API - CRUD for peers, interfaces and users (#340)

Public REST API implementation to handle peers, interfaces and users. It also includes some simple provisioning endpoints.

The Swagger API documentation is available under /api/v1/doc.html

internal/config/config.go

@@ -39,6 +39,7 @@ type Config struct {
 		ExpiryCheckInterval time.Duration `yaml:"expiry_check_interval"`
 		RulePrioOffset      int           `yaml:"rule_prio_offset"`
 		RouteTableOffset    int           `yaml:"route_table_offset"`
+		ApiAdminOnly        bool          `yaml:"api_admin_only"` // if true, only admin users can access the API
 	} `yaml:"advanced"`
 
 	Statistics struct {
@@ -126,6 +127,7 @@ func defaultConfig() *Config {
 	cfg.Advanced.ExpiryCheckInterval = 15 * time.Minute
 	cfg.Advanced.RulePrioOffset = 20000
 	cfg.Advanced.RouteTableOffset = 20000
+	cfg.Advanced.ApiAdminOnly = true
 
 	cfg.Statistics.UsePingChecks = true
 	cfg.Statistics.PingCheckWorkers = 10