fix gpg setting

Init is actually never called and I have no clue why it is there if it is
not called.
Take this opportunity to introduce a New function which only does the
helper lookup and panics iff that fails. Panic may be a bit too aggressive,
but seems the most certain way to get out of not finding a suitable gpg1
binary.

context/context.go

@@ -400,7 +400,7 @@ func (context *AptlyContext) GetSigner() pgp.Signer {
 	defer context.Unlock()
 
 	if context.pgpProvider() == "gpg" { // nolint: goconst
-		return &pgp.GpgSigner{}
+		return pgp.NewGpgSigner()
 	}
 
 	return &pgp.GoSigner{}
@@ -412,7 +412,7 @@ func (context *AptlyContext) GetVerifier() pgp.Verifier {
 	defer context.Unlock()
 
 	if context.pgpProvider() == "gpg" { // nolint: goconst
-		return &pgp.GpgVerifier{}
+		return pgp.NewGpgVerifier()
 	}
 
 	return &pgp.GoVerifier{}

pgp/gnupg.go

@@ -114,14 +114,17 @@ func findGPGV1() (string, error) {
 	return "", fmt.Errorf("Couldn't find a suitable gpgv executable. Make sure gpgv1 is available as either gpgv or gpgv1 in $PATH")
 }
 
+// NewGpgSigner creates a new gpg signer
+func NewGpgSigner() *GpgSigner {
+	gpg, err := findGPG1()
+	if err != nil {
+		panic(err)
+	}
+	return &GpgSigner{gpg: gpg}
+}
+
 // Init verifies availability of gpg & presence of keys
 func (g *GpgSigner) Init() error {
-	cmd, err := findGPG1()
-	if err != nil {
-		return err
-	}
-	g.gpg = cmd
-
 	output, err := exec.Command(g.gpg, "--list-keys", "--dry-run", "--no-auto-check-trustdb").CombinedOutput()
 	if err != nil {
 		return fmt.Errorf("unable to execute gpg: %s (is gpg installed?): %s", err, string(output))
@@ -168,6 +171,21 @@ type GpgVerifier struct {
 	keyRings []string
 }
 
+// NewGpgVerifier creates a new gpg signer
+func NewGpgVerifier() *GpgVerifier {
+	gpg, err := findGPG1()
+	if err != nil {
+		panic(err)
+	}
+
+	gpgv, err := findGPGV1()
+	if err != nil {
+		panic(err)
+	}
+
+	return &GpgVerifier{gpg: gpg, gpgv: gpgv}
+}
+
 // InitKeyring verifies that gpg is installed and some keys are trusted
 func (g *GpgVerifier) InitKeyring() error {
 	cmd, err := findGPG1()

pgp/gnupg_test.go

@@ -26,9 +26,7 @@ func (s *GnupgSuite) TestGPG1(c *C) {
 	os.Setenv("PATH", filepath.Join(s.bins, "gpg1"))
 	defer func() { os.Setenv("PATH", origPath) }()
 
-	signer := GpgSigner{}
-	err := signer.Init()
-	c.Assert(err, IsNil)
+	signer := NewGpgSigner()
 	c.Assert(signer.gpg, Equals, "gpg")
 }
 
@@ -38,9 +36,7 @@ func (s *GnupgSuite) TestGPG1Not2(c *C) {
 	os.Setenv("PATH", filepath.Join(s.bins, "gpg2-and-1"))
 	defer func() { os.Setenv("PATH", origPath) }()
 
-	signer := GpgSigner{}
-	err := signer.Init()
-	c.Assert(err, IsNil)
+	signer := NewGpgSigner()
 	c.Assert(signer.gpg, Equals, "gpg1")
 }
 
@@ -50,10 +46,7 @@ func (s *GnupgSuite) TestGPGNothing(c *C) {
 	os.Setenv("PATH", filepath.Join(s.bins, "gpg2-only"))
 	defer func() { os.Setenv("PATH", origPath) }()
 
-	signer := GpgSigner{}
-	err := signer.Init()
-	c.Assert(err, NotNil)
-	c.Assert(signer.gpg, Equals, "")
+	c.Assert(func() { NewGpgSigner() }, PanicMatches, `Couldn't find a suitable gpg executable.+`)
 }
 
 // If gpgv == gpgv1 = pick gpgv
@@ -62,9 +55,7 @@ func (s *GnupgSuite) TestGPGV1(c *C) {
 	os.Setenv("PATH", filepath.Join(s.bins, "gpgv1")+":"+filepath.Join(s.bins, "gpg1"))
 	defer func() { os.Setenv("PATH", origPath) }()
 
-	verifier := GpgVerifier{}
-	err := verifier.InitKeyring()
-	c.Assert(err, IsNil)
+	verifier := NewGpgVerifier()
 	c.Assert(verifier.gpgv, Equals, "gpgv")
 }
 
@@ -74,9 +65,7 @@ func (s *GnupgSuite) TestGPGV1Not2(c *C) {
 	os.Setenv("PATH", filepath.Join(s.bins, "gpgv2-and-1")+":"+filepath.Join(s.bins, "gpg1"))
 	defer func() { os.Setenv("PATH", origPath) }()
 
-	verifier := GpgVerifier{}
-	err := verifier.InitKeyring()
-	c.Assert(err, IsNil)
+	verifier := NewGpgVerifier()
 	c.Assert(verifier.gpgv, Equals, "gpgv1")
 }
 
@@ -86,8 +75,5 @@ func (s *GnupgSuite) TestGPGVNothing(c *C) {
 	os.Setenv("PATH", filepath.Join(s.bins, "gpgv2-only")+":"+filepath.Join(s.bins, "gpg1"))
 	defer func() { os.Setenv("PATH", origPath) }()
 
-	verifier := GpgVerifier{}
-	err := verifier.InitKeyring()
-	c.Assert(err, NotNil)
-	c.Assert(verifier.gpgv, Equals, "")
+	c.Assert(func() { NewGpgVerifier() }, PanicMatches, `Couldn't find a suitable gpgv executable.+`)
 }