# Using Micronaut with NubesGen

This documentation is for running Micronaut applications with NubesGen. There are two other options that might interest you:

You can also use Java with NubesGen, which is similar, but does not use the specific Micronaut Framework application properties.
As Micronaut Framework applications can be packaged with Docker, you can also run them as Docker applications with NubesGen.

# Tutorial: running a Micronaut Launch project with NubesGen

This tutorial is similar to the Java on NubesGen tutorial, as this simple Micronaut application is also a Java application.

Prerequisites:

Tip: You can go to https://aka.ms/nubesgen-azure-shell (opens new window) to have those prerequisites installed, and run the script from a Web browser.

Bash (opens new window), which is installed by default on most Linux distributions and on Mac OS X. If you're using Windows, one solution is to use WSL (opens new window).
Azure CLI (opens new window). To login, use az login.
(optional) GitHub CLI (opens new window). To login, use gh auth login.

Steps:

Create a sample Java Web application using https://launch.micronaut.io/ . Here we are requesting a Gradle build.

curl --location --request GET 'https://launch.micronaut.io/create/default/com.example.micronaut-sample-app?lang=JAVA&build=GRADLE&test=JUNIT&javaVersion=JDK_11' | tar -xzvf -

Create a project on GitHub called micronaut-sample-app, and push the generated project to that repository. Change <your-github-account> by the name of your GitHub account:

cd micronaut-sample-app
git init
git add .
git commit -m "first commit"
git remote add origin https://github.com/<your-github-account>/micronaut-sample-app.git
git branch -M main
git push -u origin main

In the cloned project (cd micronaut-sample-app), set up GitOps with NubesGen by running the NubesGen CLI (more information here):
```
 ./nubesgen-cli-linux gitops
```

Use the command-line with NubesGen (more information here) to generate a NubesGen configuration:

curl "https://nubesgen.com/demo.tgz?runtime=micronaut_gradle&application=app_service.standard&gitops=true" | tar -xzvf -

Or if you have chosen a Maven build, then use the following command:

curl "https://nubesgen.com/demo.tgz?runtime=micronaut&application=app_service.standard&gitops=true" | tar -xzvf -

Push the generated terraform and GitHub action to the main branch of the repository:

cd micronaut-sample-app
git add .
git commit -m "Configure GitOps with NubesGen"
git push -u origin main

Create a new branch called env-dev, and push it to trigger a build:

git checkout -b env-dev
git push --set-upstream origin env-dev

Go to your GitHub project, and check that the GitHub Action is running.
You can go to the Azure Portal (opens new window) to check the created resources.
The application should be deployed on your App Service instance. Its URL should be in the form https://app-demo-XXXX-XXXX-XXXX-XXXX-dev-001.azurewebsites.net/, and you can also find it in the GitHub Action workflow (Job: "display-information", step "Display Azure infrastructure information"), or in the Azure portal. As it is an empty application, you should get a 404 page with JSON describing the request.
Once you have finished, you should clean up your resources:
1. Delete the resource group that was created by NubesGen to host your resources, which is named rg-demo-XXXX-XXXX-XXXX-XXXX-001.
2. Delete the storage account used to store your Terraform state, in the rg-terraform-001 resource group.

# Tutorial 2: running a Micronaut Guide project with a PostgreSQL database

For this tutorial, we will take the Maven/Java Micronaut GraphQL guide project and deploy it to Azure using NubesGen GitOps.

Go to the Maven/Java version of the Micronaut Todos GraphQL guide (opens new window).
Download the solution (opens new window) and extract it.

Create a project on GitHub called micronaut-graphql-todo and push the downloaded project to that repository. Change <your-github-account> by the name of your GitHub account:

cd micronaut-graphql-todo
git init
git add .
git commit -m "first commit"
git remote add origin https://github.com/<your-github-account>/micronaut-graphql-todo.git
git branch -M main
git push -u origin main

In the same directory, set up GitOps with NubesGen by running the NubesGen CLI (more information here):
```
 ./nubesgen-cli-linux gitops
```

Use the command-line with NubesGen (more information here) to generate a NubesGen configuration:

curl "https://nubesgen.com/demo.tgz?database=postgresql&runtime=micronaut&application=app_service.standard&gitops=true" | tar -xzvf -

Or, if you are using a Gradle build, you will need to change runtime to micronaut_gradle like so:

curl "https://nubesgen.com/demo.tgz?database=postgresql&runtime=micronaut_gradle&application=app_service.standard&gitops=true" | tar -xzvf -

Push the generated terraform and GitHub action to the main branch of the repository:
```
git add .
git commit -m "Configure GitOps with NubesGen"
git push
```
Create a new branch called env-dev, and push it to trigger a build:
```
git checkout -b env-dev
git push -u origin env-dev
```
Go to your GitHub project, and check that the GitHub Action is running.
You can go to the Azure Portal (opens new window) to check the created resources.
Once deployed, you can access the application at https://app-demo-XXXX-XXXX-XXXX-XXXX-dev-001.azurewebsites.net/. Add a TODO to the database:

> curl -X POST 'https://app-demo-XXXX-XXXX-XXXX-XXXX-dev-001.azurewebsites.net/graphql' \
       -H 'content-type: application/json' \
       --data-binary '{"query":"mutation { createToDo(title:\"Create GraphQL Guide\", author:\"Tim Yates\") { id } }"}'

{"data":{"createToDo":{"id":"1"}}}

List the current TODOs:

> curl -X POST 'https://app-demo-XXXX-XXXX-XXXX-XXXX-dev-001.azurewebsites.net/graphql' \
       -H 'content-type: application/json' \
       --data-binary '{"query":"{ toDos { title, completed, author { username } } }"}'

{"data":{"toDos":[{"title":"Create GraphQL Guide","completed":false,"author":{"username":"Tim Yates"}}]}}

Once you have finished, you should clean up your resources:
Delete the resource group that was created by NubesGen to host your resources, which is named rg-demo-XXXX-XXXX-XXXX-XXXX-001.
Delete the storage account used to store your Terraform state, in the rg-terraform-001 resource group.

# Which Azure resources will be created

If you deploy your Micronaut application to an Azure App Service instance, NubesGen will generate:

An Azure App Service plan (opens new window) to define the type of App Service instance you will use.
An Azure App Service instance (opens new window), configured to run Java code natively.

If you deploy your Micronaut application to an Azure Function, NubesGen will generate:

An Azure App Service plan (opens new window) to define the type of Azure Functions instance you will use.
An Azure Functions instance (opens new window), configured to run Java code natively.
An Azure Storage Account (opens new window), to store your Java application.

# Maven vs Gradle

NubesGen supports both Maven and Gradle, so you can use the build system you prefer. For Maven, change runtime=micronaut_gradle to runtime=micronaut in Step 5 above.

# Configuration options

In the generated terraform/modules/app-service/main.tf file, NubesGen will configure some environment variables for your application. Those are standard Micronaut properties, so your Micronaut application should be automatically configured (for example: your database connection should be working out-of-the-box).

DATASOURCES_DEFAULT_URL: the JDBC URL to your database
DATASOURCES_DEFAULT_USERNAME: the database user name
DATASOURCES_DEFAULT_PASSWORD: the database password
REDIS_HOST: the Redis host name
REDIS_PASSWORD: the Redis password
REDIS_PORT: the Redis port (by default 6380)
REDIS_SSL: if Redis uses SSL (by default true)
MONGODB_URI: the MongoDB database URL

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