Nacos源码启动

一、下载源码

为保证速度，国内推荐使用gitee：https://gitee.com/mirrors/Nacos.git

 二、导入IDE中

参考之前文章配置国内Maven私服，快速更新工程。

 三、启动过程，各种问题

找到启动入口：

先直接启动测试下：

 

Caused by: java.net.UnknownHostException: jmenv.tbsite.net
	at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:567)
	at java.base/java.net.Socket.connect(Socket.java:633)
	at java.base/sun.net.NetworkClient.doConnect(NetworkClient.java:178)
	at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:531)
	at java.base/sun.net.www.http.HttpClient.openServer(HttpClient.java:636)
	at java.base/sun.net.www.http.HttpClient.(HttpClient.java:279)
	at java.base/sun.net.www.http.HttpClient.New(HttpClient.java:384)
	at java.base/sun.net.www.http.HttpClient.New(HttpClient.java:406)
	at java.base/sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1309)
	at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1242)
	at java.base/sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1128)
	at java.base/sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:1057)
	at com.alibaba.nacos.common.http.client.request.JdkHttpClientRequest.execute(JdkHttpClientRequest.java:114)
	at com.alibaba.nacos.common.http.client.NacosRestTemplate.execute(NacosRestTemplate.java:482)
	at com.alibaba.nacos.common.http.client.NacosRestTemplate.get(NacosRestTemplate.java:72)
	at com.alibaba.nacos.core.cluster.lookup.AddressServerMemberLookup.syncFromAddressUrl(AddressServerMemberLookup.java:175)
	at com.alibaba.nacos.core.cluster.lookup.AddressServerMemberLookup.run(AddressServerMemberLookup.java:143)

报错：解析不了这个域名jmenv.tbsite.net。AddressServerMemberLookup这些关键类看着是以集群形式启动了。先配置成单机启动：

-Dnacos.standalone=true

在以下位置配置：

注意是nacos. 我看到其他文档此处介绍有错误。

 接下来打开application.properties中DB配置：

 执行初始化sql脚本：

 初始化后的表如下：

 给配置中心的表比较多。

启动报错如下：

Caused by: java.lang.IllegalArgumentException: The specified key byte array is 0 bits which is not secure enough for any JWT HMAC-SHA algorithm.  The JWT JWA Specification (RFC 7518, Section 3.2) states that keys used with HMAC-SHA algorithms MUST have a size >= 256 bits (the key size must be greater than or equal to the hash output size).  See https://tools.ietf.org/html/rfc7518#section-3.2 for more information.
	at com.alibaba.nacos.plugin.auth.impl.jwt.NacosJwtParser.(NacosJwtParser.java:56)
	at com.alibaba.nacos.plugin.auth.impl.token.impl.JwtTokenManager.processProperties(JwtTokenManager.java:71)
	... 111 common frames omitted

跟到代码里面发现有个key设置：

 属性是：public static final String TOKEN_SECRET_KEY = "nacos.core.auth.plugin.nacos.token.secret.key";

在application.properties中找到这个配置项，默认是""。设置一个大于256bit的值试试。

 此时再运行，报一个类找不到了，全是com.alibaba.nacos.consistency包下面的类，看了下源码里面确实没有？懵不懵！！

原因是com.alibaba.nacos.consistency.entity下面类是由protobuf在编译时自动生成。在eclipse下执行如下动作即可：

 还有另外个项目也需要执行Maven generate，nacos-istio。但再次不信，执行过程中报找不到nacos其他模块的依赖。一种解决办法是先注释掉，再执行生成，执行完后取消注释，成功了！

最后再次运行启动：

2023-02-23 20:49:21.827 INFO 8284 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8848 (http) with context path '/nacos'

2023-02-23 20:49:21.848 INFO 8284 --- [ main] c.a.n.c.l.StartingApplicationListener : Nacos started successfully in stand alone mode. use embedded storage

2023-02-23 20:49:47.535 INFO 8284 --- [nio-8848-exec-5] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'

2023-02-23 20:49:47.538 INFO 8284 --- [nio-8848-exec-5] o.s.web.servlet.DispatcherServlet : Completed initialization in 2 ms

访问http://127.0.0.1:8848/nacos/

成功进入控制台。