feat(rpm): properly handle optional fields (#809)

closes  #619

Signed-off-by: Carlos Alexandro Becker <caarlos0@users.noreply.github.com>

go.mod

@@ -11,7 +11,7 @@ require (
 	github.com/blakesmith/ar v0.0.0-20190502131153-809d4375e1fb
 	github.com/caarlos0/go-rpmutils v0.2.1-0.20240105125627-01185134a559
 	github.com/caarlos0/go-version v0.1.1
-	github.com/google/rpmpack v0.6.0
+	github.com/google/rpmpack v0.6.1-0.20240329070804-c2247cbb881a
 	github.com/goreleaser/chglog v0.5.0
 	github.com/goreleaser/fileglob v1.3.0
 	github.com/invopop/jsonschema v0.12.0

go.sum

@@ -66,8 +66,8 @@ github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJA
 github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l8iNU+DwB5epxmsaqB+rhGL0m5jtYqE=
 github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
-github.com/google/rpmpack v0.6.0 h1:LoQuqlw6kHRwg25n3M0xtYrW+z2pTkR0ae1xx11hRw8=
-github.com/google/rpmpack v0.6.0/go.mod h1:uqVAUVQLq8UY2hCDfmJ/+rtO3aw7qyhc90rCVEabEfI=
+github.com/google/rpmpack v0.6.1-0.20240329070804-c2247cbb881a h1:JJBdjSfqSy3mnDT0940ASQFghwcZ4y4cb6ttjAoXqwE=
+github.com/google/rpmpack v0.6.1-0.20240329070804-c2247cbb881a/go.mod h1:uqVAUVQLq8UY2hCDfmJ/+rtO3aw7qyhc90rCVEabEfI=
 github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

rpm/rpm.go

@@ -208,8 +208,13 @@ func buildRPMMeta(info *nfpm.Info) (*rpmpack.RPMMetaData, error) {
 	if info.RPM.Compression == "" {
 		info.RPM.Compression = "gzip:-1"
 	}
-	if epoch, err = strconv.ParseUint(defaultTo(info.Epoch, "0"), 10, 32); err != nil {
-		return nil, err
+
+	if info.Epoch == "" {
+		epoch = uint64(rpmpack.NoEpoch)
+	} else {
+		if epoch, err = strconv.ParseUint(info.Epoch, 10, 32); err != nil {
+			return nil, err
+		}
 	}
 	if provides, err = toRelation(info.Provides); err != nil {
 		return nil, err

rpm/rpm_test.go

@@ -29,6 +29,8 @@ func exampleInfo() *nfpm.Info {
 		Priority:    "extra",
 		Maintainer:  "Carlos A Becker <pkg@carlosbecker.com>",
 		Version:     "1.0.0",
+		Release:     "1",
+		Epoch:       "0",
 		Section:     "default",
 		Homepage:    "http://carlosbecker.com",
 		Vendor:      "nope",
@@ -78,6 +80,7 @@ func exampleInfo() *nfpm.Info {
 				PostRemove:  "../testdata/scripts/postremove.sh",
 			},
 			RPM: nfpm.RPM{
+				Group:    "foo",
 				Prefixes: []string{"/opt"},
 				Scripts: nfpm.RPMScripts{
 					PreTrans:  "../testdata/scripts/pretrans.sh",
@@ -134,7 +137,7 @@ func TestRPM(t *testing.T) {
 
 	group, err := rpm.Header.GetString(rpmutils.GROUP)
 	require.NoError(t, err)
-	require.Equal(t, "", group)
+	require.Equal(t, "foo", group)
 
 	summary, err := rpm.Header.GetString(rpmutils.SUMMARY)
 	require.NoError(t, err)
@@ -145,6 +148,60 @@ func TestRPM(t *testing.T) {
 	require.Equal(t, "Foo does things", description)
 }
 
+func TestRPMMandatoryFieldsOnly(t *testing.T) {
+	f, err := os.CreateTemp(t.TempDir(), "test.rpm")
+	require.NoError(t, err)
+	require.NoError(t, Default.Package(&nfpm.Info{
+		Name:        "foo",
+		Arch:        "amd64",
+		Version:     "1.2",
+		Release:     "1",
+		Description: "summary\nfoo bar\nlong description",
+		License:     "MIT",
+	}, f))
+
+	file, err := os.OpenFile(f.Name(), os.O_RDONLY, 0o600) //nolint:gosec
+	require.NoError(t, err)
+	defer func() {
+		f.Close()
+		file.Close()
+		err = os.Remove(file.Name())
+		require.NoError(t, err)
+	}()
+	rpm, err := rpmutils.ReadRpm(file)
+	require.NoError(t, err)
+
+	os, err := rpm.Header.GetString(rpmutils.OS)
+	require.NoError(t, err)
+	require.Equal(t, "linux", os)
+
+	arch, err := rpm.Header.GetString(rpmutils.ARCH)
+	require.NoError(t, err)
+	require.Equal(t, archToRPM["amd64"], arch)
+
+	version, err := rpm.Header.GetString(rpmutils.VERSION)
+	require.NoError(t, err)
+	require.Equal(t, "1.2", version)
+
+	release, err := rpm.Header.GetString(rpmutils.RELEASE)
+	require.NoError(t, err)
+	require.Equal(t, "1", release)
+
+	_, err = rpm.Header.Get(rpmutils.EPOCH)
+	require.Error(t, err, "epoch should not be set")
+
+	_, err = rpm.Header.GetString(rpmutils.GROUP)
+	require.Error(t, err, "group should not be set")
+
+	summary, err := rpm.Header.GetString(rpmutils.SUMMARY)
+	require.NoError(t, err)
+	require.Equal(t, "summary", summary)
+
+	description, err := rpm.Header.GetString(rpmutils.DESCRIPTION)
+	require.NoError(t, err)
+	require.Equal(t, "summary\nfoo bar\nlong description", description)
+}
+
 func TestRPMPlatform(t *testing.T) {
 	f, err := os.CreateTemp(t.TempDir(), "test*.rpm")
 	require.NoError(t, err)