Improve gpg binary detection and error handling (#522)

Fixes #521

action/action.go

@@ -12,6 +12,7 @@ import (
 	gpgcli "github.com/justwatchcom/gopass/backend/gpg/cli"
 	"github.com/justwatchcom/gopass/config"
 	"github.com/justwatchcom/gopass/store/root"
+	"github.com/justwatchcom/gopass/utils/out"
 )
 
 type gpger interface {
@@ -58,7 +59,7 @@ func New(ctx context.Context, cfg *config.Config, sv semver.Version) (*Action, e
 		Args:  gpgOpts(),
 	})
 	if err != nil {
-		return nil, err
+		out.Red(ctx, "Warning: GPG not found: %s", err)
 	}
 
 	store, err := root.New(ctx, cfg, act.gpg)
@@ -94,3 +95,8 @@ func gpgOpts() []string {
 func (s *Action) String() string {
 	return s.Store.String()
 }
+
+// HasGPG returns true if the GPG wrapper is initialized
+func (s *Action) HasGPG() bool {
+	return s.gpg != nil
+}

action/init.go

@@ -18,6 +18,9 @@ import (
 // Initialized returns an error if the store is not properly
 // prepared.
 func (s *Action) Initialized(ctx context.Context, c *cli.Context) error {
+	if s.gpg.Binary() == "" {
+		return s.exitError(ctx, ExitGPG, nil, "gpg not found but required")
+	}
 	if s.gpg.Version(ctx).LT(semver.Version{Major: 2, Minor: 0, Patch: 0}) {
 		out.Red(ctx, "Warning: Using GPG 1.x. Using GPG 2.0 or later is highly recommended")
 	}

backend/gpg/cli/gpg.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 
 	"github.com/justwatchcom/gopass/backend/gpg"
+	"github.com/justwatchcom/gopass/utils/ctxutil"
 	"github.com/justwatchcom/gopass/utils/out"
 	"github.com/pkg/errors"
 )
@@ -61,7 +62,12 @@ func New(cfg Config) (*GPG, error) {
 		binary: "gpg",
 		args:   append(defaultArgs, cfg.Args...),
 	}
-	if err := g.detectBinary(cfg.Binary); err != nil {
+
+	ctx := context.Background()
+	if gdb := os.Getenv("GOPASS_DEBUG"); gdb == "true" {
+		ctx = ctxutil.WithDebug(ctx, true)
+	}
+	if err := g.detectBinary(ctx, cfg.Binary); err != nil {
 		return nil, err
 	}
 
@@ -70,6 +76,9 @@ func New(cfg Config) (*GPG, error) {
 
 // Binary returns the GPG binary location
 func (g *GPG) Binary() string {
+	if g == nil {
+		return ""
+	}
 	return g.binary
 }
 

backend/gpg/cli/version.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 
 	"github.com/blang/semver"
+	"github.com/justwatchcom/gopass/utils/out"
 )
 
 type gpgBin struct {
@@ -33,7 +34,7 @@ func (v byVersion) Less(i, j int) bool {
 
 // Version will returns GPG version information
 func (g *GPG) Version(ctx context.Context) semver.Version {
-	return version(ctx, g.binary)
+	return version(ctx, g.Binary())
 }
 
 func version(ctx context.Context, binary string) semver.Version {
@@ -60,24 +61,28 @@ func version(ctx context.Context, binary string) semver.Version {
 	return v
 }
 
-func (g *GPG) detectBinary(bin string) error {
+func (g *GPG) detectBinary(ctx context.Context, bin string) error {
 	bins, err := g.detectBinaryCandidates(bin)
 	if err != nil {
 		return err
 	}
 	bv := make(byVersion, 0, len(bins))
 	for _, b := range bins {
+		out.Debug(ctx, "gpg.detectBinary - Looking for '%s' ...", b)
 		if p, err := exec.LookPath(b); err == nil {
-			bv = append(bv, gpgBin{
+			gb := gpgBin{
 				path: p,
-				ver:  version(context.Background(), p),
-			})
+				ver:  version(ctx, p),
+			}
+			out.Debug(ctx, "gpg.detectBinary - Found '%s' at '%s' (%s)", b, p, gb.ver.String())
+			bv = append(bv, gb)
 		}
 	}
-	sort.Sort(bv)
 	if len(bv) < 1 {
 		return errors.New("no gpg binary found")
 	}
+	sort.Sort(bv)
 	g.binary = bv[len(bv)-1].path
+	out.Debug(ctx, "gpg.detectBinary - using '%s'", g.binary)
 	return nil
 }

main.go

@@ -689,6 +689,12 @@ func main() {
 			Usage: "Initialize new password store.",
 			Description: "" +
 				"Initialize new password storage and use gpg-id for encryption.",
+			Before: func(c *cli.Context) error {
+				if !action.HasGPG() {
+					return fmt.Errorf("gpg not found")
+				}
+				return nil
+			},
 			Action: func(c *cli.Context) error {
 				return action.Init(withGlobalFlags(ctx, c), c)
 			},