希望在自己的机器模拟一下公司中微服务的构建,使用docker部署了mysql实例,使用spring boot进行了CRUD(增删改查)操作进行了一下验证,在后面的学习中也可以尝试更多的框架和组件。
ps:实验环境是:ubuntu 14.04, 64位
1.获取mysql镜像
从docker hub的仓库中拉取mysql镜像
sudo docker pull mysql
查看镜像
1
2
3
|
sudo docker images
mysql latest 18f13d72f7f0 2 weeks ago 383.4 MB
|
2.运行一个mysql容器
运行一个mysql实例的命令如下:
sudo docker run --name first-mysql -p 3306:3306 -e MYSQL\_ROOT\_PASSWORD=123456 -d mysql
5b6bf6f629bfe46b4c8786b555d8db1947680138b2de1f268f310a15ced7247a
上述命令各个参数含义:
run 运行一个容器
--name 后面是这个镜像的名称
-p 3306:3306 表示在这个容器中使用3306端口(第二个)映射到本机的端口号也为3306(第一个)
-d 表示使用守护进程运行,即服务挂在后台
查看当前运行的容器状态:
sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES5b6bf6f629bf
mysql "docker-entrypoint.sh" 32 hours ago Up 5 hours 0.0.0.0:3306->3306/tcp first-mysql
想要访问mysql数据库,我的机器上需要装一个mysql-client。
sudo apt-get install mysql-client-core-5.6
下面我们使用mysql命令访问服务器,密码如刚才所示为123456,192.168.95.4为我这台机器的ip, 3306为刚才所示的占用本物理机的端口(不是在docker内部的端口)
mysql -h192.168.95.4 -P3306 -uroot -p123456
访问的结果如下:
1
2
3
4
5
6
7
8
9
10
11
12
|
mysql> show databases;
+ --------------------+
| Database |
+ --------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+ --------------------+
4 rows in set (0.00 sec)
|
3.运行第二个mysql实例
使用docker相对于虚拟机而言的原因是耗费很少的资源,可以"开辟"非常多的隔离的环境,所以我们继续运行第二个mysql实例,还用之前的镜像,名字为second-mysql。
sudo docker run --name second-mysql -p 3306:3307 -e MYSQL\_ROOT\_PASSWORD=123456 -d
mysql2de4ddb5bfb9b9434af8e72368631e7f4c3f83ee354157328049d7d0
f5523661docker: Error response from daemon: driver failed programming external connectivity on endpoint second-mysql (33aa29d891a1cb540de250bcbbbe9a0a41cd98f61a4e9f129a2ad5db69da4984): Bind for 0.0.0.0:3306 failed: port is already allocated.
为了验证第一个是本机的端口号,就仍然使用了3306这个端口,那么创建如上所示,发生了错误,但是产生了一个容器id,当我们修改端口后还会报错,因为名字冲突了,也即这次失败的创建会占用这个名字:
sudo docker run --name second-mysql -p 3307:3306 -e MYSQL\_ROOT\_PASSWORD=123456 -d
mysqldocker: Error response from daemon: Conflict. The name "/second-mysql" is already in use by container 2de4ddb5bfb9b9434af8e72368631e7f4c3f83ee354157328049d7d0f5523661.
You have to remove (or rename) that container to be able to reuse that name..
为了验证second-mysql这个容器还在docker的进程中,我们使用ps -a这个命令,我们可以观察到first-mysql的状态为Up 34 minutes,说明已经工作了34分钟,而second-mysql只是刚刚创建的。
1
2
3
4
5
|
sudo docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2de4ddb5bfb9 mysql "docker-entrypoint.sh" About a minute ago Created second-mysql
5b6bf6f629bf mysql "docker-entrypoint.sh" 34 minutes ago Up 34 minutes 0.0.0.0:3306->3306 /tcp first-mysql
|
我们用rm命令删除这个容器,如下面命令所示:
1
2
3
4
5
6
|
maintain@maintain-dev1:~$ sudo docker rm second-mysql
maintain@maintain-dev1:~$ sudo docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5b6bf6f629bf mysql "docker-entrypoint.sh" 42 minutes ago Up 42 minutes 0.0.0.0:3306->3306 /tcp first-mysql
|
重新建立second-mysql这个容器,占用物理机的3307端口:
1
2
3
4
5
6
7
8
9
|
sudo docker run --name second-mysql -p 3307:3306 -e MYSQL\_ROOT\_PASSWORD=123456 -d mysql
5404fb11f29cba07b991f34056d6b40ed0888aa905a45e637e396d071bd7f331
sudo docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5404fb11f29c mysql "docker-entrypoint.sh" 12 seconds ago Up 11 seconds 0.0.0.0:3307->3306 /tcp second-mysql
5b6bf6f629bf mysql "docker-entrypoint.sh" 43 minutes ago Up 43 minutes 0.0.0.0:3306->3306 /tcp first-mysql
|
如上图所示,两个实例都正常运行了,为了访问第二个容器,我们指定端口3307登录到这个mysql的client。
1
2
3
4
5
6
7
8
9
|
mysql -h192.168.95.4 -P3307 -uroot -p123456
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.15 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and /or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and /or itsaffiliates. Other names may be trademarks of their respectiveowners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
|
4.jdbc测试(maven & Spring boot)
例子来源:http://spring.io/guides/gs/relational-data-access/
使用java spring对数据库进行操作,使用了spring官网的例子,用JdbcTemplate这个裸写sql的方法,没有用hibernate或者myibatis.
spring官网的例子使用h2一个内置的内存数据库,没有配置文件生成为对象的烦恼,
为了练习下yaml替代xml,使用了如下的mysql jdbc配置,application.yaml.
1
2
3
4
5
6
7
8
9
|
### application.yaml
### mysql config
spring:
datasource:
dbcp:
driver-class-name: com.mysql.jdbc.Driver
url: jdbc:mysql: //192 .168.18.129:3306 /test1
username: root
password: 123456
|
找了半天自动将依赖注入为一个JdbcTemplate对象,也没有搞定,就只好像下面一样自己先生成DataSource,再new一个JdbcTemlate对象,最后使用jdbcTemplate对数据库进行操作,这样写的很丑,希望各位可以指点一下。
1
2
3
4
5
6
7
8
9
|
@Bean
@ConfigurationProperties(prefix = "spring.datasource.dbcp" )
public DataSource mysqlSource() {
return DataSourceBuilder.create().build();
}
@Bean
public JdbcTemplate mysqlJdbcTemplate() {
return new JdbcTemplate(mysqlSource());
}
|
下面是对数据库的一些CRUD操作,使用jdk8的函数式编程:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
JdbcTemplate jdbcTemplate = mysqlJdbcTemplate();
jdbcTemplate.execute( "DROP TABLE IF EXISTS customers" );
jdbcTemplate.execute( "CREATE TABLE customers(" + "id SERIAL, first_name VARCHAR(255), last_name VARCHAR(255))" );
// Split up the array of whole names into an array of first /last names
List<Object[]> splitUpNames = Arrays.asList( "John Woo" , "Jeff Dean" , "Josh Bloch" , "Josh Long" )
.stream() .map(name -> name. split ( " " )) .collect(Collectors.toList());
// Use a Java 8 stream to print out each tuple of the list
splitUpNames.forEach(name -> log.info(String. format ( "Inserting customer record for %s %s" , name[0], name[1])));
// Uses JdbcTemplate's batchUpdate operation to bulk load data
jdbcTemplate.batchUpdate( "INSERT INTO customers(first_name, last_name) VALUES (?,?)" , splitUpNames);
log.info( "Querying for customer records where first_name = 'Josh':" );
jdbcTemplate.query(
"SELECT id, first_name, last_name FROM customers WHERE first_name = ?" ,
new Object[]{ "Josh" }, (rs, rowNum) -> new Customer(rs.getLong( "id" ), rs.getString( "first_name" ), rs.getString( "last_name" )))
.forEach(customer -> log.info(customer.toString()));
|
下面在mysql的客户端进行了验证:
1
2
3
4
5
6
7
8
9
10
11
|
mysql> select * from customers;
+----+------------+-----------+
| id | first_name | last_name |
+----+------------+-----------+
| 1 | John | Woo |
| 2 | Jeff | Dean |
| 3 | Josh | Bloch |
| 4 | Josh | Long |
+----+------------+-----------+
4 rows in set (0.00 sec)
|
5. 遇到的一些坑
maven配置
使用了jdk8的lamda表达式,必须在maven中配置java.version
1
2
3
|
<properties>
<java.version> 1.8 </java.version>
</properties>
|
docker服务重启
docker这个服务挂了,容器也就跟着挂了,并没有重启,应该在运行容器的时候带上--restart=always这个参数