Add config for openid auth

config.yml.sample

@@ -215,3 +215,26 @@ legal:
 keyvalue:
   # The type of the storage backend. Can be either "memory" or "redis". If "redis" is chosen it needs to be configured seperately.
   type: "memory"
+
+auth:
+  # Local authentication will let users log in and register (if enabled) through the db.
+  # This is the default auth mechanism and does not require any additional configuration.
+  local:
+    # Enable or disable local authentication
+    enabled: true
+  # OpenID configuration will allow users to authenticate through a third-party OpenID Connect compatible provider.
+  # The provider needs to support the `openid`, `profile` and `email` scopes.
+  openid:
+    # Enable or disable OpenID Connect authentication
+    enabled: false
+    # The url to redirect clients to. Defaults to the configured frontend url. If you're using Vikunja with the official
+    # frontend, you don't need to change this value.
+    redirecturl: <frontend url>
+    # A list of enabled providers
+    providers:
+        # The name of the provider as it will appear in the frontend.
+      - name:
+        # The auth url to send users to if they want to authenticate using OpenID Connect.
+        authurl:
+        # The client ID used to authenticate Vikunja at the OpenID Connect provider.
+        clientid:

pkg/config/config.go

@@ -52,6 +52,11 @@ const (
 	ServiceEnableTotp            Key = `service.enabletotp`
 	ServiceSentryDsn             Key = `service.sentrydsn`
 
+	AuthLocalEnabled      Key = `auth.local.enabled`
+	AuthOpenIDEnabled     Key = `auth.openid.enabled`
+	AuthOpenIDRedirectURL Key = `auth.openid.redirecturl`
+	AuthOpenIDProviders   Key = `auth.openid.providers`
+
 	LegalImprintURL Key = `legal.imprinturl`
 	LegalPrivacyURL Key = `legal.privacyurl`
 
@@ -158,6 +163,11 @@ func (k Key) GetStringSlice() []string {
 	return viper.GetStringSlice(string(k))
 }
 
+// Get returns the raw value from a config option
+func (k Key) Get() interface{} {
+	return viper.Get(string(k))
+}
+
 var timezone *time.Location
 
 // GetTimeZone returns the time zone configured for vikunja
@@ -216,6 +226,10 @@ func InitDefaultConfig() {
 	ServiceEnableTaskComments.setDefault(true)
 	ServiceEnableTotp.setDefault(true)
 
+	// Auth
+	AuthLocalEnabled.setDefault(true)
+	AuthOpenIDEnabled.setDefault(false)
+
 	// Database
 	DatabaseType.setDefault("sqlite")
 	DatabaseHost.setDefault("localhost")