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:

[cpp] view
plaincopyprint?

<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>

[cpp] view
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<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

[python] view
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<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

[python] view
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<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