,23 +15,22 @@
 package commands
 
 import (
-	"log"
+	"errors"
 	"os"
 	"os/exec"
 
 	"github.com/spf13/cobra"
 )
 
 // runCmd is suitable for use with cobra.Command's Run field.
-type runCmd func(*cobra.Command, []string)
+type runCmd func(*cobra.Command, []string) error
 
 // passthru returns a runCmd that simply passes our CLI arguments
 // through to a binary named command.
 func passthru(command string) runCmd {
-	return func(_ *cobra.Command, _ []string) {
+	return func(_ *cobra.Command, _ []string) error {
 		if !isKubectlAvailable() {
-			log.Print("error: kubectl is not available. kubectl must be installed to use ko delete.")
-			return
+			return errors.New("error: kubectl is not available. kubectl must be installed to use ko delete")
 		}
 
 		// Cancel on signals.
@@ -49,9 +48,7 @@ func passthru(command string) runCmd {
 		cmd.Stdin = os.Stdin
 
 		// Run it.
-		if err := cmd.Run(); err != nil {
-			log.Fatalf("error executing %q command with args: %v; %v", command, os.Args[1:], err)
-		}
+		return cmd.Run()
 	}
 }
 
@@ -60,7 +57,7 @@ func addDelete(topLevel *cobra.Command) {
 	topLevel.AddCommand(&cobra.Command{
 		Use:   "delete",
 		Short: `See "kubectl help delete" for detailed usage.`,
-		Run:   passthru("kubectl"),
+		RunE:  passthru("kubectl"),
 		// We ignore unknown flags to avoid importing everything Go exposes
 		// from our commands.
 		FParseErrWhitelist: cobra.FParseErrWhitelist{

pkg/commands/publish.go

@@ -16,7 +16,6 @@ package commands
 
 import (
 	"fmt"
-	"log"
 
 	"github.com/google/ko/pkg/commands/options"
 	"github.com/spf13/cobra"
@@ -57,24 +56,25 @@ func addPublish(topLevel *cobra.Command) {
   # This always preserves import paths.
   ko publish --local github.com/foo/bar/cmd/baz github.com/foo/bar/cmd/blah`,
 		Args: cobra.MinimumNArgs(1),
-		Run: func(_ *cobra.Command, args []string) {
+		RunE: func(_ *cobra.Command, args []string) error {
 			ctx := createCancellableContext()
 			builder, err := makeBuilder(ctx, bo)
 			if err != nil {
-				log.Fatalf("error creating builder: %v", err)
+				return fmt.Errorf("error creating builder: %v", err)
 			}
 			publisher, err := makePublisher(po)
 			if err != nil {
-				log.Fatalf("error creating publisher: %v", err)
+				return fmt.Errorf("error creating publisher: %v", err)
 			}
 			defer publisher.Close()
 			images, err := publishImages(ctx, args, publisher, builder)
 			if err != nil {
-				log.Fatalf("failed to publish images: %v", err)
+				return fmt.Errorf("failed to publish images: %v", err)
 			}
 			for _, img := range images {
 				fmt.Println(img)
 			}
+			return nil
 		},
 	}
 	options.AddPublishArg(publish, po)

pkg/commands/resolve.go

@@ -15,7 +15,7 @@
 package commands
 
 import (
-	"log"
+	"fmt"
 	"os"
 
 	"github.com/google/ko/pkg/commands/options"
@@ -54,20 +54,18 @@ func addResolve(topLevel *cobra.Command) {
   # This always preserves import paths.
   ko resolve --local -f config/`,
 		Args: cobra.NoArgs,
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			ctx := createCancellableContext()
 			builder, err := makeBuilder(ctx, bo)
 			if err != nil {
-				log.Fatalf("error creating builder: %v", err)
+				return fmt.Errorf("error creating builder: %v", err)
 			}
 			publisher, err := makePublisher(po)
 			if err != nil {
-				log.Fatalf("error creating publisher: %v", err)
+				return fmt.Errorf("error creating publisher: %v", err)
 			}
 			defer publisher.Close()
-			if err := resolveFilesToWriter(ctx, builder, publisher, fo, so, os.Stdout); err != nil {
-				log.Fatal(err)
-			}
+			return resolveFilesToWriter(ctx, builder, publisher, fo, so, os.Stdout)
 		},
 	}
 	options.AddPublishArg(resolve, po)

pkg/commands/run.go

@@ -15,6 +15,8 @@
 package commands
 
 import (
+	"errors"
+	"fmt"
 	"log"
 	"os"
 	"os/exec"
@@ -46,7 +48,7 @@ func addRun(topLevel *cobra.Command) {
 
   # You can also supply args and flags to the command.
   ko run ./cmd/baz -- -v arg1 arg2 --yes`,
-		Run: func(cmd *cobra.Command, args []string) {
+		RunE: func(cmd *cobra.Command, args []string) error {
 			ctx := createCancellableContext()
 
 			// Args after -- are for kubectl, so only consider importPaths before it.
@@ -56,7 +58,7 @@ func addRun(topLevel *cobra.Command) {
 				importPaths = args[:cmd.Flags().ArgsLenAtDash()]
 			}
 			if len(importPaths) == 0 {
-				log.Fatalf("ko run: no importpaths listed")
+				return errors.New("ko run: no importpaths listed")
 			}
 
 			kubectlArgs := []string{}
@@ -67,24 +69,24 @@ func addRun(topLevel *cobra.Command) {
 
 			builder, err := makeBuilder(ctx, bo)
 			if err != nil {
-				log.Fatalf("error creating builder: %v", err)
+				return fmt.Errorf("error creating builder: %v", err)
 			}
 			publisher, err := makePublisher(po)
 			if err != nil {
-				log.Fatalf("error creating publisher: %v", err)
+				return fmt.Errorf("error creating publisher: %v", err)
 			}
 			defer publisher.Close()
 
 			if len(os.Args) < 3 {
-				log.Fatalf("usage: %s run <package>", os.Args[0])
+				return fmt.Errorf("usage: %s run <package>", os.Args[0])
 			}
 			ip := os.Args[2]
 			if strings.HasPrefix(ip, "-") {
-				log.Fatalf("expected first arg to be positional, got %q", ip)
+				return fmt.Errorf("expected first arg to be positional, got %q", ip)
 			}
 			imgs, err := publishImages(ctx, importPaths, publisher, builder)
 			if err != nil {
-				log.Fatalf("failed to publish images: %v", err)
+				return fmt.Errorf("failed to publish images: %v", err)
 			}
 
 			// Usually only one, but this is the simple way to access the
@@ -127,9 +129,10 @@ func addRun(topLevel *cobra.Command) {
 
 				// Run it.
 				if err := kubectlCmd.Run(); err != nil {
-					log.Fatalf("error executing \"kubectl run\": %v", err)
+					return err
 				}
 			}
+			return nil
 		},
 		// We ignore unknown flags to avoid importing everything Go exposes
 		// from our commands.