support empty worktree with links

config_test.go

@@ -110,9 +110,11 @@ func Test_diffWorktrees(t *testing.T) {
 				Worktrees: []mirror.WorktreeConfig{
 					{Link: "link", Ref: "master", Pathspecs: nil},
 					{Link: "link2", Ref: "other-branch", Pathspecs: []string{"path1", "path2/**/*.yaml", "*.c"}},
+					{Link: "", Ref: "master", Pathspecs: nil},
 				},
 			},
 			wantNewWTCs: []mirror.WorktreeConfig{
+				{Link: "", Ref: "master", Pathspecs: nil},
 				{Link: "link", Ref: "master"},
 				{Link: "link2", Ref: "other-branch", Pathspecs: []string{"path1", "path2/**/*.yaml", "*.c"}},
 			},
@@ -127,6 +129,7 @@ func Test_diffWorktrees(t *testing.T) {
 					{Link: "link", Ref: "master", Pathspecs: nil},
 					{Link: "link2", Ref: "other-branch", Pathspecs: []string{"path1", "path2/**/*.yaml", "*.c"}},
 					{Link: "link3", Ref: "other-branch", Pathspecs: []string{"path"}},
+					{Link: "", Ref: "master", Pathspecs: nil},
 				},
 			},
 			newRepoConf: &mirror.RepositoryConfig{
@@ -136,14 +139,16 @@ func Test_diffWorktrees(t *testing.T) {
 					{Link: "link", Ref: "master", Pathspecs: []string{"new-path"}},
 					{Link: "link2", Ref: "new-branch", Pathspecs: []string{"path1", "path2/**/*.yaml", "*.c"}},
 					{Link: "link3", Ref: "other-branch", Pathspecs: []string{"path", "new-path"}},
+					{Link: "", Ref: "new-branch", Pathspecs: nil},
 				},
 			},
 			wantNewWTCs: []mirror.WorktreeConfig{
+				{Link: "", Ref: "new-branch", Pathspecs: nil},
 				{Link: "link", Ref: "master", Pathspecs: []string{"new-path"}},
 				{Link: "link2", Ref: "new-branch", Pathspecs: []string{"path1", "path2/**/*.yaml", "*.c"}},
 				{Link: "link3", Ref: "other-branch", Pathspecs: []string{"path", "new-path"}},
 			},
-			wantRemovedWTs: []string{"link", "link2", "link3"},
+			wantRemovedWTs: []string{"link", "link2", "link3", "repo1/master"},
 		},
 		{
 			name: "rearrange-path",
@@ -182,9 +187,11 @@ func Test_diffWorktrees(t *testing.T) {
 				Worktrees: []mirror.WorktreeConfig{
 					{Link: "link", Ref: "master", Pathspecs: nil},
 					{Link: "link3", Ref: "other-branch", Pathspecs: []string{"path1", "path2/**/*.yaml", "*.c"}},
+					{Link: "", Ref: "master", Pathspecs: nil},
 				},
 			},
 			wantNewWTCs: []mirror.WorktreeConfig{
+				{Ref: "master"},
 				{Link: "link3", Ref: "other-branch", Pathspecs: []string{"path1", "path2/**/*.yaml", "*.c"}},
 			},
 			wantRemovedWTs: []string{"link2"},
@@ -193,6 +200,10 @@ func Test_diffWorktrees(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 
+			if err := tt.initialRepoConf.PopulateEmptyLinkPaths(); err != nil {
+				t.Fatalf("failed to create repo error = %v", err)
+			}
+
 			repo, err := mirror.NewRepository(*tt.initialRepoConf, nil, slog.Default())
 			if err != nil {
 				t.Fatalf("failed to create repo error = %v", err)

pkg/mirror/config.go

@@ -3,9 +3,16 @@ package mirror
 import (
 	"fmt"
 	"path/filepath"
+	"regexp"
+	"strings"
 	"time"
+
+	"github.com/utilitywarehouse/git-mirror/pkg/giturl"
 )
 
+var matchSpecialCharReg = regexp.MustCompile(`[\\:\/*?"<>|\s]`)
+var matchDupUnderscoreReg = regexp.MustCompile(`_+`)
+
 // RepoPoolConfig is the configuration to create repoPool
 type RepoPoolConfig struct {
 	// default config for all the repositories if not set
@@ -21,6 +28,13 @@ type DefaultConfig struct {
 	// specified in repo config
 	Root string `yaml:"root"`
 
+	// LinkRoot is the absolute path to the dir which is the root for the worktree links
+	// if link is a relative path it will be relative to this dir
+	// if link is not specified it will be constructed from repo name and worktree ref
+	// and it will be placed in this dir
+	// if not specified it will be same as root
+	LinkRoot string `yaml:"link_root"`
+
 	// Interval is time duration for how long to wait between mirrors
 	Interval time.Duration `yaml:"interval"`
 
@@ -46,6 +60,13 @@ type RepositoryConfig struct {
 	// absolute path is not provided
 	Root string `yaml:"root"`
 
+	// LinkRoot is the absolute path to the dir which is the root for the worktree links
+	// if link is a relative path it will be relative to this dir
+	// if link is not specified it will be constructed from repo name and worktree ref
+	// and it will be placed in this dir
+	// if not specified it will be same as root
+	LinkRoot string `yaml:"link_root"`
+
 	// Interval is time duration for how long to wait between mirrors
 	Interval time.Duration `yaml:"interval"`
 
@@ -67,7 +88,9 @@ type RepositoryConfig struct {
 // Worktree represents maintained worktree on given link.
 type WorktreeConfig struct {
 	// Link is the path at which to create a symlink to the worktree dir
-	// if path is not absolute it will be created under repository root
+	// if path is not absolute it will be created under repository link_root
+	// if link is not specified it will be constructed from repo name and worktree ref
+	// and it will be placed in link_root dir
 	Link string `yaml:"link"`
 
 	// Ref represents the git reference of the worktree branch, tags or hash
@@ -87,8 +110,8 @@ type Auth struct {
 	SSHKnownHostsPath string `yaml:"ssh_known_hosts_path"`
 }
 
-// ValidateDefaults will verify default config
-func (rpc *RepoPoolConfig) ValidateDefaults() error {
+// validateDefaults will verify default config
+func (rpc *RepoPoolConfig) validateDefaults() error {
 	dc := rpc.Defaults
 
 	var errs []error
@@ -99,6 +122,12 @@ func (rpc *RepoPoolConfig) ValidateDefaults() error {
 		}
 	}
 
+	if dc.LinkRoot != "" {
+		if !filepath.IsAbs(dc.LinkRoot) {
+			errs = append(errs, fmt.Errorf("repository link_root '%s' must be absolute", dc.Root))
+		}
+	}
+
 	if dc.Interval != 0 {
 		if dc.Interval < minAllowedInterval {
 			errs = append(errs, fmt.Errorf("provided interval between mirroring is too sort (%s), must be > %s", dc.Interval, minAllowedInterval))
@@ -130,14 +159,22 @@ func DefaultRepoDir(root string) string {
 	return filepath.Join(root, "repo-mirrors")
 }
 
-// ApplyDefaults will add  given default config to repository config if where needed
-func (rpc *RepoPoolConfig) ApplyDefaults() {
+// applyDefaults will add  given default config to repository config if where needed
+func (rpc *RepoPoolConfig) applyDefaults() {
+	if rpc.Defaults.LinkRoot == "" {
+		rpc.Defaults.LinkRoot = rpc.Defaults.Root
+	}
+
 	for i := range rpc.Repositories {
 		repo := &rpc.Repositories[i]
 		if repo.Root == "" {
 			repo.Root = rpc.Defaults.Root
 		}
 
+		if repo.LinkRoot == "" {
+			repo.LinkRoot = rpc.Defaults.LinkRoot
+		}
+
 		if repo.Interval == 0 {
 			repo.Interval = rpc.Defaults.Interval
 		}
@@ -156,21 +193,66 @@ func (rpc *RepoPoolConfig) ApplyDefaults() {
 	}
 }
 
+func normaliseReference(ref string) string {
+	ref = strings.TrimSpace(ref)
+	// remove special char not allowed in file name
+	ref = matchSpecialCharReg.ReplaceAllString(ref, "_")
+	ref = matchDupUnderscoreReg.ReplaceAllString(ref, "_")
+	return ref
+}
+
+func generateLink(remote, ref string) (string, error) {
+	gitURL, err := giturl.Parse(remote)
+	if err != nil {
+		return "", err
+	}
+	normalisedRef := normaliseReference(ref)
+
+	// reject ref with all special char and . and .. has special meaning
+	if normalisedRef == "_" ||
+		normalisedRef == "." || normalisedRef == ".." {
+		return "", fmt.Errorf("reference cant be normalised")
+	}
+
+	// if reference is an hash then shorter version can be used as link path
+	if IsFullCommitHash(normalisedRef) {
+		normalisedRef = normalisedRef[:7]
+	}
+
+	return filepath.Join(strings.TrimRight(gitURL.Repo, ".git"), normalisedRef), nil
+}
+
+// PopulateEmptyLinkPaths will try and generate missing link paths
+func (repo *RepositoryConfig) PopulateEmptyLinkPaths() error {
+	for i := range repo.Worktrees {
+		if repo.Worktrees[i].Link != "" {
+			continue
+		}
+		if repo.Worktrees[i].Ref == "" {
+			repo.Worktrees[i].Ref = "HEAD"
+		}
+		link, err := generateLink(repo.Remote, repo.Worktrees[i].Ref)
+		if err != nil {
+			return err
+		}
+		repo.Worktrees[i].Link = link
+	}
+	return nil
+}
+
 // It is possible that same root is used for multiple repositories
 // since Links are placed at the root, we need to make sure that all link's
 // name (path) are diff.
-// ValidateLinkPaths makes sures all link's absolute paths are different.
-func (rpc *RepoPoolConfig) ValidateLinkPaths() error {
+// validateLinkPaths makes sures all link's absolute paths are different.
+func (rpc *RepoPoolConfig) validateLinkPaths() error {
 	var errs []error
 
 	absLinks := make(map[string]bool)
 
-	rpc.ApplyDefaults()
-
 	// add defaults before checking abs link paths
 	for _, repo := range rpc.Repositories {
 		for _, l := range repo.Worktrees {
-			absL := absLink(repo.Root, l.Link)
+			absL := absLink(repo.LinkRoot, l.Link)
 			if ok := absLinks[absL]; ok {
 				errs = append(errs, fmt.Errorf("links with overlapping abs path found name:%s path:%s",
 					l.Link, absL))
@@ -190,15 +272,22 @@ func (rpc *RepoPoolConfig) ValidateLinkPaths() error {
 
 // ValidateAndApplyDefaults will validate link paths and default and apply defaults
 func (conf *RepoPoolConfig) ValidateAndApplyDefaults() error {
-	if err := conf.ValidateDefaults(); err != nil {
+	if err := conf.validateDefaults(); err != nil {
 		return err
 	}
 
-	if err := conf.ValidateLinkPaths(); err != nil {
+	conf.applyDefaults()
+
+	for _, repo := range conf.Repositories {
+		if err := repo.PopulateEmptyLinkPaths(); err != nil {
+			return err
+		}
+	}
+
+	if err := conf.validateLinkPaths(); err != nil {
 		return err
 	}
 
-	conf.ApplyDefaults()
 	return nil
 }