Kubernetes+Flannel 环境中部署HBase集群

2015-12-14注：加入新节点不更改运行节点参数需求已满足，将在后续文章中陆续总结。

注：目前方案不满足加入新节点（master节点或regionserver节点）而不更改已运行节点的参数的需求，具体讨论见第六部分。

一、背景知识

先看下HBase的组成：

Master：Master主要负责管理RegionServer集群，如负载均衡及资源分配等，它本身也可以以集群方式运行，但同一时刻只有一个master处于激活状态。当工作中的master宕掉后，zookeeper会切换到其它备选的master上。

RegionServer：负责具体数据块的读写操作。

ZooKeeper：负责集群元数据的维护并监控集群的状态以防止单点故障。部署HBase时可以使用自带的ZooKeeper也可以使用独立的集群，是HBase跑起来的先决条件。

HDFS：写入HBase中的数据最终都持久化到了HDFS中，也是HBase运行的先决条件。

二、skyDNS部署

skyDNS并不是必需项，但设置了skyDNS后可以为k8s的service绑定域名，进行hbase的参数设置时可以以域名代替service的IP地址。k8s环境中的skyDNS由三部分组成： 存储IP地址和域名映射关系的ETCD；进行域名解析的skyDNS；连接k8s和skyDNS的桥梁kube2sky。k8s的域名构成为 service_name.namespace.k8s_cluster_domain。k8s的文档中有对部署skyDNS的简略说明（戳这里），其中要用到Google镜像仓库中的image，国内访问不到，可以使用DockerHub上的替换方案，如：

skyDNS: docker pull shenshouer/skydns:2015-09-22

kube2sky: docker pull shenshouer/kube2sky:1.11

ETCD: 只要是2.x版本的ETCD都可以，也可以和上面的保持一致使用 docker pull shenshouer/etcd:2.0.9

pull下来之后打上tag再push到私有仓库中。

下面创建一个service和一个pod来部署skyDNS，设定 skyDNS service 的服务地址为 172.16.40.1 (53/UDP, 53/TCP)，注意该IP地址要在kube-apiserver启动时设定的service的子网范围内；k8s集群的域名后缀为 domeos.sohu，注意这个后缀的选择最好包含两部分，否则kube2sky可能会出问题（具体讨论戳这里）。

首先创建skydns.yaml文件：

apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  labels:
    app: kube-dns
    version: v8
spec:
  selector:
    app: kube-dns
    version: v8
  type: ClusterIP
  clusterIP: 172.16.40.1
  ports:
    - name: dns port: 53 protocol: UDP - name: dns-tcp port: 53 protocol: TCP --- apiVersion: v1 kind: ReplicationController metadata: name: kube-dns-v8 labels: app: kube-dns version: v8 spec: replicas: 1 selector: app: kube-dns version: v8 template: metadata: labels: app: kube-dns version: v8 spec: containers: - name: etcd image: 10.11.150.76:5000/openxxs/etcd:2.0.3 command: - "etcd" args: - "--data-dir=/var/etcd/data" - "--listen-client-urls=http://127.0.0.1:2379,http://127.0.0.1:4001" - "--advertise-client-urls=http://127.0.0.1:2379,http://127.0.0.1:4001" - "--initial-cluster-token=skydns-etcd" volumeMounts: - name: etcd-storage mountPath: /var/etcd/data - name: kube2sky image: 10.11.150.76:5000/openxxs/kube2sky:k8s-dns args: - "--domain=domeos.sohu" - "--kube_master_url=http://10.16.42.200:8080" - name: skydns image: 10.11.150.76:5000/openxxs/skydns:2015-09-22 args: - "--machines=http://localhost:4001" - "--addr=0.0.0.0:53" - "--domain=domeos.sohu" ports: - containerPort: 53 name: dns protocol: UDP - containerPort: 53 name: dns-tcp protocol: TCP volumes: - name: etcd-storage emptyDir: {} dnsPolicy: Default

kube2sky中的 --kube_master_url 参数用于指定 kube-apiserver 的地址；kube2sky中的 --domain 和 skydns中的 --domain 要保持一致。

然后 kubectl create -f skydns.yaml 创建服务和pod：

$kubectl create -f skydns.yaml 
service "kube-dns" created
replicationcontroller "kube-dns-v8" created
$kubectl get pods
NAME                    READY     STATUS           RESTARTS   AGE
kube-dns-v8-61aie       3/3       Running          0          9s
$kubectl get service
NAME                    CLUSTER_IP       EXTERNAL_IP    PORT(S)              SELECTOR                     AGE
kube-dns                172.16.40.1               53/UDP,53/TCP        app=kube-dns,version=v8      6m

最后，重启 kubelet 加上dns相关的设置参数 --cluster_dns 和 --cluster_domain，参数值要与前面yaml文件中写的一致，如：

./kubelet --logtostderr=true --v=0 --api_servers=http://bx-42-200:8080 --address=0.0.0.0 --hostname_override=bx-42-198 --allow_privileged=false --pod-infra-container-image=10.11.150.76:5000/kubernetes/pause:latest --cluster_dns=172.16.40.1 --cluster_domain=domeos.sohu &

注意：只有在kubelet加了dns设置参数重启之后创建的pods才会使用skyDNS。

此时进入到etcd的container中就可以发现k8s的service域名信息已被写入etcd当中了：

$ docker exec -it 13e243510e3e sh
/ # etcdctl ls --recursive /
/skydns
/skydns/sohu
/skydns/sohu/domeos
/skydns/sohu/domeos/default
/skydns/sohu/domeos/default/kube-dns
/skydns/sohu/domeos/default/kubernetes
/skydns/sohu/domeos/default/zookeeper-1
/skydns/sohu/domeos/default/zookeeper-2
/skydns/sohu/domeos/default/zookeeper-3
/skydns/sohu/domeos/svc
/skydns/sohu/domeos/svc/default
/skydns/sohu/domeos/svc/default/zookeeper-2
/skydns/sohu/domeos/svc/default/zookeeper-2/b8757496
/skydns/sohu/domeos/svc/default/zookeeper-3
/skydns/sohu/domeos/svc/default/zookeeper-3/8687b21f
/skydns/sohu/domeos/svc/default/kube-dns
/skydns/sohu/domeos/svc/default/kube-dns/a9f11e6f
/skydns/sohu/domeos/svc/default/kubernetes
/skydns/sohu/domeos/svc/default/kubernetes/cf07aead
/skydns/sohu/domeos/svc/default/zookeeper-1
/skydns/sohu/domeos/svc/default/zookeeper-1/75512011
/ # etcdctl get /skydns/sohu/domeos/default/zookeeper-1
{"host":"172.16.11.1","priority":10,"weight":10,"ttl":30,"targetstrip":0}

以 /skydns/sohu/domeos/default/zookeeper-1 这条记录为例，其对应的域名即为 zookeeper-1.default.domeos.sohu ，IP 为 172.16.11.1，服务名称为zookeeper-1，k8s的namespace为default，k8s设定的域为 domeos.sohu。在任一重启kubelet之后创建的pod中都可以以 zookeeper-1.default.domeos.sohu 的方式访问zookeeper-1服务，如：

[@bx_42_199 ~]# docker exec -it 0662660e8708 /bin/bash
[root@test-3-2h0fx /]# curl zookeeper-1.default.domeos.sohu:2181
curl: (52) Empty reply from server

三、HDFS集群部署

HDFS由namenode和datanode组成，首先从DockerHub上pull合适的镜像再push到自己的私有仓库中：

# pull 远程images
docker pull bioshrek/hadoop-hdfs-datanode:cdh5
docker pull bioshrek/hadoop-hdfs-namenode:cdh5
# 打上tag
# docker tag  <自己的私有仓库IP:PORT/名称:TAG>
docker tag c89c3ebcccae 10.11.150.76:5000/hdfs-datanode:latest
docker tag ca19d4c7e359 10.11.150.76:5000/hdfs-namenode:latest
# push到仓库中
docker push 10.11.150.76:5000/hdfs-datanode:latest
docker push 10.11.150.76:5000/hdfs-namenode:latest

然后创建如下hdfs.yaml文件：

  1 apiVersion: v1
  2 kind: Service
  3 metadata:
  4   name: hdfs-namenode-service
  5 spec:
  6   selector:
  7     app: hdfs-namenode
  8   type: ClusterIP
  9   clusterIP: "172.16.20.1"
 10   ports:
 11     - name: rpc
 12       port: 4231
 13       targetPort: 8020
 14     - name: p1
 15       port: 50020
 16     - name: p2
 17       port: 50090
 18     - name: p3
 19       port: 50070
 20     - name: p4
 21       port: 50010
 22     - name: p5
 23       port: 50075
 24     - name: p6
 25       port: 8031
 26     - name: p7
 27       port: 8032
 28     - name: p8
 29       port: 8033
 30     - name: p9
 31       port: 8040
 32     - name: p10
 33       port: 8042
 34     - name: p11
 35       port: 49707
 36     - name: p12
 37       port: 22
 38     - name: p13
 39       port: 8088
 40     - name: p14
 41       port: 8030
 42 ---
 43 apiVersion: v1
 44 kind: ReplicationController
 45 metadata:
 46     name: hdfs-namenode-1
 47 spec:
 48   replicas: 1
 49   template:
 50     metadata:
 51       labels:
 52         app: hdfs-namenode
 53     spec:
 54       containers:
 55         - name: hdfs-namenode
 56           image: 10.11.150.76:5000/hdfs-namenode:latest
 57           volumeMounts:
 58             - name: data1
 59               mountPath: /var/lib/hadoop-hdfs/cache/hdfs/dfs/name
 60             - name: data2
 61               mountPath: /home/chianyu/shared_with_docker_container/cdh5/nn
 62           ports:
 63             - containerPort: 50020
 64             - containerPort: 50090
 65             - containerPort: 50070
 66             - containerPort: 50010
 67             - containerPort: 50075
 68             - containerPort: 8031
 69             - containerPort: 8032
 70             - containerPort: 8033
 71             - containerPort: 8040
 72             - containerPort: 8042
 73             - containerPort: 49707
 74             - containerPort: 22
 75             - containerPort: 8088
 76             - containerPort: 8030
 77             - containerPort: 8020
 78       nodeSelector:
 79         kubernetes.io/hostname: bx-42-199
 80       volumes:
 81         - hostPath:
 82             path: /data1/kubernetes/hdfs-namenode/data1
 83           name: data1
 84         - hostPath:
 85             path: /data1/kubernetes/hdfs-namenode/data2
 86           name: data2
 87 ---
 88 apiVersion: v1
 89 kind: ReplicationController
 90 metadata:
 91     name: hdfs-datanode-1
 92 spec:
 93   replicas: 1
 94   template:
 95     metadata:
 96       labels:
 97         app: hdfs-datanode
 98         server-id: "1"
 99     spec:
100       containers:
101         - name: hdfs-datanode-1
102           image: 10.11.150.76:5000/hdfs-datanode:latest
103           volumeMounts:
104             - name: data1
105               mountPath: /var/lib/hadoop-hdfs/cache/hdfs/dfs/name
106             - name: data2
107               mountPath: /home/chianyu/shared_with_docker_container/cdh5/dn
108           env:
109             - name: HDFSNAMENODERPC_SERVICE_HOST
110               value: "172.16.20.1"
111             - name: HDFSNAMENODERPC_SERVICE_PORT
112               value: "4231"
113           ports:
114             - containerPort: 50020
115             - containerPort: 50090
116             - containerPort: 50070
117             - containerPort: 50010
118             - containerPort: 50075
119             - containerPort: 8031
120             - containerPort: 8032
121             - containerPort: 8033
122             - containerPort: 8040
123             - containerPort: 8042
124             - containerPort: 49707
125             - containerPort: 22
126             - containerPort: 8088
127             - containerPort: 8030
128             - containerPort: 8020
129       nodeSelector:
130         kubernetes.io/hostname: bx-42-199
131       volumes:
132         - hostPath:
133             path: /data1/kubernetes/hdfs-datanode1/data1
134           name: data1
135         - hostPath:
136             path: /data1/kubernetes/hdfs-datanode1/data2
137           name: data2
138 ---
139 apiVersion: v1
140 kind: ReplicationController
141 metadata:
142     name: hdfs-datanode-2
143 spec:
144   replicas: 1
145   template:
146     metadata:
147       labels:
148         app: hdfs-datanode
149         server-id: "2"
150     spec:
151       containers:
152         - name: hdfs-datanode-2
153           image: 10.11.150.76:5000/hdfs-datanode:latest
154           volumeMounts:
155             - name: data1
156               mountPath: /var/lib/hadoop-hdfs/cache/hdfs/dfs/name
157             - name: data2
158               mountPath: /home/chianyu/shared_with_docker_container/cdh5/dn
159           env:
160             - name: HDFSNAMENODERPC_SERVICE_HOST
161               value: "172.16.20.1"
162             - name: HDFSNAMENODERPC_SERVICE_PORT
163               value: "4231"
164           ports:
165             - containerPort: 50020
166             - containerPort: 50090
167             - containerPort: 50070
168             - containerPort: 50010
169             - containerPort: 50075
170             - containerPort: 8031
171             - containerPort: 8032
172             - containerPort: 8033
173             - containerPort: 8040
174             - containerPort: 8042
175             - containerPort: 49707
176             - containerPort: 22
177             - containerPort: 8088
178             - containerPort: 8030
179       nodeSelector:
180         kubernetes.io/hostname: bx-42-199
181       volumes:
182         - name: data1
183           hostPath:
184             path: /data2/kubernetes/hdfs-datanode2/data1
185         - name: data2
186           hostPath:
187             path: /data2/kubernetes/hdfs-datanode2/data2
188 ---
189 apiVersion: v1
190 kind: ReplicationController
191 metadata:
192     name: hdfs-datanode-3
193 spec:
194   replicas: 1
195   template:
196     metadata:
197       labels:
198         app: hdfs-datanode
199         server-id: "3"
200     spec:
201       containers:
202         - name: hdfs-datanode-3
203           image: 10.11.150.76:5000/hdfs-datanode:latest
204           volumeMounts:
205             - name: data1
206               mountPath: /var/lib/hadoop-hdfs/cache/hdfs/dfs/name
207             - name: data2
208               mountPath: /home/chianyu/shared_with_docker_container/cdh5/dn
209           env:
210             - name: HDFSNAMENODERPC_SERVICE_HOST
211               value: "172.16.20.1"
212             - name: HDFSNAMENODERPC_SERVICE_PORT
213               value: "4231"
214           ports:
215             - containerPort: 50020
216             - containerPort: 50090
217             - containerPort: 50070
218             - containerPort: 50010
219             - containerPort: 50075
220             - containerPort: 8031
221             - containerPort: 8032
222             - containerPort: 8033
223             - containerPort: 8040
224             - containerPort: 8042
225             - containerPort: 49707
226             - containerPort: 22
227             - containerPort: 8088
228             - containerPort: 8030
229       nodeSelector:
230         kubernetes.io/hostname: bx-42-199
231       volumes:
232         - name: data1
233           hostPath:
234             path: /data3/kubernetes/hdfs-datanode3/data1
235         - name: data2
236           hostPath:
237             path: /data3/kubernetes/hdfs-datanode3/data2

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通过 kubectl create -f hdfs.yaml 即创建一个名为hdfs-namenode-service的service，四个分别名为hdfs-namenode-1、hdfs-datanode-1、hdfs-datanode-2、hdfs-datanode-3的RC。通过 kubectl get services/rc/pods 可以看到对应的service和pod都已经正常启动了。

下面对HDFS进行测试是否可以正常使用：

# 查看HDFS pods
kubectl get pods

# 通过describe查看pods跑在哪个k8s node上
kubectl describe pod hdfs-datanode-3-h4jvt

# 进入容器内部
docker ps | grep hdfs-datanode-3
docker exec -it 2e2c4df0c0a9 /bin/bash

# 切换至 hdfs 用户
su hdfs

# 创建目录
hadoop fs -mkdir /test
# 创建本地文件
echo "Hello" > hello
# 将本地文件复制到HDFS文件系统中
hadoop fs -put hello /test
# 查看HDFS中的文件信息
hadoop fs -ls /test

# 类似的，可以 docker exec 到其它datanode中查看文件信息，如：
root@hdfs-datanode-1-nek2l:/# hadoop fs -ls /test
Found 1 items
-rw-r--r--   2 hdfs hadoop          6 2015-11-27 08:36 /test/hello

四、ZooKeeper集群部署

在 fabric8/zookeeper 的image基础上进行修改，修改后Dockerfile文件内容如下：

 1 FROM jboss/base-jdk:7
 2 
 3 MAINTAINER [email protected]
 4 
 5 USER root
 6 
 7 ENV ZOOKEEPER_VERSION 3.4.6
 8 EXPOSE 2181 2888 3888
 9 
10 RUN yum -y install wget bind-utils && yum clean all \
11     && wget -q -O - http://apache.mirrors.pair.com/zookeeper/zookeeper-${ZOOKEEPER_VERSION}/zookeeper-${ZOOKEEPER_VERSION}.tar.gz | tar -xzf - -C /opt \
12     && mv /opt/zookeeper-${ZOOKEEPER_VERSION} /opt/zookeeper \
13     && cp /opt/zookeeper/conf/zoo_sample.cfg /opt/zookeeper/conf/zoo.cfg \
14     && mkdir -p /opt/zookeeper/{data,log}
15 
16 WORKDIR /opt/zookeeper
17 VOLUME ["/opt/zookeeper/conf", "/opt/zookeeper/data", "/opt/zookeeper/log"]
18 
19 COPY config-and-run.sh ./bin/
20 COPY zoo.cfg ./conf/
21 
22 CMD ["/opt/zookeeper/bin/config-and-run.sh"]

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zoo.cfg 文件内容如下：

 1 # The number of milliseconds of each tick
 2 tickTime=2000
 3 # The number of ticks that the initial
 4 # synchronization phase can take
 5 initLimit=10
 6 # The number of ticks that can pass between
 7 # sending a request and getting an acknowledgement
 8 syncLimit=5
 9 # the directory where the snapshot is stored.
10 dataDir=/opt/zookeeper/data
11 #This option will direct the machine to write the transaction log to the dataLogDir rather than the dataDir. This allows a dedicated log device to be used, and helps avoid competition between logging and snaphots.
12 dataLogDir=/opt/zookeeper/log
13 
14 # the port at which the clients will connect
15 clientPort=2181
16 #
17 # Be sure to read the maintenance section of the
18 # administrator guide before turning on autopurge.
19 #
20 # http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance
21 #
22 # The number of snapshots to retain in dataDir
23 #autopurge.snapRetainCount=3
24 # Purge task interval in hours
25 # Set to "0" to disable auto purge feature
26 #autopurge.purgeInterval=1

View Code

config-and-run.sh 文件内容如下：

#!/bin/bash

echo "$SERVER_ID / $MAX_SERVERS" 
if [ ! -z "$SERVER_ID" ] && [ ! -z "$MAX_SERVERS" ]; then
  echo "Starting up in clustered mode"
  echo "" >> /opt/zookeeper/conf/zoo.cfg
  echo "#Server List" >> /opt/zookeeper/conf/zoo.cfg
  for i in $( eval echo {1..$MAX_SERVERS});do
    HostEnv="ZOOKEEPER_${i}_SERVICE_HOST"
    HOST=${!HostEnv}
    FollowerPortEnv="ZOOKEEPER_${i}_SERVICE_PORT_FOLLOWERS"
    FOLLOWERPORT=${!FollowerPortEnv}
    ElectionPortEnv="ZOOKEEPER_${i}_SERVICE_PORT_ELECTION"
    ELECTIONPORT=${!ElectionPortEnv}
    if [ "$SERVER_ID" = "$i" ];then
      echo "server.$i=0.0.0.0:$FOLLOWERPORT:$ELECTIONPORT" >> /opt/zookeeper/conf/zoo.cfg
    else
      echo "server.$i=$HOST:$FOLLOWERPORT:$ELECTIONPORT" >> /opt/zookeeper/conf/zoo.cfg
    fi
  done
  cat /opt/zookeeper/conf/zoo.cfg

  # Persists the ID of the current instance of Zookeeper
  echo ${SERVER_ID} > /opt/zookeeper/data/myid
  else
      echo "Starting up in standalone mode"
fi

exec /opt/zookeeper/bin/zkServer.sh start-foreground

修改完后创建镜像并push到私有仓库中(镜像名为10.11.150.76:5000/zookeeper-kb:3.4.6-1)。

创建zookeeper.yaml文件：

  1 apiVersion: v1
  2 kind: Service
  3 metadata:
  4   name: zookeeper-1
  5   labels:
  6       name: zookeeper-1
  7 spec:
  8   ports:
  9     - name: client
 10       port: 2181
 11       targetPort: 2181
 12     - name: followers
 13       port: 2888
 14       targetPort: 2888
 15     - name: election
 16       port: 3888
 17       targetPort: 3888
 18   selector:
 19     name: zookeeper
 20     server-id: "1"
 21   type: ClusterIP
 22   clusterIP: 172.16.11.1
 23 ---
 24 apiVersion: v1
 25 kind: Service
 26 metadata:
 27   name: zookeeper-2
 28   labels:
 29       name: zookeeper-2
 30 spec:
 31   ports:
 32     - name: client
 33       port: 2181
 34       targetPort: 2181
 35     - name: followers
 36       port: 2888
 37       targetPort: 2888
 38     - name: election
 39       port: 3888
 40       targetPort: 3888
 41   selector:
 42     name: zookeeper
 43     server-id: "2"
 44   type: ClusterIP
 45   clusterIP: 172.16.11.2
 46 ---
 47 apiVersion: v1
 48 kind: Service
 49 metadata:
 50   name: zookeeper-3
 51   labels:
 52       name: zookeeper-3
 53 spec:
 54   ports:
 55     - name: client
 56       port: 2181
 57       targetPort: 2181
 58     - name: followers
 59       port: 2888
 60       targetPort: 2888
 61     - name: election
 62       port: 3888
 63       targetPort: 3888
 64   selector:
 65     name: zookeeper
 66     server-id: "3"
 67   type: ClusterIP
 68   clusterIP: 172.16.11.3
 69 ---
 70 apiVersion: v1
 71 kind: ReplicationController
 72 metadata:
 73   name: zookeeper-1
 74 spec:
 75   replicas: 1
 76   template:
 77     metadata:
 78       labels:
 79         name: zookeeper
 80         server-id: "1"
 81     spec:
 82       volumes:
 83         - hostPath:
 84             path: /data1/kubernetes/zookeeper/data1
 85           name: data
 86         - hostPath:
 87             path: /data1/kubernetes/zookeeper/log1
 88           name: log
 89       containers:
 90         - name: server
 91           image: 10.11.150.76:5000/zookeeper-kb:3.4.6-1
 92           env:
 93             - name: SERVER_ID
 94               value: "1"
 95             - name: MAX_SERVERS
 96               value: "3"
 97           ports:
 98             - containerPort: 2181
 99             - containerPort: 2888
100             - containerPort: 3888
101           volumeMounts:
102             - mountPath: /opt/zookeeper/data
103               name: data
104             - mountPath: /opt/zookeeper/log
105               name: log
106       nodeSelector:
107         kubernetes.io/hostname: bx-42-199
108 ---
109 apiVersion: v1
110 kind: ReplicationController
111 metadata:
112   name: zookeeper-2
113 spec:
114   replicas: 1
115   template:
116     metadata:
117       labels:
118         name: zookeeper
119         server-id: "2"
120     spec:
121       volumes:
122         - hostPath:
123             path: /data1/kubernetes/zookeeper/data2
124           name: data
125         - hostPath:
126             path: /data1/kubernetes/zookeeper/log2
127           name: log
128       containers:
129         - name: server
130           image: 10.11.150.76:5000/zookeeper-kb:3.4.6-1
131           env:
132             - name: SERVER_ID
133               value: "2"
134             - name: MAX_SERVERS
135               value: "3"
136           ports:
137             - containerPort: 2181
138             - containerPort: 2888
139             - containerPort: 3888
140           volumeMounts:
141             - mountPath: /opt/zookeeper/data
142               name: data
143             - mountPath: /opt/zookeeper/log
144               name: log
145       nodeSelector:
146         kubernetes.io/hostname: bx-42-199
147 ---
148 apiVersion: v1
149 kind: ReplicationController
150 metadata:
151   name: zookeeper-3
152 spec:
153   replicas: 1
154   template:
155     metadata:
156       labels:
157         name: zookeeper
158         server-id: "3"
159     spec:
160       volumes:
161         - hostPath:
162             path: /data1/kubernetes/zookeeper/data3
163           name: data
164         - hostPath:
165             path: /data1/kubernetes/zookeeper/log3
166           name: log
167       containers:
168         - name: server
169           image: 10.11.150.76:5000/zookeeper-kb:3.4.6-1
170           env:
171             - name: SERVER_ID
172               value: "3"
173             - name: MAX_SERVERS
174               value: "3"
175           ports:
176             - containerPort: 2181
177             - containerPort: 2888
178             - containerPort: 3888
179           volumeMounts:
180             - mountPath: /opt/zookeeper/data
181               name: data
182             - mountPath: /opt/zookeeper/log
183               name: log
184       nodeSelector:
185         kubernetes.io/hostname: bx-42-199

View Code

通过 kubectl create -f zookeeper.yaml 创建三个service和对应的RC。注意container中已经把ZooKeeper的data和log目录映射到了主机的对应目录上用于持久化存储。

创建完之后即可进行测试：

# 进入zookeeper对应的容器后找到zkCli.sh，用该客户端进行测试
/opt/zookeeper/bin/zkCli.sh
[zk: localhost:2181(CONNECTED) 0]

# 连接到k8s创建的zookeeper service (三个service任意一个都行)
[zk: localhost:2181(CONNECTED) 0] connect 172.16.11.2:2181
[zk: 172.16.11.2:2181(CONNECTED) 1]

# 查看目录信息
[zk: 172.16.11.2:2181(CONNECTED) 1] ls /
[zookeeper]
[zk: 172.16.11.2:2181(CONNECTED) 2] get /zookeeper

cZxid = 0x0
ctime = Thu Jan 01 00:00:00 UTC 1970
mZxid = 0x0
mtime = Thu Jan 01 00:00:00 UTC 1970
pZxid = 0x0
cversion = -1
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x0
dataLength = 0
numChildren = 1
[zk: 172.16.11.2:2181(CONNECTED) 3]

五、HBase部署

以上准备工作做好后，下面部署具有两个master和两个regionserver的HBase集群，其中两个master分别位于两个节点上，两个regionserver也分别位于两个节点上；使用独立的HDFS和ZooKeeper服务。

首先需要创建HBase的镜像，选择的HBase版本为hbase-0.98.10.1-hadoop2。Dockerfile内容如下：

 1 FROM centos:6.6
 2 MAINTAINER openxxs 
 3 
 4 RUN yum install -y java-1.7.0-openjdk-devel.x86_64
 5 ENV JAVA_HOME=/usr/lib/jvm/jre
 6 
 7 RUN yum install -y nc \
 8     && yum install -y tar \
 9     && mkdir /hbase-setup
10 
11 WORKDIR /hbase-setup
12 
13 COPY hbase-0.98.10.1-hadoop2-bin.tar.gz /hbase-setup/hbase-0.98.10.1-hadoop2-bin.tar.gz
14 RUN tar zxf hbase-0.98.10.1-hadoop2-bin.tar.gz -C /opt/ \
15     && ln -s /opt/hbase-0.98.10.1-hadoop2 /opt/hbase
16 
17 ADD hbase-site.xml /opt/hbase/conf/hbase-site.xml
18 ADD start-k8s-hbase.sh /opt/hbase/bin/start-k8s-hbase.sh
19 RUN chmod +x /opt/hbase/bin/start-k8s-hbase.sh
20 
21 WORKDIR /opt/hbase/bin
22 
23 ENV PATH=$PATH:/opt/hbase/bin
24 
25 CMD /opt/hbase/bin/start-k8s-hbase.sh

配置文件hbase-site.xml内容如下：

"1.0"?>
"text/xsl" href="configuration.xsl"?>
  
    
      hbase.cluster.distributed
      true
    
    
      hbase.master.port
      @HBASE_MASTER_PORT@
    
    
      hbase.master.info.port
      @HBASE_MASTER_INFO_PORT@
    
    
      hbase.regionserver.port
      @HBASE_REGION_PORT@
    
    
      hbase.regionserver.info.port
      @HBASE_REGION_INFO_PORT@
    
    
      hbase.rootdir
      hdfs://@HDFS_PATH@/@ZNODE_PARENT@
    
    
      hbase.zookeeper.quorum
      @ZOOKEEPER_IP_LIST@
    
    
      hbase.zookeeper.property.clientPort
      @ZOOKEEPER_PORT@
    
    
      zookeeper.znode.parent
      /@ZNODE_PARENT@
    
  

启动脚本 start-k8s-hbase.sh 主要完成参数替换、写入/etc/hosts、启动 hbase 的功能，内容如下：

 1 #!/bin/bash
 2 
 3 export HBASE_CONF_FILE=/opt/hbase/conf/hbase-site.xml
 4 export HADOOP_USER_NAME=hdfs
 5 export HBASE_MANAGES_ZK=false
 6 
 7 sed -i "s/@HBASE_MASTER_PORT@/$HBASE_MASTER_PORT/g" $HBASE_CONF_FILE
 8 sed -i "s/@HBASE_MASTER_INFO_PORT@/$HBASE_MASTER_INFO_PORT/g" $HBASE_CONF_FILE
 9 sed -i "s/@HBASE_REGION_PORT@/$HBASE_REGION_PORT/g" $HBASE_CONF_FILE
10 sed -i "s/@HBASE_REGION_INFO_PORT@/$HBASE_REGION_INFO_PORT/g" $HBASE_CONF_FILE
11 sed -i "s/@HDFS_PATH@/$HDFS_SERVICE:$HDFS_PORT\/$ZNODE_PARENT/g" $HBASE_CONF_FILE
12 sed -i "s/@ZOOKEEPER_IP_LIST@/$ZOOKEEPER_SERVICE_LIST/g" $HBASE_CONF_FILE
13 sed -i "s/@ZOOKEEPER_PORT@/$ZOOKEEPER_PORT/g" $HBASE_CONF_FILE
14 sed -i "s/@ZNODE_PARENT@/$ZNODE_PARENT/g" $HBASE_CONF_FILE
15 
16 for i in ${HBASE_MASTER_LIST[@]}
17 do
18    arr=(${i//:/ })
19    echo "${arr[0]} ${arr[1]}" >> /etc/hosts
20 done
21 
22 for i in ${HBASE_REGION_LIST[@]}
23 do
24    arr=(${i//:/ })
25    echo "${arr[0]} ${arr[1]}" >> /etc/hosts
26 done
27 
28 if [ "$HBASE_SERVER_TYPE" = "master" ]; then
29     /opt/hbase/bin/hbase master start > logmaster.log 2>&1
30 elif [ "$HBASE_SERVER_TYPE" = "regionserver" ]; then
31     /opt/hbase/bin/hbase regionserver start > logregion.log 2>&1
32 fi

其中导出HADOOP_USER_NAME为hdfs用户，否则会报Permission Denied的错误；HBASE_MANAGES_ZK=false表示不使用HBase自带的ZooKeeper；HBASE_MASTER_LIST为HBase集群中除当前master外的其余master的服务地址和pod名的对应关系；HBASE_REGION_LIST为HBase集群中除当前regionserver外的其余regionserver的服务地址和pod名的对应关系；最后根据 HBASE_SERVER_TYPE 的取值来确定是启master还是regionserver。

准备好这些文件后即可创建HBase的image：

docker build -t 10.11.150.76:5000/openxxs/hbase:1.0 .
docker push 10.11.150.76:5000/openxxs/hbase:1.0

 随后创建hbase.yaml文件，内容如下：

  1 apiVersion: v1
  2 kind: Service
  3 metadata:
  4   name: hbase-master-1
  5 spec:
  6   selector:
  7     app: hbase-master
  8     server-id: "1"
  9   type: ClusterIP
 10   clusterIP: "172.16.30.1"
 11   ports:
 12     - name: rpc
 13       port: 60000
 14       targetPort: 60000
 15     - name: info
 16       port: 60001
 17       targetPort: 60001
 18 ---
 19 apiVersion: v1
 20 kind: Service
 21 metadata:
 22   name: hbase-master-2
 23 spec:
 24   selector:
 25     app: hbase-master
 26     server-id: "2"
 27   type: ClusterIP
 28   clusterIP: "172.16.30.2"
 29   ports:
 30     - name: rpc
 31       port: 60000
 32       targetPort: 60000
 33     - name: info
 34       port: 60001
 35       targetPort: 60001
 36 ---
 37 apiVersion: v1
 38 kind: Service
 39 metadata:
 40   name: hbase-region-1
 41 spec:
 42   selector:
 43     app: hbase-region
 44     server-id: "1"
 45   type: ClusterIP
 46   clusterIP: "172.16.30.3"
 47   ports:
 48     - name: rpc
 49       port: 60010
 50       targetPort: 60010
 51     - name: info
 52       port: 60011
 53       targetPort: 60011
 54 ---
 55 apiVersion: v1
 56 kind: Service
 57 metadata:
 58   name: hbase-region-2
 59 spec:
 60   selector:
 61     app: hbase-region
 62     server-id: "2"
 63   type: ClusterIP
 64   clusterIP: "172.16.30.4"
 65   ports:
 66     - name: rpc
 67       port: 60010
 68       targetPort: 60010
 69     - name: info
 70       port: 60011
 71       targetPort: 60011
 72 ---
 73 apiVersion: v1
 74 kind: Pod
 75 metadata:
 76   name: hbase-master-1
 77   labels:
 78     app: hbase-master
 79     server-id: "1"
 80 spec:
 81   containers:
 82     - name: hbase-master-1
 83       image: 10.11.150.76:5000/openxxs/hbase:1.0
 84       ports:
 85         - containerPort: 60000
 86         - containerPort: 60001
 87       env:
 88         - name: HBASE_SERVER_TYPE
 89           value: master
 90         - name: HBASE_MASTER_PORT
 91           value: "60000"
 92         - name: HBASE_MASTER_INFO_PORT
 93           value: "60001"
 94         - name: HBASE_REGION_PORT
 95           value: "60010"
 96         - name: HBASE_REGION_INFO_PORT
 97           value: "60011"
 98         - name: HDFS_SERVICE
 99           value: "hdfs-namenode-service.default.domeos.sohu"
100         - name: HDFS_PORT
101           value: "4231"
102         - name: ZOOKEEPER_SERVICE_LIST
103           value: "zookeeper-1.default.domeos.sohu,zookeeper-2.default.domeos.sohu,zookeeper-3.default.domeos.sohu"
104         - name: ZOOKEEPER_PORT
105           value: "2181"
106         - name: ZNODE_PARENT
107           value: hbase
108         - name: HBASE_MASTER_LIST
109           value: "172.16.30.2:hbase-master-2"
110         - name: HBASE_REGION_LIST
111           value: "172.16.30.3:hbase-region-1 172.16.30.4:hbase-region-2"
112   restartPolicy: Always
113   nodeSelector:
114     kubernetes.io/hostname: bx-42-199
115 ---
116 apiVersion: v1
117 kind: Pod
118 metadata:
119   name: hbase-master-2
120   labels:
121     app: hbase-master
122     server-id: "2"
123 spec:
124   containers:
125     - name: hbase-master-1
126       image: 10.11.150.76:5000/openxxs/hbase:1.0
127       ports:
128         - containerPort: 60000
129         - containerPort: 60001
130       env:
131         - name: HBASE_SERVER_TYPE
132           value: master
133         - name: HBASE_MASTER_PORT
134           value: "60000"
135         - name: HBASE_MASTER_INFO_PORT
136           value: "60001"
137         - name: HBASE_REGION_PORT
138           value: "60010"
139         - name: HBASE_REGION_INFO_PORT
140           value: "60011"
141         - name: HDFS_SERVICE
142           value: "hdfs-namenode-service.default.domeos.sohu"
143         - name: HDFS_PORT
144           value: "4231"
145         - name: ZOOKEEPER_SERVICE_LIST
146           value: "zookeeper-1.default.domeos.sohu,zookeeper-2.default.domeos.sohu,zookeeper-3.default.domeos.sohu"
147         - name: ZOOKEEPER_PORT
148           value: "2181"
149         - name: ZNODE_PARENT
150           value: hbase
151         - name: HBASE_MASTER_LIST
152           value: "172.16.30.1:hbase-master-1"
153         - name: HBASE_REGION_LIST
154           value: "172.16.30.3:hbase-region-1 172.16.30.4:hbase-region-2"
155   restartPolicy: Always
156   nodeSelector:
157     kubernetes.io/hostname: bx-42-198
158 ---
159 apiVersion: v1
160 kind: Pod
161 metadata:
162     name: hbase-region-1
163     labels:
164       app: hbase-region-1
165       server-id: "1"
166 spec:
167   containers:
168     - name: hbase-region-1
169       image: 10.11.150.76:5000/openxxs/hbase:1.0
170       ports:
171         - containerPort: 60010
172         - containerPort: 60011
173       env:
174         - name: HBASE_SERVER_TYPE
175           value: regionserver
176         - name: HBASE_MASTER_PORT
177           value: "60000"
178         - name: HBASE_MASTER_INFO_PORT
179           value: "60001"
180         - name: HBASE_REGION_PORT
181           value: "60010"
182         - name: HBASE_REGION_INFO_PORT
183           value: "60011"
184         - name: HDFS_SERVICE
185           value: "hdfs-namenode-service.default.domeos.sohu"
186         - name: HDFS_PORT
187           value: "4231"
188         - name: ZOOKEEPER_SERVICE_LIST
189           value: "zookeeper-1.default.domeos.sohu,zookeeper-2.default.domeos.sohu,zookeeper-3.default.domeos.sohu"
190         - name: ZOOKEEPER_PORT
191           value: "2181"
192         - name: ZNODE_PARENT
193           value: hbase
194         - name: HBASE_MASTER_LIST
195           value: "172.16.30.1:hbase-master-1 172.16.30.2:hbase-master-2"
196         - name: HBASE_REGION_LIST
197           value: "172.16.30.4:hbase-region-2"
198   restartPolicy: Always
199   nodeSelector:
200     kubernetes.io/hostname: bx-42-199
201 ---
202 apiVersion: v1
203 kind: Pod
204 metadata:
205     name: hbase-region-2
206     labels:
207       app: hbase-region-2
208       server-id: "2"
209 spec:
210   containers:
211     - name: hbase-region-2
212       image: 10.11.150.76:5000/openxxs/hbase:1.0
213       ports:
214         - containerPort: 60010
215         - containerPort: 60011
216       env:
217         - name: HBASE_SERVER_TYPE
218           value: regionserver
219         - name: HBASE_MASTER_PORT
220           value: "60000"
221         - name: HBASE_MASTER_INFO_PORT
222           value: "60001"
223         - name: HBASE_REGION_PORT
224           value: "60010"
225         - name: HBASE_REGION_INFO_PORT
226           value: "60011"
227         - name: HDFS_SERVICE
228           value: "hdfs-namenode-service.default.domeos.sohu"
229         - name: HDFS_PORT
230           value: "4231"
231         - name: ZOOKEEPER_SERVICE_LIST
232           value: "zookeeper-1.default.domeos.sohu,zookeeper-2.default.domeos.sohu,zookeeper-3.default.domeos.sohu"
233         - name: ZOOKEEPER_PORT
234           value: "2181"
235         - name: ZNODE_PARENT
236           value: hbase
237         - name: HBASE_MASTER_LIST
238           value: "172.16.30.1:hbase-master-1 172.16.30.2:hbase-master-2"
239         - name: HBASE_REGION_LIST
240           value: "172.16.30.3:hbase-region-1"
241   restartPolicy: Always
242   nodeSelector:
243     kubernetes.io/hostname: bx-42-198

View Code

说明：该yaml文件共创建了两个master服务、两个regionserver服务，以及对应的两个master Pods和两个regionserver Pods；Pod的restartPolicy设为Always表示如果该Pod挂掉的话将一直尝试重新启动它；以环境变量的形式将参数传递进Pod中，其中HDFS_SERVICE为HDFS服务经过skyDNS之后的对应域名，若未设置skyDNS则此处值设为HDFS服务对应的IP地址，ZOOKEEPER_SERVICE_LIST同理；HBASE_MASTER_LIST的值格式为 :，多个项之间以空格分隔，HBASE_REGION_LIST同理。

接着就可以创建和查看HBase服务了：

# 创建
$kubectl create -f hbase.yaml
service "hbase-master-1" created
service "hbase-master-2" created
service "hbase-region-1" created
service "hbase-region-2" created
pod "hbase-master-1" created
pod "hbase-master-2" created
pod "hbase-region-1" created
pod "hbase-region-2" created

# 查看pods
$kubectl get pods
NAME                    READY     STATUS           RESTARTS   AGE
hbase-master-1          1/1       Running          0          5s
hbase-master-2          0/1       Pending          0          5s
hbase-region-1          1/1       Running          0          5s
hbase-region-2          0/1       Pending          0          5s
hdfs-datanode-1-nek2l   1/1       Running          3          7d
hdfs-datanode-2-vkbbt   1/1       Running          3          7d
hdfs-datanode-3-h4jvt   1/1       Running          3          7d
hdfs-namenode-1-cl0pj   1/1       Running          3          7d
kube-dns-v8-x8igc       3/3       Running          0          4h
zookeeper-1-ojhmy       1/1       Running          0          12h
zookeeper-2-cr73i       1/1       Running          0          12h
zookeeper-3-79ls0       1/1       Running          0          12h

# 查看service
$kubectl get service
NAME                    CLUSTER_IP       EXTERNAL_IP    PORT(S)                                                                                                                                      SELECTOR                       AGE
hbase-master-1          172.16.30.1               60000/TCP,60001/TCP                                                                                                                          app=hbase-master,server-id=1   17m
hbase-master-2          172.16.30.2               60000/TCP,60001/TCP                                                                                                                          app=hbase-master,server-id=2   17m
hbase-region-1          172.16.30.3               60010/TCP,60011/TCP                                                                                                                          app=hbase-region,server-id=1   17m
hbase-region-2          172.16.30.4               60010/TCP,60011/TCP                                                                                                                          app=hbase-region,server-id=2   17m
hdfs-namenode-service   172.16.20.1               4231/TCP,50020/TCP,50090/TCP,50070/TCP,50010/TCP,50075/TCP,8031/TCP,8032/TCP,8033/TCP,8040/TCP,8042/TCP,49707/TCP,22/TCP,8088/TCP,8030/TCP   app=hdfs-namenode              7d
kube-dns                172.16.40.1               53/UDP,53/TCP                                                                                                                                app=kube-dns,version=v8        10h
kubernetes              172.16.0.1                443/TCP                                                                                                                                                               12d
zookeeper-1             172.16.11.1               2181/TCP,2888/TCP,3888/TCP                                                                                                                   name=zookeeper,server-id=1     13h
zookeeper-2             172.16.11.2               2181/TCP,2888/TCP,3888/TCP                                                                                                                   name=zookeeper,server-id=2     13h
zookeeper-3             172.16.11.3               2181/TCP,2888/TCP,3888/TCP                                                                                                                   name=zookeeper,server-id=3     13h

通过ZooKeeper的zkCli.sh可以看到/hbase下对应的master和rs的记录（显示乱码是由于系统显示时编码的原因，无影响）：

[zk: localhost:2181(CONNECTED) 0] ls /hbase
[meta-region-server, backup-masters, table, draining, region-in-transition, table-lock, running, master, namespace, hbaseid, online-snapshot, replication, splitWAL, recovering-regions, rs]
[zk: localhost:2181(CONNECTED) 1] ls /hbase/rs
[172.27.0.0,60010,1448896399329, 172.28.0.115,60010,1448896360650]
[zk: localhost:2181(CONNECTED) 2] get /hbase/master
?master:60000??E*?O=PBUF

base-master-1???????*
cZxid = 0x100000186
ctime = Mon Nov 30 15:12:42 UTC 2015
mZxid = 0x100000186
mtime = Mon Nov 30 15:12:42 UTC 2015
pZxid = 0x100000186
cversion = 0
dataVersion = 0
aclVersion = 0
ephemeralOwner = 0x151563a5e37001a
dataLength = 60
numChildren = 0

可以通过docker exec进入到HBase对应的容器中进行表操作以测试HBase的工作状态：

# 进入198的hbase-master-2容器中
[@bx_42_198 /opt/scs/openxxs]# docker exec -it f131fcf15a72 /bin/bash

# 使用hbase shell对hbase进行操作
[root@hbase-master-2 bin]# hbase shell
2015-11-30 15:15:58,632 INFO  [main] Configuration.deprecation: hadoop.native.lib is deprecated. Instead, use io.native.lib.available
HBase Shell; enter 'help' for list of supported commands.
Type "exit" to leave the HBase Shell
Version 0.98.10.1-hadoop2, rd5014b47660a58485a6bdd0776dea52114c7041e, Tue Feb 10 11:34:09 PST 2015

# 通过status查看状态，这里显示的 2 dead 是之前测试时遗留的记录，无影响
hbase(main):001:0> status
2015-11-30 15:16:03,551 WARN  [main] util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2 servers, 2 dead, 1.5000 average load

# 创建表
hbase(main):002:0> create 'test','id','name'
0 row(s) in 0.8330 seconds

=> Hbase::Table - test

# 查看表
hbase(main):003:0> list
TABLE                                                                                                                                                                                
member                                                                                                                                                                               
test                                                                                                                                                                                 
2 row(s) in 0.0240 seconds

=> ["member", "test"]

# 插入数据
hbase(main):004:0> put 'test','test1','id:5','addon'
0 row(s) in 0.1540 seconds

# 查看数据
hbase(main):005:0> get 'test','test1'
COLUMN                                         CELL                                                                                                                                  
 id:5                                          timestamp=1448906130803, value=addon                                                                                                  
1 row(s) in 0.0490 seconds

# 进入199的hbase-master-1容器中查看从198上插入的数据
hbase(main):001:0> get 'test','test1'
2015-11-30 18:01:23,944 WARN  [main] util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
COLUMN                                         CELL                                                                                                                                  
 id:5                                          timestamp=1448906130803, value=addon                                                                                                  
1 row(s) in 0.2430 seconds

从以上结果可以看出HBase算是在k8s中以不怎么完善的方式跑起来了。

六、讨论

不得不维护/etc/hosts记录的原因是HBase中master之间、regionserver之间、master与regionserver之间都是通过hostname来彼此识别对方的，而k8s的DNS只针对service并没有对Pod进行解析。而如果把master和regionserver放在同一个Pod下的话存在磁盘资源共享冲突的问题（还没仔细研究）。Github讨论中下面的这段话很直白地说明了HBase对hostname的依赖：

1. Master uses ZooKeeper to run master election, the winner puts its
hostname:port in ZooKeeper.
2. RegionServers will register themselves to the winning Master through its
hostname registered in ZooKeeper.
3. We have a RegionServer with meta table/region (which stores Region ->
RegionServer map), it stores its hostname:port in ZooKeeper.
4. When a client starts a request to HBase, it gets the hostname of the
RegionServer with meta table from ZooKeeper, scan the meta table, and find
out the hostname of the RegionServer it interests, and finally talks to the
RegionServer through hostname.

为解决这个问题目前尝试过的方法如下：

1. 配置skyDNS：skyDNS只针对service进行解析，无法解析Pod的名称。如果向skyDNS中插入hostname的相关记录并动态维护的话或许可以解决该问题，目前正在尝试中。

2. 更改创建 ReplicationController、Server、Pod、Container 时的各种设置参数，如 name、generateName等，然并卵。

3. 创建container后启动 master 前通过脚本更改 hostname：Docker只允许在Create Container时进行hostname的修改（docker run自身有一个hostname的参数可以指定Container的hostname），但在容器运行之后并不允许修改，修改则报如下错误：docker Error: hostname: you must be root to change the hostname. 这个错误有些误导，事实上是docker的机制不允许你去修改hostname而不是权限问题，用root也没法改。

4. 修改HBase参数使其上报到ZK中的值不是hostname而是IP地址：这个一度是前景光明的解决方案，但将hostname写入ZK在HBase中是硬编码在代码中的，并没有参数可以去设置此项。有人给出了个patch（戳这里），但测试结果并不好。

关于第五部分HBase部署方案的说明：选择使用单Pod而不是ReplicationController，是因为k8s会在RC中Container的hostname后面加上随机字符以区分彼此，而单Pod的Pod name和hostname是一致的；restartPolicy设为Always算是为单Pod方式鲁棒性提供点小小的补偿吧；如果将Pod name设置为对应service的IP或域名怎样？然而hostname并不允许带点号；写入 /etc/hosts 中的IP选择了service的而非Pod的，因为Pod中的IP在运行前并不能获取到，而且在重启Pod后也会发生改变，而service的IP是不变的，因此选择了 serviceIP:PodName 这种对应关系。

最根本的解决方案是让k8s支持hostname（或者说Pod）的DNS解析，前面配置ZooKeeper同样存在hostname这个问题（戳这里），后面将要部署的Kafka也会有这个问题。k8s的开发团队已经进行了许多讨论并准备解决这个问题了（戳这里），希望下个版本会有相关设置。

关于Pod和hostname的DNS更多讨论可以参考：戳这里，这里，还有这里，再戳，戳，别再戳了。

转载于:https://www.cnblogs.com/openxxs/p/5001721.html