Deploy Go Lambda functions with container images
There are two ways to build a container image for a Go Lambda function:
-
Using an AWS OS-only base image
Go is implemented differently than other managed runtimes. Because Go compiles natively to an executable binary, it doesn't require a dedicated language runtime. Use an OS-only base image to build Go images for Lambda. To make the image compatible with Lambda, you must include the
aws-lambda-go/lambda
package in the image. -
You can use an alternative base image from another container registry, such as Alpine Linux or Debian. You can also use a custom image created by your organization. To make the image compatible with Lambda, you must include the
aws-lambda-go/lambda
package in the image.
Tip
To reduce the time it takes for Lambda container functions to become active, see Use multi-stage builds
This page explains how to build, test, and deploy container images for Lambda.
AWS base images for deploying Go functions
Go is implemented differently than other managed runtimes. Because Go compiles natively to an executable binary, it doesn't require a dedicated language runtime. Use an OS-only base image to deploy Go functions to Lambda.
Name | Identifier | Operating system | Deprecation date | Block function create | Block function update |
---|---|---|---|---|---|
OS-only Runtime |
|
Amazon Linux 2023 |
Not scheduled |
Not scheduled |
Not scheduled |
OS-only Runtime |
|
Amazon Linux 2 |
Not scheduled |
Not scheduled |
Not scheduled |
Amazon Elastic Container Registry Public Gallery: gallery.ecr.aws/lambda/provided
Go runtime interface client
The aws-lambda-go/lambda
package includes an implementation of the runtime interface. For examples of how to use aws-lambda-go/lambda
in your image, see Using an AWS OS-only base image or Using a non-AWS base image.
Using an AWS OS-only base image
Go is implemented differently than other managed runtimes. Because Go compiles natively to an executable binary, it doesn't require a dedicated language runtime. Use an OS-only base image to build container images for Go functions.
Tags | Runtime | Operating system | Dockerfile | Deprecation |
---|---|---|---|---|
al2023 |
OS-only Runtime | Amazon Linux 2023 | Dockerfile
for OS-only Runtime on GitHub |
Not scheduled |
al2 |
OS-only Runtime | Amazon Linux 2 | Dockerfile
for OS-only Runtime on GitHub |
Not scheduled |
For more information
about these base images, see provided
You must include the aws-lambda-go/lambda
To complete the steps in this section, you must have the following:
To build and deploy a Go function with the provided.al2023
base image
-
Create a directory for the project, and then switch to that directory.
mkdir hello cd hello
-
Initialize a new Go module.
go mod init
example.com/hello-world
-
Add the lambda library as a dependency of your new module.
go get github.com/aws/aws-lambda-go/lambda
-
Create a file named
main.go
and then open it in a text editor. This is the code for the Lambda function. You can use the following sample code for testing, or replace it with your own.package main import ( "context" "github.com/aws/aws-lambda-go/events" "github.com/aws/aws-lambda-go/lambda" ) func handler(ctx context.Context, event events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) { response := events.APIGatewayProxyResponse{ StatusCode: 200, Body: "\"Hello from Lambda!\"", } return response, nil } func main() { lambda.Start(handler) }
-
Use a text editor to create a Dockerfile in your project directory.
-
The following example Dockerfile uses a multi-stage build
. This allows you to use a different base image in each step. You can use one image, such as a Go base image , to compile your code and build the executable binary. You can then use a different image, such as provided.al2023
, in the finalFROM
statement to define the image that you deploy to Lambda. The build process is separated from the final deployment image, so the final image only contains the files needed to run the application. -
You can use the optional
lambda.norpc
tag to exclude the Remote Procedure Call (RPC) component of the lambdalibrary. The RPC component is only required if you are using the deprecated Go 1.x runtime. Excluding the RPC reduces the size of the deployment package. -
Note that the example Dockerfile does not include a USER instruction
. When you deploy a container image to Lambda, Lambda automatically defines a default Linux user with least-privileged permissions. This is different from standard Docker behavior which defaults to the root
user when noUSER
instruction is provided.
Example — Multi-stage build Dockerfile
Note
Make sure that the version of Go that you specify in your Dockerfile (for example,
golang:1.20
) is the same version of Go that you used to create your application.FROM
golang:1.20
as build WORKDIR /helloworld # Copy dependencies list COPY go.mod go.sum ./ # Build with optional lambda.norpc tag COPY main.go . RUN go build-tags lambda.norpc
-o main main.go # Copy artifacts to a clean image FROMpublic.ecr.aws/lambda/provided:al2023
COPY --from=build /helloworld/main ./main ENTRYPOINT [ "./main" ] -
-
Build the Docker image with the docker build
command. The following example names the image docker-image
and gives it thetest
tag. docker build --platform linux/amd64 -t
docker-image
:test
.Note
The command specifies the
--platform linux/amd64
option to ensure that your container is compatible with the Lambda execution environment regardless of the architecture of your build machine. If you intend to create a Lambda function using the ARM64 instruction set architecture, be sure to change the command to use the--platform linux/arm64
option instead.
Use the runtime interface emulatorprovided.al2023
base image.
To run the runtime interface emulator on your local machine
-
Start the Docker image with the docker run command. Note the following:
-
docker-image
is the image name andtest
is the tag. -
./main
is theENTRYPOINT
from your Dockerfile.
docker run -d -p 9000:8080 \ --entrypoint /usr/local/bin/aws-lambda-rie \
docker-image:test ./main
This command runs the image as a container and creates a local endpoint at
localhost:9000/2015-03-31/functions/function/invocations
. -
-
From a new terminal window, post an event to the following endpoint using a curl command:
curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'
This command invokes the function with an empty event and returns a response. Some functions might require a JSON payload. Example:
curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '
{"payload":"hello world!"}
' -
Get the container ID.
docker ps
-
Use the docker kill
command to stop the container. In this command, replace 3766c4ab331c
with the container ID from the previous step.docker kill
3766c4ab331c
To upload the image to Amazon ECR and create the Lambda function
-
Run the get-login-password
command to authenticate the Docker CLI to your Amazon ECR registry. -
Set the
--region
value to the AWS Region where you want to create the Amazon ECR repository. -
Replace
111122223333
with your AWS account ID.
aws ecr get-login-password --region
us-east-1
| docker login --username AWS --password-stdin111122223333
.dkr.ecr.us-east-1
.amazonaws.com -
-
Create a repository in Amazon ECR using the create-repository
command. aws ecr create-repository --repository-name
hello-world
--regionus-east-1
--image-scanning-configuration scanOnPush=true --image-tag-mutability MUTABLENote
The Amazon ECR repository must be in the same AWS Region as the Lambda function.
If successful, you see a response like this:
{ "repository": { "repositoryArn": "arn:aws:ecr:us-east-1:111122223333:repository/hello-world", "registryId": "111122223333", "repositoryName": "hello-world", "repositoryUri": "111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world", "createdAt": "2023-03-09T10:39:01+00:00", "imageTagMutability": "MUTABLE", "imageScanningConfiguration": { "scanOnPush": true }, "encryptionConfiguration": { "encryptionType": "AES256" } } }
-
Copy the
repositoryUri
from the output in the previous step. -
Run the docker tag
command to tag your local image into your Amazon ECR repository as the latest version. In this command: -
docker-image:test
is the name and tagof your Docker image. This is the image name and tag that you specified in the docker build
command. -
Replace
<ECRrepositoryUri>
with therepositoryUri
that you copied. Make sure to include:latest
at the end of the URI.
docker tag docker-image:test
<ECRrepositoryUri>
:latestExample:
docker tag
docker-image
:test
111122223333
.dkr.ecr.us-east-1
.amazonaws.com/hello-world
:latest -
-
Run the docker push
command to deploy your local image to the Amazon ECR repository. Make sure to include :latest
at the end of the repository URI.docker push
111122223333
.dkr.ecr.us-east-1
.amazonaws.com/hello-world
:latest -
Create an execution role for the function, if you don't already have one. You need the Amazon Resource Name (ARN) of the role in the next step.
-
Create the Lambda function. For
ImageUri
, specify the repository URI from earlier. Make sure to include:latest
at the end of the URI.aws lambda create-function \ --function-name
hello-world
\ --package-type Image \ --code ImageUri=111122223333
.dkr.ecr.us-east-1
.amazonaws.com/hello-world
:latest \ --rolearn:aws:iam::111122223333:role/lambda-ex
Note
You can create a function using an image in a different AWS account, as long as the image is in the same Region as the Lambda function. For more information, see Amazon ECR cross-account permissions.
-
Invoke the function.
aws lambda invoke --function-name
hello-world
response.jsonYou should see a response like this:
{ "ExecutedVersion": "$LATEST", "StatusCode": 200 }
-
To see the output of the function, check the
response.json
file.
To update the function code, you must build the image again, upload the new image to the Amazon ECR repository, and then use the update-function-code
Lambda resolves the image tag to a specific image digest. This means that if you point the image tag that was used to deploy the function to a new image in Amazon ECR, Lambda doesn't automatically update the function to use the new image.
To deploy the new image to the same Lambda function, you must use the update-function-code--publish
option creates a new version of the function using the updated container image.
aws lambda update-function-code \ --function-name
hello-world
\ --image-uri111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
\ --publish
Using a non-AWS base image
You can build a container image for Go from a non-AWS base image. The example Dockerfile in the following steps uses an
Alpine base image
You must include the aws-lambda-go/lambda
To complete the steps in this section, you must have the following:
To build and deploy a Go function with an Alpine base image
-
Create a directory for the project, and then switch to that directory.
mkdir hello cd hello
-
Initialize a new Go module.
go mod init
example.com/hello-world
-
Add the lambda library as a dependency of your new module.
go get github.com/aws/aws-lambda-go/lambda
-
Create a file named
main.go
and then open it in a text editor. This is the code for the Lambda function. You can use the following sample code for testing, or replace it with your own.package main import ( "context" "github.com/aws/aws-lambda-go/events" "github.com/aws/aws-lambda-go/lambda" ) func handler(ctx context.Context, event events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) { response := events.APIGatewayProxyResponse{ StatusCode: 200, Body: "\"Hello from Lambda!\"", } return response, nil } func main() { lambda.Start(handler) }
-
Use a text editor to create a Dockerfile in your project directory. The following example Dockerfile uses an Alpine base image
. Note that the example Dockerfile does not include a USER instruction . When you deploy a container image to Lambda, Lambda automatically defines a default Linux user with least-privileged permissions. This is different from standard Docker behavior which defaults to the root
user when noUSER
instruction is provided.Example Dockerfile
Note
Make sure that the version of Go that you specify in your Dockerfile (for example,
golang:1.20
) is the same version of Go that you used to create your application.FROM golang:1.20.2-alpine3.16 as build WORKDIR /helloworld # Copy dependencies list COPY go.mod go.sum ./ # Build COPY main.go . RUN go build -o main main.go # Copy artifacts to a clean image FROM alpine:3.16 COPY --from=build /helloworld/main /main ENTRYPOINT [ "/main" ]
-
Build the Docker image with the docker build
command. The following example names the image docker-image
and gives it thetest
tag. docker build --platform linux/amd64 -t
docker-image
:test
.Note
The command specifies the
--platform linux/amd64
option to ensure that your container is compatible with the Lambda execution environment regardless of the architecture of your build machine. If you intend to create a Lambda function using the ARM64 instruction set architecture, be sure to change the command to use the--platform linux/arm64
option instead.
Use the runtime interface emulator
To install and run the runtime interface emulator on your local machine
-
From your project directory, run the following command to download the runtime interface emulator (x86-64 architecture) from GitHub and install it on your local machine.
-
Start the Docker image with the docker run command. Note the following:
-
docker-image
is the image name andtest
is the tag. -
/main
is theENTRYPOINT
from your Dockerfile.
This command runs the image as a container and creates a local endpoint at
localhost:9000/2015-03-31/functions/function/invocations
.Note
If you built the Docker image for the ARM64 instruction set architecture, be sure to use the
--platform linux/
option instead ofarm64
--platform linux/
.amd64
-
-
Post an event to the local endpoint.
-
Get the container ID.
docker ps
-
Use the docker kill
command to stop the container. In this command, replace 3766c4ab331c
with the container ID from the previous step.docker kill
3766c4ab331c
To upload the image to Amazon ECR and create the Lambda function
-
Run the get-login-password
command to authenticate the Docker CLI to your Amazon ECR registry. -
Set the
--region
value to the AWS Region where you want to create the Amazon ECR repository. -
Replace
111122223333
with your AWS account ID.
aws ecr get-login-password --region
us-east-1
| docker login --username AWS --password-stdin111122223333
.dkr.ecr.us-east-1
.amazonaws.com -
-
Create a repository in Amazon ECR using the create-repository
command. aws ecr create-repository --repository-name
hello-world
--regionus-east-1
--image-scanning-configuration scanOnPush=true --image-tag-mutability MUTABLENote
The Amazon ECR repository must be in the same AWS Region as the Lambda function.
If successful, you see a response like this:
{ "repository": { "repositoryArn": "arn:aws:ecr:us-east-1:111122223333:repository/hello-world", "registryId": "111122223333", "repositoryName": "hello-world", "repositoryUri": "111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world", "createdAt": "2023-03-09T10:39:01+00:00", "imageTagMutability": "MUTABLE", "imageScanningConfiguration": { "scanOnPush": true }, "encryptionConfiguration": { "encryptionType": "AES256" } } }
-
Copy the
repositoryUri
from the output in the previous step. -
Run the docker tag
command to tag your local image into your Amazon ECR repository as the latest version. In this command: -
docker-image:test
is the name and tagof your Docker image. This is the image name and tag that you specified in the docker build
command. -
Replace
<ECRrepositoryUri>
with therepositoryUri
that you copied. Make sure to include:latest
at the end of the URI.
docker tag docker-image:test
<ECRrepositoryUri>
:latestExample:
docker tag
docker-image
:test
111122223333
.dkr.ecr.us-east-1
.amazonaws.com/hello-world
:latest -
-
Run the docker push
command to deploy your local image to the Amazon ECR repository. Make sure to include :latest
at the end of the repository URI.docker push
111122223333
.dkr.ecr.us-east-1
.amazonaws.com/hello-world
:latest -
Create an execution role for the function, if you don't already have one. You need the Amazon Resource Name (ARN) of the role in the next step.
-
Create the Lambda function. For
ImageUri
, specify the repository URI from earlier. Make sure to include:latest
at the end of the URI.aws lambda create-function \ --function-name
hello-world
\ --package-type Image \ --code ImageUri=111122223333
.dkr.ecr.us-east-1
.amazonaws.com/hello-world
:latest \ --rolearn:aws:iam::111122223333:role/lambda-ex
Note
You can create a function using an image in a different AWS account, as long as the image is in the same Region as the Lambda function. For more information, see Amazon ECR cross-account permissions.
-
Invoke the function.
aws lambda invoke --function-name
hello-world
response.jsonYou should see a response like this:
{ "ExecutedVersion": "$LATEST", "StatusCode": 200 }
-
To see the output of the function, check the
response.json
file.
To update the function code, you must build the image again, upload the new image to the Amazon ECR repository, and then use the update-function-code
Lambda resolves the image tag to a specific image digest. This means that if you point the image tag that was used to deploy the function to a new image in Amazon ECR, Lambda doesn't automatically update the function to use the new image.
To deploy the new image to the same Lambda function, you must use the update-function-code--publish
option creates a new version of the function using the updated container image.
aws lambda update-function-code \ --function-name
hello-world
\ --image-uri111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
\ --publish