OpenLegacy Proof of Concept

• OpenLegacy Proof of Concept
  • Warnings and Limitations
  • Overview
    • Personas
      • API Designer / Integration Developer
      • Application Developer
  • Integration Options
    • No Code Service
    • Code Project
    • Application Accelerator
    • Backstage Plugin
  • Modifications to OpenLegacy generated files

Warnings and Limitations

• The proof-of-concept accelerator adds the user supplied license and api keys to the applications properties. Secrets should be fetched not hardcoded.
• Tiltfile live_update sync assumes VisualStudio Code which auto-compiles Java into `./bin/main

Overview

This proof-of-concept illustrates several integration options between OpenLegacy and Tanzu Application Platform (TAP) and assumes TAP infrastructure based on the TAP Reference Architecture has already been created and configured per corporate operations and security standards.

Personas

The boundary between the personas below will change depending on the integration option that best fits the customer.

API Designer / Integration Developer

• Knows and has access to OpenLegacy Hub and Tanzu Application Platform
• Activities
  • Understands company API needs
  • Uses OpenLegacy Hub to create and configure projects to satisy API needs
  • Generates Services from OpenLegacy Hub
  • Provides the generated service to Application Developer by:
    1. Providing the Applicaiton Developer the URL to the OpenAPI endpoints
    2. An archive containing the generated service
    3. Wrapping the generated service into a TAP Accelerator and publishing it

Application Developer

• Does not have access to OpenLegacy Hub, the TAP Secure Software Supply Chain or QA/Test/Prod Run clusters
• Requires access to a TAP Iterate Kubernetes Cluster
• Only needs basic knowledge of tanzu and kubectl CLIs
• Activities
  • Depending on the integration style is provided:
    1. URL to the OpenAPI endpoints
    2. The archive
    3. The name of a TAP Accelerator

Integration Options

No Code Service

API Designer / Integration Developer

• Creates a code repository for the generated service
• Deploys the service with either:
  • DockerFile

    tanzu apps workload create docker-cics \
    --git-repo https://github.com/PeterEltgroth/account-cics-microservice.git \
    --git-branch docker \
    --label "app.kubernetes.io/part-of=docker-cics" \
    --param dockerfile=Dockerfile \
    --type web

  • The build

    tanzu app workload apply -f config/workload.yaml

    or

    tanzu app workload create WORKLOAD_NAME \
    --git-repo REPO_URL \
    --git-branch REPO_BRANCH \
    --label "app.kubernetes.io/part-of=WORKLOAD_NAME" \
    --type web

• Provides the URL to OpenAPI endpoints and access information

Appplication Developer

• Starts making API calls to the OpenAPI endpoints in an existing or new project

Code Project

API Designer / Integration Developer

• Provides the developer with the generated .zip or creates a source code repository and provides it

Appplication Developer

• Extracts or fetches/clones the archive
• Modifies configuration (application properties, workload, Tiltfile, etc.)
• Ensures they are pointed at the correct development/iterate Kubernetes cluster
• Runs tilt up to deploy and begin development
  • The Tiltfile applies the TAP Workload to the developers namespace and configures live update to synchronize local file changes to the remote Kubernetes pod.
  • The initial tilt up takes some time as a full image build and push is run. After this a full build only runs if a non-live updatable file is changed, for example a gradle build file.
• Runs tilt down to delete the TAP workload.

Application Accelerator

API Designer / Integration Developer

• Creates and publishes an Application Accelerator

Appplication Developer

• Goes to TAP, finds the accelerator, fills in required fields, and clicks Generate Accelerator.
• Downlaods the zip
• Creates a source code repository at the location they specified in the TAP Accelerator
• Ensures they are pointed at the correct development/iterate Kubernetes cluster
• Runs tilt up to deploy and work and tilt down to delete the workload

Backstage Plugin

Tanzu Application Platform GUI is built on Backstage which has many plugins; however, TAP GUI currently DOES NOT support the installation of third-party plugins.

Modifications to OpenLegacy generated files

• build.gradle.kts
  • Builpacks
    • Hardcoded kotlin and java versions in plugins section as they were not getting resolved in the build pod
    • Commented out withSourcesJar(). If two jar files are built neither is exploded preventing live reload from working. Having a sources jar in the container which could be deployed to production is also problematic.
• application.yaml
  • Replaced the license and api-key values in application.yml with placeholders. These should be retrieved from a secret store at runtime. In this PoC the Accelerator will substitute them back into application.yml based on user input.
• Dockerfile
  • Modified into a multi-stage build Docker to first build the application with gradle 7.4.2-jdk11-alpine, and then run it.
• Added a gradle wrapper and updated gradle to 7.4.2