feat: Support custom command and extra files in snaps (#1553)

internal/pipe/snapcraft/snapcraft.go

@@ -173,6 +173,21 @@ func create(ctx *context.Context, snap config.Snapcraft, arch string, binaries [
 		return err
 	}
 
+	for _, file := range snap.Files {
+		if file.Destination == "" {
+			file.Destination = file.Source
+		}
+		if file.Mode == 0 {
+			file.Mode = 0644
+		}
+		if err := os.MkdirAll(filepath.Join(primeDir, filepath.Dir(file.Destination)), 0755); err != nil {
+			return errors.Wrapf(err, "failed to link extra file '%s'", file.Source)
+		}
+		if err := link(file.Source, filepath.Join(primeDir, file.Destination), os.FileMode(file.Mode)); err != nil {
+			return errors.Wrapf(err, "failed to link extra file '%s'", file.Source)
+		}
+	}
+
 	var file = filepath.Join(primeDir, "meta", "snap.yaml")
 	log.WithField("file", file).Debug("creating snap metadata")
 
@@ -231,11 +246,16 @@ func create(ctx *context.Context, snap config.Snapcraft, arch string, binaries [
 				WithField("name", name).
 				Debug("passed binary to snapcraft")
 
+			command := name
+			if config.Command != "" {
+				command = config.Command
+			}
+
 			// TODO: test that the correct binary is used in Command
 			// See https://github.com/goreleaser/goreleaser/pull/1449
 			appMetadata := AppMetadata{
 				Command: strings.TrimSpace(strings.Join([]string{
-					name,
+					command,
 					config.Args,
 				}, " ")),
 				Plugs:  config.Plugs,
@@ -314,3 +334,29 @@ func push(ctx *context.Context, snap *artifact.Artifact) error {
 	ctx.Artifacts.Add(snap)
 	return nil
 }
+
+// walks the src, recreating dirs and hard-linking files.
+func link(src, dest string, mode os.FileMode) error {
+	return filepath.Walk(src, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		// We have the following:
+		// - src = "a/b"
+		// - dest = "dist/linuxamd64/b"
+		// - path = "a/b/c.txt"
+		// So we join "a/b" with "c.txt" and use it as the destination.
+		var dst = filepath.Join(dest, strings.Replace(path, src, "", 1))
+		log.WithFields(log.Fields{
+			"src": path,
+			"dst": dst,
+		}).Debug("extra file")
+		if info.IsDir() {
+			return os.MkdirAll(dst, info.Mode())
+		}
+		if err := os.Link(path, dst); err != nil {
+			return err
+		}
+		return os.Chmod(dst, mode)
+	})
+}

internal/pipe/snapcraft/snapcraft_test.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"syscall"
 	"testing"
 
 	"github.com/goreleaser/goreleaser/internal/artifact"
@@ -327,6 +328,100 @@ func TestCompleter(t *testing.T) {
 	assert.Equal(t, "testdata/mybin-completer.bash", metadata.Apps["mybin"].Completer)
 }
 
+func TestCommand(t *testing.T) {
+	folder, err := ioutil.TempDir("", "archivetest")
+	require.NoError(t, err)
+	defer os.RemoveAll(folder)
+	var dist = filepath.Join(folder, "dist")
+	require.NoError(t, os.Mkdir(dist, 0755))
+	require.NoError(t, err)
+	var ctx = context.New(config.Project{
+		ProjectName: "testprojectname",
+		Dist:        dist,
+		Snapcrafts: []config.Snapcraft{
+			{
+				NameTemplate: "foo_{{.Arch}}",
+				Summary:      "test summary",
+				Description:  "test description",
+				Apps: map[string]config.SnapcraftAppMetadata{
+					"mybin": {
+						Daemon:  "simple",
+						Args:    "",
+						Command: "custom command",
+					},
+				},
+				Builds: []string{"foo"},
+			},
+		},
+	})
+	ctx.Git.CurrentTag = "v1.2.3"
+	ctx.Version = "v1.2.3"
+	addBinaries(t, ctx, "foo", dist, "mybin")
+	require.NoError(t, Pipe{}.Run(ctx))
+	yamlFile, err := ioutil.ReadFile(filepath.Join(dist, "foo_amd64", "prime", "meta", "snap.yaml"))
+	require.NoError(t, err)
+	var metadata Metadata
+	err = yaml.Unmarshal(yamlFile, &metadata)
+	require.NoError(t, err)
+	assert.Equal(t, "custom command", metadata.Apps["mybin"].Command)
+}
+
+func TestExtraFile(t *testing.T) {
+	folder, err := ioutil.TempDir("", "archivetest")
+	require.NoError(t, err)
+	defer os.RemoveAll(folder)
+	var dist = filepath.Join(folder, "dist")
+	require.NoError(t, os.Mkdir(dist, 0755))
+	require.NoError(t, err)
+	var ctx = context.New(config.Project{
+		ProjectName: "testprojectname",
+		Dist:        dist,
+		Snapcrafts: []config.Snapcraft{
+			{
+				NameTemplate: "foo_{{.Arch}}",
+				Summary:      "test summary",
+				Description:  "test description",
+				Apps: map[string]config.SnapcraftAppMetadata{
+					"mybin": {
+						Daemon:  "simple",
+						Args:    "",
+						Command: "custom command",
+					},
+				},
+				Files: []config.SnapcraftExtraFiles{
+					{
+						Source:      "testdata/extra-file.txt",
+						Destination: "a/b/c/extra-file.txt",
+						Mode:        0755,
+					},
+					{
+						Source: "testdata/extra-file-2.txt",
+					},
+				},
+				Builds: []string{"foo"},
+			},
+		},
+	})
+	ctx.Git.CurrentTag = "v1.2.3"
+	ctx.Version = "v1.2.3"
+	addBinaries(t, ctx, "foo", dist, "mybin")
+	require.NoError(t, Pipe{}.Run(ctx))
+
+	srcFile, err := os.Stat("testdata/extra-file.txt")
+	require.NoError(t, err)
+	destFile, err := os.Stat(filepath.Join(dist, "foo_amd64", "prime", "a", "b", "c", "extra-file.txt"))
+	require.NoError(t, err)
+	assert.Equal(t, inode(srcFile), inode(destFile))
+	assert.Equal(t, destFile.Mode(), os.FileMode(0755))
+
+	srcFile, err = os.Stat("testdata/extra-file-2.txt")
+	require.NoError(t, err)
+	destFileWithDefaults, err := os.Stat(filepath.Join(dist, "foo_amd64", "prime", "testdata", "extra-file-2.txt"))
+	require.NoError(t, err)
+	assert.Equal(t, destFileWithDefaults.Mode(), os.FileMode(0644))
+	assert.Equal(t, inode(srcFile), inode(destFileWithDefaults))
+}
+
 func TestDefault(t *testing.T) {
 	var ctx = context.New(config.Project{
 		Builds: []config.Build{
@@ -439,3 +534,8 @@ func Test_isValidArch(t *testing.T) {
 		})
 	}
 }
+
+func inode(info os.FileInfo) uint64 {
+	stat := info.Sys().(*syscall.Stat_t)
+	return stat.Ino
+}

internal/pipe/snapcraft/testdata/extra-file-2.txt

@@ -0,0 +1 @@
+test2

internal/pipe/snapcraft/testdata/extra-file.txt

@@ -0,0 +1 @@
+test

pkg/config/config.go

@@ -329,6 +329,7 @@ type SnapcraftAppMetadata struct {
 	Daemon    string
 	Args      string
 	Completer string `yaml:",omitempty"`
+	Command   string `yaml:"command"`
 }
 
 // Snapcraft config.
@@ -348,6 +349,15 @@ type Snapcraft struct {
 	Confinement string                          `yaml:",omitempty"`
 	Apps        map[string]SnapcraftAppMetadata `yaml:",omitempty"`
 	Plugs       map[string]interface{}          `yaml:",omitempty"`
+
+	Files []SnapcraftExtraFiles `yaml:"extra_files,omitempty"`
+}
+
+// SnapcraftExtraFiles config.
+type SnapcraftExtraFiles struct {
+	Source      string `yaml:"source"`
+	Destination string `yaml:"destination,omitempty"`
+	Mode        uint32 `yaml:"mode,omitempty"`
 }
 
 // Snapshot config.

www/docs/customization/snapcraft.md

@@ -88,6 +88,16 @@ snapcrafts:
     # Default is empty.
     base: core18
 
+    # Add extra files on the resulting snap. Useful for including wrapper
+    # scripts or other useful static files. Source filenames are relative to the
+    # project directory. Destination filenames are relative to the snap prime
+    # directory.
+    # Default is empty.
+    extra_files:
+      - source: drumroll.wrapper
+        destination: bin/drumroll.wrapper
+        mode: 0755
+
     # Each binary built by GoReleaser is an app inside the snap. In this section
     # you can declare extra details for those binaries. It is optional.
     apps:
@@ -114,6 +124,10 @@ snapcrafts:
         # https://docs.snapcraft.io/tab-completion-for-snaps.
         completer: drumroll-completion.bash
 
+        # You can override the command name.
+        # Defaults is the app name.
+        command: bin/drumroll.wrapper
+
     # Allows plugs to be configured. Plugs like system-files and personal-files
     # require this.
     # Default is empty.