Ktor Starter (In Progress)

• Overview
• Pre-requisites
• Up & Running
• Live Reload
• Troubleshooting
• Additional Topics
  • Local Development with Minikube

Overview

This starter is a set of utilities built on top of Ktor to quickly bootstrap a microservice. This starter sets up the following features:

Service

• Application architecture that favors grouping by feature.
• The follow service feautures using ktor plugins are setup :
  • Ignore trailing slashes in routes. (e.g. foo/ and foo are treated the same)
  • Default headers
  • Response compression
  • Kubernetes style startup, readiness and liveness health checks using Cohort.
  • Swagger UI for API documentation using Tegral's Ktor OpenAPI
• The following Kotlin quality plugins are setup: ktlint, detekt and kover
• Supplement Ktor's command line configuration with the ability to load configuration from a file using Hoplite.

Infrastructure

• Multi-environment Terraform setup using Terragrunt

Pre-Requisites

1. Docker
2. Terraform - for infrastructure as code.
3. Terragrunt - for managing multiple Terraform environments.
4. Gradle - via your preferred development workflow.

I typically manage installations using asdf, but to each their own. If you do use, asdf, there is a .tool-versions file in the root of the project that you can use for installation.

Up & Running

Let's first clone the repo and fire up our system,

git clone git@github.com:aedenj/ktor-starter.git ~/projects/ktor-starter
cd ~/projects/ktor-starter;docker compose up

This will start the app on port 8080. Navigate to http://localhost:8080 to see the app running.

Live Reload

When running the service via docker compose Ktor's auto-reload functionality is enabled. This means that if you open a separate terminal and run the command ./gradlew -t build -x test -i when you make changes to the code, the service will automatically reload.

Troubleshooting

• The jib task may fail initially from an authentication error like following,

Got output:

credentials not found in native keychain

The credential helper (docker-credential-desktop) has nothing for server URL: registry-1.docker.io

Make sure the task is actually failing. Jib tries serveral hosts and you may have credentials setup for one of them. If the task is failing, you can fix this by running the following commands,

1. Run docker login registry-1.docker.io and enter your Docker Hub credentials.

2. Re-run the JIB task.