fix: respect ~/.gitconfig's core.excludesFile option

coder · DanielleMaywood · Jul 24, 2025 · Jul 23, 2025 · Jul 23, 2025 · Jul 23, 2025
commit 0a438a87ce7192b68bbd1773090a67a5b42a3ba1
diff --git a/agent/agentcontainers/api.go b/agent/agentcontainers/api.go
@@ -471,12 +471,14 @@
 }
 
 func (api *API) discoverDevcontainersInProject(projectPath string) error {
+	globalPatterns, err := ignore.LoadGlobalPatterns(api.fs)
+
 	patterns, err := ignore.ReadPatterns(api.fs, projectPath)
 	if err != nil {
 		return xerrors.Errorf("read git ignore patterns: %w", err)
 	}
 
-	matcher := gitignore.NewMatcher(patterns)
+	matcher := gitignore.NewMatcher(append(globalPatterns, patterns...))
 
 	devcontainerConfigPaths := []string{
 		"/.devcontainer/devcontainer.json",

diff --git a/agent/agentcontainers/api_test.go b/agent/agentcontainers/api_test.go
@@ -9,6 +9,7 @@ import (
 	"net/http/httptest"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"runtime"
 	"slices"
 	"strings"
@@ -3211,6 +3212,9 @@ func TestDevcontainerDiscovery(t *testing.T) {
 	// repositories to find any `.devcontainer/devcontainer.json`
 	// files. These tests are to validate that behavior.
 
+	homeDir, err := os.UserHomeDir()
+	require.NoError(t, err)
+
 	tests := []struct {
 		name     string
 		agentDir string
@@ -3402,6 +3406,28 @@ func TestDevcontainerDiscovery(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:     "RespectHomeGitConfig",
+			agentDir: homeDir,
+			fs: map[string]string{
+				"/tmp/.gitignore": "node_modules/",
+				filepath.Join(homeDir, ".gitconfig"): `
+					[core]
+					excludesFile = /tmp/.gitignore
+				`,
+
+				filepath.Join(homeDir, ".git/HEAD"):                         "",
+				filepath.Join(homeDir, ".devcontainer.json"):                "",
+				filepath.Join(homeDir, "node_modules/y/.devcontainer.json"): "",
+			},
+			expected: []codersdk.WorkspaceAgentDevcontainer{
+				{
+					WorkspaceFolder: homeDir,
+					ConfigPath:      filepath.Join(homeDir, ".devcontainer.json"),
+					Status:          codersdk.WorkspaceAgentDevcontainerStatusStopped,
+				},
+			},
+		},
 	}
 
 	initFS := func(t *testing.T, files map[string]string) afero.Fs {
@@ -3454,7 +3480,7 @@ func TestDevcontainerDiscovery(t *testing.T) {
 				err := json.NewDecoder(rec.Body).Decode(&got)
 				require.NoError(t, err)
 
-				return len(got.Devcontainers) == len(tt.expected)
+				return len(got.Devcontainers) >= len(tt.expected)
 			}, testutil.WaitShort, testutil.IntervalFast, "dev containers never found")
 
 			// Now projects have been discovered, we'll allow the updater loop

diff --git a/agent/agentcontainers/ignore/dir.go b/agent/agentcontainers/ignore/dir.go
@@ -1,17 +1,21 @@
 package ignore
 
 import (
+	"bytes"
 	"errors"
 	"io/fs"
 	"os"
 	"path/filepath"
 	"strings"
 
+	"github.com/go-git/go-git/v5/plumbing/format/config"
 	"github.com/go-git/go-git/v5/plumbing/format/gitignore"
 	"github.com/spf13/afero"
+	"golang.org/x/xerrors"
 )
 
 const (
+	gitconfigFile      = ".gitconfig"
 	gitignoreFile      = ".gitignore"
 	gitInfoExcludeFile = ".git/info/exclude"
 )
@@ -78,3 +82,33 @@ func ReadPatterns(fileSystem afero.Fs, path string) ([]gitignore.Pattern, error)
 
 	return ps, nil
 }
+
+func loadPatterns(fileSystem afero.Fs, path string) ([]gitignore.Pattern, error) {
+	data, err := afero.ReadFile(fileSystem, path)
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return nil, err
+	}
+
+	decoder := config.NewDecoder(bytes.NewBuffer(data))
+
+	conf := config.New()
+	if err := decoder.Decode(conf); err != nil {
+		return nil, xerrors.Errorf("decode config: %w", err)
+	}
+
+	excludes := conf.Section("core").Options.Get("excludesfile")
+	if excludes == "" {
+		return nil, nil
+	}
+
+	return readIgnoreFile(fileSystem, "", excludes)
+}
+
+func LoadGlobalPatterns(fileSystem afero.Fs) ([]gitignore.Pattern, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return nil, err
+	}
+
+	return loadPatterns(fileSystem, filepath.Join(home, gitconfigFile))
+}