在 Docker 官网查阅 API 调用方式
例如:查询正在运行的容器列表,HTTP 方式如下:
$ curl --unix-socket /var/run/docker.sock http:/v1.24/containers/json
[{
"Id":"ae63e8b89a26f01f6b4b2c9a7817c31a1b6196acf560f66586fbc8809ffcd772",
"Names":["/tender_wing"],
"Image":"bfirsh/reticulate-splines",
...
}]
分析 API 请求的过程
在本机执行如下命令
curl -v --unix-socket /var/run/docker.sock http:/v1.24/containers/json
Java 模拟调用 API 的代码实现
1、引入 UnixSocket 工具包
<dependency>
<groupId>com.github.jnr</groupId>
<artifactId>jnr-unixsocket</artifactId>
<version>0.18</version>
</dependency>
2、测试代码
public static void main(String[] args) {
// 建立 Unix Socket 连接
File sockFile = new File("/var/run/docker.sock");
UnixSocketAddress address = new UnixSocketAddress(sockFile);
UnixSocketChannel channel = UnixSocketChannel.open(address);
UnixSocket unixSocket = new UnixSocket(channel);
// 调用 Docker API
PrintWriter w = new PrintWriter(unixSocket.getOutputStream());
w.println("GET /v1.24/containers/json HTTP/1.1");
w.println("Host: http");
w.println("Accept: */*");
w.println("");
w.flush();
// 关闭 Output,否则会导致下面的 read 操作一直阻塞
unixSocket.shutdownOutput();
// 获取返回结果
System.out.println("---- Docker Response ----");
BufferedReader br = new BufferedReader(new InputStreamReader(unixSocket.getInputStream()));
String line;
while ((line = br.readLine()) != null){
System.out.println(line);
}
unixSocket.close();
}