e614e04f27
* Code cleanup: Deleted multiple functions which have become stale. Removed cluster example as we replaced the need to create the Cluster object. * Cleaned up ZK connection code by using the backoff function. Added a test to the end to end to test that we're getting the host correctly from ZK. Changed clusters test to be an outside package. * Added LeaderFromZKURL test to end to end tests. * Added logger to realisConfig so that users can attach their own Loggers to the client. Logger is an interface that shadows most popular logging libraries. Only Print, Println, and Printf are needed to be a realis.Logger type. Example in the client uses the std library log. * Moved most fmt.Print* calls to be redirected to user provided logger. Logger by default is a no-op logger. * Adding CreateService to realis interface. Uses the StartJobUpdate API to create services instead of the createJobs API. * Bumping up version number inside client in anticipation of new release.
105 lines
2.8 KiB
Go
105 lines
2.8 KiB
Go
/**
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
package realis
|
|
|
|
import (
|
|
"encoding/json"
|
|
"fmt"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
|
|
"github.com/pkg/errors"
|
|
"github.com/samuel/go-zookeeper/zk"
|
|
)
|
|
|
|
type Endpoint struct {
|
|
Host string `json:"host"`
|
|
Port int `json:"port"`
|
|
}
|
|
|
|
type ServiceInstance struct {
|
|
Service Endpoint `json:"serviceEndpoint"`
|
|
AdditionalEndpoints map[string]Endpoint `json:"additionalEndpoints"`
|
|
Status string `json:"status"`
|
|
}
|
|
|
|
|
|
// Retrieves current Aurora leader from ZK.
|
|
func LeaderFromZK(cluster Cluster) (string, error) {
|
|
|
|
var zkurl string
|
|
|
|
retryErr := ExponentialBackoff(defaultBackoff, func() (bool, error) {
|
|
|
|
endpoints := strings.Split(cluster.ZK, ",")
|
|
|
|
//TODO (rdelvalle): When enabling debugging, change logger here
|
|
c, _, err := zk.Connect(endpoints, time.Second*10, func(c *zk.Conn) { c.SetLogger(NoopLogger{}) })
|
|
if err != nil {
|
|
return false, errors.Wrap(err, "Failed to connect to Zookeeper at "+cluster.ZK)
|
|
}
|
|
|
|
defer c.Close()
|
|
|
|
// Open up descriptor for the ZK path given
|
|
children, _, _, err := c.ChildrenW(cluster.SchedZKPath)
|
|
if err != nil {
|
|
return false, errors.Wrapf(err, "Path %s doesn't exist on Zookeeper ", cluster.SchedZKPath)
|
|
}
|
|
|
|
// Search for the leader through all the children in the given path
|
|
serviceInst := new(ServiceInstance)
|
|
for _, child := range children {
|
|
|
|
// Only the leader will start with member_
|
|
if strings.HasPrefix(child, "member_") {
|
|
|
|
data, _, err := c.Get(cluster.SchedZKPath + "/" + child)
|
|
if err != nil {
|
|
return false, errors.Wrap(err, "Error fetching contents of leader")
|
|
}
|
|
|
|
err = json.Unmarshal([]byte(data), serviceInst)
|
|
if err != nil {
|
|
return false, errors.Wrap(err, "Unable to unmarshall contents of leader")
|
|
}
|
|
|
|
// Should only be one endpoint
|
|
if len(serviceInst.AdditionalEndpoints) > 1 {
|
|
fmt.Errorf("Ambiguous end points schemes")
|
|
}
|
|
|
|
var scheme, host, port string
|
|
for k, v := range serviceInst.AdditionalEndpoints {
|
|
scheme = k
|
|
host = v.Host
|
|
port = strconv.Itoa(v.Port)
|
|
}
|
|
|
|
zkurl = scheme + "://" + host + ":" + port
|
|
return true, nil
|
|
}
|
|
}
|
|
|
|
return false, errors.New("No leader found")
|
|
})
|
|
|
|
if retryErr != nil {
|
|
return "", errors.Wrapf(retryErr, "Failed to determine leader after %v attempts", defaultBackoff.Steps)
|
|
}
|
|
|
|
return zkurl, nil
|
|
}
|