feat: Add BuildHost option to RPM packages (#914)

This commit adds the BuildHost option to the RPM specific configurations. If the build
host is not provided it will default to os.Hostname() which is the previous behavior.
This allows reproduce-able builds when the build environment spans
multiple hosts.

Co-authored-by: onshorechet <[email protected]>

Author: onshorechet

nfpm.go

@@ -377,6 +377,7 @@ type ArchLinuxScripts struct {
 // RPM is custom configs that are only available on RPM packages.
 type RPM struct {
 	Arch        string       `yaml:"arch,omitempty" json:"arch,omitempty" jsonschema:"title=architecture in rpm nomenclature"`
+	BuildHost   string       `yaml:"buildhost,omitempty" json:"buildhost,omitempty" jsonschema:"title=host name of the build environment, default=os.Hostname()"`
 	Scripts     RPMScripts   `yaml:"scripts,omitempty" json:"scripts,omitempty" jsonschema:"title=rpm-specific scripts"`
 	Group       string       `yaml:"group,omitempty" json:"group,omitempty" jsonschema:"title=package group,example=Unspecified"`
 	Summary     string       `yaml:"summary,omitempty" json:"summary,omitempty" jsonschema:"title=package summary"`

rpm/rpm.go

@@ -235,9 +235,12 @@ func buildRPMMeta(info *nfpm.Info) (*rpmpack.RPMMetaData, error) {
 		return nil, err
 	}
 
-	hostname, err := os.Hostname()
-	if err != nil {
-		return nil, err
+	hostname := info.RPM.BuildHost
+	if hostname == "" {
+		hostname, err = os.Hostname()
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	return &rpmpack.RPMMetaData{

rpm/rpm_test.go

@@ -80,8 +80,9 @@ func exampleInfo() *nfpm.Info {
 				PostRemove:  "../testdata/scripts/postremove.sh",
 			},
 			RPM: nfpm.RPM{
-				Group:    "foo",
-				Prefixes: []string{"/opt"},
+				Group:     "foo",
+				BuildHost: "barhost",
+				Prefixes:  []string{"/opt"},
 				Scripts: nfpm.RPMScripts{
 					PreTrans:  "../testdata/scripts/pretrans.sh",
 					PostTrans: "../testdata/scripts/posttrans.sh",
@@ -139,6 +140,10 @@ func TestRPM(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, "foo", group)
 
+	buildhost, err := rpm.Header.GetString(rpmutils.BUILDHOST)
+	require.NoError(t, err)
+	require.Equal(t, "barhost", buildhost)
+
 	summary, err := rpm.Header.GetString(rpmutils.SUMMARY)
 	require.NoError(t, err)
 	require.Equal(t, "Foo does things", summary)

www/docs/configuration.md

@@ -351,6 +351,10 @@ rpm:
   # This will expand any env var you set in the field, e.g. packager: ${PACKAGER}
   packager: GoReleaser <[email protected]>
 
+  # The hostname of the machine the rpm was built with.  If ommited os.Hostname()
+  # will be used.
+  buildhost: buildserver1
+
   # Compression algorithm (gzip (default), zstd, lzma or xz).
   compression: zstd