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카테고리: [ Cloud Computing & MSA ]
조회수: 4394

1. 개요


2. 설치

sudo apt install etcd로 설치한다.

Get:1 http://ap-northeast-1.ec2.archive.ubuntu.com/ubuntu bionic/universe amd64 pipexec amd64 2.5.5-1 [16.8 kB]
Get:2 http://ap-northeast-1.ec2.archive.ubuntu.com/ubuntu bionic/universe amd64 etcd-client amd64 3.2.17+dfsg-1 [8137 kB]
Get:3 http://ap-northeast-1.ec2.archive.ubuntu.com/ubuntu bionic/universe amd64 etcd-server amd64 3.2.17+dfsg-1 [4285 kB]
Get:4 http://ap-northeast-1.ec2.archive.ubuntu.com/ubuntu bionic/universe amd64 etcd all 3.2.17+dfsg-1 [2516 B]
Fetched 12.4 MB in 2s (5531 kB/s)
Selecting previously unselected package pipexec.
(Reading database ... 84333 files and directories currently installed.)
Preparing to unpack .../pipexec_2.5.5-1_amd64.deb ...
Unpacking pipexec (2.5.5-1) ...
Selecting previously unselected package etcd-client.
Preparing to unpack .../etcd-client_3.2.17+dfsg-1_amd64.deb ...
Unpacking etcd-client (3.2.17+dfsg-1) ...
Selecting previously unselected package etcd-server.
Preparing to unpack .../etcd-server_3.2.17+dfsg-1_amd64.deb ...
Unpacking etcd-server (3.2.17+dfsg-1) ...
Selecting previously unselected package etcd.
Preparing to unpack .../etcd_3.2.17+dfsg-1_all.deb ...
Unpacking etcd (3.2.17+dfsg-1) ...
Processing triggers for ureadahead (0.100.0-21) ...
Setting up pipexec (2.5.5-1) ...
Setting up etcd-client (3.2.17+dfsg-1) ...
Processing triggers for systemd (237-3ubuntu10.29) ...
Processing triggers for man-db (2.8.3-2ubuntu0.1) ...
Setting up etcd-server (3.2.17+dfsg-1) ...
Adding system user `etcd' (UID 111) ...
Adding new group `etcd' (GID 116) ...
Adding new user `etcd' (UID 111) with group `etcd' ...
Creating home directory `/var/lib/etcd/' ...
Setting up etcd (3.2.17+dfsg-1) ...
Processing triggers for systemd (237-3ubuntu10.29) ...
Processing triggers for ureadahead (0.100.0-21) ...

3. 버전 확인

$ etcdctl --version
etcdctl version: 3.2.17
API version: 2

4. 프로세스 확인

$ ps -ef | grep etcd
etcd     19854     1  0 14:00 ?        00:00:01 /usr/bin/etcd
ubuntu   20034 19562  0 14:10 pts/0    00:00:00 grep --color=auto etcd

5. 포트 확인

$ sudo netstat -anp | grep 2379
tcp        0      0 127.0.0.1:2379          0.0.0.0:*               LISTEN      19854/etcd
tcp        0      0 127.0.0.1:53088         127.0.0.1:2379          TIME_WAIT   -
tcp        0      0 127.0.0.1:53076         127.0.0.1:2379          ESTABLISHED 19854/etcd
tcp        0      0 127.0.0.1:2379          127.0.0.1:53076         ESTABLISHED 19854/etcd
$ ps -ef | grep 19854
etcd     19854     1  0 14:00 ?        00:00:02 /usr/bin/etcd
ubuntu   20087 19562  0 14:16 pts/0    00:00:00 grep --color=auto 19854

6. curl을 통한 모니터링

$ curl -L http://127.0.0.1:2379/version
{"etcdserver":"3.2.17","etcdcluster":"3.2.0"}
$ curl -L http://127.0.0.1:2379/health
{"health": "true"}

7. 이리저리 데이터 넣었다 빼기

$ etcdctl set name stdio
stdio
$ etcdctl get name
stdio
$ etcdctl set name helloworld
helloworld
$ etcdctl get name
helloworld
$ curl http://127.0.0.1:2379/v2/keys/name | json_pp
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    96  100    96    0     0  19200      0 --:--:-- --:--:-- --:--:-- 19200
{
   "node" : {
      "createdIndex" : 6,
      "key" : "/name",
      "modifiedIndex" : 6,
      "value" : "helloworld"
   },
   "action" : "get"
}
$ curl -L http://127.0.0.1:2379/v2/keys/name -XPUT -d value="sarc"
{"action":"set","node":{"key":"/name","value":"sarc","modifiedIndex":7,"createdIndex":7},"prevNode":{"key":"/name","value":"helloworld","modifiedIndex":6,"createdIndex":6}}
$ etcdctl get name
sarc
$ curl http://127.0.0.1:2379/v2/keys/name | json_pp
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    90  100    90    0     0  90000      0 --:--:-- --:--:-- --:--:-- 90000
{
   "action" : "get",
   "node" : {
      "modifiedIndex" : 7,
      "key" : "/name",
      "value" : "sarc",
      "createdIndex" : 7
   }
}

8. 클러스터 상태 확인

지금은 단일 노드에 설치한 것이라 클러스터를 봐도 의미는 없다.

$ etcdctl cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://localhost:2379
cluster is healthy
$ etcdctl member list
8e9e05c52164694d: name=ip-172-31-37-200 peerURLs=http://localhost:2380 clientURLs=http://localhost:2379 isLeader=true

일단 etcd 설정 파일이 /etc/default/etcd라는 것만 알아두자.


9. 이중화

etcd를 설치한 서버를 동일하게 복제하여 #2번 서버를 생성하였다. 그래서 다음과 같은 환경이 구성되었다.

9.1. 설정 파일 수정

현재는 #1, #2 서버 모두 기본 etcd 설정(/etc/default/etcd)을 사용 중인 상태이다. 두 서버의 설정을 이렇게 수정한다.

< #1번 서버 >

ETCD_NAME="etcd-01"
ETCD_DATA_DIR="/var/lib/etcd"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster-01"
ETCD_INITIAL_CLUSTER="etcd-01=http://172.31.37.200:2380,etcd-02=http://172.31.33.222:2380"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://172.31.37.200:2380"
ETCD_ADVERTISE_CLIENT_URLS="http://172.31.37.200:2379"
ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://172.31.37.200:2379,http://127.0.0.1:2379"

< #2번 서버 >

ETCD_NAME="etcd-02"
ETCD_DATA_DIR="/var/lib/etcd"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster-01"
ETCD_INITIAL_CLUSTER="etcd-01=http://172.31.37.200:2380,etcd-02=http://172.31.33.222:2380"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://172.31.33.222:2380"
ETCD_ADVERTISE_CLIENT_URLS="http://172.31.33.222:2379"
ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://172.31.33.222:2379,http://127.0.0.1:2379"

9.2. 각각 서비스 재기동

9.3. 확인

$ etcdctl member list
8d70aeafa0bed77e: name=etcd-02 peerURLs=http://172.31.33.222:2380 clientURLs=http://172.31.33.222:2379 isLeader=false
d81a31603e6f8367: name=etcd-01 peerURLs=http://172.31.37.200:2380 clientURLs=http://172.31.37.200:2379 isLeader=true