package main import ( "fmt" "net" "github.com/stevenroose/gonfig" ) const clusterKeyLen = 32 type config struct { ClusterKey []byte `id:"cluster-key" desc:"shared key for cluster membership; must be 32 bytes base64 encoded; will be generated if not provided"` Join []string `desc:"comma separated list of hostnames or IP addresses to existing cluster members; if not provided, will attempt resuming any known state or otherwise wait for further members."` BindAddr string `id:"bind-addr" desc:"IP address to bind to for cluster membership" default:"0.0.0.0"` ClusterPort int `id:"cluster-port" desc:"port used for membership gossip traffic (both TCP and UDP); must be the same across cluster" default:"7946"` WireguardPort int `id:"wireguard-port" desc:"port used for wireguard traffic (UDP); must be the same across cluster" default:"51820"` OverlayNet *network `id:"overlay-net" desc:"the network in which to allocate addresses for the overlay mesh network (CIDR format); smaller networks increase the chance of IP collision" default:"10.0.0.0/8"` Interface string `desc:"name of the wireguard interface to create and manage" default:"wgoverlay"` NoEtcHosts bool `id:"no-etc-hosts" desc:"disable writing of entries to /etc/hosts"` LogLevel string `id:"log-level" desc:"set the verbosity (debug/info/warn/error)" default:"warn"` Version bool `desc:"display current version and exit"` // for easier local testing; will break etchosts entry UseIPAsName bool `id:"ip-as-name" default:"false" opts:"hidden"` } func loadConfig() (*config, error) { var config config err := gonfig.Load(&config, gonfig.Conf{EnvPrefix: "WESHER_"}) if err != nil { return nil, err } // perform some validation if len(config.ClusterKey) != 0 && len(config.ClusterKey) != clusterKeyLen { return nil, fmt.Errorf("unsupported cluster key length; expected %d, got %d", clusterKeyLen, len(config.ClusterKey)) } if bits, _ := ((*net.IPNet)(config.OverlayNet)).Mask.Size(); bits%8 != 0 { return nil, fmt.Errorf("unsupported overlay network size; net mask must be multiple of 8, got %d", bits) } return &config, nil } type network net.IPNet // UnmarshalText parses the provided byte array into the network receiver func (n *network) UnmarshalText(data []byte) error { _, ipnet, err := net.ParseCIDR(string(data)) if err != nil { return err } *n = network(*ipnet) return nil }