Sample of buildspec.yml for AWS CodeBuild that builds a Docker image from code and push it to ECR to be deployed via CodePipeline

buildspec.yml

version: 0.2
env:
  variables:
    #
    # NOTE: You need to replace these values!
    #
    ACCOUNT_NUMBER: "REPLACE_ME"
    ECR_REGION: "REPLACE_ME"
    ECR_REPOSITORY_NAME: "REPLACE_ME"
    ECS_CONTAINER_NAME: "REPLACE_ME"
phases:
  install:
    runtime-versions:
      docker: 18
  pre_build:
    commands:
      - echo Logging in to Amazon ECR...
      - aws --version
      - $(aws ecr get-login --region $ECR_REGION --no-include-email)
      - REPOSITORY_URI=$ACCOUNT_NUMBER.dkr.ecr.$ECR_REGION.amazonaws.com/$ECR_REPOSITORY_NAME
      - COMMIT_HASH=$(echo $CODEBUILD_RESOLVED_SOURCE_VERSION | cut -c 1-7)
      - IMAGE_TAG=${COMMIT_HASH:=latest}
  build:
    commands:
      - echo Build started on `date`
      - echo Building the Docker image...          
      - docker build -t $REPOSITORY_URI:latest .
      - docker tag $REPOSITORY_URI:latest $REPOSITORY_URI:$IMAGE_TAG
  post_build:
    commands:
      - echo Build completed on `date`
      - echo Pushing the Docker images...
      - docker push $REPOSITORY_URI:latest
      - docker push $REPOSITORY_URI:$IMAGE_TAG
      - echo Writing image definitions file...
      - printf '[{"name”:"$ECS_CONTAINER_NAME","imageUri":"%s"}]' $REPOSITORY_URI:$IMAGE_TAG > imagedefinitions.json
artifacts:
  files: imagedefinitions.json

@adshrc

$__ECR_REGION__ , $__ACCOUNT_NUMBER__ , $__ECR_REGION__ need to be configured somewhere ?

Yes you can configure them in environment variables in AWS codebuild during creating a new project

Buildspec runs in the build stage of your pipeline.

version: 0.2
phases:
install:
runtime-versions:
docker: 28
commands:
- echo "cd into $CODEBUILD_SRC_DIR/backend"
- cd $CODEBUILD_SRC_DIR/backend-flask
- aws ecr get-login-password --region $AWS_DEFAULT_REGION | docker login --username AWS --password-stdin $IMAGE_URL
build:
commands:
- echo Build started on date
- echo Building the Docker image...
- docker build -t backend-flask .
- "docker tag $REPO_NAME $IMAGE_URL/$REPO_NAME"
post_build:
commands:
- echo Build completed on date
- echo Pushing the Docker image..
- docker push $IMAGE_URL/$REPO_NAME
- cd $CODEBUILD_SRC_DIR
- echo "imagedefinitions.json > [{"name":"$CONTAINER_NAME","imageUri":"$IMAGE_URL/$REPO_NAME"}]" > imagedefinitions.json
- printf "[{"name":"$CONTAINER_NAME","imageUri":"$IMAGE_URL/$REPO_NAME"}]" > imagedefinitions.json

env:
variables:
AWS_ACCOUNT_ID: 651746472793
AWS_DEFAULT_REGION: ap-south-1
CONTAINER_NAME: backend-flask
IMAGE_URL: 651746472793.dkr.ecr.ap-south-1.amazonaws.com
REPO_NAME: backend-flask:latest
artifacts:
files:
- imagedefinitions.json

i am getting this error can you help

Did a few changes in the gist. Hopefully the updated version makes it easier to understand and use.

where can I see the available versions of docker runtime? I am talking about docker: 28 and docker: 18 in line 14