Add use-legacy-storage flag

Adds the flag `use-legacy-storage` which will override the
`domain-config-source` flag when enabled and will use disk serving along
with configuration source. This is a temporary  flag that will allow
self-managed instances use legacy storage while migrating to Object
Storage and making API-based configuration work.

Changelog: added

3 files changed, 43 insertions, 17 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
index 7e44abbc..85f0aad2 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -48,6 +48,7 @@ type Config struct {
 type General struct {
 	Domain                    string
 	DomainConfigurationSource string
+	UseLegacyStorage          bool
 	HTTP2                     bool
 	MaxConns                  int
 	MetricsAddress            string
@@ -252,6 +253,10 @@ func (config Config) GitlabJWTTokenExpiry() time.Duration {
 }
 
 func (config Config) DomainConfigSource() string {
+	if config.General.UseLegacyStorage {
+		return "disk"
+	}
+
 	return config.General.DomainConfigurationSource
 }
 
@@ -260,6 +265,7 @@ func loadConfig() *Config {
 		General: General{
 			Domain:                     strings.ToLower(*pagesDomain),
 			DomainConfigurationSource:  *domainConfigSource,
+			UseLegacyStorage:           *useLegacyStorage,
 			HTTP2:                      *useHTTP2,
 			MaxConns:                   *maxConns,
 			MetricsAddress:             *metricsAddress,
@@ -389,6 +395,7 @@ func LogConfig(config *Config) {
 		"internal-gitlab-server":        config.GitLab.InternalServer,
 		"api-secret-key":                *gitLabAPISecretKey,
 		"domain-config-source":          config.General.DomainConfigurationSource,
+		"use-legacy-storage":            config.General.UseLegacyStorage,
 		"auth-redirect-uri":             config.Authentication.RedirectURI,
 		"auth-scope":                    config.Authentication.Scope,
 		"zip-cache-expiration":          config.Zip.ExpirationInterval,
diff --git a/internal/config/flags.go b/internal/config/flags.go
index d2cee32d..c51298e8 100644
--- a/internal/config/flags.go
+++ b/internal/config/flags.go
@@ -40,18 +40,21 @@ var (
 	gitlabClientHTTPTimeout = flag.Duration("gitlab-client-http-timeout", 10*time.Second, "GitLab API HTTP client connection timeout in seconds (default: 10s)")
 	gitlabClientJWTExpiry   = flag.Duration("gitlab-client-jwt-expiry", 30*time.Second, "JWT Token expiry time in seconds (default: 30s)")
 	domainConfigSource      = flag.String("domain-config-source", "auto", "Domain configuration source 'disk', 'auto' or 'gitlab' (default: 'auto'). DEPRECATED: gitlab-pages will use the API-based configuration starting from 14.0 see https://gitlab.com/gitlab-org/gitlab-pages/-/issues/382")
-	clientID                = flag.String("auth-client-id", "", "GitLab application Client ID")
-	clientSecret            = flag.String("auth-client-secret", "", "GitLab application Client Secret")
-	redirectURI             = flag.String("auth-redirect-uri", "", "GitLab application redirect URI")
-	authScope               = flag.String("auth-scope", "api", "Scope to be used for authentication (must match GitLab Pages OAuth application settings)")
-	maxConns                = flag.Int("max-conns", 5000, "Limit on the number of concurrent connections to the HTTP, HTTPS or proxy listeners")
-	insecureCiphers         = flag.Bool("insecure-ciphers", false, "Use default list of cipher suites, may contain insecure ones like 3DES and RC4")
-	tlsMinVersion           = flag.String("tls-min-version", "tls1.2", tlsconfig.FlagUsage("min"))
-	tlsMaxVersion           = flag.String("tls-max-version", "", tlsconfig.FlagUsage("max"))
-	zipCacheExpiration      = flag.Duration("zip-cache-expiration", 60*time.Second, "Zip serving archive cache expiration interval")
-	zipCacheCleanup         = flag.Duration("zip-cache-cleanup", 30*time.Second, "Zip serving archive cache cleanup interval")
-	zipCacheRefresh         = flag.Duration("zip-cache-refresh", 30*time.Second, "Zip serving archive cache refresh interval")
-	zipOpenTimeout          = flag.Duration("zip-open-timeout", 30*time.Second, "Zip archive open timeout")
+	// TODO: remove this flag https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/6009
+	useLegacyStorage = flag.Bool("use-legacy-storage", false, "Temporary flag that enables legacy serving from disk/NFS. API-Based configuration and object storage are preferred https://docs.gitlab.com/ee/administration/pages/ and will be the only available solution starting from 14.4")
+
+	clientID           = flag.String("auth-client-id", "", "GitLab application Client ID")
+	clientSecret       = flag.String("auth-client-secret", "", "GitLab application Client Secret")
+	redirectURI        = flag.String("auth-redirect-uri", "", "GitLab application redirect URI")
+	authScope          = flag.String("auth-scope", "api", "Scope to be used for authentication (must match GitLab Pages OAuth application settings)")
+	maxConns           = flag.Int("max-conns", 5000, "Limit on the number of concurrent connections to the HTTP, HTTPS or proxy listeners")
+	insecureCiphers    = flag.Bool("insecure-ciphers", false, "Use default list of cipher suites, may contain insecure ones like 3DES and RC4")
+	tlsMinVersion      = flag.String("tls-min-version", "tls1.2", tlsconfig.FlagUsage("min"))
+	tlsMaxVersion      = flag.String("tls-max-version", "", tlsconfig.FlagUsage("max"))
+	zipCacheExpiration = flag.Duration("zip-cache-expiration", 60*time.Second, "Zip serving archive cache expiration interval")
+	zipCacheCleanup    = flag.Duration("zip-cache-cleanup", 30*time.Second, "Zip serving archive cache cleanup interval")
+	zipCacheRefresh    = flag.Duration("zip-cache-refresh", 30*time.Second, "Zip serving archive cache refresh interval")
+	zipOpenTimeout     = flag.Duration("zip-open-timeout", 30*time.Second, "Zip archive open timeout")
 
 	disableCrossOriginRequests = flag.Bool("disable-cross-origin-requests", false, "Disable cross-origin requests")
 
diff --git a/test/acceptance/serving_test.go b/test/acceptance/serving_test.go
index 19476830..07dc0345 100644
--- a/test/acceptance/serving_test.go
+++ b/test/acceptance/serving_test.go
@@ -378,10 +378,11 @@ func TestDomainsSource(t *testing.T) {
 	skipUnlessEnabled(t)
 
 	type args struct {
-		configSource string
-		domain       string
-		urlSuffix    string
-		readyCount   int
+		configSource     string
+		useLegacyStorage bool
+		domain           string
+		urlSuffix        string
+		readyCount       int
 	}
 	type want struct {
 		statusCode int
@@ -481,6 +482,19 @@ func TestDomainsSource(t *testing.T) {
 				apiCalled:  true,
 			},
 		},
+		{
+			name: "use_legacy_storage_overrides_domain_source",
+			args: args{
+				useLegacyStorage: true,
+				domain:           "test.domain.com",
+				urlSuffix:        "/",
+			},
+			want: want{
+				statusCode: http.StatusOK,
+				content:    "main-dir\n",
+				apiCalled:  false,
+			},
+		},
 	}
 
 	for _, tt := range tests {
@@ -495,7 +509,9 @@ func TestDomainsSource(t *testing.T) {
 
 			gitLabAPISecretKey := CreateGitLabAPISecretKeyFixtureFile(t)
 
-			pagesArgs := []string{"-gitlab-server", source.URL, "-api-secret-key", gitLabAPISecretKey, "-domain-config-source", tt.args.configSource}
+			pagesArgs := []string{"-gitlab-server", source.URL, "-api-secret-key", gitLabAPISecretKey, "-domain-config-source", tt.args.configSource,
+				// TODO: remove in https://gitlab.com/gitlab-org/omnibus-gitlab/-/issues/6009
+				fmt.Sprintf("-use-legacy-storage=%t", tt.args.useLegacyStorage)}
 			teardown := RunPagesProcessWithEnvs(t, true, *pagesBinary, []ListenSpec{httpListener}, "", []string{}, pagesArgs...)
 			defer teardown()