Tech Summit FY26 Lab: GitHub Copilot App Modernization for Java - Migrate to Azure

A short lab that walks through assessing and migrating the sample Java application "asset-manager" from AWS/RabbitMQ/Postgres to Azure Blob Storage, Azure Service Bus, and Azure Database for PostgreSQL using GitHub Copilot App Modernization for Java.

• Tech Summit FY26 Lab: GitHub Copilot App Modernization for Java - Migrate to Azure
  • Overview
  • Audience & Objectives
  • Estimated time & difficulty
  • About the Project
    • Original Infrastructure
    • Original Architecture
    • Migrated Infrastructure
    • Migrated Architecture
  • Prerequisites
  • Lab: Migrate the Sample Java Application
    • Assess Your Java Application
    • Migrate to Azure Database for PostgreSQL Flexible Server
    • Migrate from AWS S3 to Azure Blob Storage
    • Migrate from AMQP RabbitMQ to Azure Service Bus
    • Completion
    • Manual Verification & Checkpoints:
    • Trouble Shooting
      • GHCP seems to be doing something unclear
  • References & resources

Overview

This hands-on lab demonstrates assessing and migrating a Java web + worker application to Azure using GitHub Copilot App Modernization for Java. The lab is organized as small focused tasks with verification points after each major step.

GitHub Copilot App Modernization for Java, also referred to as App Modernization for Java or AppMod, assists with app assessment, planning and code remediation using a Visual Studio Code Extension and GitHub Copilot. It automates repetitive tasks, boosting developer confidence and speeding up the Azure migration and ongoing optimization.

Audience & Objectives

• Audience: Cloud Solution Architects & Solution Engineers performing Java Cloud Migrations & Modernization.
• Learning objectives:
  • Run an automated assessment for cloud readiness.
  • Apply Copilot-generated migrations for DB, storage, and messaging.
  • Verify migrated code locally.

Estimated time & difficulty

• Estimated time: 60–90 minutes
• Difficulty: Intermediate (familiarity with Java, Maven, VS Code, and Azure CLI recommended)

About the Project

This application consists of two sub-modules, Web and Worker. Both of them contain functions of using storage service and message queue.

Original Infrastructure

The project uses the following original infrastructure:

• AWS S3 for image storage, using password-based authentication (access key/secret key)
• RabbitMQ for message queuing, using password-based authentication
• PostgreSQL database for metadata storage, using password-based authentication

Original Architecture

flowchart TD

%% Applications
WebApp[Web Application]
Worker[Worker Service]

%% Storage Components
S3[(AWS S3)]
LocalFS[("Local File System<br/>dev only")]

%% Message Broker
RabbitMQ(RabbitMQ)

%% Database
PostgreSQL[(PostgreSQL)]

%% Queues
Queue[image-processing queue]
RetryQueue[image-processing.retry queue]

%% User
User([User])

%% User Flow
User -->|Upload Image| WebApp
User -->|View Images| WebApp

%% Web App Flows
WebApp -->|Store Original Image| S3
WebApp -->|Store Original Image| LocalFS
WebApp -->|Send Processing Message| RabbitMQ
WebApp -->|Store Metadata| PostgreSQL
WebApp -->|Retrieve Images| S3
WebApp -->|Retrieve Images| LocalFS
WebApp -->|Retrieve Metadata| PostgreSQL

%% RabbitMQ Flow
RabbitMQ -->|Push Message| Queue
Queue -->|Processing Failed| RetryQueue
RetryQueue -->|After 1 min delay| Queue
Queue -->|Consume Message| Worker

%% Worker Flow
Worker -->|Download Original| S3
Worker -->|Download Original| LocalFS
Worker -->|Upload Thumbnail| S3
Worker -->|Upload Thumbnail| LocalFS
Worker -->|Store Metadata| PostgreSQL
Worker -->|Retrieve Metadata| PostgreSQL

%% Styling
classDef app fill:#90caf9,stroke:#0d47a1,color:#0d47a1
classDef storage fill:#a5d6a7,stroke:#1b5e20,color:#1b5e20
classDef broker fill:#ffcc80,stroke:#e65100,color:#e65100
classDef db fill:#ce93d8,stroke:#4a148c,color:#4a148c
classDef queue fill:#fff59d,stroke:#f57f17,color:#f57f17
classDef user fill:#ef9a9a,stroke:#b71c1c,color:#b71c1c

class WebApp,Worker app
class S3,LocalFS storage
class RabbitMQ broker
class PostgreSQL db
class Queue,RetryQueue queue
class User user

Loading

Password-based authentication

Migrated Infrastructure

After migration, the project will use the following Azure services, in expected branch:

• Azure Blob Storage for image storage, using managed identity authentication
• Azure Service Bus for message queuing, using managed identity authentication
• Azure Database for PostgreSQL for metadata storage, using managed identity authentication

Migrated Architecture

flowchart TD

%% Applications
WebApp[Web Application]
Worker[Worker Service]

%% Azure Storage Components
AzBlob[(Azure Blob Storage)]
LocalFS[("Local File System<br/>dev only")]

%% Azure Message Broker
ServiceBus(Azure Service Bus)

%% Azure Database
AzPostgreSQL[(Azure PostgreSQL)]

%% Queues
Queue[image-processing queue]
RetryQueue[retry queue]

%% User
User([User])

%% User Flow
User -->|Upload Image| WebApp
User -->|View Images| WebApp

%% Web App Flows
WebApp -->|Store Original Image| AzBlob
WebApp -->|Store Original Image| LocalFS
WebApp -->|Send Processing Message| ServiceBus
WebApp -->|Store Metadata| AzPostgreSQL
WebApp -->|Retrieve Images| AzBlob
WebApp -->|Retrieve Images| LocalFS
WebApp -->|Retrieve Metadata| AzPostgreSQL

%% Service Bus Flow
ServiceBus -->|Push Message| Queue
Queue -->|Processing Failed| RetryQueue
RetryQueue -->|After 1 min delay| Queue
Queue -->|Consume Message| Worker

%% Worker Flow
Worker -->|Download Original| AzBlob
Worker -->|Download Original| LocalFS
Worker -->|Upload Thumbnail| AzBlob
Worker -->|Upload Thumbnail| LocalFS
Worker -->|Store Metadata| AzPostgreSQL
Worker -->|Retrieve Metadata| AzPostgreSQL

%% Styling
classDef app fill:#90caf9,stroke:#0d47a1,color:#0d47a1
classDef storage fill:#68B3A1,stroke:#006064,color:#006064
classDef broker fill:#B39DDB,stroke:#4527A0,color:#4527A0
classDef db fill:#90CAF9,stroke:#1565C0,color:#1565C0
classDef queue fill:#81C784,stroke:#2E7D32,color:#2E7D32
classDef user fill:#ef9a9a,stroke:#b71c1c,color:#b71c1c

class WebApp,Worker app
class AzBlob,LocalFS storage
class ServiceBus broker
class AzPostgreSQL db
class Queue,RetryQueue queue
class User user

Loading

Managed identity based authentication

Prerequisites

To successfully complete this workshop, you need the following:

• VSCode: The latest version is recommended.
• A Github account with Github Copilot enabled: All plans are supported, including the Free plan.
• GitHub Copilot extension in VSCode: The latest version is recommended.
• GitHub Copilot app modernization for Java Extension: The extension needed for migration
• AppCAT: Required for the app assessment feature.
• JDK 21: Required for the code remediation feature and running the initial application locally.
• Maven 3.9.9: Required for the assessment and code remediation feature.
• Azure subscription: Required if you want to deploy the migrated application to Azure.
• Azure CLI: Required if you want to deploy the migrated application to Azure locally. The latest version is recommended.

Lab: Migrate the Sample Java Application

The following sections guide you through the process of migrating the sample Java application called asset-manager to Azure using GitHub Copilot App Modernization for Java.

Assess Your Java Application

The first step is to assess the sample Java application called asset-manager. The assessment provides insights into the application's readiness for migration to Azure.

1. Open the VS code with all the prerequisites installed. Then open the project by running code . in the project directory or open the project inside VS Code.

2. Open the extension GitHub Copilot App Modernization for Java.

3. Hover the mouse over the Assessment section and click Assess button which looks like a triangle pointing right. Then, the Github Copilot Chat window will be opened and propose to run Modernization Assessor. Please confirm the tool usage by clicking Continue.

   

   NOTE: If you are asked to allow the tool access the language models provided by GitHub Copilot Chat, select Allow to proceed.

4. After each step, please manually input "continue" to confirm and proceed.

5. App Mod will then run a precheck asessment to see if AppCAT is installed:

   

NOTE: AppCAT should be installed already using the devcontainer.

1. App Mod will try to install appcat eventually to make sure it's in the right place

   

2. It will start the assessment after all prechecks and install have been completed.

   

   NOTE: You can click on the arrow dropdown next to *Running appmod-run-asessment to view the params that are sent to the MCP server.

3. Wait for the assessment to be completed and the report to be generated.

   

4. Review the Summary report. Take a look at the Cloud Readiness report under the Issues tab to view the proposed solutions for the issues identified in the summary report.

Migrate to Azure Database for PostgreSQL Flexible Server

1. For this workshop, we will start with the Database Migration. Select Migrate to Azure Database for PostgreSQL (SDK on Public Cloud) in the Solution report dropdown on the right.

   

2. Right next to the Dropdown, click Migrate.

3. After clicking the Migrate button in the Solution Report, Copilot chat window will be opened with Agent Mode.

4. You should see GitHub Copilot run #appmod-run-task by kbId: managed-identity-azure-sdk-public-cloud/mi-postgresql-azure-sdk-public-cloud

   

5. GHCP will continue to run appmod-run-task, appmod-fetch-knowledgebase,appmod-search-file and other tasks using the MCP Server. During each step, please manually click Continue repeatedly to allow, confirm and proceed. The Copilot Agent uses various tools to facilitate application modernization. Each tool's usage requires confirmation by clicking the Continue button.

6. Wait for the tasks to complete and a progress overview will show up as well as a migration plan inside GitHub Copilot Chat. Durch each step, please manually input or click "confirm" or "continue" to confirm and proceed. You can find these files under .github/appmod-java/code-migration/managed-identity-azure-sdk-public-cloud/progress.md.

   

7. Click Continue to confirm to run Java Application Build-Fix tool. This tool will attempt to resolve any build errors, in up to 10 iterations.

8. After the Build-Fix tool begins, click Continue to proceed and show progress and migration summary.

9. Review the proposed code changes and click Keep to apply them.

   

   

10. GHCP will continue to run appmod-consistency-validation. Continue and Confirm until it runs appmod-create-migration-summary.

11. Once GitHub Copilot provides oyu with next recommended actions after the Summary has been generated, this part of the lab is concluded.

12. Take a look at the summary.md file to review the changes. .github/appmod-java/code-migration/managed-identity-azure-sdk-public-cloud/mi-postgresql-azure-sdk-public-cloud/summary.md

Migrate from AWS S3 to Azure Blob Storage

The Application asset-manager uses AWS S3 for image storage. Let's move to Azure Blob Storage instead.

1. Open the Assessment Report. You can always find it by opening the GitHub Copilot App Modernization for Java Extension and look under Assessment.

2. For this part of the workshop, we will take a look at the Storage Migration. We will Migrate from AWS S3 to Azure Blob Storage.

   

3. Click Migrate.

4. GitHub Copilot runs #appmod-run-task by kbId: s3-to-azure-blob-storage

5. GHCP will continue to run appmod-run-task, appmod-fetch-knowledgebase,appmod-search-file and other tasks using the MCP Server. During each step, please manually click Continue repeatedly to allow, confirm and proceed. The Copilot Agent uses various tools to facilitate application modernization. Each tool's usage requires confirmation by clicking the Continue button.

6. Review the proposed code changes and click Keep to apply them.

   

Migrate from AMQP RabbitMQ to Azure Service Bus

The Application asset-manager uses Spring AMQP with RabbitMQ for message queuing. Let's move to Azure Service Bus instead.

1. For this part of the workshop, we will take a look at the Messaging Service Migration. We will Migrate from AMQP RabbitMQ to Azure Service Bus.

   

2. Click Migrate.

3. GitHub Copilot runs #appmod-run-task by kbId: amqp-rabbitmq-servicebus

4. GHCP will continue to run appmod-run-task, appmod-fetch-knowledgebase,appmod-search-file and other tasks using the MCP Server. During each step, please manually click Continue repeatedly to allow, confirm and proceed. The Copilot Agent uses various tools to facilitate application modernization. Each tool's usage requires confirmation by clicking the Continue button.

5. Review the proposed code changes and click Keep to apply them.

Completion

Congratulations — you completed the lab!

• You ran an automated assessment and applied Copilot-generated migrations for database, storage, and messaging.
• You reviewed and accepted the generated code changes and migration summary.

Next steps

• You are free to deploy the migrated application to Azure using the provided deployment scripts in the main repo: (scripts\deploy-to-azure.cmd or scripts/deploy-to-azure.sh).
• Explore the expected branch to compare the final migrated state and learn from the changes.
• When finished, run the cleanup script to remove Azure resources (scripts\cleanup-azure-resources.cmd or scripts/cleanup-azure-resources.sh).

Resources

• Review .github/appmod-java/.../summary.md and plan.md for migration details.
• See the References & resources section above for SDK and CLI documentation.

Well done! We hope this lab improved your confidence with App Modernization for Java and Azure migrations.

Manual Verification & Checkpoints:

After each major step you can run for build checks: mvn -f web/ clean package mvn -f worker/ clean package

Trouble Shooting

GHCP seems to be doing something unclear

Go and take a look at .github/appmod-java/code-migration/managed-identity-azure-sdk-public-cloud/progress.md and .github/appmod-java/code-migration/managed-identity-azure-sdk-public-cloud/plan.md. You will find the Migration Session ID in plan.md which you can always use to refer to the current migration plan.

References & resources

• GitHub Copilot App Modernization for Java
• Azure CLI docs
• Azure Database for PostgreSQL
• Azure Blob Storage SDK for Java
• Azure Service Bus SDK for Java