feat(fs/git): add support for a directory scope

go.work.sum

@@ -255,6 +255,7 @@ github.com/bugsnag/osext v0.0.0-20130617224835-0dd3f918b21b/go.mod h1:obH5gd0Bsq
 github.com/bugsnag/panicwrap v0.0.0-20151223152923-e2c28503fcd0/go.mod h1:D/8v3kj0zr8ZAKg1AQ6crr+5VwKN5eIywRkfhyM/+dE=
 github.com/cenkalti/backoff/v4 v4.1.1/go.mod h1:scbssz8iZGpm3xbr14ovlUdkxfGXNInqkPWOWmG2CLw=
 github.com/cenkalti/backoff/v4 v4.1.2/go.mod h1:scbssz8iZGpm3xbr14ovlUdkxfGXNInqkPWOWmG2CLw=
+github.com/cenkalti/backoff/v4 v4.2.1/go.mod h1:Y3VNntkOUPxTVeUxJ/G5vcM//AlwfmyYozVcomhLiZE=
 github.com/census-instrumentation/opencensus-proto v0.4.1/go.mod h1:4T9NM4+4Vw91VeyqjLS6ao50K5bOcLKN6Q42XnYaRYw=
 github.com/certifi/gocertifi v0.0.0-20191021191039-0944d244cd40/go.mod h1:sGbDF6GwGcLpkNXPUTkMRoywsNa/ol15pxFe6ERfguA=
 github.com/certifi/gocertifi v0.0.0-20200922220541-2c3bb06c6054/go.mod h1:sGbDF6GwGcLpkNXPUTkMRoywsNa/ol15pxFe6ERfguA=

internal/config/config_test.go

@@ -726,6 +726,23 @@ func TestLoad(t *testing.T) {
 				return cfg
 			},
 		},
+		{
+			name: "git config provided with directory",
+			path: "./testdata/storage/git_provided_with_directory.yml",
+			expected: func() *Config {
+				cfg := Default()
+				cfg.Storage = StorageConfig{
+					Type: GitStorageType,
+					Git: &Git{
+						Ref:          "main",
+						Repository:   "git@github.com:foo/bar.git",
+						Directory:    "baz",
+						PollInterval: 30 * time.Second,
+					},
+				}
+				return cfg
+			},
+		},
 		{
 			name:    "git repository not provided",
 			path:    "./testdata/storage/invalid_git_repo_not_specified.yml",

internal/config/storage.go

@@ -146,6 +146,7 @@ type Local struct {
 type Git struct {
 	Repository      string         `json:"repository,omitempty" mapstructure:"repository" yaml:"repository,omitempty"`
 	Ref             string         `json:"ref,omitempty" mapstructure:"ref" yaml:"ref,omitempty"`
+	Directory       string         `json:"directory,omitempty" mapstructure:"directory" yaml:"directory,omitempty"`
 	CaCertBytes     string         `json:"-" mapstructure:"ca_cert_bytes" yaml:"-" `
 	CaCertPath      string         `json:"-" mapstructure:"ca_cert_path" yaml:"-" `
 	InsecureSkipTLS bool           `json:"-" mapstructure:"insecure_skip_tls" yaml:"-"`

internal/config/testdata/storage/git_provided_with_directory.yml

@@ -0,0 +1,5 @@
+storage:
+  type: git
+  git:
+    repository: "git@github.com:foo/bar.git"
+    directory: "baz"

internal/storage/fs/git/store.go

@@ -3,6 +3,7 @@ package git
 import (
 	"context"
 	"errors"
+	"io/fs"
 	"sync"
 
 	"github.com/go-git/go-git/v5"
@@ -34,6 +35,7 @@ type SnapshotStore struct {
 	logger          *zap.Logger
 	url             string
 	baseRef         string
+	directory       string
 	auth            transport.AuthMethod
 	insecureSkipTLS bool
 	caBundle        []byte
@@ -88,6 +90,14 @@ func WithCABundle(caCertBytes []byte) containers.Option[SnapshotStore] {
 	}
 }
 
+// WithDirectory sets a root directory which the store will walk from
+// to discover feature flag state files.
+func WithDirectory(directory string) containers.Option[SnapshotStore] {
+	return func(ss *SnapshotStore) {
+		ss.directory = directory
+	}
+}
+
 // NewSnapshotStore constructs and configures a Store.
 // The store uses the connection and credential details provided to build
 // fs.FS implementations around a target git repository.
@@ -256,10 +266,18 @@ func (s *SnapshotStore) resolve(ref string) (plumbing.Hash, error) {
 
 // buildSnapshot builds a new store snapshot based on the provided hash.
 func (s *SnapshotStore) buildSnapshot(ctx context.Context, hash plumbing.Hash) (*storagefs.Snapshot, error) {
-	fs, err := gitfs.NewFromRepoHash(s.logger, s.repo, hash)
+	var gfs fs.FS
+	gfs, err := gitfs.NewFromRepoHash(s.logger, s.repo, hash)
 	if err != nil {
 		return nil, err
 	}
 
-	return storagefs.SnapshotFromFS(s.logger, fs)
+	if s.directory != "" {
+		gfs, err = fs.Sub(gfs, s.directory)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return storagefs.SnapshotFromFS(s.logger, gfs)
 }

internal/storage/fs/git/store_test.go

@@ -43,7 +43,7 @@ func Test_Store_Subscribe_Hash(t *testing.T) {
 	testStore(t, gitRepoURL, WithRef(head))
 }
 
-func Test_Store_Subscribe(t *testing.T) {
+func Test_Store_View(t *testing.T) {
 	ch := make(chan struct{})
 	store, skip := testStore(t, gitRepoURL, WithPollOptions(
 		fs.WithInterval(time.Second),
@@ -121,7 +121,7 @@ flags:
 	}))
 }
 
-func Test_Store_Subscribe_WithRevision(t *testing.T) {
+func Test_Store_View_WithRevision(t *testing.T) {
 	ch := make(chan struct{})
 	store, skip := testStore(t, gitRepoURL, WithPollOptions(
 		fs.WithInterval(time.Second),
@@ -216,6 +216,49 @@ flags:
 	}))
 }
 
+func Test_Store_View_WithDirectory(t *testing.T) {
+	ch := make(chan struct{})
+	store, skip := testStore(t, gitRepoURL, WithPollOptions(
+		fs.WithInterval(time.Second),
+		fs.WithNotify(t, func(modified bool) {
+			if modified {
+				close(ch)
+			}
+		}),
+	),
+		// scope flag state discovery to sub-directory
+		WithDirectory("subdir"),
+	)
+	if skip {
+		return
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	t.Cleanup(cancel)
+
+	// pull repo
+	workdir := memfs.New()
+	repo, err := git.Clone(memory.NewStorage(), workdir, &git.CloneOptions{
+		Auth:          &http.BasicAuth{Username: "root", Password: "password"},
+		URL:           gitRepoURL,
+		RemoteName:    "origin",
+		ReferenceName: plumbing.NewBranchReferenceName("main"),
+	})
+	require.NoError(t, err)
+
+	tree, err := repo.Worktree()
+	require.NoError(t, err)
+
+	require.NoError(t, tree.Checkout(&git.CheckoutOptions{
+		Branch: "refs/heads/main",
+	}))
+
+	require.NoError(t, store.View(ctx, "", func(s storage.ReadOnlyStore) error {
+		_, err = s.GetFlag(ctx, storage.NewResource("alternative", "otherflag"))
+		return err
+	}))
+}
+
 func Test_Store_SelfSignedSkipTLS(t *testing.T) {
 	ts := httptest.NewTLSServer(nil)
 	defer ts.Close()

internal/storage/fs/git/testdata/subdir/.flipt.yml

@@ -0,0 +1,3 @@
+version: "1.0"
+include:
+- "alternative.yml"

internal/storage/fs/git/testdata/subdir/alternative.yml

@@ -0,0 +1,5 @@
+namespace: "alternative"
+flags:
+- key: otherflag
+  name: Other Flag
+

internal/storage/fs/store/store.go

@@ -38,6 +38,7 @@ func NewStore(ctx context.Context, logger *zap.Logger, cfg *config.Config) (_ st
 				storagefs.WithInterval(cfg.Storage.Git.PollInterval),
 			),
 			git.WithInsecureTLS(cfg.Storage.Git.InsecureSkipTLS),
+			git.WithDirectory(cfg.Storage.Git.Directory),
 		}
 
 		if cfg.Storage.Git.CaCertBytes != "" {