package main import ( "fmt" "net" "github.com/costela/wesher/cluster" "github.com/hashicorp/go-sockaddr" "github.com/pkg/errors" "github.com/stevenroose/gonfig" ) 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."` Rejoin int `desc:"interval at which join nodes are joined again if away, 0 disables rejoining altogether" default:"0"` Init bool `desc:"whether to explicitly (re)initialize the cluster; any known state from previous runs will be forgotten"` BindAddr string `id:"bind-addr" desc:"IP address to bind to for cluster membership traffic (cannot be used with --bind-iface)"` BindIface string `id:"bind-iface" desc:"Interface to bind to for cluster membership traffic (cannot be used with --bind-addr)"` 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"` BaseMtu int `id:"mtu" desc:"MTU of the underlying network, taking intermediary hops into account" default:"1500"` 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"` RoutedNet *network `id:"routed-net" desc:"network used to filter routes that nodes are allowed to announce (CIDR format)" default:"0.0.0.0/32"` 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"` KeepaliveInterval string `id:"keepalive-interval" desc:"interval for which to send keepalive packets" default:"30s"` // 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) != cluster.KeyLen { return nil, fmt.Errorf("unsupported cluster key length; expected %d, got %d", cluster.KeyLen, 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) } if config.BindAddr != "" && config.BindIface != "" { return nil, fmt.Errorf("setting both bind address and bind interface is not supported") } else if config.BindIface != "" { // Compute the actual bind address based on the provided interface iface, err := net.InterfaceByName(config.BindIface) if err != nil { return nil, errors.Wrapf(err, "could not get interface by name %s", config.BindIface) } addrs, err := iface.Addrs() if err != nil { return nil, errors.Wrapf(err, "could not get addresses for interface %s", config.BindIface) } if len(addrs) > 0 { if addr, ok := addrs[0].(*net.IPNet); ok { config.BindAddr = addr.IP.String() } } } else if config.BindAddr == "" && config.BindIface == "" { // FIXME: this is a workaround for memberlist refusing to listen on public IPs if BindAddr==0.0.0.0 detectedBindAddr, err := sockaddr.GetPublicIP() if err != nil { return nil, err } // if we cannot find a public IP, let memberlist do its thing if detectedBindAddr != "" { config.BindAddr = detectedBindAddr } else { config.BindAddr = "0.0.0.0" } } return &config, nil } type network net.IPNet // UnmarshalText parses the provided byte array into the network receiver func (n *network) UnmarshalText(data []byte) error { ip, ipnet, err := net.ParseCIDR(string(data)) if err != nil { return err } ipnet.IP = ip *n = network(*ipnet) return nil }