// +build kvdb_etcd package etcd import ( "context" "fmt" "net" "net/url" "sync/atomic" "time" "github.com/coreos/etcd/embed" ) const ( // readyTimeout is the time until the embedded etcd instance should start. readyTimeout = 10 * time.Second // defaultEtcdPort is the start of the range for listening ports of // embedded etcd servers. Ports are monotonically increasing starting // from this number and are determined by the results of getFreePort(). defaultEtcdPort = 2379 ) var ( // lastPort is the last port determined to be free for use by a new // embedded etcd server. It should be used atomically. lastPort uint32 = defaultEtcdPort ) // getFreePort returns the first port that is available for listening by a new // embedded etcd server. It panics if no port is found and the maximum available // TCP port is reached. func getFreePort() int { port := atomic.AddUint32(&lastPort, 1) for port < 65535 { // If there are no errors while attempting to listen on this // port, close the socket and return it as available. addr := fmt.Sprintf("127.0.0.1:%d", port) l, err := net.Listen("tcp4", addr) if err == nil { err := l.Close() if err == nil { return int(port) } } port = atomic.AddUint32(&lastPort, 1) } // No ports available? Must be a mistake. panic("no ports available for listening") } // NewEmbeddedEtcdInstance creates an embedded etcd instance for testing, // listening on random open ports. Returns the backend config and a cleanup // func that will stop the etcd instance. func NewEmbeddedEtcdInstance(path string) (*BackendConfig, func(), error) { cfg := embed.NewConfig() cfg.Dir = path // To ensure that we can submit large transactions. cfg.MaxTxnOps = 8192 cfg.MaxRequestBytes = 16384 * 1024 // Listen on random free ports. clientURL := fmt.Sprintf("127.0.0.1:%d", getFreePort()) peerURL := fmt.Sprintf("127.0.0.1:%d", getFreePort()) cfg.LCUrls = []url.URL{{Host: clientURL}} cfg.LPUrls = []url.URL{{Host: peerURL}} etcd, err := embed.StartEtcd(cfg) if err != nil { return nil, nil, err } select { case <-etcd.Server.ReadyNotify(): case <-time.After(readyTimeout): etcd.Close() return nil, nil, fmt.Errorf("etcd failed to start after: %v", readyTimeout) } ctx, cancel := context.WithCancel(context.Background()) connConfig := &BackendConfig{ Ctx: ctx, Host: "http://" + peerURL, User: "user", Pass: "pass", InsecureSkipVerify: true, } return connConfig, func() { cancel() etcd.Close() }, nil }