AWS Code Build

Intro

AWS code build is a tool that helps on the process of building docker images and push them to the docker registry. It uses a manifest file buildspec.yml (you can rename it if you want to) as a specification on how to build, tag, and push the image to the registry.

Create Build Project

In order to start with code build you need to login into your AWS account. Once you are there you need to go to “Services” and then search for “Code Build”

There you need to click on “Create build project” to start the journey

The first step of the build is to type the name of the project you can also type a description as shown on the image bellow.

Code Build - Source

Then you need to connect the “Source” in this example I will use github but you can use any of the available options.

Select “Github” in the “Source provider” then “Repository in my github account” and connect using Oauth, once you connect AWS with your github account you can find the project on the “Github repository” typeahead look at the image for an example

The next step is to select an event on which the images are going to be built, in the previous image you can see that is going to build the image every time a push is done to the branch develop.

You can use different regex to build the images in different scenarios for example you can use the following regex to build the image if a PUSH is done to either develop or master refs/heads/(develop|master)

Code Build - Environment

Ok we have the “Source” in place now it time to configure the environment used for building the image, the first thing is to select the image we are going to use, select “Managed Images” from Environment image and then select “Ubuntu” as operating system, for “Runtime(s)” select “Standard”, and use the latest image available on the list. Important note: select elevated privileges this is important to build the image on the environment.

Finally create a new “Service role”, remember the name that you use we are going to use it later.

Also you might need to fill environment variables to do that open “Additional configurations”, the following variables are going to be used on the buildspec.yml

AWS_ACCOUNT_ID (the value is the id shown on the docker registry)
IMAGE_REPO_NAME (the name that you use for the docker registry)

See the following image for reference:

Code Build - buildspec

Select Use a buildspec file as shown bellow and then click on Create build project

Give role necessary rights

Last step is to give the necessary rights to the role we created on the previous step to do that go to “Services”, then search for “IAM” and click on it.

Click on Roles and search for the role you just created

Click on “Attach policies” and add the following policies

AmazonEC2ContainerRegistryFullAccess
AmazonS3FullAccess

Then you are ready to use the buildspec.yml on your project just make sure to include the following file in the root of your project and you will start building your docker images.

1version: 0.2
2
3phases:
4  pre_build:
5    commands:
6      - echo Logging in to Amazon ECR...
7      - aws ecr get-login-password --region $AWS_DEFAULT_REGION | docker login --username AWS --password-stdin $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com
8      - echo Generating tag...
9      - COMMIT_HASH=$(echo $CODEBUILD_RESOLVED_SOURCE_VERSION | cut -c 1-7)
10      - IMAGE_TAG=${COMMIT_HASH:=latest}
11  build:
12    commands:
13      - echo Build started on `date`
14      - echo Building the Docker image...
15      - docker build -t $IMAGE_REPO_NAME:$IMAGE_TAG . -f Dockerfile
16      - docker tag $IMAGE_REPO_NAME:$IMAGE_TAG $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/$IMAGE_REPO_NAME:$IMAGE_TAG
17      - docker tag $IMAGE_REPO_NAME:$IMAGE_TAG $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/$IMAGE_REPO_NAME:$DEPLOY_TAG
18  post_build:
19    commands:
20      - echo Build completed on `date`
21      - echo Pushing the Docker image...
22      - docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/$IMAGE_REPO_NAME:$IMAGE_TAG
23      - docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/$IMAGE_REPO_NAME:$DEPLOY_TAG

NOTE:

This script assumes that the Dockerfile is in the root of your application if that is not the case please change the line 15 where the dockerfile is build.