aws(学习笔记第二课) AWS SDK（node js）

aws(学习笔记第二课)

使用AWS SDK（node js）

学习内容：

使用AWS SDK（node js）

1. `AWS SDK（node js）`

AWS支持多种SDK开发(除了AWS CLI，还支持其他的SDK)
- Android
- Python
- Node.js(Javascript)
- Java
- Browsers(Javascript)
- Ruby
- PHP
- .NET
- IOS
- Go

使用Node.js来控制AWS

安装Node.js
这是前提条件，这里采用windows + git bash的方式练习，首先安装Node.js
Node.js的程序结构
index.js
这个是main程序入口，定义了以下的功能
- listServer(list servers 展示所有的ec2 server列表)
- listAMIs.js(create server 创建ec2 server)
- listServers.js( terminate server 终止ec2 server)
\lib下的各个*.js
- createServer.js 创建ec2 server
  注意，这里的KeyName一定要和前面设定的密钥对名字一致。
- listAMIs.js 列出全部可用ami
- listServers.js 列出全部可用ec2 server
- listSubnets.js 列出全部可用subnet
- showServer.js 列出所有创建的ec2 server
- terminateServer.js 终止列出的ec2 server

index.js以及各个lib/*.js

index.js

var blessed = require('blessed');

var screen = blessed.screen({
	autoPadding: true,
	smartCSR: true,
	log: "./nodecc.log"
});

screen.title = 'Node Control Center for AWS';

var content = blessed.box({  
	parent: screen,
	width: '70%',
	height: '90%',
	top: '10%',
	left: '30%',
	border: {
		type: 'none',
		fg: '#ffffff'
	},
	fg: 'white',
	bg: 'blue',
	content: '{bold}Node Control Center for AWS{/bold}\n\nPlease select one of the actions from the left and press return.\n\nYou can always go back with the left arrow key.\n\nYou can terminate the application by pressing ESC or q.',
	tags: true
});

var progress = blessed.progressbar({
	parent: screen,
	width: '70%',
	height: '10%',
	top: '0%',
	left: '30%',
	orientation: 'horizontal',
	border: {
		type: 'line',
		fg: '#ffffff'
	},
	fg: 'white',
	bg: 'blue',
	barFg: 'green',
	barBg: 'green',
	filled: 0
});

var list = blessed.list({  
	parent: screen,
	width: '30%',
	height: '100%',
	top: '0%',
	left: '0%',
	border: {
		type: 'line',
		fg: '#ffffff'
	},
	fg: 'white',
	bg: 'blue',
	selectedBg: 'green',
	mouse: true,
	keys: true,
	vi: true,
	label: 'actions',
	items: ['list servers', 'create server', 'terminate server']
});
list.on('select', function(ev, i) {
	content.border.type = 'line';
	content.focus();
	list.border.type = 'none';
	open(i);
	screen.render(); 
});
list.focus();

function open(i) {
	screen.log('open(' + i + ')');
	if (i === 0) {
		loading();
		require('./lib/listServers.js')(function(err, instanceIds) {
			loaded();
			if (err) {
				log('error', 'listServers cb err: ' + err);
			} else {
				var instanceList = blessed.list({
					fg: 'white',
					bg: 'blue',
					selectedBg: 'green',
					mouse: true,
					keys: true,
					vi: true,
					items: instanceIds
				});
				content.append(instanceList);
				instanceList.focus();
				instanceList.on('select', function(ev, i) {
					loading();
					require('./lib/showServer.js')(instanceIds[i], function(err, instance) {
						loaded();
						if (err) {
							log('error', 'showServer cb err: ' + err);
						} else {
							var serverContent = blessed.box({  
								fg: 'white',
								bg: 'blue',
								content:
									'InstanceId: ' + instance.InstanceId + '\n' +
									'InstanceType: ' + instance.InstanceType + '\n' +
									'LaunchTime: ' + instance.LaunchTime + '\n' +
									'ImageId: ' + instance.ImageId + '\n' +
									'PublicDnsName: ' + instance.PublicDnsName
							});
							content.append(serverContent);
						}
						screen.render(); 
					});
				});
				screen.render(); 
			}
			screen.render(); 
		});
	} else if (i === 1) {
		loading();
		require('./lib/listAMIs.js')(function(err, result) {
			loaded();
			if (err) {
				log('error', 'listAMIs cb err: ' + err);
			} else {
				var amiList = blessed.list({
					fg: 'white',
					bg: 'blue',
					selectedBg: 'green',
					mouse: true,
					keys: true,
					vi: true,
					items: result.descriptions
				});
				content.append(amiList);
				amiList.focus();
				amiList.on('select', function(ev, i) {
					var amiId = result.amiIds[i];
					loading();
					require('./lib/listSubnets.js')(function(err, subnetIds) {
						loaded();
						if (err) {
							log('error', 'listSubnets cb err: ' + err);
						} else {
							var subnetList = blessed.list({
								fg: 'white',
								bg: 'blue',
								selectedBg: 'green',
								mouse: true,
								keys: true,
								vi: true,
								items: subnetIds
							});
							content.append(subnetList);
							subnetList.focus();
							subnetList.on('select', function(ev, i) {
								loading();
								require('./lib/createServer.js')(amiId, subnetIds[i], function(err) {
									loaded();
									if (err) {
										log('error', 'createServer cb err: ' + err);
									} else {
										var serverContent = blessed.box({  
											fg: 'white',
											bg: 'blue',
											content: 'starting ...'
										});
										content.append(serverContent);
									}
									screen.render(); 
								});
							});
							screen.render(); 
						}
						screen.render(); 
					});
				});
				screen.render(); 
			}
			screen.render(); 
		});
	} else if (i === 2) {
		loading();
		require('./lib/listServers.js')(function(err, instanceIds) {
			loaded();
			if (err) {
				log('error', 'listServers cb err: ' + err);
			} else {
				var instanceList = blessed.list({
					fg: 'white',
					bg: 'blue',
					selectedBg: 'green',
					mouse: true,
					keys: true,
					vi: true,
					items: instanceIds
				});
				content.append(instanceList);
				instanceList.focus();
				instanceList.on('select', function(ev, i) {
					loading();
					require('./lib/terminateServer.js')(instanceIds[i], function(err) {
						loaded();
						if (err) {
							log('error', 'terminateServer cb err: ' + err);
						} else {
							var serverContent = blessed.box({  
								fg: 'white',
								bg: 'blue',
								content: 'terminating ...'
							});
							content.append(serverContent);
						}
						screen.render(); 
					});
				});
				screen.render(); 
			}
			screen.render(); 
		});
	} else {
		log('error', 'not supported');
		screen.render(); 
	}
}

screen.key('left', function(ch, key) {  
	content.border.type = 'none';
	content.children.slice().forEach(function(child) {
		content.remove(child);
	});
	list.border.type = 'line';
	list.focus();
	screen.render(); 
});

screen.key(['escape', 'q', 'C-c'], function(ch, key) { 
	return process.exit(0);
});

var loadingInterval;

function loading() {
	progress.reset();
	clearInterval(loadingInterval);
	loadingInterval = setInterval(function() {
		if (progress.filled < 75) {
			progress.progress(progress.filled + 5);
		}
		screen.render(); 
	}, 200);
}

function loaded() {
	clearInterval(loadingInterval);
	progress.progress(100);
	screen.render(); 
}

function log(level, message) {
	screen.log('[' + level + ']: ' + message);
}

screen.render();

/lib/createServer.js

var AWS = require('aws-sdk');
var ec2 = new AWS.EC2({
	"region": "ap-northeast-1"
});

module.exports = function(amiId, subnetId, cb) {
	ec2.runInstances({
		"ImageId": amiId,
		"MinCount": 1,
		"MaxCount": 1,
		"KeyName": "my-cli-key",
		"InstanceType": "t2.micro",
		"SubnetId": subnetId
	}, function(err) {
		if (err) {
			cb(err);
		} else {
			cb(null);
		}
	});
};

/lib/listAMIs.js

var jmespath = require('jmespath');
var AWS = require('aws-sdk');
var ec2 = new AWS.EC2({
	"region": "ap-northeast-1"
});

module.exports = function(cb) {
	ec2.describeImages({
		"Filters": [{
			"Name": "description",
			"Values": ["Amazon Linux AMI *"]
		}]
	}, function(err, data) {
		if (err) {
			cb(err);
		} else {
			var amiIds = jmespath.search(data, 'Images[*].ImageId');
			var descriptions = jmespath.search(data, 'Images[*].Description');
			cb(null, {"amiIds": amiIds, "descriptions": descriptions});
		}
	});
};

/lib/listServers.js

var jmespath = require('jmespath');
var AWS = require('aws-sdk');
var ec2 = new AWS.EC2({
	"region": "ap-northeast-1"
});

module.exports = function(cb) {
	ec2.describeInstances({
		"Filters": [{
			"Name": "instance-state-name",
			"Values": ["pending", "running"]
		}],
		"MaxResults": 10
	}, function(err, data) {
		if (err) {
			cb(err);
		} else {
			var instanceIds = jmespath.search(data, 'Reservations[].Instances[].InstanceId');
			cb(null, instanceIds);
		}
	});
};

/lib/listSubnets.js 注意，这里默认的vpc

var jmespath = require('jmespath');
var AWS = require('aws-sdk');
var ec2 = new AWS.EC2({
	"region": "ap-northeast-1"
});

module.exports = function(cb) {
	ec2.describeVpcs({
		"Filters": [{
			"Name": "isDefault",
			"Values": ["true"]
		}]
	}, function(err, data) {
		if (err) {
			cb(err);
		} else {
			var vpcId = data.Vpcs[0].VpcId;
			ec2.describeSubnets({
				"Filters": [{
					"Name": "vpc-id",
					"Values": [vpcId]
				}]
			}, function(err, data) {
				if (err) {
					cb(err);
				} else {
					var subnetIds = jmespath.search(data, 'Subnets[*].SubnetId');
					cb(null, subnetIds);
				}
			});
		}
	});
};

/lib/showServer.js

var AWS = require('aws-sdk');
var ec2 = new AWS.EC2({
	"region": "ap-northeast-1"
});

module.exports = function(instanceId, cb) {
	ec2.describeInstances({
		"InstanceIds": [instanceId]
	}, function(err, data) {
		if (err) {
			cb(err);
		} else {
			cb(null, data.Reservations[0].Instances[0]);
		}
	});
};

/lib/terminateServer.js

var AWS = require('aws-sdk');
var ec2 = new AWS.EC2({
	"region": "ap-northeast-1"
});

module.exports = function(instanceId, cb) {
	ec2.terminateInstances({
		"InstanceIds": [instanceId]
	}, function(err) {
		if (err) {
			cb(err);
		} else {
			cb(null);
		}
	});
};

启动Node.js的AWS SDK的应用程序nodecc press escape key to exit
```
npm install
node index.js
```

使用应用程序nodecc控制AWS
- 启动主程序，创建ec2 server
  create server-> 选择Amazon Linux AMI 2018.03.0.20230322.0这个ami。注意，这里的InstanceType: t2micro,会导致一些ami会创建ec2 server失败。
- 进入主菜单(left key to return main menu in the left)，进入list servers。
- 选择subnet
  这里存在唯一default subnet，因此就显示一个subnet。
- 创建了ec2 server之后，进入list server进行检查
  注意，可以在create server的同时，执行tail -f nodecc.log，因为可能有些原因，导致create server失败
- 进入AWS Console进行检查
- 登录创建的ec2 server
- 及时终止创建的ec2 server
  练习完毕，利用terminate server进行ec2 server的终止，以免发生费用。