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.
- #1 서버 : 172.31.37.200
- #2 서버 : 172.31.33.222
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