I've been working on a SlackBot project based in Scala using Gradle and have been looking into ways to leverage Gitlab-CI for the purpose of deploying to AWS EC2.
I am able to fully build and test my application with Gitlab-CI.
How can I perform a deployment from Gitlab-CI to Amazon EC2 Using CodeDeploy and CodePipeline?
Answer to follow as a Guide to do this.
I have created a set of sample files to go with the Guide provided below. These files are available at the following link: https://gitlab.com/autronix/gitlabci-ec2-deployment-samples-guide/
This guide assumes the following
The provided .gitlab-ci.yml sample is based on a Java/Scala + Gradle project. The script is provided as a generic example and will need to be adapted to your specific needs when implementing Continuous Delivery through this method.
The guide will assume that the user has basic knowledge about AWS services and how to perform the necessary tasks.
Note: The guide provided in this sample uses the AWS console to perform tasks. While there are likely CLI equivalent for the tasks performed here, these will not be covered throughout the guide.
The motivation for creating these scripts and deployment guide came from the lack of availability of a proper tutorial showing how to implement Continuous Delivery using Gitlab and AWS EC2. Gitlab introduced their freely available CI engine by partnering with Digital Ocean, which enables user repositories to benefit from good quality CI for free.
One of the main advantages of using Gitlab is that they provide built-in Continuous Integration containers for running through the various steps and validate a build. Unfortunately, Gitblab nor AWS provide an integration that would allow to perform Continuous Deliver following passing builds.
This Guide and Scripts (https://gitlab.com/autronix/gitlabci-ec2-deployment-samples-guide/) provide a simplified version of the steps that I've undertaken in order to have a successful CI and CD using both Gitlab and AWS EC2 that can help anyone else get started with this type of implementation.
The first step in ensuring a successful Continuous Delivery process is to set up the necessary objects on AWS in order to allow the deployment process to succeed.
The initial requirement will be to set up an IAM user:
https://console.aws.amazon.com/iam/home?#users
Attach the following permissions:
Generate security credentials
Note: The policies listed above are very broad in scope. You may adjust to your requirements by creating custom policies that limit access only to certain recources.
Note: Please keep these credentials in a safe location. You will need them in a later step.
https://console.aws.amazon.com/iam/home?region=us-east-1#roles
Create a new Role that will be assigned to your EC2 Instance in order to access S3,
MyDeploymentAppRole)Amazon EC2 in order to allow EC2 instances to run other AWS servicesNote: The policies listed above are very broad in scope. You may adjust to your requirements by creating custom policies that limit access only to certain recources.
https://console.aws.amazon.com/ec2/v2/home?region=us-east-1#
Click on Launch Instance and follow these steps:
Amazon Linux AMI 2016.03.3 (HVM), SSD Volume TypeIAM Role to be MyDeploymentAppRole (based on the name created in the previous section) MyApp-Production-Instance) You will be provided with the possibility to either generate or use SSH keys. Please select the appropriate applicable method.
Install CodeDeploy Agent
Log into your newly created EC2 instance and follow the instructions:
CodeDeploy important paths:
/opt/codedeploy-agent/deployment-root//var/log/aws/codedeploy-agent/codedeploy-agent.logTip: run tail -f /var/log/aws/codedeploy-agent/codedeploy-agent.log to keep track of the deployment in real time.
Install your project prerequisites If your project has any prerequisites to run, make sure that you install those before running the deployment, otherwise your startup script may fail.
https://console.aws.amazon.com/s3/home?region=us-east-1
In this step you will need to create an S3 bucket that will be holding your deployment files.
Simply follow these steps:
Create Bucket my-app-codepipeline-deployment)Properties Versioning menuEnable Versioninghttps://console.aws.amazon.com/codedeploy/home?region=us-east-1#/applications
Now that the basic elements are set, we are ready to create the Deployment application in CodeDeploy
To create a CodeDeploy deployment application follow these steps:
Create New ApplicationMyApp-Production )MyApp-Production-Fleet)Search by Tags Key Select NameValue Select MyApp-Production-InstanceService Role, Select MyDeploymentAppRole Create ApplicationNote: You may assign the deployment to any relevant Tag that applied to the desired instances targeted for deployment. For simplicity's sake, only the Name Tag has been used to chose the instance previously defined.
https://console.aws.amazon.com/codepipeline/home?region=us-east-1#/dashboard
The next step is to proceed with creating the CodePipeline, which is in charge of performing the connection between the S3 bucket and the CodeDeploy process.
To create a CodePipeline, follow these steps:
Create PipelineMyAppDeploymentPipeline ) Source Provider to Amazon S3 Amazon S3 location to the address of your bucket and target deployment file (ie. s3://my-app-codepipeline-deployment/myapp.zip )Build Provider to None - This is already handled by Gitlab-CI as will be covered later Deployment Provider to AWS CodeDeploy Application Name to the name of your CodeDeploy Application (ie. MyApp-Production)Deployment Group to the name of your CodeDeploy Deployment Group (ie. MyApp-Production-Fleet ) Create PipelineNow that The AWS environment has been prepared to receive the application deployment we can proceed with setting up the CI environment and settings to ensure that the code is built and deployed to an EC2 Instance using S3, CodeDeploy and the CodePipeline.
In order for the deployment to work, we will need to set a few environment variables in the project repository.
In your Gitlab Project, navigate to the Variables area for your project and set the following variables:
AWS_DEFAULT_REGION => your AWS regionAWS_SECRET_ACCESS_KEY => your AWS user credential secret key (obtained when you generated the credentials for the user)AWS_ACCESS_KEY_ID => your AWS user credential key ID (obtained when you generated the credentials for the user)AWS_S3_LOCATION => the location of your deployment zip file (ie. s3://my-app-codepipeline-deployment/my_app.zip )These variables will be accessible by the scripts executed by the Gitlab-CI containers.
A simple startup script has been provided (https://gitlab.com/autronix/gitlabci-ec2-deployment-samples-guide/blob/master/deploy/extras/my_app.sh) to allow the deployment to perform the following tasks:
You may find this script under deploy/extras/my_app.sh
The gitlab-ci.yml file is in charge of performing the Continuous Integration tasks associated with a given commit. It acts as a simplified group of shell scripts that are organized in stages which correspond to the different phases in your Continuous Integration steps.
For more information on the details and reference, please refer to the following two links:
You may validate the syntax of your gitlab-ci.yml file at any time with the following tool: https://gitlab.com/ci/lint
For the purpose of deployment, we will cover only the last piece of the sample provided with this guide:
deploy-job: # Script to run for deploying application to AWS script: - apt-get --quiet install --yes python-pip # AWS CLI requires python-pip, python is installed by default - pip install -U pip # pip update - pip install awscli # AWS CLI installation - $G build -x test -x distTar # # Build the project with Gradle - $G distZip # creates distribution zip for deployment - aws s3 cp $BUNDLE_SRC $AWS_S3_LOCATION # Uploads the zipfile to S3 and expects the AWS Code Pipeline/Code Deploy to pick up # requires previous CI stages to succeed in order to execute when: on_success stage: deploy environment: production cache: key: "$CI_BUILD_NAME/$CI_BUILD_REF_NAME" untracked: true paths: - build/ # Applies only to tags matching the regex: ie: v1.0.0-My-App-Release only: - /^v\d+\.\d+\.\d+-.*$/ except: - branches - triggers This part represents the whole job associated with the deployment following the previous, if any, C.I. stages.
The relevant part associated with the deployment is this:
# Script to run for deploying application to AWS script: - apt-get --quiet install --yes python-pip # AWS CLI requires python-pip, python is installed by default - pip install -U pip # pip update - pip install awscli # AWS CLI installation - $G build -x test -x distTar # # Build the project with Gradle - $G distZip # creates distribution zip for deployment - aws s3 cp $BUNDLE_SRC $AWS_S3_LOCATION # Uploads the zipfile to S3 and expects the AWS Code Pipeline/Code Deploy to pick up The first step involves installing the python package management system: pip. pip is required to install AWS CLI, which is necessary to upload the deployment file to AWS S3
In this example, we are using Gradle (defined by the environment variable $G); Gradle provides a module to automatically Zip the deployment files. Depending on the type of project you are deploying this method will be different for generating the distribution zip file my_app.zip.
The aws s3 cp $BUNDLE_SRC $AWS_S3_LOCATION command uploads the distribution zip file to the Amazon S3 location that we defined earlier. This file is then automatically detected by CodePipeline, processed and sent to CodeDeploy. Finally, CodeDeploy performs the necessary tasks through the CodeDeploy agent as specified by the appspec.yml file.
The appspec.yml defines the behavior to be followed by CodeDeploy once a deployment file has been received.
A sample file has been provided along with this guide along with sample scripts to be executed during the various phases of the deployment.
Please refer to the specification for the CodeDeploy AppSpec for more information on how to build the appspec.yml file: http://docs.aws.amazon.com/codedeploy/latest/userguide/app-spec-ref.html
In order for CodeDeploy to work properly, you must create a properly generated zip file of your application.
The zip file must contain:
appspec.yml => CodeDeploy deployment instructionsscripts directory in the zip file, would require the presence my_app.sh script to be added at the root of your application directory (ie. my_app directory in the zip)my_app directoryTools such as Gradle and Maven are capable of generating distribution zip files with certain alterations to the zip generation process. If you do not use such a tool, you may have to instruct Gitlab-CI to generate this zip file in a different manner; this method is outside of the scope of this guide.
The final step in this guide is actually performing a successful deployment.
The stages of Continuous integration are defined by the rules set in the gitlab-ci.yml. The example provided with this guide will initiate a deploy for any reference matching the following regex: /^v\d+\.\d+\.\d+-.*$/.
In this case, pushing a Tag v1.0.0-My-App-Alpha-Release through git onto your remote Gitlab would initiate the deployment process. You may adjust these rules as applicable to your project requirements.
The gitlab-ci.yml example provided would perform the following jobs when detecting the Tag v1.0.0-My-App-Alpha-Release:
Once the distribution zip has been uploaded to Amazon S3, the following steps happen:
files section of appspec.ymlSuccessful deployment screenshots:
