🚀 BG Deployer: A Shell-Based Blue-Green Deployment Solution

BG Deployer is a Linux shell script wrapper around AWS CLI that automates blue-green and canary deployments. It’s designed to simplify backend application deployments with minimal changes to your Auto Scaling Groups (ASGs) or Application Load Balancers (ALBs).

This script provides a fully automated, zero-downtime deployment experience by managing ASG counts and ALB listener rules, leaving the actual deployment tasks to be configured in the instance userdata (e.g., using Ansible playbooks).

🔧 Key Features

• 🎯 Fully Automated: Streamlined deployment with zero downtime.
• ⚡ Flexible: Customizable to suit any deployment process.
• 🛠️ Full Userdata Control: Configure deployments remotely via userdata scripts.
• 🔄 Easy Rollbacks: Automated/manual rollback in case of deployment failures.
• 🚦 Traffic Control: Gradual traffic migration from 1% to 100% for smooth transitions.
• ✅ Success Checks: Optional validation of 2xx HTTP requests to ensure deployment success.
• 📊 Faster Deployments: Dynamic, optimized execution—usually under 2 minutes (depends on userdata execution).
• 💼 Simplified Rollbacks: Reset to the previous version effortlessly.
• 🕒 Scheduled Actions: Migrates active ASG schedules without hassle.

📋 Prerequisites

To use BG Deployer effectively:

1. Infrastructure Requirements:
   • Two ASGs: One for the Blue environment and one for the Green environment.
   • Weighted traffic routing configured at the ALB level.
   • Required tags added to both ASGs (explained below).
2. Linux Packages:
   • AWS CLI (v2): For interacting with AWS resources.
   • Common Linux utilities: jq, awk, grep, etc.
3. Jenkins Integration:
   • Jenkins server with access to your ASGs.
   • Configured jobs for build creation and deployment.

🖥️ How It Works

BG Deployer operates by managing the ASG counts and ALB listener rules. The deployment process involves:

1. 🚀 Preparing the Green Environment:
   • Increase the instance count of the passive ASG (Green) to match the active ASG (Blue).
   • Userdata handles the deployment using Ansible playbooks configured in EC2.
2. 🔄 Traffic Shifting:
   • Gradually shifts traffic to the Green environment via ALB’s weighted traffic routing.
   • Monitors traffic metrics using AWS CloudWatch.
3. ✅ Validation:
   • Evaluates deployment success based on 2xx HTTP response codes or other predefined metrics.
4. 🔙 Rollback (if required):
   • Reverts traffic to the Blue environment in case of any issues.
5. 🔧 Update Tags and Resources:
   • Dynamically updates ASG tags, ALB listener rules, and ASG scheduled actions.

🔑 Important Notes

• BG Deployer controls only ASG counts and traffic routing; it does not execute deployment steps directly on instances.
• Deployment logic (e.g., pulling builds, configuring applications) must be defined in Userdata.

For example, Ansible playbooks can be included in Userdata to automate deployments on ASG instances.

🏗️ Setup Requirements

1️⃣ Infrastructure Prerequisites

• Two ASGs (e.g., blue and green) configured with BG Deployer Tags.
• Weighted traffic routing enabled at ALB level.
• Proper IAM roles and permissions for AWS CLI operations.

2️⃣ BG Deployer Tags for ASGs

Add the following tags to both ASGs:

Tag	Required	Blue ASG	Green ASG	Type	Remarks
TechTeam	✅	project-abc	project-abc	Static	Identifies the project team.
Environment	✅	Staging	Staging	Static	Defines the environment (e.g., Staging, Prod).
Stack	✅	myapp-stage	myapp-stage	Static & Unique	Unique identifier for the app stack.
Service	❌	myapp-stage-blue	myapp-stage-green	Static & Unique	Used for remote Ansible runs.
BuildType	❌	rpm or jar	rpm or jar	Static	Defines the type of build artifact.
Cluster	✅	blue	green	Static	Denotes the ASG type (blue/green).
ActiveCluster	✅	blue	blue	Dynamic	Dynamically updated during deployment.

3️⃣ Build Creation

• A Jenkins job creates the application build (.jar, .rpm, .war) and uploads it to S3 in the following structure:

  s3://<bucket>/<project>/<env>/builds/<Build_Profile>/<Stack>/<AppName>/<BuildNo>-<Branch>-<Build_Profile>-<AppName>-<Build_TimeStamp>.<extension>
  

  Example:

  s3://mys3bucket/project/nonprod/builds/stage/myapp-stage/myapp-name/73-develop-stage-myapp-name-27Jul23-09-20.rpm
  

4️⃣ Deployment Execution

• Trigger a Jenkins deployment job that runs the BG Deployer script with specified parameters (e.g., build number, traffic percentage).
• The script performs the following:
  1. Identifies the passive ASG (e.g., Green) and updates its instance count to match the active ASG.
  2. Updates ASG tags:
     • ActiveCluster tag is toggled between blue and green.
  3. Modifies ALB listener rules to route traffic safely.
  4. Migrates scheduled actions to the active ASG.

5️⃣ Userdata Configuration

• Configure userdata for ASGs to deploy the correct build.
• The userdata script should:
  • Download the build info file (yaml, sh) from S3.
  • Deploy the specified build artifact (e.g., filename.jar).

6️⃣ Traffic Migration

• Gradually migrate traffic from the Blue environment to the Green environment based on the specified percentage.
• Monitor deployment success using optional 2xx checks.

7️⃣ Rollback (if necessary)

• If any stage fails, BG Deployer can revert traffic back to the Blue environment.
• Manual or automated rollbacks ensure minimal downtime and quick recovery.

🔄 Workflow

(Editable in diagrams.net)

📥 Download and Setup

1. Download BG Deployer Script:

   wget https://github/repo/owner/src/master/extras/bgdeployer-v3.sh
   chmod +x bgdeployer-v3.sh
   

2. Run the Script:
   Integrate it with your Jenkins pipeline for deployment automation.

🌟 Why Choose BG Deployer?

• Automates complex deployments with ease.
• Provides robust traffic control for safer transitions.
• Simplifies integration with existing blue-green infrastructure.
• Enables faster, dynamic deployments.

🖥 Conclusion

BG Deployer simplifies Blue-Green and Canary deployments with zero-downtime, dynamic traffic control, and robust rollback mechanisms. It’s fast, efficient, and integrates seamlessly with existing infrastructure.

🌟 Ready to optimize your deployments? Try BG Deployer now! 🚀