Spring Boot Admin 集成自定义监控预警

前言
 
Spring Boot Admin 是一个社区项目，可以用来监控和管理 Spring Boot 应用并且提供 UI，详细可以参考 官方文档。
 
Spring Boot Admin 本身提供监控告警功能，但是默认只提供了 Hipchat、Slack 等国外流行的通讯软件的集成，虽然也有邮件通知，不过考虑到使用体检决定二次开发增加 钉钉 通知。
 
ASP站长网本文基于 Spring Boot Admin 目前最新版 1.5.7。
 
准备工作
1.Spring Boot Admin Server，参考文档 http://codecentric.github.io/spring-boot-admin/1.5.7/#getting-started
2.钉钉自定义机器人，参考文档 https://open-doc.dingtalk.com/docs/doc.htm?spm=a219a.7629140.0.0.64Ddtm&treeId=257&articleId=105735&docType=1
 
参考自带通知源码
 
由于官方文档上并没有增加自定义通知相关的文档，所以我们参考一下 Slack 通知源码 SlackNotifier.java。
 
源码比较长就不全部贴了，看一下关键部分：
public class SlackNotifier extends AbstractStatusChangeNotifier
protected void doNotify(ClientApplicationEvent event) throws Exception {
    this.restTemplate.postForEntity(this.webhookUrl, this.createMessage(event), Void.class);
}
 
可以看到流程还是比较简单的，继承 AbstractStatusChangeNotifier 类，实现了 doNotify 方法，当应用状态改变的时候会回调 doNotify 方法。
 
实现钉钉通知
 
DingTalkNotifier.java
public class DingTalkNotifier extends AbstractStatusChangeNotifier {
    private final SpelExpressionParser parser = new SpelExpressionParser();
    private RestTemplate restTemplate = new RestTemplate();
    private String webhookToken;
    private String atMobiles;
    private String msgtype = "markdown";
    private String title = "服务告警";
    private Expression message;
 
    public DingTalkNotifier() {
        this.message = this.parser.parseExpression("**#{application.name}** (#{application.id}) is **#{to.status}**", ParserContext.TEMPLATE_EXPRESSION);
    }
 
    @Override
    protected void doNotify(ClientApplicationEvent event) {
        this.restTemplate.postForEntity(this.webhookToken, this.createMessage(event), Void.class);
    }
 
    private HttpEntity<Map<String, Object>> createMessage(ClientApplicationEvent event) {
        Map<String, Object> messageJson = new HashMap<>();
        HashMap<String, String> params = new HashMap<>();
        params.put("text", this.getMessage(event));
        params.put("title", this.title);
        messageJson.put("dinggroup", this.dingGroup);
        messageJson.put("atMobiles", this.atMobiles);
        messageJson.put("msgtype", this.msgtype);
        messageJson.put(this.msgtype, params);
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
        return new HttpEntity<>(messageJson, headers);
    }
 
    private String getAtMobilesString(String s) {
        StringBuilder atMobiles = new StringBuilder();
        String[] mobiles = s.split(",");
        for (String mobile : mobiles) {
            atMobiles.append("@").append(mobile);
        }
        return atMobiles.toString();
    }
 
    private String getMessage(ClientApplicationEvent event) {
        return this.atMobiles == null ? this.message.getValue(event, String.class) : this.message.getValue(event, String.class) + "\n >" + this.getAtMobilesString(this.atMobiles);
    }
 
    public void setRestTemplate(RestTemplate restTemplate) {
        this.restTemplate = restTemplate;
    }
 
    public String getWebhookToken() {
        return webhookToken;
    }
 
    public void setWebhookToken(String webhookToken) {
        this.webhookToken = webhookToken;
    }
 
    public String getAtMobiles() {
        return atMobiles;
    }
 
    public void setAtMobiles(String atMobiles) {
        this.atMobiles = atMobiles;
    }
 
    public String getMsgtype() {
        return msgtype;
    }
 
    public void setMsgtype(String msgtype) {
        this.msgtype = msgtype;
    }
 
    public Expression getMessage() {
        return message;
    }
 
    public void setMessage(String message) {
        this.message = this.parser.parseExpression(message, ParserContext.TEMPLATE_EXPRESSION);
    }
 
    public String getTitle() {
        return title;
    }
 
    public void setTitle(String title) {
        this.title = title;
    }
}
 
代码逻辑也比较简单就不一一解释了。
 
增加钉钉通知自动配置
 
DingTalkNotifierConfiguration.java
@Configuration
@ConditionalOnProperty(
        prefix = "spring.boot.admin.notify.dingtalk",
        name = {"webhook-token"}
)
@AutoConfigureBefore({NotifierConfiguration.NotifierListenerConfiguration.class, NotifierConfiguration.CompositeNotifierConfiguration.class})
public class DingTalkNotifierConfiguration {
    public DingTalkNotifierConfiguration() {
    }
 
    @Bean
    @ConditionalOnMissingBean
    @ConfigurationProperties(prefix = "spring.boot.admin.notify.dingtalk")
    public DingTalkNotifier dingTalkNotifier() {
        return new DingTalkNotifier();
    }
 
}