很多业务场景，业务功能必须用pg数据库，这时候注册中心如果用mysql的话，显得浪费资源，基于此，nacos源码修改持久化到postgreSQL数据库是一个必然需求，此处我们修改为只支持pg数据库，2.4版本的源码。
源码拉取和编译参考：前置内容
1、修改配置文件
修改console和nacos-distribution模块中的application.properties配置文件，内容如下：
spring.sql.init.platform=postgresql
db.num=1
db.url.0=jdbc:postgresql://14.xx.78.188:5432/nacos
db.user.0=postgres
db.password.0=1234562、修改pom文件
#nacos-all中添加依赖
<dependency><groupId>org.postgresql</groupId><artifactId>postgresql</artifactId><version>42.2.18</version>
</dependency>#naming模块中添加依赖：
<dependency><groupId>org.postgresql</groupId><artifactId>postgresql</artifactId>
</dependency>#config模块中添加依赖：
<dependency><groupId>org.postgresql</groupId><artifactId>postgresql</artifactId>
</dependency>
3、修改驱动加载相关类
ExternalDataSourceProperties.java 中的方法修改为：
private static final String JDBC_DRIVER_NAME = "org.postgresql.Driver";List<HikariDataSource> build(Environment environment, Callback<HikariDataSource> callback) {List<HikariDataSource> dataSources = new ArrayList<>();Binder.get(environment).bind("db", Bindable.ofInstance(this));Preconditions.checkArgument(Objects.nonNull(num), "db.num is null");Preconditions.checkArgument(CollectionUtils.isNotEmpty(user), "db.user or db.user.[index] is null");Preconditions.checkArgument(CollectionUtils.isNotEmpty(password), "db.password or db.password.[index] is null");for (int index = 0; index < num; index++) {int currentSize = index + 1;Preconditions.checkArgument(url.size() >= currentSize, "db.url.%s is null", index);DataSourcePoolProperties poolProperties = DataSourcePoolProperties.build(environment);//修改如下if (StringUtils.isEmpty(poolProperties.getDataSource().getDriverClassName())) {String driverClassName = JDBC_DRIVER_NAME;if ("postgresql".equals(EnvUtil.getProperty("spring.datasource.platform"))) {driverClassName = "org.postgresql.Driver";poolProperties.setDriverClassName(driverClassName);}}poolProperties.setJdbcUrl(url.get(index).trim());poolProperties.setUsername(getOrDefault(user, index, user.get(0)).trim());poolProperties.setPassword(getOrDefault(password, index, password.get(0)).trim());HikariDataSource ds = poolProperties.getDataSource();if (StringUtils.isEmpty(ds.getConnectionTestQuery())) {ds.setConnectionTestQuery(TEST_QUERY);}dataSources.add(ds);callback.accept(ds);}Preconditions.checkArgument(CollectionUtils.isNotEmpty(dataSources), "no datasource available");return dataSources;}ExternalDataSourceServiceImpl.java 和
LocalDataSourceServiceImpl.java 类中修改：
private String dataSourceType = "postgresql";
4、配置中心数据加载配置
MapperManager.java 类中方法的修改
public <R extends Mapper> R findMapper(String dataSource, String tableName) {if (LOGGER.isDebugEnabled()) {LOGGER.debug("[MapperManager] findMapper dataSource: {}, tableName: {}", dataSource, tableName);}if (StringUtils.isBlank(dataSource) || StringUtils.isBlank(tableName)) {throw new NacosRuntimeException(FIND_DATASOURCE_ERROR_CODE, "dataSource or tableName is null");}Map<String, Mapper> mysql = MAPPER_SPI_MAP.get("mysql");MAPPER_SPI_MAP.put("postgresql", mysql);//添加pg数据库注册中心的表结构Map<String, Mapper> tableMapper = MAPPER_SPI_MAP.get(dataSource);if (Objects.isNull(tableMapper)) {throw new NacosRuntimeException(FIND_DATASOURCE_ERROR_CODE,"[MapperManager] Failed to find the datasource,dataSource:" + dataSource);}Mapper mapper = tableMapper.get(tableName);if (Objects.isNull(mapper)) {throw new NacosRuntimeException(FIND_TABLE_ERROR_CODE,"[MapperManager] Failed to find the table ,tableName:" + tableName);}if (dataSourceLogEnable) {return MapperProxy.createSingleProxy(mapper);}return (R) mapper;}5、所有limit ?,? 替换为 offset ? limit ? 以支持pg
WhereBuilder.java中修改：
public WhereBuilder limit(int startRow, int pageSize) {where.append(" OFFSET ").append(startRow).append(" LIMIT ")//注意要有空格.append(pageSize);return this;}
另外，修改mysql目录下的文件：
举例：ConfigInfoMapperByMySql.java
@Overridepublic MapperResult findConfigInfoByAppFetchRows(MapperContext context) {final String appName = (String) context.getWhereParameter(FieldConstant.APP_NAME);final String tenantId = (String) context.getWhereParameter(FieldConstant.TENANT_ID);String sql = "SELECT id,data_id,group_id,tenant_id,app_name,content FROM config_info"+ " WHERE tenant_id LIKE ? AND app_name= ?" + " OFFSET " + context.getStartRow() + " LIMIT "+ context.getPageSize();return new MapperResult(sql, CollectionUtils.list(tenantId, appName));}其他类依次修改完成即可。
注意： LIMIT 左右要有空格！
6、nacos 表结构导入pg
方案一：通过navicat 15以上版本，工具--数据传输，把mysql数据库中nacos的表结构和数据导入到pg库中：
成功之后，再pg库添加主键序列，比如：
CREATE SEQUENCE config_info_id_seq START WITH 1;
ALTER TABLE config_info ALTER COLUMN id SET DEFAULT nextval('config_info_id_seq');CREATE SEQUENCE config_info_aggr_id_seq START WITH 18;
ALTER TABLE config_info_aggr ALTER COLUMN id SET DEFAULT nextval('config_info_aggr_id_seq');CREATE SEQUENCE config_info_tag_id_seq START WITH 18;
ALTER TABLE config_info_tag ALTER COLUMN id SET DEFAULT nextval('config_info_tag_id_seq');CREATE SEQUENCE config_tags_relation_id_seq START WITH 18;
ALTER TABLE config_tags_relation ALTER COLUMN id SET DEFAULT nextval('config_tags_relation_id_seq');CREATE SEQUENCE group_capacity_id_seq START WITH 18;
ALTER TABLE group_capacity ALTER COLUMN id SET DEFAULT nextval('group_capacity_id_seq');CREATE SEQUENCE his_config_info_nid_seq START WITH 1;
ALTER TABLE his_config_info ALTER COLUMN id SET DEFAULT nextval('his_config_info_nid_seq');CREATE SEQUENCE permissions_id_seq START WITH 18;
ALTER TABLE permissions ALTER COLUMN id SET DEFAULT nextval('permissions_id_seq');CREATE SEQUENCE roles_id_seq START WITH 18;
ALTER TABLE roles ALTER COLUMN id SET DEFAULT nextval('roles_id_seq');CREATE SEQUENCE tenant_capacity_id_seq START WITH 18;
ALTER TABLE tenant_capacity ALTER COLUMN id SET DEFAULT nextval('tenant_capacity_id_seq');CREATE SEQUENCE tenant_info_id_seq START WITH 18;
ALTER TABLE tenant_info ALTER COLUMN id SET DEFAULT nextval('tenant_info_id_seq');数据不全，可以自行补充序列。
7、修改后的源码编译打包
mvn -Prelease-nacos clean install -U -DskipTests
打包成功
8、应用程序启动nacos
nacos-distribution 目录下找到 nacos-server-2.4.2.zip 文件
此包解压缩在win或者Linux环境 就可以启动了，比如在win环境启动：在bin目录下创建执行脚本
yd-startup.bat
startup.cmd -m standalone其实执行命令也行。 此时访问 http://localhost:8848/nacos/ 没有进入登录页面，即没有鉴权，不安全，如果需要鉴权关闭服务，修改配置。
9、开启鉴权配置
修改console和nacos-distribution模块中的application.properties配置文件
### If turn on auth system: 修改
nacos.core.auth.enabled=true### Turn on/off caching of auth information. By turning on this switch, the update of auth information would have a 15 seconds delay.
nacos.core.auth.caching.enabled=true### Since 1.4.1, Turn on/off white auth for user-agent: nacos-server, only for upgrade from old version. 修改
nacos.core.auth.enable.userAgentAuthWhite=true### Since 1.4.1, worked when nacos.core.auth.enabled=true and nacos.core.auth.enable.userAgentAuthWhite=false.
### The two properties is the white list for auth and used by identity the request from other server.修改
nacos.core.auth.server.identity.key=nacos
nacos.core.auth.server.identity.value=nacos### worked when nacos.core.auth.system.type=nacos
### The token expiration in seconds:
nacos.core.auth.plugin.nacos.token.cache.enable=false
nacos.core.auth.plugin.nacos.token.expire.seconds=18000
### The default token (Base64 string):放开
nacos.core.auth.plugin.nacos.token.secret.key=SecretKey012345678901234567890123678901234567890123456789
#nacos.core.auth.plugin.nacos.token.secret.key=然后再启动后就进入登录页面。
10、用户表结构修改
创建用户时失败：
原因是：代码里标识参数是bool类型，而数据库表结构里是int2类型，说明是数据表结构传输过程出错了，
修改方案sql：
ALTER TABLE users
ALTER COLUMN enabled
TYPE BOOLEAN
USING CASE WHEN enabled = 1 THEN TRUE ELSE FALSE
END;
到此，nacos源码修改持久化到postgreSQL数据库分享完成，当然持久到pg还有其他方案，后期可以分享nacos同时支持多种数据库，敬请期待！
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