我想创建一个EC2 cloudformation堆栈，基本上可以按照以下步骤进行描述：
1.-启动实例
2.-提供实例
3.-停止实例并从中创建AMI图像
4.-创建一个自动缩放组，将创建的AMI图像作为源来启动新实例。
基本上我可以在一个cloudformation模板中执行1和2，在第二个模板中执行4。我似乎无法做的是从云信息模板中的实例创建AMI图像，如果我想删除堆栈，基本上会产生必须手动删除AMI的问题。
话虽如此，我的问题是：
1.-有没有办法从云形态模板中的实例创建AMI图像？
2.-如果1的答案为否，是否有办法添加AMI图像（或任何其他资源）以使其成为完整堆栈的一部分？
编辑：
为了澄清一下，我已经解决了创建AMI并在云信息模板中使用它的问题，我无法在云形态模板中创建AMI INSIDE或以某种方式将其添加到创建的堆栈中。
正如我对Rico的答案所评论的那样，我现在所做的是使用一个基本上有3个步骤的ansible playbook：
1.-使用云形态模板创建基本实例
2.-使用ansible创建在步骤1中创建的实例的AMI
3.-使用第二个云形式模板创建堆栈的其余部分（ELB，自动调节组等），该模板更新在步骤1中创建的模板，并使用在步骤2中创建的AMI来启动实例。
这就是我现在管理它的方式，但我想知道是否有任何方法可以创建AMI INSIDE一个云形态模板，或者是否可以将创建的AMI添加到堆栈中（类似于告诉堆栈，“嘿，这也属于你，所以处理它“）。
答案 0 :(得分：33)
是的，您可以在CloudFormation模板中的EC2实例中创建AMI，方法是实现在创建时调用Custom Resource API的CreateImage（并调用DeregisterImage和{{3删除时的API）。
由于AMI有时需要很长时间才能创建，因此如果在Lambda函数超时之前等待尚未完成，则Lambda支持的自定义资源将需要重新调用自身。
这是一个完整的例子：
Description: Create an AMI from an EC2 instance.
Parameters:
ImageId:
Description: Image ID for base EC2 instance.
Type: AWS::EC2::Image::Id
# amzn-ami-hvm-2016.09.1.20161221-x86_64-gp2
Default: ami-9be6f38c
InstanceType:
Description: Instance type to launch EC2 instances.
Type: String
Default: m3.medium
AllowedValues: [ m3.medium, m3.large, m3.xlarge, m3.2xlarge ]
Resources:
# Completes when the instance is fully provisioned and ready for AMI creation.
AMICreate:
Type: AWS::CloudFormation::WaitCondition
CreationPolicy:
ResourceSignal:
Timeout: PT10M
Instance:
Type: AWS::EC2::Instance
Properties:
ImageId: !Ref ImageId
InstanceType: !Ref InstanceType
UserData:
"Fn::Base64": !Sub |
#!/bin/bash -x
yum -y install mysql # provisioning example
/opt/aws/bin/cfn-signal \
-e $? \
--stack ${AWS::StackName} \
--region ${AWS::Region} \
--resource AMICreate
shutdown -h now
AMI:
Type: Custom::AMI
DependsOn: AMICreate
Properties:
ServiceToken: !GetAtt AMIFunction.Arn
InstanceId: !Ref Instance
AMIFunction:
Type: AWS::Lambda::Function
Properties:
Handler: index.handler
Role: !GetAtt LambdaExecutionRole.Arn
Code:
ZipFile: !Sub |
var response = require('cfn-response');
var AWS = require('aws-sdk');
exports.handler = function(event, context) {
console.log("Request received:\n", JSON.stringify(event));
var physicalId = event.PhysicalResourceId;
function success(data) {
return response.send(event, context, response.SUCCESS, data, physicalId);
}
function failed(e) {
return response.send(event, context, response.FAILED, e, physicalId);
}
// Call ec2.waitFor, continuing if not finished before Lambda function timeout.
function wait(waiter) {
console.log("Waiting: ", JSON.stringify(waiter));
event.waiter = waiter;
event.PhysicalResourceId = physicalId;
var request = ec2.waitFor(waiter.state, waiter.params);
setTimeout(()=>{
request.abort();
console.log("Timeout reached, continuing function. Params:\n", JSON.stringify(event));
var lambda = new AWS.Lambda();
lambda.invoke({
FunctionName: context.invokedFunctionArn,
InvocationType: 'Event',
Payload: JSON.stringify(event)
}).promise().then((data)=>context.done()).catch((err)=>context.fail(err));
}, context.getRemainingTimeInMillis() - 5000);
return request.promise().catch((err)=>
(err.code == 'RequestAbortedError') ?
new Promise(()=>context.done()) :
Promise.reject(err)
);
}
var ec2 = new AWS.EC2(),
instanceId = event.ResourceProperties.InstanceId;
if (event.waiter) {
wait(event.waiter).then((data)=>success({})).catch((err)=>failed(err));
} else if (event.RequestType == 'Create' || event.RequestType == 'Update') {
if (!instanceId) { failed('InstanceID required'); }
ec2.waitFor('instanceStopped', {InstanceIds: [instanceId]}).promise()
.then((data)=>
ec2.createImage({
InstanceId: instanceId,
Name: event.RequestId
}).promise()
).then((data)=>
wait({
state: 'imageAvailable',
params: {ImageIds: [physicalId = data.ImageId]}
})
).then((data)=>success({})).catch((err)=>failed(err));
} else if (event.RequestType == 'Delete') {
if (physicalId.indexOf('ami-') !== 0) { return success({});}
ec2.describeImages({ImageIds: [physicalId]}).promise()
.then((data)=>
(data.Images.length == 0) ? success({}) :
ec2.deregisterImage({ImageId: physicalId}).promise()
).then((data)=>
ec2.describeSnapshots({Filters: [{
Name: 'description',
Values: ["*" + physicalId + "*"]
}]}).promise()
).then((data)=>
(data.Snapshots.length === 0) ? success({}) :
ec2.deleteSnapshot({SnapshotId: data.Snapshots[0].SnapshotId}).promise()
).then((data)=>success({})).catch((err)=>failed(err));
}
};
Runtime: nodejs4.3
Timeout: 300
LambdaExecutionRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Principal: {Service: [lambda.amazonaws.com]}
Action: ['sts:AssumeRole']
Path: /
ManagedPolicyArns:
- arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
- arn:aws:iam::aws:policy/service-role/AWSLambdaRole
Policies:
- PolicyName: EC2Policy
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action:
- 'ec2:DescribeInstances'
- 'ec2:DescribeImages'
- 'ec2:CreateImage'
- 'ec2:DeregisterImage'
- 'ec2:DescribeSnapshots'
- 'ec2:DeleteSnapshot'
Resource: ['*']
Outputs:
AMI:
Value: !Ref AMI
答案 1 :(得分：5)
对于它的价值，这里是wjordan的AMIFunction定义in the original answer的Python变体。原始yaml中的所有其他资源保持不变：
AMIFunction:
Type: AWS::Lambda::Function
Properties:
Handler: index.handler
Role: !GetAtt LambdaExecutionRole.Arn
Code:
ZipFile: !Sub |
import logging
import cfnresponse
import json
import boto3
from threading import Timer
from botocore.exceptions import WaiterError
logger = logging.getLogger()
logger.setLevel(logging.INFO)
def handler(event, context):
ec2 = boto3.resource('ec2')
physicalId = event['PhysicalResourceId'] if 'PhysicalResourceId' in event else None
def success(data={}):
cfnresponse.send(event, context, cfnresponse.SUCCESS, data, physicalId)
def failed(e):
cfnresponse.send(event, context, cfnresponse.FAILED, str(e), physicalId)
logger.info('Request received: %s\n' % json.dumps(event))
try:
instanceId = event['ResourceProperties']['InstanceId']
if (not instanceId):
raise 'InstanceID required'
if not 'RequestType' in event:
success({'Data': 'Unhandled request type'})
return
if event['RequestType'] == 'Delete':
if (not physicalId.startswith('ami-')):
raise 'Unknown PhysicalId: %s' % physicalId
ec2client = boto3.client('ec2')
images = ec2client.describe_images(ImageIds=[physicalId])
for image in images['Images']:
ec2.Image(image['ImageId']).deregister()
snapshots = ([bdm['Ebs']['SnapshotId']
for bdm in image['BlockDeviceMappings']
if 'Ebs' in bdm and 'SnapshotId' in bdm['Ebs']])
for snapshot in snapshots:
ec2.Snapshot(snapshot).delete()
success({'Data': 'OK'})
elif event['RequestType'] in set(['Create', 'Update']):
if not physicalId: # AMI creation has not been requested yet
instance = ec2.Instance(instanceId)
instance.wait_until_stopped()
image = instance.create_image(Name="Automatic from CloudFormation stack ${AWS::StackName}")
physicalId = image.image_id
else:
logger.info('Continuing in awaiting image available: %s\n' % physicalId)
ec2client = boto3.client('ec2')
waiter = ec2client.get_waiter('image_available')
try:
waiter.wait(ImageIds=[physicalId], WaiterConfig={'Delay': 30, 'MaxAttempts': 6})
except WaiterError as e:
# Request the same event but set PhysicalResourceId so that the AMI is not created again
event['PhysicalResourceId'] = physicalId
logger.info('Timeout reached, continuing function: %s\n' % json.dumps(event))
lambda_client = boto3.client('lambda')
lambda_client.invoke(FunctionName=context.invoked_function_arn,
InvocationType='Event',
Payload=json.dumps(event))
return
success({'Data': 'OK'})
else:
success({'Data': 'OK'})
except Exception as e:
failed(e)
Runtime: python2.7
Timeout: 300
答案 2 :(得分：2)
为什么不在最初的云形态之外创建AMI，然后在最终的云形态模板中使用AMI？
另一种选择是编写一些自动化来创建两个云形成堆栈，一旦你创建的AMI完成，你就可以删除第一个。
答案 3 :(得分：1)
虽然@ wjdordan的解决方案适用于简单的用例，但更新用户数据不会更新AMI。
（免责声明：我是原作者）cloudformation-ami旨在允许您在CloudFormation中声明可以可靠地创建，更新和删除的AMI。使用cloudformation-ami您可以声明这样的自定义AMI：
MyAMI:
Type: Custom::AMI
Properties:
ServiceToken: !ImportValue AMILambdaFunctionArn
Image:
Name: my-image
Description: some description for the image
TemplateInstance:
ImageId: ami-467ca739
IamInstanceProfile:
Arn: arn:aws:iam::1234567890:instance-profile/MyProfile-ASDNSDLKJ
UserData:
Fn::Base64: !Sub |
#!/bin/bash -x
yum -y install mysql # provisioning example
# Signal that the instance is ready
INSTANCE_ID=`wget -q -O - http://169.254.169.254/latest/meta-data/instance-id`
aws ec2 create-tags --resources $INSTANCE_ID --tags Key=UserDataFinished,Value=true --region ${AWS::Region}
KeyName: my-key
InstanceType: t2.nano
SecurityGroupIds:
- sg-d7bf78b0
SubnetId: subnet-ba03aa91
BlockDeviceMappings:
- DeviceName: "/dev/xvda"
Ebs:
VolumeSize: '10'
VolumeType: gp2