利用Docker部署PostgreSQL 12.4主从方式

[root@lei ~]# docker pull postgres:12.4-alpine

docker network create --driver bridge --subnet=172.18.12.0/16 --gateway=172.18.12.1 mynet

[root@lei ~]# docker inspect mynet
[
    {
        "Name": "mynet",
        "Id": "9bcbf9f08168af8ee61f766014629bce6adbe11e00842f53ab2bc84615ddc2e2",
        "Created": "2020-11-09T16:01:03.276711818+08:00",
        "Scope": "local",
        "Driver": "bridge",
        "EnableIPv6": false,
        "IPAM": {
            "Driver": "default",
            "Options": {},
            "Config": [
                {
                    "Subnet": "172.18.12.0/16",
                    "Gateway": "172.18.12.1"
                }
            ]
        },
        "Internal": false,
        "Attachable": false,
        "Containers": {},
        "Options": {},
        "Labels": {}
    }
]

[root@lei ~]# mkdir -p  /home/pg_p/data

[root@lei ~]# docker run --name pg_p --restart=always --network=mynet --ip 172.18.12.100 -v /home/pg_p/data:/var/lib/postgresql/data -e POSTGRES_PASSWORD=123456 -p 5432:5432 -d postgres:12.4-alpine

[root@lei ~]# mkdir -p  /home/pg_s/data

[root@lei ~]# docker run --name pg_s --restart=always --network=mynet --ip 172.18.12.101 -v /home/pg_s/data:/var/lib/postgresql/data -e POSTGRES_PASSWORD=123456 -p 5433:5432 -d postgres:12.4-alpine

[root@lei ~]# docker exec -it pg_p /bin/bash
bash-5.0# su - postgres
bff818d570c9:~$ psql
psql (12.4)
Type "help" for help.

postgres=#

CREATE ROLE replica login replication encrypted password 'replica';

postgres=# \du
                                   List of roles
 Role name |                         Attributes                         | Member of
-----------+------------------------------------------------------------+-----------
 postgres  | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
 replica   | Replication                                                | {}

host   replication      replica       172.18.12.101/32          trust   #允许172.18.12.101使用 replica 用户来复制

listen_addresses = '*'        # 监听所有IP
archive_mode = on             # 允许归档
wal_level = replica           # 开启热备
archive_command = '/bin/date' # 用该命令来归档logfile segment,这里取消归档。
max_wal_senders = 32          # 这个设置了可以最多有几个流复制连接，差不多有几个从，就设置几个
wal_keep_segments = 64        # 设置流复制保留的最多的xlog数目，一份是 16M，注意机器磁盘 16M*64 = 1G
wal_sender_timeout = 60s      # 设置流复制主机发送数据的超时时间
max_connections = 200         # 这个设置要注意下，从库的max_connections必须要大于主库的

docker restart pg_p

postgres=# show archive_mode; archive_mode-------------- on(1 row)

[root@lei ~]# docker exec -it pg_s /bin/bash
bash-5.0# su - postgres
# 删除原有数据文件
cedd81ee4e30:~$ rm -rf /var/lib/postgresql/data/*
# 备份恢复
cedd81ee4e30:~$ pg_basebackup -h 172.18.12.100 -p 5432 -U replica -Fp -Xs -Pv -R -D /var/lib/postgresql/data
pg_basebackup: initiating base backup, waiting for checkpoint to complete
pg_basebackup: checkpoint completed
pg_basebackup: write-ahead log start point: 0/2000028 on timeline 1
pg_basebackup: starting background WAL receiver
pg_basebackup: created temporary replication slot "pg_basebackup_43"
24636/24636 kB (100%), 1/1 tablespace
pg_basebackup: write-ahead log end point: 0/2000138
pg_basebackup: waiting for background process to finish streaming ...
pg_basebackup: syncing data to disk ...
pg_basebackup: base backup completed

standby_mode = 'on'

wal_level = replica   # WAL 日志级别为 replica
primary_conninfo = 'host=172.18.12.100 port=5432 user=replica password=replica'   # 主库连接信息	
hot_standby = on                     # 恢复期间，允许查询
recovery_target_timeline = latest    # 默认
max_connections = 120                # 大于等于主节点，正式环境应当重新考虑此值的大小

[root@lei ~]# docker restart pg_s

postgres=# select client_addr,sync_state from pg_stat_replication;
  client_addr  | sync_state
---------------+------------
 172.18.12.101 | async
(1 row)

CREATE DATABASE
postgres=#
postgres=# \c lei
You are now connected to database "lei" as user "postgres".
lei=# create table test(name varchar(50));
CREATE TABLE
lei=# insert into test values('tom');
INSERT 0 1

postgres-# \l
                                 List of databases
   Name    |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges
-----------+----------+----------+------------+------------+-----------------------
 lei       | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 postgres  | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 template0 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
 template1 | postgres | UTF8     | en_US.utf8 | en_US.utf8 | =c/postgres          +
           |          |          |            |            | postgres=CTc/postgres
(4 rows)

postgres-# \c lei
You are now connected to database "lei" as user "postgres".
lei=# select * from test;
 name
------
 tom
(1 row)