Serverless APIGateway Service Proxy
This Serverless Framework plugin supports the AWS service proxy integration feature of API Gateway. You can directly connect API Gateway to AWS services without Lambda.
TOC
Install
Run serverless plugin install
in your Serverless project.
serverless plugin install -n serverless-apigateway-service-proxy
Supported AWS services
Here is a services list which this plugin supports for now. But will expand to other services in the feature.
Please pull request if you are intersted in it.
- Kinesis Streams
- SQS
- S3
- SNS
- DynamoDB
- EventBridge
How to use
Define settings of the AWS services you want to integrate under custom > apiGatewayServiceProxies
and run serverless deploy
.
Kinesis
Sample syntax for Kinesis proxy in serverless.yml
.
custom:
apiGatewayServiceProxies:
- kinesis:
path: /kinesis
method: post
streamName: { Ref: 'YourStream' }
cors: true
- kinesis:
path: /kinesis
method: post
partitionKey: 'hardcordedkey'
streamName: { Ref: 'YourStream' }
cors: true
- kinesis:
path: /kinesis/{myKey}
method: post
partitionKey:
pathParam: myKey
streamName: { Ref: 'YourStream' }
cors: true
- kinesis:
path: /kinesis
method: post
partitionKey:
bodyParam: data.myKey
streamName: { Ref: 'YourStream' }
cors: true
- kinesis:
path: /kinesis
method: post
partitionKey:
queryStringParam: myKey
streamName: { Ref: 'YourStream' }
cors: true
- kinesis:
path: /kinesis
method: post
action: PutRecords
streamName: { Ref: 'YourStream' }
cors: true
resources:
Resources:
YourStream:
Type: AWS::Kinesis::Stream
Properties:
ShardCount: 1
Sample request after deploying.
curl https://xxxxxxx.execute-api.us-east-1.amazonaws.com/dev/kinesis -d '{"message": "some data"}' -H 'Content-Type:application/json'
SQS
Sample syntax for SQS proxy in serverless.yml
.
custom:
apiGatewayServiceProxies:
- sqs:
path: /sqs
method: post
queueName: { 'Fn::GetAtt': ['SQSQueue', 'QueueName'] }
cors: true
resources:
Resources:
SQSQueue:
Type: 'AWS::SQS::Queue'
Sample request after deploying.
curl https://xxxxxx.execute-api.us-east-1.amazonaws.com/dev/sqs -d '{"message": "testtest"}' -H 'Content-Type:application/json'
Customizing request parameters
If you'd like to pass additional data to the integration request, you can do so by including your custom API Gateway request parameters in serverless.yml
like so:
custom:
apiGatewayServiceProxies:
- sqs:
path: /queue
method: post
queueName: !GetAtt MyQueue.QueueName
cors: true
requestParameters:
'integration.request.querystring.MessageAttribute.1.Name': "'cognitoIdentityId'"
'integration.request.querystring.MessageAttribute.1.Value.StringValue': 'context.identity.cognitoIdentityId'
'integration.request.querystring.MessageAttribute.1.Value.DataType': "'String'"
'integration.request.querystring.MessageAttribute.2.Name': "'cognitoAuthenticationProvider'"
'integration.request.querystring.MessageAttribute.2.Value.StringValue': 'context.identity.cognitoAuthenticationProvider'
'integration.request.querystring.MessageAttribute.2.Value.DataType': "'String'"
The alternative way to pass MessageAttribute
parameters is via a request body mapping template.
Customizing request body mapping templates
See the SQS section under Customizing request body mapping templates
Customizing responses
Simplified response template customization
You can get a simple customization of the responses by providing a template for the possible responses. The template is assumed to be application/json
.
custom:
apiGatewayServiceProxies:
- sqs:
path: /queue
method: post
queueName: !GetAtt MyQueue.QueueName
cors: true
response:
template:
success: |-
{ "message: "accepted" }
clientError: |-
{ "message": "there is an error in your request" }
serverError: |-
{ "message": "there was an error handling your request" }
Full response customization
If you want more control over the integration response, you can
provide an array of objects for the response
value:
custom:
apiGatewayServiceProxies:
- sqs:
path: /queue
method: post
queueName: !GetAtt MyQueue.QueueName
cors: true
response:
- statusCode: 200
selectionPattern: '2\\d{2}'
responseParameters: {}
responseTemplates:
application/json: |-
{ "message": "accepted" }
The object keys correspond to the API Gateway integration response object.
S3
Sample syntax for S3 proxy in serverless.yml
.
custom:
apiGatewayServiceProxies:
- s3:
path: /s3
method: post
action: PutObject
bucket:
Ref: S3Bucket
key: static-key.json
cors: true
- s3:
path: /s3/{myKey}
method: get
action: GetObject
bucket:
Ref: S3Bucket
key:
pathParam: myKey
cors: true
- s3:
path: /s3
method: delete
action: DeleteObject
bucket:
Ref: S3Bucket
key:
queryStringParam: key
cors: true
resources:
Resources:
S3Bucket:
Type: 'AWS::S3::Bucket'
Sample request after deploying.
curl https://xxxxxx.execute-api.us-east-1.amazonaws.com/dev/s3 -d '{"message": "testtest"}' -H 'Content-Type:application/json'
Customizing request parameters
Similar to the SQS support, you can customize the default request parameters serverless.yml
like so:
custom:
apiGatewayServiceProxies:
- s3:
path: /s3
method: post
action: PutObject
bucket:
Ref: S3Bucket
cors: true
requestParameters:
'integration.request.path.object': 'context.requestId'
'integration.request.header.cache-control': "'public, max-age=31536000, immutable'"
Customizing request templates
If you'd like use custom API Gateway request templates, you can do so like so:
custom:
apiGatewayServiceProxies:
- s3:
path: /s3
method: get
action: GetObject
bucket:
Ref: S3Bucket
request:
template:
application/json: |
#set ($specialStuff = $context.request.header.x-special)
#set ($context.requestOverride.path.object = $specialStuff.replaceAll('_', '-'))
{}
Note that if the client does not provide a Content-Type
header in the request, ApiGateway defaults to application/json
.
Customize the Path Override in API Gateway
Added the new customization parameter that lets the user set a custom Path Override in API Gateway other than the {bucket}/{object}
This parameter is optional and if not set, will fall back to {bucket}/{object}
The Path Override will add {bucket}/
automatically in front
Please keep in mind, that key or path.object still needs to be set at the moment (maybe this will be made optional later on with this)
Usage (With 2 Path Parameters (folder and file and a fixed file extension)):
custom:
apiGatewayServiceProxies:
- s3:
path: /s3/{folder}/{file}
method: get
action: GetObject
pathOverride: '{folder}/{file}.xml'
bucket:
Ref: S3Bucket
cors: true
requestParameters:
'integration.request.path.folder': 'method.request.path.folder'
'integration.request.path.file': 'method.request.path.file'
'integration.request.path.object': 'context.requestId'
'integration.request.header.cache-control': "'public, max-age=31536000, immutable'"
This will result in API Gateway setting the Path Override attribute to {bucket}/{folder}/{file}.xml
So for example if you navigate to the API Gatway endpoint /language/en
it will fetch the file in S3 from {bucket}/language/en.xml
Can use greedy, for deeper Folders
The forementioned example can also be shortened by a greedy approach. Thanks to @taylorreece for mentioning this.
custom:
apiGatewayServiceProxies:
- s3:
path: /s3/{myPath+}
method: get
action: GetObject
pathOverride: '{myPath}.xml'
bucket:
Ref: S3Bucket
cors: true
requestParameters:
'integration.request.path.myPath': 'method.request.path.myPath'
'integration.request.path.object': 'context.requestId'
'integration.request.header.cache-control': "'public, max-age=31536000, immutable'"
This will translate for example /s3/a/b/c
to a/b/c.xml
Customizing responses
You can get a simple customization of the responses by providing a template for the possible responses. The template is assumed to be application/json
.
custom:
apiGatewayServiceProxies:
- s3:
path: /s3
method: post
action: PutObject
bucket:
Ref: S3Bucket
key: static-key.json
response:
template:
success: |-
{ "message: "accepted" }
clientError: |-
{ "message": "there is an error in your request" }
serverError: |-
{ "message": "there was an error handling your request" }
Allow Binary Type
In order to allow the browser to recognize binary type (e.g. images), add the following.
This would impact Rest API settings which is called by our plugin
provider:
apiGateway:
binaryMediaTypes: "*/*"
SNS
Sample syntax for SNS proxy in serverless.yml
.
custom:
apiGatewayServiceProxies:
- sns:
path: /sns
method: post
topicName: { 'Fn::GetAtt': ['SNSTopic', 'TopicName'] }
cors: true
resources:
Resources:
SNSTopic:
Type: AWS::SNS::Topic
Sample request after deploying.
curl https://xxxxxx.execute-api.us-east-1.amazonaws.com/dev/sns -d '{"message": "testtest"}' -H 'Content-Type:application/json'
Customizing responses
Simplified response template customization
You can get a simple customization of the responses by providing a template for the possible responses. The template is assumed to be application/json
.
custom:
apiGatewayServiceProxies:
- sns:
path: /sns
method: post
topicName: { 'Fn::GetAtt': ['SNSTopic', 'TopicName'] }
cors: true
response:
template:
success: |-
{ "message": "accepted" }
clientError: |-
{ "message": "there is an error in your request" }
serverError: |-
{ "message": "there was an error handling your request" }
Full response customization
If you want more control over the integration response, you can
provide an array of objects for the response
value:
custom:
apiGatewayServiceProxies:
- sns:
path: /sns
method: post
topicName: { 'Fn::GetAtt': ['SNSTopic', 'TopicName'] }
cors: true
response:
- statusCode: 200
selectionPattern: '2\d{2}'
responseParameters: {}
responseTemplates:
application/json: |-
{ "message": "accepted" }
The object keys correspond to the API Gateway integration response object.
Content Handling and Pass Through Behaviour customization
If you want to work with binary fata, you can not specify contentHandling
and PassThrough
inside the request
object.
custom:
apiGatewayServiceProxies:
- sns:
path: /sns
method: post
topicName: { 'Fn::GetAtt': ['SNSTopic', 'TopicName'] }
request:
contentHandling: CONVERT_TO_TEXT
passThrough: WHEN_NO_TEMPLATES
The allowed values correspond with the API Gateway Method integration for ContentHandling and PassthroughBehavior
DynamoDB
Sample syntax for DynamoDB proxy in serverless.yml
. Currently, the supported DynamoDB Operations are PutItem
, GetItem
and DeleteItem
.
custom:
apiGatewayServiceProxies:
- dynamodb:
path: /dynamodb/{id}/{sort}
method: put
tableName: { Ref: 'YourTable' }
hashKey:
pathParam: id
attributeType: S
rangeKey:
pathParam: sort
attributeType: S
action: PutItem
condition: attribute_not_exists(Id)
cors: true
- dynamodb:
path: /dynamodb
method: get
tableName: { Ref: 'YourTable' }
hashKey:
queryStringParam: id
attributeType: S
rangeKey:
queryStringParam: sort
attributeType: S
action: GetItem
cors: true
- dynamodb:
path: /dynamodb/{id}
method: delete
tableName: { Ref: 'YourTable' }
hashKey:
pathParam: id
attributeType: S
action: DeleteItem
cors: true
resources:
Resources:
YourTable:
Type: AWS::DynamoDB::Table
Properties:
TableName: YourTable
AttributeDefinitions:
- AttributeName: id
AttributeType: S
- AttributeName: sort
AttributeType: S
KeySchema:
- AttributeName: id
KeyType: HASH
- AttributeName: sort
KeyType: RANGE
ProvisionedThroughput:
ReadCapacityUnits: 1
WriteCapacityUnits: 1
Sample request after deploying.
curl -XPUT https://xxxxxxx.execute-api.us-east-1.amazonaws.com/dev/dynamodb/<hashKey>/<sortkey> \
-d '{"name":{"S":"john"},"address":{"S":"xxxxx"}}' \
-H 'Content-Type:application/json'
Customizing responses
Simplified response template customization
You can get a simple customization of the responses by providing a template for the possible responses. The template returns the same kind of response for both application/json
and application/x-www-form-urlendcoded
.
custom:
apiGatewayServiceProxies:
- dynamodb:
path: /dynamodb
method: get
tableName: { Ref: 'YourTable' }
hashKey:
queryStringParam: id
attributeType: S
rangeKey:
queryStringParam: sort
attributeType: S
action: GetItem
cors: true
response:
template:
success: |-
#set($item = $input.path('$.Item')){ "Item": $item }
clientError: |-
{ "message": "there is an error in your request" }
serverError: |-
{ "message": "there was an error handling your request" }
Full response customization
If you want more control over the integration response, you can
provide an array of objects for the response
value:
custom:
apiGatewayServiceProxies:
- dynamodb:
path: /dynamodb
method: get
tableName: { Ref: 'YourTable' }
hashKey:
queryStringParam: id
attributeType: S
rangeKey:
queryStringParam: sort
attributeType: S
action: GetItem
cors: true
response:
- statusCode: 200
selectionPattern: '2\\d{2}'
responseParameters: {}
responseTemplates:
application/json: |-
#set($item = $input.path('$.Item')){ "Item": $item }
EventBridge
Sample syntax for EventBridge proxy in serverless.yml
.
custom:
apiGatewayServiceProxies:
- eventbridge:
path: /eventbridge
method: post
source: 'hardcoded_source'
detailType: 'hardcoded_detailType'
eventBusName: { Ref: 'YourBusName' }
cors: true
- eventbridge:
path: /eventbridge/{detailTypeKey}/{sourceKey}
method: post
detailType:
pathParam: detailTypeKey
source:
pathParam: sourceKey
eventBusName: { Ref: 'YourBusName' }
cors: true
- eventbridge:
path: /eventbridge/{detailTypeKey}/{sourceKey}
method: post
detailType:
bodyParam: data.detailType
source:
bodyParam: data.source
detail:
bodyParam: data.detail
eventBusName: { Ref: 'YourBusName' }
cors: true
resources:
Resources:
YourBus:
Type: AWS::Events::EventBus
Properties:
Name: YourEventBus
Sample request after deploying.
curl https://xxxxxxx.execute-api.us-east-1.amazonaws.com/dev/eventbridge -d '{"message": "some data"}' -H 'Content-Type:application/json'
Common API Gateway features
Enabling CORS
To set CORS configurations for your HTTP endpoints, simply modify your event configurations as follows:
custom:
apiGatewayServiceProxies:
- kinesis:
path: /kinesis
method: post
streamName: { Ref: 'YourStream' }
cors: true
Setting cors to true assumes a default configuration which is equivalent to:
custom:
apiGatewayServiceProxies:
- kinesis:
path: /kinesis
method: post
streamName: { Ref: 'YourStream' }
cors:
origin: '*'
headers:
- Content-Type
- X-Amz-Date
- Authorization
- X-Api-Key
- X-Amz-Security-Token
- X-Amz-User-Agent
allowCredentials: false
Configuring the cors property sets Access-Control-Allow-Origin, Access-Control-Allow-Headers, Access-Control-Allow-Methods,Access-Control-Allow-Credentials headers in the CORS preflight response.
To enable the Access-Control-Max-Age preflight response header, set the maxAge property in the cors object:
custom:
apiGatewayServiceProxies:
- kinesis:
path: /kinesis
method: post
streamName: { Ref: 'YourStream' }
cors:
origin: '*'
maxAge: 86400
If you are using CloudFront or another CDN for your API Gateway, you may want to setup a Cache-Control header to allow for OPTIONS request to be cached to avoid the additional hop.
To enable the Cache-Control header on preflight response, set the cacheControl property in the cors object:
custom:
apiGatewayServiceProxies:
- kinesis:
path: /kinesis
method: post
streamName: { Ref: 'YourStream' }
cors:
origin: '*'
headers:
- Content-Type
- X-Amz-Date
- Authorization
- X-Api-Key
- X-Amz-Security-Token
- X-Amz-User-Agent
allowCredentials: false
cacheControl: 'max-age=600, s-maxage=600, proxy-revalidate'
Adding Authorization
You can pass in any supported authorization type:
custom:
apiGatewayServiceProxies:
- sqs:
path: /sqs
method: post
queueName: { 'Fn::GetAtt': ['SQSQueue', 'QueueName'] }
cors: true
authorizationType: 'AWS_IAM'
resources:
Resources:
SQSQueue:
Type: 'AWS::SQS::Queue'
Source: AWS::ApiGateway::Method docs
Enabling API Token Authentication
You can indicate whether the method requires clients to submit a valid API key using private
flag:
custom:
apiGatewayServiceProxies:
- sqs:
path: /sqs
method: post
queueName: { 'Fn::GetAtt': ['SQSQueue', 'QueueName'] }
cors: true
private: true
resources:
Resources:
SQSQueue:
Type: 'AWS::SQS::Queue'
which is the same syntax used in Serverless framework.
Source: Serverless: Setting API keys for your Rest API
Source: AWS::ApiGateway::Method docs
Using a Custom IAM Role
By default, the plugin will generate a role with the required permissions for each service type that is configured.
You can configure your own role by setting the roleArn
attribute:
custom:
apiGatewayServiceProxies:
- sqs:
path: /sqs
method: post
queueName: { 'Fn::GetAtt': ['SQSQueue', 'QueueName'] }
cors: true
roleArn:
Fn::GetAtt: [CustomS3Role, Arn]
resources:
Resources:
SQSQueue:
Type: 'AWS::SQS::Queue'
CustomS3Role:
Type: 'AWS::IAM::Role'
Customizing API Gateway parameters
The plugin allows one to specify which parameters the API Gateway method accepts.
A common use case is to pass custom data to the integration request:
custom:
apiGatewayServiceProxies:
- sqs:
path: /sqs
method: post
queueName: { 'Fn::GetAtt': ['SqsQueue', 'QueueName'] }
cors: true
acceptParameters:
'method.request.header.Custom-Header': true
requestParameters:
'integration.request.querystring.MessageAttribute.1.Name': "'custom-Header'"
'integration.request.querystring.MessageAttribute.1.Value.StringValue': 'method.request.header.Custom-Header'
'integration.request.querystring.MessageAttribute.1.Value.DataType': "'String'"
resources:
Resources:
SqsQueue:
Type: 'AWS::SQS::Queue'
Any published SQS message will have the Custom-Header
value added as a message attribute.
Customizing request body mapping templates
Kinesis
If you'd like to add content types or customize the default templates, you can do so by including your custom API Gateway request mapping template in serverless.yml
like so:
plugins:
- serverless-cloudformation-sub-variables
custom:
apiGatewayServiceProxies:
- kinesis:
path: /kinesis
method: post
streamName: { Ref: 'MyStream' }
request:
template:
text/plain:
Fn::Sub:
- |
#set($msgBody = $util.parseJson($input.body))
#set($msgId = $msgBody.MessageId)
{
"Data": "$util.base64Encode($input.body)",
"PartitionKey": "$msgId",
"StreamName": "#{MyStreamArn}"
}
- MyStreamArn:
Fn::GetAtt: [MyStream, Arn]
It is important that the mapping template will return a valid application/json
string
Source: How to connect SNS to Kinesis for cross-account delivery via API Gateway
SQS
Customizing SQS request templates requires us to force all requests to use an application/x-www-form-urlencoded
style body. The plugin sets the Content-Type
header to application/x-www-form-urlencoded
for you, but API Gateway will still look for the template under the application/json
request template type, so that is where you need to configure you request body in serverless.yml
:
custom:
apiGatewayServiceProxies:
- sqs:
path: /{version}/event/receiver
method: post
queueName: { 'Fn::GetAtt': ['SqsQueue', 'QueueName'] }
request:
template:
application/json: |-
#set ($body = $util.parseJson($input.body))
Action=SendMessage##
&MessageGroupId=$util.urlEncode($body.event_type)##
&MessageDeduplicationId=$util.urlEncode($body.event_id)##
&MessageAttribute.1.Name=$util.urlEncode("X-Custom-Signature")##
&MessageAttribute.1.Value.DataType=String##
&MessageAttribute.1.Value.StringValue=$util.urlEncode($input.params("X-Custom-Signature"))##
&MessageBody=$util.urlEncode($input.body)
Note that the ##
at the end of each line is an empty comment. In VTL this has the effect of stripping the newline from the end of the line (as it is commented out), which makes API Gateway read all the lines in the template as one line.
Be careful when mixing additional requestParameters
into your SQS endpoint as you may overwrite the integration.request.header.Content-Type
and stop the request template from being parsed correctly. You may also unintentionally create conflicts between parameters passed using requestParameters
and those in your request template. Typically you should only use the request template if you need to manipulate the incoming request body in some way.
Your custom template must also set the Action
and MessageBody
parameters, as these will not be added for you by the plugin.
When using a custom request body, headers sent by a client will no longer be passed through to the SQS queue (PassthroughBehavior
is automatically set to NEVER
). You will need to pass through headers sent by the client explicitly in the request body. Also, any custom querystring parameters in the requestParameters
array will be ignored. These also need to be added via the custom request body.
SNS
Similar to the Kinesis support, you can customize the default request mapping templates in serverless.yml
like so:
plugins:
- serverless-cloudformation-sub-variables
custom:
apiGatewayServiceProxies:
- kinesis:
path: /sns
method: post
topicName: { 'Fn::GetAtt': ['SNSTopic', 'TopicName'] }
request:
template:
application/json:
Fn::Sub:
- "Action=Publish&Message=$util.urlEncode('This is a fixed message')&TopicArn=$util.urlEncode('#{MyTopicArn}')"
- MyTopicArn: { Ref: MyTopic }
It is important that the mapping template will return a valid application/x-www-form-urlencoded
string
Source: Connect AWS API Gateway directly to SNS using a service integration
Custom response body mapping templates
You can customize the response body by providing mapping templates for success, server errors (5xx) and client errors (4xx).
Templates must be in JSON format. If a template isn't provided, the integration response will be returned as-is to the client.
Kinesis Example
custom:
apiGatewayServiceProxies:
- kinesis:
path: /kinesis
method: post
streamName: { Ref: 'MyStream' }
response:
template:
success: |
{
"success": true
}
serverError: |
{
"success": false,
"errorMessage": "Server Error"
}
clientError: |
{
"success": false,
"errorMessage": "Client Error"
}