func (p *DataStoreHandler) makeConnection() {
// Only make once
if p.connection.Client != nil {
return
}
var err error
p.connection, err = etcdMisc.MakeEtcdConnection(&http.Client{Timeout: 0}, nil, "http", p.etcdAddr, p.etcdPort)
if err != nil {
logger.Printf("Failed to connect to etcd: %s", err)
}
}
func main() {
connection, err := etcdMisc.MakeEtcdConnection(&http.Client{Timeout: 0}, nil, "http", "localhost", 4001)
fmt.Printf("Connection: %s\n", connection)
// ---------------------------------------------------------------------------------------------------
// Protective Delete of a directory, might be non-existant
r, err := connection.DeleteDir("/junk", true)
if err != nil {
fmt.Println("Failed to delete directory:", err)
} else {
fmt.Printf("Deleted directory: %s\n", r)
}
// Start making a directory
r, err = connection.Mkdir("/junk")
if err != nil {
fmt.Println("Failed to create directory:", err)
os.Exit(-1)
}
fmt.Printf("Created directory successfully: %s\n", r)
// Add to the previous directory
r, err = connection.Mkdir("/junk/one")
if err != nil {
fmt.Println("Failed to create directory:", err)
os.Exit(-1)
}
fmt.Printf("Created directory successfully: %s\n", r)
// ---------------------------------------------------------------------------------------------------
// Set followed by a 'Get' to verify
r, err = connection.SetValue("/junk/blob1", "Hello")
if err != nil {
fmt.Println("Failed to set etcd value:", err)
os.Exit(-1)
}
fmt.Printf("SetValue with string(\"Hello\") Response: %s\n", r)
r, err = connection.GetValue("/junk/blob1", false, false)
if err != nil {
fmt.Println("Failed to get etcd value:", err)
os.Exit(-1)
}
fmt.Printf("GetValue Response: %s\n", r)
if r.Node.Value != "Hello" {
fmt.Printf("FAILED: get should return 'Hello'\n")
os.Exit(-1)
}
// Delete Key
r, err = connection.DeleteKey("/junk/blob1")
if err != nil {
fmt.Println("Failed to delete etcd key:", err)
os.Exit(-1)
}
fmt.Printf("DeleteKey Response: %s\n", r)
// ---------------------------------------------------------------------------------------------------
// Delete non-existant Key
r, err = connection.DeleteKey("/junk/doesNotExist")
if err == nil {
fmt.Printf("Found no error deleting a missing etcd key: %s/%s\n", err, r)
os.Exit(-1)
}
fmt.Printf("DeleteKey errored as expected deleting a missing key: %s\n", err)
// ---------------------------------------------------------------------------------------------------
// Set with a TTL
r, err = connection.SetValue("/junk/blob3", "Hello", 2)
if err != nil {
fmt.Println("Failed to set etcd value:", err)
os.Exit(-1)
}
fmt.Printf("SetValue with string(\"Hello\", TTL=1) Response: %s\n", r)
// Verify it was set
r, err = connection.GetValue("/junk/blob3", false, false)
if err != nil {
fmt.Println("Failed to get etcd value:", err)
os.Exit(-1)
}
fmt.Printf("GetValue Response: %s\n", r)
if r.Node.Value != "Hello" {
fmt.Printf("FAILED: get should return 'Hello'\n")
os.Exit(-1)
}
// wait for the TTL above to expire and verify it is gone
fmt.Printf("Sleep 3 seconds ..... to wait for key to expire\n")
time.Sleep(3 * time.Second)
r, err = connection.GetValue("/junk/blob3", false, false)
if err == nil {
fmt.Println("Failed to NOT get expired etcd value:", err)
os.Exit(-1)
}
fmt.Println("Received expected error GETting expired key (missing key)")
// ---------------------------------------------------------------------------------------------------
// Background function to make 4 changes that will be picked up by the
// coming watchers that require at least 4 changes to avoid timeouts.
go func(keyRoot string) {
time.Sleep(1 * time.Second)
for t := 0; t < 4; t++ {
newVal := keyRoot + strconv.Itoa(t)
fmt.Printf("SetValue background Value for watcher test: %s\n", newVal)
// Set followed by a 'Get' to verify
_, err := connection.SetValue(newVal, "miscSillyValue")
if err != nil {
fmt.Println("Failed to set etcd value:", err)
os.Exit(-1)
}
time.Sleep(time.Second / 2)
}
}("/junk/foobarOne")
// ---------------------------------------------------------------------------------------------------
// Get a single event for the watched key (blocking call) (consumes one of the background events)
// Use the bool channel to abort this query if needed.
ctrl := make(chan bool)
r, err = connection.Watcher(ctrl, "/", true)
if err != nil {
fmt.Println("Failed: ", err)
} else {
fmt.Printf("EtcdResponse: %s\n", r)
}
// ---------------------------------------------------------------------------------------------------
// Non-blocking event stream. Shutdown via bool channel. Consumes 3 of the background events.
// Create event stream from key on cmd line, recursive == true
events := connection.EventStream(ctrl, "/", true)
// Receive exactly three events
for i := 0; i < 3; i++ {
timer := time.NewTimer(time.Second * 3)
select {
case msg := <-events:
if msg.GetError() != nil {
fmt.Println("Event ERR:", msg.GetError())
// Shutdown the event stream and restart ... most likely out of sync or etcd is dead
ctrl <- true
events = connection.EventStream(ctrl, "/junk", true)
} else {
fmt.Println("Event: ", msg)
}
case <-timer.C:
fmt.Println("TIMEOUT: FAILED TO RECEIVE WATCHER EVENT from etcd")
os.Exit(-1)
}
}
// Shutdown event stream
ctrl <- true
close(ctrl)
// ---------------------------------------------------------------------------------------------------
// Recursive Get
r, err = connection.GetValue("/", true, false)
if err != nil {
fmt.Println("Failed recursive GET:", err)
os.Exit(-1)
}
fmt.Printf("Recursive GET results:\n%s", r)
// -------------------------------------------------------------------------------------------------------
// Background competing set/get calls
c1 := make(chan bool)
go setAndCheck(&connection, c1, "/junk/key1", "Hello", 4000, 100)
c2 := make(chan bool)
go setAndCheck(&connection, c2, "/junk/key2", "HelloAgain", 1000, 1000000)
// Sync up after both have finished
<-c1
<-c2
// -------------------------------------------------------------------------------------------------------
// Final cleanup ... must exist
r, err = connection.DeleteDir("/junk", true)
if err != nil {
fmt.Println("Failed to delete directory:", err)
os.Exit(-1)
}
fmt.Printf("Successfully cleaned up by Deleting directory: %s\n", r)
}