菜鸟玩云计算之六：Ubuntu Server 12.10 上安装 nodejs, zeromq

Ubuntu Server 12.10 上安装 python, nodejs, zeromq

nodejs是一个基于google v8+javascript的服务端编程框架。对于搞云计算，用nj来做系统管理Web站点是非常合适的。理由是：

a.足够简单。
b.足够快。
c.足够小巧。
d.前后端一致性。

下面是安装步骤：

1 首先确保系统安装了python, gcc, g++，如果没有则安装：

$ sudo apt-get install python
$ sudo apt-get install build-essential
$ sudo apt-get install gcc
$ sudo apt-get install g++

2 安装 python bindings

2.1 安装python自动安装工具: easy_install

$ sudo apt-get install python-setuptools

2.2 安装python的编译环境

$ sudo apt-get install python-dev

2.3 安装 pythong zmq 的 binding:

$ sudo easy_install pyzmq

3 下载最新版源代码包：node-v0.8.14.tar.gz

3.1 解压:

$ sudo tar -zxf node-v0.8.14.tar.gz
$ cd node-v0.8.14

3.2 默认方式安装：

$ ./configure
$ make
$ sudo make install

3.3 选择目录方式安装：

$ ./configure --prefix=/opt/node
$ make -j 3     # 3=CPU核数+1
$ sudo make install

安装结束后, 用下面的命令检查安装的版本:
$ node --version
v0.8.14

3.4 接下来参考下面的文章开始你的nodejs编程之旅吧:

http://www.nodebeginner.org/index-zh-cn.html#a-full-blown-web-application-with-nodejs

4 zeromq

zmq 是一个基于c的消息队列编程框架。zeromq用处很多, 它具有：

a.足够简单。
b.足够快。
c.足够小巧。

等优点. 下面是安装步骤：

4.1 下载: zero-3.2.1

http://www.zeromq.org/

$ tar -xzf zeromq-3.2.1.tar.gz
$ ./configure
$ make
$ sudo make install
$ sudo ldconfig

4.2 下面写一个c的客户端mqclient.c和一个服务端mqserver.c测试:

 <span style="font-size:12px;">//
 // mqclient.c
 // Hello World client
 // Connects REQ socket to tcp://localhost:5555
 // Sends "Hello" to server, expects "World" back
 //
 #include <zmq.h>
 #include <string.h>
 #include <stdio.h>
 #include <unistd.h>

 int main (void)
 {
     void *context = zmq_ctx_new ();

     // Socket to talk to server
     printf ("Connecting to hello world server…\n");
     void *requester = zmq_socket (context, ZMQ_REQ);
     zmq_connect (requester, "tcp://localhost:5555");

     int request_nbr;
     for (request_nbr = 0; request_nbr != 10; request_nbr++) {
         zmq_msg_t request;

         zmq_msg_init_data (&request, "Hello", 6, 0, 0);

         printf ("Sending Hello %d…\n", request_nbr);
         zmq_msg_send (&request, requester, 0);
         zmq_msg_close (&request);
                 printf ("prepare recv message\n");

         zmq_msg_t reply;
         zmq_msg_init (&reply);
         if (-1==zmq_msg_recv (&reply, requester, 0)) {
             printf("recv data error.\n");
         }
         printf ("Received World %d\n", request_nbr);
         zmq_msg_close (&reply);
     }
     zmq_close (requester);
     zmq_ctx_destroy (context);
     return 0;
 }</span>

 <span style="font-size:12px;">//
 // mqserver.c
 // Hello World server
 // Binds REP socket to tcp://*:5555
 // Expects "Hello" from client, replies with "World"
 //
 #include <zmq.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>

 int main (void)
 {
     int ret;
     char buf[5]="world";
     buf[5] = 0;
     void *context = zmq_ctx_new ();

     // Socket to talk to clients
     void *responder = zmq_socket (context, ZMQ_REP);
     ret = zmq_bind (responder, "tcp://*:5555");
         if (ret==0) {
         printf("zmq_bind success\n");
     } else {
         printf("zmq_bind error=%d:%s\n", ret, strerror(errno));
         exit(ret);
         }
     while (1==1) {
         // Wait for next request from client
                 printf("wait for clients...\n");
         zmq_msg_t request;
         zmq_msg_init (&request);
         ret = zmq_msg_recv (&request, responder, 0);
         printf ("Received=%d\n", ret);
         zmq_msg_close (&request);

         // Do some 'work'
         sleep (1);

         // Send reply back to client
         zmq_msg_t reply;
         zmq_msg_init_data (&reply, buf, 6, 0, 0);
         ret = zmq_msg_send (&reply, responder, 0);
                 printf("zmq_msg_send ret=%d\n", ret);
         zmq_msg_close (&reply);
     }
     // We never get here but if we did, this would be how we end
     zmq_close (responder);
     zmq_ctx_destroy (context);
     return 0;
 }</span>

下面是编译命令:
$ gcc mqclient.c -o mqclnt -lzmq
$ gcc mqserver.c -o mqsrvr -lzmq

运行:
$ ./mqsrvr &

$ ./mqclnt

5 使用python来编写zeromq程序

参考:  http://zguide.zeromq.org/py:all

这是一个发布（PUB）和订阅（SUB）模型。发布者发布信息，订阅者接收并处理和自己相关的信息。一个发布者对应多个订阅者。

               |----->SUB a
PUB------>|----->SUB b
               |----->SUB c

5.1 发布者：mqpub.py

 <span style="font-size:12px;">#############################################################
 # mqpub.py
 # Weather update server
 # Binds PUB socket to tcp://*:5556
 # Publishes random weather updates
 #############################################################

 import zmq
 import random

 context = zmq.Context()
 socket = context.socket(zmq.PUB)
 socket.bind("tcp://*:5556")

 while True:
     zipcode = random.randrange(1,100000)
     temperature = random.randrange(1,215) - 80
     relhumidity = random.randrange(1,50) + 10

 socket.send("%d %d %d" % (zipcode, temperature, relhumidity))</span>

5.2 订阅者：mqsub.py

 <span style="font-size:12px;">#############################################################
 # mqsub.py
 # Weather update client
 # Connects SUB socket to tcp://localhost:5556
 # Collects weather updates and finds avg temp in zipcode
 #############################################################

 import sys
 import zmq

 # Socket to talk to server
 context = zmq.Context()
 socket = context.socket(zmq.SUB)

 print "Collecting updates from weather server"
 socket.connect ("tcp://localhost:5556")

 # Subscribe to zipcode, default is NYC, 10001
 zip_filter = sys.argv[1] if len(sys.argv) > 1 else "10001"
 socket.setsockopt(zmq.SUBSCRIBE, zip_filter)

 # Process 5 updates
 total_temp = 0
 for update_nbr in range (5):
     string = socket.recv()
     zipcode, temperature, relhumidity = string.split()
     total_temp += int(temperature)

 print "Average temperature for zipcode '%s' was %dF" % (zip_filter, total_temp / update_nbr)</span>

5.3 打开2个终端，分别运行：

$ python ./mqpub.py

$ python ./mqsub.py