Apache ServiceComb集成Apache CouchDB开发过程

Apache CouchDB概述

‌Apache CouchDB是一个‌开源的文档型数据库管理系统‌，专为现代Web应用设计。CouchDB以JSON文档为单位存储数据，这种数据结构非常适合表示复杂的数据关系‌。高可用性与可扩展性‌：即使在容易出现故障的硬件上，CouchDB也能提供高可用性和高可靠性，并且具有高度可伸缩性‌。

ServiceComb概述

Apache ServiceComb是一个实现Open API规范的RPC框架，提供了配置管理、服务发现、动态路由、可观察性和服务治理功能。

参考文档

• CouchDB官网：https://docs.couchdb.org/
• CouchDB API文档：https://docs.couchdb.org/en/stable/intro/api.html#databases
• ServiceComb官网：https://servicecomb.apache.org/
• DEMO演示地址：https://gitcode.com/weiwenman/opensource-demo-hibernate/overview?ref=couchdb
• 博客地址：https://bbs.huaweicloud.com/blogs/442100

开发过程

第一步：CCE部署Apache CouchDB,部署yaml如下

root@DESKTOP-7490:~/k8s# cat deploy-couchdb.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: couchdb
  labels:
    app: couchdb-pods
spec:
  replicas: 1
  selector:
    matchLabels:
      app: couchdb-pods
  template:
    metadata:
      name: couchdb-pod
      labels:
        app: couchdb-pods
    spec:
      containers:
        - name: couchdb-container
          image: apache/couchdb:latest
          imagePullPolicy: IfNotPresent
          env:
            - name: COUCHDB_USER
              value: admin
            - name: COUCHDB_PASSWORD
              value: admin
          ports:
          - containerPort: 5984
            protocol: TCP
          resources:
            requests:
              memory: "512Mi"
              cpu: "250m"
            limits:
              memory: "512Mi"
              cpu: "250m"
      restartPolicy: Always

---

apiVersion: v1
kind: Service
metadata:
  name: couchdb
spec:
  selector:
    app: couchdb-pods
  ports:
    - protocol: TCP
      port: 5984
      targetPort: 5984
  type: LoadBalancer

启动CouchDB之后可通过访问：http://ip:5984/_utils ,输入账号admin,密码admin访问couchDB控制台

第二步：修改配置文件

1. 下载ServiceComb代码，并修改pom.xml，增加org.ektorp依赖

        <dependency>
            <groupId>org.ektorp</groupId>
            <artifactId>org.ektorp</artifactId>
            <version>1.5.0</version>
        </dependency>

2. 修改application.yml,新增CouchDB连接配置

servicecomb:
  couchdb:
    uri: http://localhost:5984
    username: admin
    password: admin

3. 新增config

@Component
@ConfigurationProperties(prefix = "servicecomb.couchdb")
public class CouchDBConfig {
    private String uri;

    private String username;

    private String password;

第三步：代码开发

1. 创建doc和domain

public class ActorDoc {
    @JsonProperty("_id")
    private String id;

    @JsonProperty("_rev")
    private String rev;

    private Actor actor;
}

public class Actor {
    private String id;
    private String name;
    private String type;
}

2. 创建service

@Component
public class CouchDBService {
    @Autowired
    private CouchDBConfig config;

    public CouchDbConnector getConnector(String dbName) throws Exception {
        HttpClient client = new StdHttpClient.Builder()
                .url(config.getUri()).username(config.getUsername()).password(config.getPassword()).build();
        CouchDbInstance dbInstance = new StdCouchDbInstance(client);
        return new StdCouchDbConnector(dbName, dbInstance);
    }

    public CouchDBConfig getConfig() {
        return config;
    }

    public void setConfig(CouchDBConfig config) {
        this.config = config;
    }
}

3. 创建Api

@RestController
@RequestMapping("/actor")
public class CouchDBDemoApi {
    @Autowired
    private CouchDBService couchDBService;

    @GetMapping("/docs/{dbName}")
    public List<String> list(@PathVariable String dbName) throws Exception {
        return couchDBService.getConnector(dbName).getAllDocIds();
    }

    @GetMapping("/doc/{dbName}/{docId}")
    public ActorDoc listActor(@PathVariable String dbName, @PathVariable String docId) throws Exception {
        CouchDbConnector connector = couchDBService.getConnector(dbName);
        return connector.get(ActorDoc.class, docId);
    }

    @PostMapping("/doc/{dbName}")
    public ActorDoc addActor(@PathVariable String dbName, @RequestBody Actor actor) throws Exception {
        ActorDoc doc = new ActorDoc();
        doc.setActor(actor);
        CouchDbConnector connector = couchDBService.getConnector(dbName);
        connector.create(doc);
        return doc;
    }
}