zappa-build

Build a Zappa app within a docker container that mimics the Lambda environment.

Since zappa deploy/update desires an active virtualenv, this build creates a virtual env and installs only requirements.txt so that the resultant Lambda deployment zip is as small as possible and has the least number of dependencies. This is also helpful when you deploy from your workstation where you'd most likely have requirements.dev.txt or other python packages outside of requirements.txt; these would make their way into the deployable code that gets side-loaded into the Lambda causing bloat and possible errors due to size limits.

You'll also want to use an isolated build when you are building dependencies that require C libraries, especially if your host system is not Amazon Linux. This helps minimize build vs run environment differences.

The work here is for a Django app, so edit to taste.

This is expecting slim_handler=true in zappa_settings.json, but PRs welcome...

Usage

Check out as a submodule in the root of your project:

git submodule add https://github.com/LyleScott/zappa-build zappa_build

Build the docker container:

docker build -t zappa_build -f zappa_build/Dockerfile .

Run the docker container with the right EnvName to produce build artifacts that will be used to update the zappa Lambda code.

docker run -it -v $(pwd)/zbuilds:/zbuilds zappa_build dev
# produces:
# the actual app code that's sideloaded with `slim_handler=true`
# zappa_build/_builds/prfoo-zappa-lyle-1590469643.tar.gz
# the Lambda code to bootstrap with (that sideloads the actual Lambda code)
# zappa_build/_builds/handler_prfoo-zappa-lyle-1590469760.zip

Example Deploy Script

It is easy to integrate zappa-build into your project!

Given an example project hierarchy:

src/zappa_settings.json     # zappa app root is in src
scripts/deploy.sh           # the script below
zappa_build/                # zappa-build git submodule

zappa_build/ is from a git submodule add https://github.com/LyleScott/zappa-build zappa_build

You may have a script to deploy zappa like the following where a docker container does the main zappa build and Lambda packaging in a Lambda-like environment and then follows up with some typical Django post-deployment commands.

#!/usr/bin/env bash

set -ex

EnvName=$1
S3Bucket="s3-bucket-to-house-zappa-deploy-files"

if [[ -z ${EnvName} ]]; then
    echo "USAGE: <env-name>"
    exit 1
fi

docker build -t zappa_build -f zappa_build/Dockerfile .
docker run -it -v $(pwd)/zappa_build/_builds:/zbuilds zappa_build ${EnvName}

# Grab the latest builds and push to S3.
dot_tar_gz=$(ls -tr zappa_build/_builds/*.tar.gz | tail -n 1)
dot_zip=$(ls -tr zappa_build/_builds/*.zip | tail -n 1)
aws s3 cp ${dot_tar_gz} s3://${S3Bucket}/
aws s3 cp ${dot_zip} s3://${S3Bucket}/

# Zappa foo (directory contains zappa_settings.json)
pushd src
if ! zappa deploy ${EnvName} -z s3://${S3Bucket}/$(basename $dot_zip); then
    zappa update ${EnvName} -z s3://${S3Bucket}/$(basename $dot_zip)
fi
zappa manage ${EnvName} 'collectstatic --noinput'
zappa manage ${EnvName} 'migrate --no-input'
zappa tail ${EnvName}