feat: Support self-hosted GitHub Enterprise servers

internal/chezmoi/github.go

@@ -4,20 +4,16 @@ import (
 	"context"
 	"net/http"
 	"os"
+	"strings"
 
 	"github.com/google/go-github/v62/github"
 	"golang.org/x/oauth2"
 )
 
 // NewGitHubClient returns a new github.Client configured with an access token
 // and a http client, if available.
-func NewGitHubClient(ctx context.Context, httpClient *http.Client) *github.Client {
-	for _, key := range []string{
-		"CHEZMOI_GITHUB_ACCESS_TOKEN",
-		"CHEZMOI_GITHUB_TOKEN",
-		"GITHUB_ACCESS_TOKEN",
-		"GITHUB_TOKEN",
-	} {
+func NewGitHubClient(ctx context.Context, httpClient *http.Client, host string) *github.Client {
+	for _, key := range accessTokenEnvKeys(host) {
 		if accessToken := os.Getenv(key); accessToken != "" {
 			httpClient = oauth2.NewClient(
 				context.WithValue(ctx, oauth2.HTTPClient, httpClient),
@@ -29,3 +25,39 @@ func NewGitHubClient(ctx context.Context, httpClient *http.Client) *github.Clien
 	}
 	return github.NewClient(httpClient)
 }
+
+func accessTokenEnvKeys(host string) []string {
+	var keys []string
+	for _, chezmoiKey := range []string{"CHEZMOI", ""} {
+		hostKeys := []string{makeHostKey(host)}
+		if host == "github.com" {
+			hostKeys = append(hostKeys, "GITHUB")
+		}
+		for _, hostKey := range hostKeys {
+			for _, accessKey := range []string{"ACCESS", ""} {
+				key := strings.Join(nonEmpty([]string{chezmoiKey, hostKey, accessKey, "TOKEN"}), "_")
+				keys = append(keys, key)
+			}
+		}
+	}
+	return keys
+}
+
+func makeHostKey(host string) string {
+	// FIXME split host on non-ASCII characters
+	// FIXME convert everything to uppercase
+	// FIXME join components with _
+	return host
+}
+
+func nonEmpty[S []T, T comparable](s S) S {
+	// FIXME use something from slices for this
+	result := make([]T, 0, len(s))
+	var zero T
+	for _, e := range s {
+		if e != zero {
+			result = append(result, e)
+		}
+	}
+	return result
+}

internal/chezmoi/github_test.go

@@ -0,0 +1,27 @@
+package chezmoi
+
+import (
+	"testing"
+
+	"github.com/alecthomas/assert/v2"
+)
+
+func TestAccessTokenEnvKeys(t *testing.T) {
+	for _, tc := range []struct {
+		host     string
+		expected []string
+	}{
+		{
+			expected: []string{
+				"CHEZMOI_GITHUB_ACCESS_TOKEN",
+				"CHEZMOI_GITHUB_TOKEN",
+				"GITHUB_ACCESS_TOKEN",
+				"GITHUB_TOKEN",
+			},
+		},
+	} {
+		t.Run(tc.host, func(t *testing.T) {
+			assert.Equal(t, tc.expected, accessTokenEnvKeys(tc.host))
+		})
+	}
+}

internal/cmd/config.go

@@ -340,6 +340,11 @@ func newConfig(options ...configOption) (*Config, error) {
 		homeDir:       userHomeDir,
 		templateFuncs: sprig.TxtFuncMap(),
 
+		// Password manager data.
+		gitHub: gitHubData{
+			clientsByHost: make(map[string]gitHubClientResult),
+		},
+
 		// Command configurations.
 		apply: applyCmdConfig{
 			filter:    chezmoi.NewEntryTypeFilter(chezmoi.EntryTypesAll, chezmoi.EntryTypesNone),

internal/cmd/doctorcmd.go

@@ -659,7 +659,7 @@ func (c *latestVersionCheck) Run(system chezmoi.System, homeDirAbsPath chezmoi.A
 
 	ctx := context.Background()
 
-	gitHubClient := chezmoi.NewGitHubClient(ctx, c.httpClient)
+	gitHubClient := chezmoi.NewGitHubClient(ctx, c.httpClient, "github.com")
 	rr, _, err := gitHubClient.Repositories.GetLatestRelease(ctx, "twpayne", "chezmoi")
 	var rateLimitErr *github.RateLimitError
 	var abuseRateLimitErr *github.AbuseRateLimitError