Add option to set working directory for restic backup (#354)

* feat: allow to set a working directory for the restic backup command

* fix: `TestRunShellWorkingDir` cross-platform compatible

* refactor: rename `ChangeWorkingDir` option to `SourceRelative`

* refactor: check if `p.Backup` is `nil`

* fix: `TestRunShellWorkingDir` for GitHub Actions on Windows

* fix: only change the backup command's working directory if `source-relative` is set

* fix: add path change report when `source-base` is not set

config/config.go

@@ -338,7 +338,7 @@ func (c *Config) DisplayConfigurationIssues() {
 		msg = append([]string{
 			"the configuration contains relative \"path\" items which may lead to unstable results in restic " +
 				"commands that select snapshots. Consider using absolute paths in \"path\" (and \"source\"), " +
-				"set \"base-dir\" in the profile or use \"tag\" instead of \"path\" (path = false) to select " +
+				"set \"base-dir\" or \"source-base\" in the profile or use \"tag\" instead of \"path\" (path = false) to select " +
 				"snapshots for restic commands.",
 			"Affected paths are:",
 		}, msg...)

config/profile.go

@@ -172,6 +172,7 @@ type BackupSection struct {
 	CheckAfter                       bool     `mapstructure:"check-after" description:"Check the repository after the backup command succeeded"`
 	UseStdin                         bool     `mapstructure:"stdin" argument:"stdin"`
 	StdinCommand                     []string `mapstructure:"stdin-command" description:"Shell command(s) that generate content to redirect into the stdin of restic. When set, the flag \"stdin\" is always set to \"true\"."`
+	SourceRelative                   bool     `mapstructure:"source-relative" description:"Enable backup with relative source paths. This will change the working directory of the \"restic backup\" command to \"source-base\", and will not expand \"source\" to an absolute path."`
 	SourceBase                       string   `mapstructure:"source-base" examples:"/;$PWD;C:\\;%cd%" description:"The base path to resolve relative backup paths against. Defaults to current directory if unset or empty (see also \"base-dir\" in profile)"`
 	Source                           []string `mapstructure:"source" examples:"/opt/;/home/user/;C:\\Users\\User\\Documents" description:"The paths to backup"`
 	Exclude                          []string `mapstructure:"exclude" argument:"exclude" argument-type:"no-glob"`
@@ -198,7 +199,7 @@ func (b *BackupSection) resolve(profile *Profile) {
 	if b.unresolvedSource == nil {
 		b.unresolvedSource = b.Source
 	}
-	b.Source = profile.resolveSourcePath(b.SourceBase, b.unresolvedSource...)
+	b.Source = profile.resolveSourcePath(b.SourceBase, b.SourceRelative, b.unresolvedSource...)
 
 	// Extras, only enabled for Version >= 2 (to remain backward compatible in version 1)
 	if profile.config != nil && profile.config.version >= Version02 {
@@ -648,18 +649,24 @@ func (p *Profile) SetRootPath(rootPath string) {
 	}
 }
 
-func (p *Profile) resolveSourcePath(sourceBase string, sourcePaths ...string) []string {
+func (p *Profile) resolveSourcePath(sourceBase string, relativePaths bool, sourcePaths ...string) []string {
 	var applySourceBase, applyBaseDir pathFix
 
-	// Backup source is NOT relative to the configuration, but to PWD or sourceBase (if not empty)
-	// Applying "sourceBase" if set
-	if sourceBase = strings.TrimSpace(sourceBase); sourceBase != "" {
-		sourceBase = fixPath(sourceBase, expandEnv, expandUserHome)
-		applySourceBase = absolutePrefix(sourceBase)
-	}
-	// Applying a custom PWD eagerly so that own commands (e.g. "show") display correct paths
-	if p.BaseDir != "" {
-		applyBaseDir = absolutePrefix(p.BaseDir)
+	sourceBase = fixPath(strings.TrimSpace(sourceBase), expandEnv, expandUserHome)
+	// When "source-relative" is set, the source paths are relative to the "source-base"
+	if !relativePaths {
+		// Backup source is NOT relative to the configuration, but to PWD or sourceBase (if not empty)
+		// Applying "sourceBase" if set
+		if sourceBase != "" {
+			applySourceBase = absolutePrefix(sourceBase)
+		}
+		// Applying a custom PWD eagerly so that own commands (e.g. "show") display correct paths
+		if p.BaseDir != "" {
+			applyBaseDir = absolutePrefix(p.BaseDir)
+		}
+
+	} else if p.BaseDir == "" && sourceBase == "" && p.config != nil {
+		p.config.reportChangedPath(".", "<none>", "source-base (for relative source)")
 	}
 
 	// prefix paths starting with "-" with a "./" to distinguish a source path from a flag
@@ -693,7 +700,7 @@ func (p *Profile) SetTag(tags ...string) {
 // SetPath will replace any path value from a boolean to sourcePaths and change paths to absolute
 func (p *Profile) SetPath(basePath string, sourcePaths ...string) {
 	resolvePath := func(origin string, paths []string, revolver func(string) []string) (resolved []string) {
-		hasAbsoluteBase := len(p.BaseDir) > 0 && filepath.IsAbs(p.BaseDir)
+		hasAbsoluteBase := len(p.BaseDir) > 0 && filepath.IsAbs(p.BaseDir) || basePath != "" && filepath.IsAbs(basePath)
 		for _, path := range paths {
 			if len(path) > 0 {
 				for _, rp := range revolver(path) {
@@ -720,7 +727,7 @@ func (p *Profile) SetPath(basePath string, sourcePaths ...string) {
 			// Replace bool-true with absolute sourcePaths
 			if !sourcePathsResolved {
 				sourcePaths = resolvePath("path (from source)", sourcePaths, func(path string) []string {
-					return fixPaths(p.resolveSourcePath(basePath, path), absolutePath)
+					return fixPaths(p.resolveSourcePath(basePath, false, path), absolutePath)
 				})
 				sourcePathsResolved = true
 			}

config/profile_test.go

@@ -636,9 +636,10 @@ func TestResolveSourcesWithFlagPrefixInBackup(t *testing.T) {
 }
 
 func TestResolveSourcesAgainstBase(t *testing.T) {
-	backupSource := func(base, source string) []string {
+	backupSource := func(base, source string, changeWorkingDir bool) []string {
 		config := `
 			[profile.backup]
+			source-relative = ` + strconv.FormatBool(changeWorkingDir) + `
 			source-base = "` + filepath.ToSlash(base) + `"
 			source = "` + filepath.ToSlash(source) + `"
 		`
@@ -653,18 +654,27 @@ func TestResolveSourcesAgainstBase(t *testing.T) {
 	assert.NoError(t, err)
 
 	t.Run("no-base", func(t *testing.T) {
-		assert.Equal(t, []string{"src"}, backupSource("", "src"))
+		assert.Equal(t, []string{"src"}, backupSource("", "src", false))
 	})
 	t.Run("relative-base", func(t *testing.T) {
-		assert.Equal(t, []string{filepath.Join("rel", "src")}, backupSource("rel", "src"))
+		assert.Equal(t, []string{filepath.Join("rel", "src")}, backupSource("rel", "src", false))
 	})
 	t.Run("absolute-base", func(t *testing.T) {
-		assert.Equal(t, []string{filepath.Join(cwd, "src")}, backupSource(cwd, "src"))
+		assert.Equal(t, []string{filepath.Join(cwd, "src")}, backupSource(cwd, "src", false))
 	})
 	t.Run("env-var-base", func(t *testing.T) {
 		assert.NoError(t, os.Setenv("RP_TEST_CWD", cwd))
 		defer os.Unsetenv("RP_TEST_CWD")
-		assert.Equal(t, []string{filepath.Join(cwd, "path", "src")}, backupSource("${RP_TEST_CWD}/path", "src"))
+		assert.Equal(t, []string{filepath.Join(cwd, "path", "src")}, backupSource("${RP_TEST_CWD}/path", "src", false))
+	})
+	t.Run("change-relative-working-dir", func(t *testing.T) {
+		assert.Equal(t, []string{"."}, backupSource("path", ".", true))
+		assert.Equal(t, []string{filepath.Join("path", ".")}, backupSource("path", ".", false))
+	})
+	t.Run("change-env-var-working-dir", func(t *testing.T) {
+		assert.NoError(t, os.Setenv("RP_TEST_ENV", "."))
+		defer os.Unsetenv("RP_TEST_ENV")
+		assert.Equal(t, []string{"."}, backupSource("path", "${RP_TEST_ENV}", true))
 	})
 }
 

docs/content/configuration/path.md

@@ -101,6 +101,7 @@ default {
 {{% notice hint %}}
 Set `base-dir` to an absolute path to resolve `files` and `local:backup` relative to it.
 Set `source-base` if you need a separate base path for backup sources.
+When you want to use relative source paths for backup, set the `source-relative` option. This will change the working directory of the `restic backup` command to `source-base` and will not expand `source` to an absolute path.
 {{% /notice %}}
 
 ## How the configuration file is resolved

shell/command.go

@@ -114,6 +114,8 @@ func (c *Command) Run() (monitor.Summary, string, error) {
 		cmd.Env = append(cmd.Env, c.Environ...)
 	}
 
+	cmd.Dir = c.Dir
+
 	start := time.Now()
 
 	// spawn the child process

shell/command_test.go

@@ -3,6 +3,7 @@ package shell
 import (
 	"bytes"
 	"fmt"
+	"github.com/creativeprojects/resticprofile/platform"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -285,6 +286,26 @@ func TestSelectCustomShell(t *testing.T) {
 	assert.Empty(t, shell)
 }
 
+func TestRunShellWorkingDir(t *testing.T) {
+	command := func() string {
+		if platform.IsWindows() {
+			return "@echo %CD%"
+		}
+		return "pwd"
+	}()
+	temp := t.TempDir()
+	buffer := new(strings.Builder)
+	cmd := NewCommand(command, nil)
+	cmd.Stdout = buffer
+	cmd.Dir = temp
+	_, _, err := cmd.Run()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	assert.Contains(t, strings.TrimSpace(buffer.String()), temp)
+}
+
 func TestRunShellEcho(t *testing.T) {
 	buffer := &bytes.Buffer{}
 	cmd := NewCommand("echo", []string{"TestRunShellEcho"})

shell_command.go

@@ -18,6 +18,7 @@ type shellCommandDefinition struct {
 	publicArgs  []string
 	env         []string
 	shell       []string
+	dir         string
 	stdin       io.ReadCloser
 	stdout      io.Writer
 	stderr      io.Writer
@@ -85,6 +86,10 @@ func runShellCommand(command shellCommandDefinition) (summary monitor.Summary, s
 		shellCmd.Environ = append(shellCmd.Environ, command.env...)
 	}
 
+	// If Dir is the empty string, Run runs the command in the
+	// calling process's current directory.
+	shellCmd.Dir = command.dir
+
 	// scan output
 	if command.scanOutput != nil {
 		shellCmd.ScanStdout = command.scanOutput

wrapper.go

@@ -366,8 +366,12 @@ func (r *resticWrapper) prepareCommand(command string, args *shell.Args, allowEx
 	args.AddArgs(moreArgs, shell.ArgCommandLineEscape)
 
 	// Special case for backup command
+	var dir string
 	if command == constants.CommandBackup {
 		args.AddArgs(r.profile.GetBackupSource(), shell.ArgConfigBackupSource)
+		if r.profile.Backup != nil && r.profile.Backup.SourceRelative {
+			dir = r.profile.Backup.SourceBase
+		}
 	}
 	// Special case for copy command
 	if command == constants.CommandCopy {
@@ -409,6 +413,7 @@ func (r *resticWrapper) prepareCommand(command string, args *shell.Args, allowEx
 	rCommand.stdout = term.GetOutput()
 	rCommand.stderr = term.GetErrorOutput()
 	rCommand.streamError = r.profile.StreamError
+	rCommand.dir = dir
 
 	return rCommand
 }