DockerConsumingSSMParameterStore.md

Consuming SSM Parameter Store from Docker image

This example is based on NodeJs 10.

Requirements

In the following example you gonna need the following env vars defined:

• APP_NAME: the application name.
• AWS_REGION: region where the parameters has been stored

Building the image

$ npm install
$ docker build \
    -t ${APP_NAME} \
    --build-arg "AWS_REGION=${AWS_REGION}" \
    --build-arg "APP_NAME=${APP_NAME}" \
    .

Granting permission

• Running on ECS: Attach an IAM Role to the Task
• Running inside EC2: Attach an IAM Role to the instance
• Running locally: you might have to either:
  1. define the AWS ENV Vars manually in the docker build command line
  2. create a valid credentials file and copy it to /root/.aws/credentials inside your image

Dockerfile

FROM node:10-alpine

ARG AWS_REGION
ENV AWS_REGION=${AWS_REGION}
ENV CHAMBER_URL="https://github.com/segmentio/chamber/releases/download/v2.5.0/chamber-v2.5.0-linux-amd64"

EXPOSE 8080

ADD entrypoint.sh /opt/application/entrypoint.sh

# It assumes you've build your app before generate the Docker image
ADD ./dist/ /opt/application/

RUN  apk add curl \
 &&  curl -o /usr/bin/chamber -LOs ${CHAMBER_URL} \
 &&  chmod +x /opt/cammy/entrypoint.sh /usr/bin/chamber

WORKDIR /opt/application
CMD /opt/application/entrypoint.sh

entrypoint.sh

#!/bin/sh
# This is an entrypoint script designed to retrieve variables from AWS SSM Parameter Store.
# It relies on Chamber to download all the parameters and expose them as BASH ENV VARIABLES.
# It will download all variables related to "global" application and those which the
# prefix matches the variable APP_NAME.
# 
# For details look at: https://github.com/segmentio/chamber

## FUNCTIONS
load_parameter_store_variables(){
  chamber export --format dotenv global | sed 's/\(.*\)/export \1/;s/\\\!/\!/g'
  chamber export --format dotenv "${APP_NAME}" | sed 's/\(.*\)/export \1/;s/\\\!/\!/g'
}

## VARIBLES
APP_NAME=${APP_NAME:-"my-app"}

## MAIN

eval $(load_parameter_store_variables)

# TODO: move npm commands to the Dockerfile
node server.js