可以通过实现一个自定义资源在CloudFormation模板中调用CreateImage API（并在删除时调用DeregisterImage和DeleteSnapshotAPI）来从EC2实例创建AMI。
由于AMI有时需要很长时间才能创建完成，因此Lambda支持的自定义资源将需要在Lambda函数超时之前重新调用自身，以等待完成。
这里是一个完整的示例：
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);
}
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
PhysicalResourceId在ec2.createImage操作完成后设置为返回的ImageId，所有有效的镜像 ID 都以ami-前缀开头。当物理 ID 设置为有效的 Image ID 时，physicalId.indexOf('ami-')将等于0，这意味着在删除资源时需要删除该镜像（通过ec2.deregisterImage）。如果在删除资源之前从未将物理资源设置为有效的 Image ID，则可以跳过deregisterImage操作。 - wjordannodejs18.x。 - undefined