环境介绍
Linux主机，安装两个docker postgres 容器，并实现主从配置。
数据库版本：12
主库端口：5433
从库端口：5434
主节点操作
（1）创建工作目录
mkdir -p /home/hadoop/data/pg/master（2）拉取镜像并启动容器
docker run -d \
-p 5433:5432 \
-e POSTGRES_PASSWORD=postgres \
-v /home/hadoop/data/pg/master/:/var/lib/postgresql/data \
--name pg12master \
-h pg12master \
-e LANG="C.UTF-8" \
-e 'TZ=Asia/Shanghai' \
-m 256m \
--memory-swap -1 \
postgres:12（3）修改配置文件
pg_hba.conf
# "local" is for Unix domain socket connections only
local all all trust
# IPv4 local connections:
host all all 127.0.0.1/32 trust
# IPv6 local connections:
host all all ::1/128 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
local replication all trust
host replication all 127.0.0.1/32 trust
host replication all ::1/128 trust
host replication all 0.0.0.0/0 md5
host replication repuser 172.17.0.0/24 md5
host all all 0.0.0.0/0 md5postgresql.conf
wal_level = logical
archive_mode = on
archive_command = '/bin/date'
max_wal_senders = 10
wal_keep_segments = 16
synchronous_standby_names = '*'（4）基础数据备份
进入master容器，备份基础数据。
[root@bigdata3 ~]# docker exec -it pg12master /bin/bash
root@pg12master:/# pg_basebackup -R -D /var/lib/postgresql/slave -Fp -Xs -v -P -h 172.17.0.1 -p 5433 -U postgres
Password: postgres
pg_basebackup: initiating base backup, waiting for checkpoint to complete
pg_basebackup: checkpoint completed
pg_basebackup: write-ahead log start point: 0/B000028 on timeline 1
pg_basebackup: starting background WAL receiver
pg_basebackup: created temporary replication slot "pg_basebackup_193"
24729/24729 kB (100%), 1/1 tablespace
pg_basebackup: write-ahead log end point: 0/B000100
pg_basebackup: waiting for background process to finish streaming ...
pg_basebackup: syncing data to disk ...
pg_basebackup: base backup completed
root@pg12master:/#将容器中的基础数据下载到本地。
docker cp pg12master:/var/lib/postgresql/slave /home/hadoop/data/pg从节点操作
（1）启动从节点容器
docker run -d \
--ip 172.17.0.5 \
-p 5434:5432 \
--name pg12slave \
-h pg12slave \
-e LANG="C.UTF-8" \
-e 'TZ=Asia/Shanghai' \
-e "POSTGRES_DB=postgres" \
-e "POSTGRES_USER=postgres" \
-e "POSTGRES_PASSWORD=postgres" \
-v /home/hadoop/data/pg/slave:/var/lib/postgresql/data \
-m 256m \
--memory-swap -1 \
postgres:12注意：IP地址为Docker的IP。
检查测试
检查主库是否可以检查到从库。
docker exec -it -u postgres pg12master /bin/bash
postgres@pg12master:/$ psql
psql (12.3 (Debian 12.3-1.pgdg100+1))
Type "help" for help.
postgres=# select * from pg_stat_replication;
pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | backend_xmin | state | sent_lsn | write_lsn | flush_lsn | replay_lsn | write_l
ag | flush_lag | replay_lag | sync_priority | sync_state | reply_time
-----+----------+---------+------------------+--------------+-----------------+-------------+-------------------------------+--------------+-----------+-----------+-----------+-----------+------------+--------
---+-----------+------------+---------------+------------+-------------------------------
149 | 16384 | repuser | walreceiver | 172.17.0.1 | | 51752 | 2021-11-25 15:21:28.80868+08 | | streaming | 0/A004518 | 0/A004518 | 0/A004518 | 0/A004518 |
| | | 1 | sync | 2021-11-25 18:42:51.27092+08
(2 rows)
postgres=#使用Navcat连接主库，建表，并查看从库是否自动建表。
