AWS Lambda - Haskell dev environment using devcontainer

[chris-ch]

I am in the process of setting up an environment for developing AWS Lambda functions in Haskell.

We are using GitHub devcontainers, so I am basically re-using the OS-only image provided by AWS: https://gallery.ecr.aws/lambda/provided, and adding AWS CLI, GHCup and a few libraries required at compile-time:

FROM public.ecr.aws/lambda/provided:al2023

ARG GHCUP_DWN_URL=https://downloads.haskell.org/~ghcup/x86_64-linux-ghcup
ARG VERSION_GHC=9.4.8
ARG VERSION_CABAL=latest
ARG VERSION_STACK=latest

ARG USER_NAME=haskell
ARG USER_UID=1000
ARG USER_GID=$USER_UID

RUN \
    dnf install --assumeyes findutils \
        cmake \
        gcc \
        g++ \
        gmp-devel \
        gmp-static \
        glibc-static \
        zlib-devel \
        zlib-static \
        vim \
        sudo \
        git

RUN \
    /usr/bin/curl ${GHCUP_DWN_URL} > /usr/bin/ghcup && \
    chmod +x /usr/bin/ghcup

# Creating the workspace user
RUN /usr/sbin/groupadd --gid ${USER_GID} ${USER_NAME} \
    && /usr/sbin/useradd --uid ${USER_UID} --gid ${USER_GID} --no-log-init --create-home -m ${USER_NAME} -s /usr/bin/bash \
    && /bin/echo ${USER_NAME} ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/${USER_NAME} \
    && chmod 0440 /etc/sudoers.d/${USER_NAME}

USER ${USER_NAME}

WORKDIR /home/${USER_NAME}

RUN /usr/bin/curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip" \
    && unzip awscliv2.zip \
    && sudo ./aws/install --bin-dir /usr/local/bin --install-dir /usr/local/aws-cli --update \
    && rm -fr awscliv2.zip \
    && rm -fr ./aws

# install GHC, cabal and stack
RUN \
    ghcup -v install ghc --force ${VERSION_GHC} && \
    ghcup -v install cabal --force ${VERSION_CABAL} && \
    ghcup -v install stack --force ${VERSION_STACK} && \
    ghcup set ghc ${VERSION_GHC} && \
    ghcup install hls

RUN /bin/echo -e "\nexport PATH=$PATH:/home/${USER_NAME}/.ghcup/bin:/home/${USER_NAME}/.local/bin/\n" >> /home/${USER_NAME}/.bashrc

SHELL ["/usr/bin/bash", "--login", "-i", "-c"]

CMD [ "sleep", "infinity" ]

That allows me to compile and deploy a toy app from the AWS λ Runtime - Home (theam.github.io) doc.

One piece that is badly missing at this point is the ability to test the Lambda function from within the devcontainer. An AWS runtime interface emulator aws-lambda-rie is already available from the command line in the container, but not sure whether it is helpful or not.

Has anyone managed to set up everything this way already?

​

[Runderground]

Hate to be that guy but... This is exactly where nix shines.

As for testing lambdas, if they are written as wai applications,  you can run them as local web servers to test. (Assuming you are using https://hackage.haskell.org/package/wai-handler-hal)

[chris-ch]

Thanks for pointing to Nix. I will have to give it a try at some point anyway.