Added ability to include custom combustion scripts in an image

README.md

@@ -66,6 +66,11 @@ the structure of this directory will be better fleshed out. For now, the require
   are no restrictions on the naming; the image configuration file will specify which image in this directory to use
   for a particular build.
 
+There are a number of optional directories that may be included in the image configuration directory:
+
+* `scripts` - If present, all the files in this directory will be included in the built image and automatically
+  executed during the combustion phase.
+
 ### Running EIB
 
 The image configuration directory must be attached to the container at runtime. This serves as both the mechanism

pkg/build/build.go

@@ -46,6 +46,11 @@ func (b *Builder) Build() error {
 		return fmt.Errorf("configuring the welcome message: %w", err)
 	}
 
+	err = b.configureScripts()
+	if err != nil {
+		return fmt.Errorf("configuring custom scripts: %w", err)
+	}
+
 	err = b.generateCombustionScript()
 	if err != nil {
 		return fmt.Errorf("generating combustion script: %w", err)

pkg/build/scripts.go

@@ -0,0 +1,54 @@
+package build
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+const (
+	scriptsDir = "scripts"
+	scriptMode = 0o744
+)
+
+func (b *Builder) configureScripts() error {
+	fullScriptsDir := filepath.Join(b.buildConfig.ImageConfigDir, scriptsDir)
+
+	// Nothing to do if the image config dir doesn't have the scripts directory
+	_, err := os.Stat(fullScriptsDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return fmt.Errorf("checking for scripts directory at %s: %w", fullScriptsDir, err)
+	}
+
+	dirListing, err := os.ReadDir(fullScriptsDir)
+	if err != nil {
+		return fmt.Errorf("reading the scripts directory at %s: %w", fullScriptsDir, err)
+	}
+
+	// If the directory exists but there's nothing in it, consider it an error case
+	if len(dirListing) == 0 {
+		return fmt.Errorf("no scripts found in directory %s", fullScriptsDir)
+	}
+
+	for _, scriptEntry := range dirListing {
+		copyMe := filepath.Join(fullScriptsDir, scriptEntry.Name())
+		copyTo := filepath.Join(b.combustionDir, scriptEntry.Name())
+
+		err = copyFile(copyMe, copyTo)
+		if err != nil {
+			return fmt.Errorf("copying script to %s: %w", copyTo, err)
+		}
+		err = os.Chmod(copyTo, scriptMode)
+		if err != nil {
+			return fmt.Errorf("modifying permissions for script %s: %w", copyTo, err)
+		}
+
+		// Make sure the combustion main script will execute the newly copied script
+		b.registerCombustionScript(scriptEntry.Name())
+	}
+
+	return nil
+}

pkg/build/scripts_test.go

@@ -0,0 +1,99 @@
+package build
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/suse-edge/edge-image-builder/pkg/config"
+)
+
+func TestConfigureScripts(t *testing.T) {
+	// Setup
+	// - Testing image config directory
+	tmpSrcDir, err := os.MkdirTemp("", "eib-")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpSrcDir)
+
+	// - scripts directory to look in
+	fullScriptsDir := filepath.Join(tmpSrcDir, scriptsDir)
+	err = os.MkdirAll(fullScriptsDir, os.ModePerm)
+	require.NoError(t, err)
+
+	// - create sample scripts to be copied
+	_, err = os.Create(filepath.Join(fullScriptsDir, "foo.sh"))
+	require.NoError(t, err)
+	_, err = os.Create(filepath.Join(fullScriptsDir, "bar.sh"))
+	require.NoError(t, err)
+
+	// - combustion directory into which the scripts should be copied
+	tmpDestDir, err := os.MkdirTemp("", "eib-")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpDestDir)
+
+	builder := New(nil, &config.BuildConfig{ImageConfigDir: tmpSrcDir})
+	builder.combustionDir = tmpDestDir
+
+	// Test
+	err = builder.configureScripts()
+
+	// Verify
+	require.NoError(t, err)
+
+	// - make sure the scripts were added to the build directory
+	foundDirListing, err := os.ReadDir(tmpDestDir)
+	require.NoError(t, err)
+	assert.Equal(t, 2, len(foundDirListing))
+
+	// - make sure the copied files have the right permissions
+	for _, entry := range foundDirListing {
+		fullEntryPath := filepath.Join(builder.combustionDir, entry.Name())
+		stats, err := os.Stat(fullEntryPath)
+		require.NoError(t, err)
+		foundMode := stats.Mode()
+		assert.Equal(t, "-rwxr--r--", foundMode.String())
+	}
+
+	// - make sure entries were added to the combustion scripts list, so they are
+	//   present in the script file that is generated
+	assert.Equal(t, 2, len(builder.combustionScripts))
+}
+
+func TestConfigureScriptsNoScriptsDir(t *testing.T) {
+	// Setup
+	tmpSrcDir, err := os.MkdirTemp("", "eib-")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpSrcDir)
+
+	builder := New(nil, &config.BuildConfig{ImageConfigDir: tmpSrcDir})
+
+	// Test
+	err = builder.configureScripts()
+
+	// Verify
+	require.NoError(t, err)
+}
+
+func TestConfigureScriptsEmptyScriptsDir(t *testing.T) {
+	// Setup
+	// - Testing image config directory
+	tmpSrcDir, err := os.MkdirTemp("", "eib-")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpSrcDir)
+
+	// - scripts directory to look in
+	fullScriptsDir := filepath.Join(tmpSrcDir, scriptsDir)
+	err = os.MkdirAll(fullScriptsDir, os.ModePerm)
+	require.NoError(t, err)
+
+	builder := New(nil, &config.BuildConfig{ImageConfigDir: tmpSrcDir})
+
+	// Test
+	err = builder.configureScripts()
+
+	// Verify
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "no scripts found in directory")
+}