使用CloudFormation创建Lambda
使用CloudFormation创建lambda有三种方式：
- inline。直接将lambda内容写到CloudFormation里。
- S3。 将lambda内容打包压缩，上传到S3。然后在CloudFormation里引用S3路径。
- S3 versoning。和上面相比，多了versioning这个选项，用于更新CloudFormation。
lambda inline
CloudFormation yaml:
Resources:
LambdaExecutionRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Action:
- sts:AssumeRole
Path: "/"
Policies:
- PolicyName: root
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action:
- "s3:*"
Resource: "*"
- Effect: Allow
Action:
- "logs:CreateLogGroup"
- "logs:CreateLogStream"
- "logs:PutLogEvents"
Resource: "*"
ListBucketsS3Lambda:
Type: "AWS::Lambda::Function"
Properties:
Handler: "index.handler"
Role:
Fn::GetAtt:
- "LambdaExecutionRole"
- "Arn"
Runtime: "python3.7"
Code:
ZipFile: |
import boto3
# Create an S3 client
s3 = boto3.client('s3')
def handler(event, context):
# Call S3 to list current buckets
response = s3.list_buckets()
# Get a list of all bucket names from the response
buckets = [bucket['Name'] for bucket in response['Buckets']]
# Print out the bucket list
print("Bucket List: %s" % buckets)
return buckets
创建完成后可以到lambda界面里找到它：
总结：
-
如果有依赖（例如依赖paromiko库），或者代码行数超过4000行，这种方式不适合。
-
这种方式适合简单的lambda。
通过S3
先建立一个桶和一个路径，用于上传打包后的lambda代码：
cloudformation代码如下(role的部分都一样，不同的是用S3指定代码位置)：
Parameters:
S3BucketParam:
Type: String
S3KeyParam:
Type: String
Resources:
LambdaExecutionRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Action:
- sts:AssumeRole
Path: "/"
Policies:
- PolicyName: root
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action:
- "s3:*"
Resource: "*"
- Effect: Allow
Action:
- "logs:CreateLogGroup"
- "logs:CreateLogStream"
- "logs:PutLogEvents"
Resource: "*"
ListBucketsS3Lambda:
Type: "AWS::Lambda::Function"
Properties:
Handler: "index.handler"
Role:
Fn::GetAtt:
- "LambdaExecutionRole"
- "Arn"
Runtime: "python3.7"
Code:
S3Bucket: !Ref S3BucketParam
S3Key: !Ref S3KeyParam
创建stack时，将S3的参数填写进去：
创建完成后的效果：
代码如果要更新，此时将代码打包上传到S3相同位置，再进行更新：
由于参数为S3 bucketname和S3 path，两次检测到相同值，不会进行更新：
一种解决方法是上传时起不同名字的zip，再将zip名称填写到cloudformation的参数中，但这种方法不太优雅。
lambda S3 Versioning
如果指定第三个变量versioning，每次更新并打包上传代码后，加上version id，cloudformation可以检测到变化，所以会进行更新:
Parameters:
S3BucketParam:
Type: String
S3KeyParam:
Type: String
S3ObjectVersionParam:
Type: String
Resources:
LambdaExecutionRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Action:
- sts:AssumeRole
Path: "/"
Policies:
- PolicyName: root
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Action:
- "s3:*"
Resource: "*"
- Effect: Allow
Action:
- "logs:CreateLogGroup"
- "logs:CreateLogStream"
- "logs:PutLogEvents"
Resource: "*"
ListBucketsS3Lambda:
Type: "AWS::Lambda::Function"
Properties:
Handler: "index.handler"
Role:
Fn::GetAtt:
- "LambdaExecutionRole"
- "Arn"
Runtime: "python3.7"
Code:
S3Bucket:
Ref: S3BucketParam
S3Key:
Ref: S3KeyParam
S3ObjectVersion:
Ref: S3ObjectVersionParam
在S3里重新上传新版本的代码。更新堆栈，填写version id：
此时可以更新成功。