cdk-lambda-bash 0.2.0

Deploy Bash Lambda Functions with AWS CDK

cdk-lambda-bash

Deploy Bash Lambda Functions with AWS CDK

Why

AWS Lambda has the docker container image support since AWS re:Invent 2020 which allows you to run your Lambda code in a custom container image. Inspired by nikovirtala/cdk-eks-experiment, cdk-lambda-bash allows you to specify a local shell script and bundle it up as a custom resource in your cdk stack. On cdk deployment, your shell script will be executed in a Lambda container environment.

BashExecFunction

At this moment, we are offering BashExecFunction construct class which is a high-level abstraction of lambda.Function. By defining the script property which poins to your local shell script, on cdk deploy, this script will be bundled into a custom docker image and published as a lambda.DockerImageFunction.

If you fn.run(), a custom resource will be created and the lambda.DockerImageFunction will be executed on deployment.

Sample

# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
app = cdk.App()

stack = cdk.Stack(app, "my-stack")

# bundle your Lambda function to execute the local demo.sh in container
fn = BashExecFunction(stack, "Demo",
    script=path.join(__dirname, "../demo.sh")
)

# run it as custom resource on deployment
fn.run()

Custom Dockerfile

In some cases, you may customize your own Dockerfile, for instances:

1. You need extra tools or utilities such as kubectl or helm
2. You need build from your own base image

In these cases, create a custom Dockerfile as below and add extra utilities i.e. kubectl:

click and view custom Dockerfile sample

FROM public.ecr.aws/lambda/provided:al2

RUN yum install -y unzip jq

# install aws-cli v2
RUN curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip" && \
  unzip awscliv2.zip && \
  ./aws/install

# install kubectl
RUN curl -o kubectl https://amazon-eks.s3.us-west-2.amazonaws.com/1.19.6/2021-01-05/bin/linux/amd64/kubectl && \
  chmod +x kubectl && \
  mv kubectl /usr/local/bin/kubectl

COPY bootstrap /var/runtime/bootstrap
COPY function.sh /var/task/function.sh
COPY main.sh /var/task/main.sh
RUN chmod +x /var/runtime/bootstrap /var/task/function.sh /var/task/main.sh

WORKDIR /var/task
CMD [ "function.sh.handler" ]

Specify your own Dockerfile with the dockerfile property.

# Example automatically generated without compilation. See https://github.com/aws/jsii/issues/826
app = cdk.App()

stack = cdk.Stack(app, "my-stack-dev", env=dev_env)

BashExecFunction(stack, "Demo",
    script=path.join(__dirname, "../demo.sh"),
    dockerfile=path.join(__dirname, "../Dockerfile")
).run()

app.synth()

In Action

See this tweet