作者简介：

赵振平，PostgreSQL中文社区主席、计算机畅销书作家、贵州省省管专家、太阳塔科技CTO、国家首批大数据高级职称、腾讯最具价值专家（TVP）、电子工业出版社签约作家、出版了技术专著《Oracle数据库精讲与疑难解析》、出版了技术专著《成功之路：Oracle 11g学习笔记》、出版了技术专著《IT架构实录》。

背景介绍

上篇介绍容器相关的基本概念，介绍如何安装docker。如果不熟悉docker的安装，可回到系列文章的第一部分《Docker与PostgreSQL 11.5系列文章（一）Docker的安装》。（请点击文章底部“阅读原文”查看）第二部分主要介绍PostgreSQL11在容器中的安装和使用。

下载镜像

这里下载的postgreSQL 11.5版本的镜像

[root@tar1 yum.repos.d]# docker pull postgres:11.511.5: Pulling from library/postgres9fc222b64b0a: Pull complete 38296355136d: Pull complete 2809e135bbdb: Pull complete 77907400401d: Pull complete 1f8ceea7d21e: Pull complete 1ede1f2cb1b8: Pull complete dcfbc2751885: Pull complete 8379f81b7622: Pull complete 08034f3aaedc: Pull complete cb6db97b313d: Pull complete 7a41d1ed6f3b: Pull complete 15f5a1254505: Pull complete 5a9451e12286: Pull complete 55bb5e2d55ba: Pull complete Digest: sha256:f766d03bb49c7dd16fe32c1eb2645d13cb315adc029557cd1e4a0a9c094933d5Status: Downloaded newer image for postgres:11.5

下载要花费一定的时间。

查看镜像

[root@tar1 yum.repos.d]# docker images |grep postpostgres            11.5                c3fe76fef0a6        9 days ago          312MB[root@tar1 yum.repos.d]#

下载成功以后，可以查看镜像的信息（包括大小）。

创建和运行容器

[root@tar1 yum.repos.d]# docker run --name dockerPG11 -e POSTGRES_PASSWORD=Xzzp2008 -p 54322:5432 -d postgres:11.5ccb3d0bb1a303e081fac20622c0b821b71720308280a8d1a55b906e792fe6452

1) run 创建并运行一个容器（实例）；

2) --name 指定创建的容器的名字；

3) -e POSTGRES_PASSWORD= Xzzp2008 设置环境变量，指定数据库的登录口令为Xzzp2008；

4) -p 54322:5432 端口映射将容器的5432端口映射到外部机器的54322端口，从外部访问就使用这个端口；

5) -d postgres:11.5 镜像的名字是postgres:11.5，镜像的名字是查询出来的，不是由用户随意定的。

查看实例

[root@tar1 yum.repos.d]# docker psCONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                NAMESccb3d0bb1a30        postgres:11.5       "docker-entrypoint..."   37 seconds ago      Up 36 seconds       5432/tcp, 0.0.0.0:54322->54333/tcp   dockerPG11

可以看到实例运行的时间，ID号等信息。

多了参数-a ，是不一样的输出

[root@tar1 yum.repos.d]# docker ps -aCONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS                         PORTS                                NAMESccb3d0bb1a3        postgres:11.5       "docker-entrypoint..."   14 minutes ago      Up 14 minutes                  5432/tcp, ...:54322->54333/tcp   dockerPG113b8d602037b4        hello-world         "/hello"                 About an hour ago   Exited () About an hour ago                                        jolly_wrightc5cdfc83f7bd        hello-world         "/hello"                 About an hour ago   Exited () About an hour ago                                        elegant_edison

查看日志

[root@tar1yum.repos.d]# docker logs ccb3d0bb1a303e081fac20622c0b821b71720308280a8d1a55b906e792fe6452The files belonging to this database system will be owned by user "postgres".This user must also own the server process.
The database cluster will be initialized with locale "en_US.utf8".The default database encoding has accordingly been set to "UTF8".The default text search configuration will be set to "english".
Data page checksums are disabled.
fixing permissions on existing directory /var/lib/postgresql/data ... okcreating subdirectories ... okselecting default max_connections ... 100selecting default shared_buffers ... 128MBselecting default timezone ... Etc/UTCselecting dynamic shared memory implementation ... posixcreating configuration files ... okrunning bootstrap script ... okperforming post-bootstrap initialization ... oksyncing data to disk ... ok
Success. You can now start the database server using:
    pg_ctl -D /var/lib/postgresql/data -l logfile start

WARNING: enabling "trust" authentication for local connectionsYou can change this by editing pg_hba.conf or using the option -A, or--auth-local and --auth-host, the next time you run initdb.waiting for server to start....2019-08-23 09:48:02.765 UTC [39] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"2019-08-23 09:48:02.791 UTC [40] LOG:  database system was shut down at 2019-08-23 09:48:01 UTC2019-08-23 09:48:02.797 UTC [39] LOG:  database system is ready to accept connections doneserver started
/usr/local/bin/docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/*
waiting for server to shut down....2019-08-23 09:48:02.846 UTC [39] LOG:  received fast shutdown request2019-08-23 09:48:02.849 UTC [39] LOG:  aborting any active transactions2019-08-23 09:48:02.852 UTC [39] LOG:  background worker "logical replication launcher" (PID 46) exited with exit code 12019-08-23 09:48:02.852 UTC [41] LOG:  shutting down2019-08-23 09:48:02.881 UTC [39] LOG:  database system is shut down doneserver stopped
PostgreSQL init process complete; ready for start up.
2019-08-23 09:48:02.967 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port 54322019-08-23 09:48:02.967 UTC [1] LOG:  listening on IPv6 address "::", port 54322019-08-23 09:48:02.973 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"2019-08-23 09:48:02.989 UTC [48] LOG:  database system was shut down at 2019-08-23 09:48:02 UTC2019-08-23 09:48:02.996 UTC [1] LOG:  database system is ready to accept connections

进入容器里面（进入容器内部）

运行中的容器其实是一个功能完备的Linux操作系统，所以我们可以像常规的系统一样登录并访问容器。

[root@tar1 yum.repos.d]# docker exec -it dockerPG11 bashroot@ccb3d0bb1a30:/#

dockerPG11是容器的名字。

ccb3d0bb1a30是容器的ID号。

查看PG进程（在容器里）

root@ccb3d0bb1a30:/# ps -ef |grep postpostgres     1     0  0 09:47 ?        00:00:00 postgrespostgres    49     1  0 09:48 ?        00:00:00 postgres: checkpointer  postgres    50     1  0 09:48 ?        00:00:00 postgres: background writer  postgres    51     1  0 09:48 ?        00:00:00 postgres: walwriter  postgres    52     1  0 09:48 ?        00:00:00 postgres: autovacuum launcher  postgres    53     1  0 09:48 ?        00:00:00 postgres: stats collector  postgres    54     1  0 09:48 ?        00:00:00 postgres: logical replication launcher  root        69    55  0 10:10 ?        00:00:00 grep post

注意：看到ID号ccb3d0bb1a30，你就知道，当前在容器内部。

切换到OS用户postgres（在容器里）

root@ccb3d0bb1a30:/# su - postgrespostgres@ccb3d0bb1a30:~$ postgres@ccb3d0bb1a30:~$

登录数据库（在容器里）

postgres@ccb3d0bb1a30:~$ psql -d postgrespsql (11.5 (Debian 11.5-1.pgdg9+1))Type "help" for help.
postgres=#

查看映射到docker外的端口

[root@tar1 ~]# netstat -ntlActive Internet connections (only servers)Proto Recv-Q Send-Q Local Address           Foreign Address         State      tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN     tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN     tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN     tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN     tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN     tcp6       0      0 ::1:25                  :::*                    LISTEN     tcp6       0      0 :::111                  :::*                    LISTEN     tcp6       0      0 :::54322                :::*                    LISTEN     tcp6       0      0 :::22                   :::*                    LISTEN     tcp6       0      0 ::1:631

54321就是访问容器内postgres数据库的端口号。

登录数据库（从容器外部）

从宿主机登录容器数据库

-bash-4.2$ psql -U postgres -h localhost -p 54322用户 postgres 的口令：psql (11.5)输入 "help" 来获取帮助信息.
postgres=#

查看版本号

postgres=# select version();                                                             version                                                              ---------------------------------------------------------------------------------- PostgreSQL 11.5 (Debian 11.5-1.pgdg90+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 6.3.0-18+deb9u1) 6.3.0 20170516, 64-bit(1 行记录)
postgres=#

54322是映射以后的密码，

DML测试

创建表，插入数据，查询数据等一系列实验：

postgres=# CREATE TABLE weather (postgres(# city varchar(80),postgres(# temp_lo int, -- low temperaturepostgres(# temp_hi int, -- high temperaturepostgres(# prcp real, -- precipitationpostgres(# date datepostgres(# );CREATE TABLEpostgres=# INSERT INTO weather VALUES ('San Francisco',46,50,0.25, '1994-11-27');INSERT 0 1postgres=# INSERT INTO weather (city, temp_lo, temp_hi, prcp, date) VALUES ('San Francisco', 43, 57, 0.0, '1994-11-29');INSERT 0 1postgres=# INSERT INTO weather (date, city, temp_hi, temp_lo) VALUES ('1994-11-29', 'Hayward', 54, 37);INSERT 0 1postgres=# SELECT * FROM weather;     city      | temp_lo | temp_hi | prcp |    date    ---------------+---------+---------+------+------------ San Francisco |      46 |      50 | 0.25 | 1994-11-27 San Francisco |      43 |      57 |    0 | 1994-11-29 Hayward       |      37 |      54 |      | 1994-11-29(3 行记录)
postgres=#
postgres=# \dt                关联列表 架构模式 |  名称   |  类型  |  拥有者  ----------+---------+--------+---------- public   | weather | 数据表 | postgres(1 行记录)

停止实例（容器）

docker stop ccb3d0bb1a30ccb3d0bb1a30是实例（容器）的ID或者（dockerPG11是容器的名字）docker stop dockerPG11

其实也是停止PG11.5。

删除容器

[root@tar1 ~]# docker rm dockerPG11dockerPG11

dockerPG11是容器的名字

删除容器以后，可以把容器所引用的卷给删除

[root@tar1 ~]# ll /var/lib/docker/volumes/总用量 32drwxr-xr-x. 3 root root    19 8月  23 23:46 cf103a7ead15ff3e25f42e83703f06544cfbf018fe469d577002dff9f692bb6f-rw-------. 1 root root 65536 8月  25 12:13 metadata.db[root@tar1 ~]# docker volume rm cf103a7ead15ff3e25f42e83703f06544cfbf018fe469d577002dff9f692bb6fcf103a7ead15ff3e25f42e83703f06544cfbf018fe469d577002dff9f692bb6f[root@tar1 ~]#  ll /var/lib/docker/volumes/总用量 32-rw-------. 1 root root 65536 8月  25 12:32 metadata.db[root@tar1 ~]#

总结

在这篇文章的学习中，需注意端口是如何映射的，还要特别注意在容器里面和容器外面看到的情况。同时注意: 如何从容器外登录数据库？如何从容器里登录数据库？停止docker服务和停止docker的区别。

ITPub博客

Docker与PostgreSQL 11.5系列文章（二）PostgreSQL 11.5安装