Deploy a Micronaut application

A Micronaut application runs on Sevalla as an application built from your Git repository: Ingot, Sevalla’s builder, recognizes the Micronaut Gradle plugin in build.gradle.kts, builds the application with the project’s Gradle wrapper, and the web process starts the executable jar that the Shadow plugin builds with java -Dmicronaut.server.port="$PORT" -jar /app/app.jar, so Micronaut listens on the port that Sevalla sets in the PORT environment variable.

At a glance


Source	A Git repository
Build	Ingot (Java 25, Gradle), or the Dockerfile
Start command	`java -Dmicronaut.server.port="$PORT" -jar /app/app.jar`
Port	The `PORT` environment variable, `8080` by default
Processes	Web process
Services	None
Disk	None
Health check	`GET /health/readiness` returns `200` (readiness probe)
Size	H1 for the web process

Environment variables

The application needs no environment variables of its own. It reads PORT, which Sevalla sets to the web process port.

Before you begin

A Sevalla company with a payment method, and a GitHub, GitLab or Bitbucket account for the repository. See Git providers.
A Java 25 JDK on your computer. The project’s Gradle wrapper downloads Gradle, so you don’t install it.

Create the project

Generate the project with Micronaut Launch: a Java application built with Gradle’s Kotlin DSL, for Java 25, with the management feature for health endpoints.

curl -o storefront.zip "https://launch.micronaut.io/create/default/com.example.storefront?lang=JAVA&build=GRADLE_KOTLIN&test=JUNIT&javaVersion=JDK_25&features=management"
unzip storefront.zip && rm storefront.zip
cd storefront

Launch uses the newest Micronaut release, 5.2.4 when this guide was written, with the Shadow plugin, which builds an executable jar with every dependency, and the Gradle wrapper (gradlew), which runs Gradle 9.6.0. The application’s package is com.example. Add a controller for the home page:

src/main/java/com/example/HelloController.java

package com.example;

import io.micronaut.http.MediaType;
import io.micronaut.http.annotation.Controller;
import io.micronaut.http.annotation.Get;
import io.micronaut.http.annotation.Produces;

@Controller
public class HelloController {

    @Get
    @Produces(MediaType.TEXT_PLAIN)
    public String index() {
        return "Hello from Micronaut on Sevalla";
    }
}

The generated .gitignore already keeps the build output in build/ and Gradle’s .gradle/ folder out of the repository.

Prepare the project for Sevalla

Replace src/main/resources/application.properties with:

src/main/resources/application.properties

micronaut.application.name=storefront
micronaut.server.port=${PORT:8080}
micronaut.lifecycle.graceful-shutdown.enabled=true
micronaut.lifecycle.graceful-shutdown.grace-period=20s

Setting	Why Sevalla needs it
`micronaut.server.port=${PORT:8080}`	Micronaut doesn’t read `PORT`. This makes it listen on the port Sevalla sets, `8080` by default, and on port 8080 on your computer. Ingot also passes `-Dmicronaut.server.port="$PORT"` on the command line; the setting gives a Dockerfile build the same behavior. Micronaut listens on all network interfaces.
`micronaut.lifecycle.graceful-shutdown.*`	Turns on graceful shutdown, which is off by default. See Shut down gracefully.

The rest of the project already has what Ingot needs:

File	Why Sevalla needs it
`build.gradle.kts`	Ingot recognizes a Gradle project by it and by `settings.gradle.kts`. It reads the Java version from `sourceCompatibility`, which Launch sets to `25`, recognizes Micronaut by the `io.micronaut.application` plugin, and runs the jar that the `com.gradleup.shadow` plugin builds, `build/libs/storefront-0.1-all.jar`. See Pin the Java version.
`gradlew` and `gradle/wrapper/`	Ingot builds with the wrapper, so the build runs the Gradle version the project pins. Commit both.
`gradle.properties`	The Micronaut version, `micronautVersion=5.2.4`

From these files, Ingot:

Builds on the Java 25 JDK with ./gradlew --no-daemon assemble, which builds the jars without running the tests; run them in CI.
Copies the Shadow jar into the image as /app/app.jar, and runs it on the Java 25 runtime (JRE) as user 1000:1000, with JAVA_TOOL_OPTIONS set to -XX:MaxRAMPercentage=75 -XX:+ExitOnOutOfMemoryError. See Size the JVM memory.

Run ./gradlew run and open http://localhost:8080 to check the application locally. Then commit everything and push it to your Git provider:

git init
git add .
git commit -m "Prepare for Sevalla"
git branch -M main
git remote add origin https://github.com/acme/storefront.git
git push -u origin main

Deploy to Sevalla

These steps build with Ingot. To build from your own Dockerfile instead, see Deploy with a Dockerfile.

Create the application

In the sidebar, click Applications, then click Create > Application. Under Source, click Private repository, then choose the Git provider, the Repository and the Branch. Under Location, choose a Data center. Keep the Size at H1 or choose a larger one, then click Create application. The application opens on its Overview tab with the status Not deployed yet: creating an application doesn’t deploy it.

Deploy

Click the Overview tab, then click Deploy now under Recent deployments. Check the Branch and click Deploy.

Turn on auto-deploy

To deploy every push to the branch automatically, click the Settings tab, then click Update auto-deploy in the Auto-deploy section. Turn on Auto-deploy and click Update auto-deploy. See Deployments.

Verify the deployment

On the Deployments tab, click the deployment. Its Build log shows Ingot’s build plan: Java 25 from sourceCompatibility in build.gradle.kts, Gradle from the wrapper, and the start command for Micronaut.

Build log

╭─ ■ Micronaut · Java 25 ───────────────────────────────────────────────────────────────────────────────────────╮
│ Java        25                                                      build.gradle.kts sourceCompatibility "25" │
│ Build tool  Gradle                                                  gradlew                                   │
│ Framework   Micronaut                                               build.gradle.kts                          │
│ Start       java -Dmicronaut.server.port="$PORT" -jar /app/app.jar  Micronaut                                 │
├─ Image ───────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Build       eclipse-temurin:25-jdk-resolute                                                                   │
│ Runtime     eclipse-temurin:25-jre-resolute                                                                   │
│ User        1000:1000                                                                                         │
│ Init        tini                                                                                              │
│ Port        $PORT, default 8080                                                                               │
╰──────────────────────────────────────────────────────────────────────────────────────────────── Ingot v0.5.0 ─╯

Wait for the deployment’s status to change to Deployed. The application’s status next to its name changes to Running.
Click the domain under the application’s name, for example storefront-x7k2m.sevalla.app. The page shows Hello from Micronaut on Sevalla.

The application header with its name, Running status, repository, branch and the domain that opens the application

/health/readiness returns {"status":"UP"}. The application’s runtime logs show Startup completed in, followed by the startup time. If the deployment fails, read its build log, then see Troubleshoot Ingot builds. To check the deployment from a terminal or an AI agent, read its status with Get deployment (getDeploymentV3) until it’s success, and its build log with Get application deployment logs (getApplicationDeploymentLogsV3), as in Deploy with the API. Then request the endpoints:

curl -s -w '\n' https://storefront-x7k2m.sevalla.app/health/readiness

{"status":"UP"}

Get application runtime logs (getApplicationRuntimeLogsV3) with search finds the startup time:

curl -s "https://api.sevalla.com/v3/applications/$APP_ID/runtime-logs?search=Startup%20completed" \
  -H "Authorization: Bearer $SEVALLA_API_KEY" | jq -r '.[].message'

[36m05:15:25.541[0;39m [1;30m[main][0;39m [34mINFO [0;39m [35mio.micronaut.runtime.Micronaut[0;39m - Startup completed in 4938ms. Server Running: http://g4-java-micronaut-nq61g-web-7fdcbfc886-rzhfd:8080

Add a health check

The management feature serves Micronaut’s readiness check at /health/readiness. A readiness probe on it makes each new instance wait until Micronaut has started before it gets traffic, so a deployment switches over only to instances that serve requests.

Open the web process

On the application’s Processes tab, click ⋯ on the Web process, then click Update process.

Turn on the readiness probe

Under Health checks, turn on Readiness probe and set the Path to /health/readiness. Keep the Port at the web process’s port, 8080 unless you changed it.

Save and deploy

Click Update process, then click Deploy in the undeployed changes bar at the bottom of the page.

The deployment’s status changes to Deployed once the new instance answers the probe. See Health checks for every probe setting. Deploy with the API sets the same probe. Get process (getProcessV3) returns it in readiness_probe:

curl -s https://api.sevalla.com/v3/applications/$APP_ID/processes/$WEB_ID \
  -H "Authorization: Bearer $SEVALLA_API_KEY" | jq -c .readiness_probe

{"httpGet":{"path":"/health/readiness","port":8080,"scheme":"HTTP"},"initialDelaySeconds":0,"periodSeconds":10,"timeoutSeconds":1,"successThreshold":1,"failureThreshold":3}

Shut down gracefully

When Sevalla stops an instance, during a deployment, a restart or a scale-down, it waits 5 seconds, sends SIGTERM, and stops the instance if it’s still running 30 seconds after the shutdown began. See How processes run. Without graceful shutdown, Micronaut closes the connections of requests still in progress when it receives SIGTERM. With micronaut.lifecycle.graceful-shutdown.enabled=true, it stops accepting requests and waits for the ones in progress, up to the 20 seconds of grace-period, which ends within the 25 seconds between SIGTERM and the end of the shutdown. The old instance’s runtime logs end with Embedded Application shutting down on every deployment.

Deploy with a Dockerfile

Ingot needs no Dockerfile. Write your own when you want full control of the image: the base image, the system packages and every layer. Add a Dockerfile and a .dockerignore to the root of the repository:

Dockerfile

FROM gradle:9-jdk25 AS build
WORKDIR /build
COPY settings.gradle.kts build.gradle.kts gradle.properties ./
RUN gradle --no-daemon --quiet dependencies > /dev/null
COPY src ./src
RUN gradle --no-daemon shadowJar

FROM eclipse-temurin:25-jre-resolute
WORKDIR /app
COPY --from=build /build/build/libs/*-all.jar app.jar
ENV JAVA_TOOL_OPTIONS="-XX:MaxRAMPercentage=75 -XX:+ExitOnOutOfMemoryError"
USER 1000:1000
EXPOSE 8080
CMD ["java", "-jar", "app.jar"]

Line or choice	Why
`gradle:9-jdk25`	Gradle 9, the major version the wrapper pins, on the Java 25 JDK. The official image has Gradle already, so the build doesn’t download it. A line tag, not a digest, so each build gets the newest Gradle 9 release and Java’s and Ubuntu’s security fixes.
Build files copied before the source	`gradle dependencies` downloads the Gradle plugins and resolves the dependencies in a layer that Docker reuses until a build file changes. A code change starts from there.
`gradle shadowJar`	Builds only the executable jar, `build/libs/storefront-0.1-all.jar`, without the tests or the other jars that `assemble` builds.
`eclipse-temurin:25-jre-resolute`	The Java 25 runtime without the compiler, on Ubuntu 26.04: the image Ingot runs Micronaut on. It has `/bin/sh` for the web terminal and custom start commands.
`COPY` without `--chown`, then `USER 1000:1000`	The application runs as user `1000` (`ubuntu` in this image). The jar stays owned by root, so the application can read it but not change it.
`JAVA_TOOL_OPTIONS`	Gives the heap 75% of the memory limit instead of 25%, and exits on `OutOfMemoryError` so Sevalla restarts the instance, as Ingot’s image does. See Size the JVM memory.
`CMD ["java", "-jar", "app.jar"]`	The exec form runs `java` as process 1, so it receives `SIGTERM` directly. The JVM handles `SIGTERM` itself and runs Micronaut’s graceful shutdown, so the image needs no init process.
`EXPOSE 8080`	Documents Sevalla’s default `PORT`. The application reads `PORT` through `micronaut.server.port`.

.dockerignore

.git
.gradle
build
.env*
*.log

The .dockerignore keeps the Git history, Gradle’s local caches, a local build in build/, local environment files and logs out of the build. Commit and push both files. Ingot doesn’t use the Dockerfile, so you can keep it in a repository that builds with Ingot. Ingot adds the .dockerignore patterns to its own, and its build plan shows Ignored 5 patterns from .dockerignore; none of them matches a file the Ingot build needs. Then switch the application to the Dockerfile build strategy:

Choose the Dockerfile build strategy

On the application’s Settings tab, in the Build strategy section, click Update build strategy. Click Dockerfile, keep the Dockerfile path Dockerfile and the Docker context ., then click Update build strategy.

Deploy

Click the Overview tab, then click Deploy now under Recent deployments. Check the Branch and click Deploy.

The deployment’s build log shows 📦 Building and pushing docker image using Dockerfile... instead of Ingot’s build plan, and its Dockerfile tab shows your file. When the deployment’s status is Deployed, the domain shows Hello from Micronaut on Sevalla again. On the next deployment after a code change, the build log shows CACHED for the gradle dependencies step. See Dockerfile. With the API, Update application (updateApplicationV3) switches the build strategy. Then deploy and wait as in Deploy with the API:

curl -s -X PATCH https://api.sevalla.com/v3/applications/$APP_ID \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"build_type":"dockerfile","dockerfile_path":"Dockerfile","docker_context":"."}' \
  | jq -c '{build_type, dockerfile_path, docker_context}'

{"build_type":"dockerfile","dockerfile_path":"Dockerfile","docker_context":"."}

The CLI does the same with sevalla apps update $APP_ID --build-type dockerfile --dockerfile-path Dockerfile. The new deployment’s build log names the Dockerfile build:

curl -s "https://api.sevalla.com/v3/applications/$APP_ID/deployments/$DEPLOYMENT_ID/logs?search=Building%20and%20pushing" \
  -H "Authorization: Bearer $SEVALLA_API_KEY" | jq -r '.[].message'

📦 Building and pushing docker image using Dockerfile...

Deploy changes

With Auto-deploy on, every push to the branch starts a deployment; otherwise, click Deploy now for each change. Each deployment builds the image, then replaces the web process’s instances. See Deployments.

Use environment variables

Add configuration on the application’s Environment variables tab, and read it in application.properties with a placeholder, as micronaut.server.port=${PORT:8080} reads PORT. Variables apply at the next deployment. With Ingot, variables marked Available during buildtime also reach the Gradle build; with a Dockerfile, they arrive as build arguments, which a stage reads only after an ARG line for each one. See Environment variables.

Add a custom domain

To serve the application from your own domain, such as shop.example.com, add the domain on the application’s Domains tab and create the DNS records that Sevalla shows. Custom domains need a web process larger than H1, so scale the web process first. See Custom domains.

Deploy with the API

These calls make the same deployment as Deploy to Sevalla and Add a health check, in an order that a script or an AI agent runs as it is. Each step names the Sevalla API operation, then the CLI command and the MCP server tool that do the same. You need:

An API key with the Company developer role, or the APP:CREATE, APP:READ and APP:UPDATE permissions, in the SEVALLA_API_KEY environment variable. The CLI reads the key from SEVALLA_API_TOKEN.
The repository on a Git provider that’s connected to your Sevalla account. See Git providers. Creating the application checks it: when Sevalla can’t read the repository, the call returns 400 with Cannot access repository https://github.com/acme/storefront: Repository not found or you don't have access., followed by where to grant access.
curl and jq.

Choose the location

List clusters (listClustersV3) returns the locations your company can use, each with its id, the display_name that the dashboard shows and its region ID in location. Keep the ID of the one you want by its region ID, such as eu-frankfurt-1 for Frankfurt, Germany. Locations lists them all:

CLUSTER_ID=$(curl -s https://api.sevalla.com/v3/resources/clusters \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  | jq -r '.[] | select(.location == "eu-frankfurt-1") | .id')

CLI: sevalla resources clusters. MCP: get_platform_options.

Create the application

Create application (createApplicationV3) creates the application with a web process. It builds with Ingot (build_type is ingot) and isn’t deployed yet:

APP_ID=$(curl -s -X POST https://api.sevalla.com/v3/applications \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"display_name":"storefront","cluster_id":"'"$CLUSTER_ID"'","source":"privateGit","git_type":"github","repo_url":"https://github.com/acme/storefront","default_branch":"main"}' \
  | jq -r .id)

CLI:

sevalla apps create --name storefront --cluster $CLUSTER_ID --source privateGit --git-type github --repository https://github.com/acme/storefront --branch main

. MCP: create_application with deploy set to false.

Find the domain

List application domains (listApplicationDomainsV3) returns the domain that Sevalla gives the application. It appears a few seconds after the application is created, so ask until it’s there:

for i in $(seq 1 24); do
  HOST=$(curl -s https://api.sevalla.com/v3/applications/$APP_ID/domains \
    -H "Authorization: Bearer $SEVALLA_API_KEY" | jq -r '.data[]? | select(.is_primary) | .name')
  [ -n "$HOST" ] && break
  sleep 5
done
echo "$HOST"

storefront-x7k2m.sevalla.app

CLI: sevalla apps domains list --app-id $APP_ID. MCP: get_application.

Find the web process

List processes (listProcessesV3) returns the web process that the application was created with:

WEB_ID=$(curl -s https://api.sevalla.com/v3/applications/$APP_ID/processes \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  | jq -r '.data[] | select(.type == "web") | .id')

CLI: sevalla apps processes list --app-id $APP_ID. MCP: get_application.

Find the H1 size

List process resource types (listProcessResourceTypesV3) returns the sizes by name, in lowercase:

H1_ID=$(curl -s https://api.sevalla.com/v3/resources/process-resource-types \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  | jq -r '.[] | select(.name == "h1") | .id')

CLI: sevalla resources process-types. MCP: get_platform_options.

Set the size and the readiness probe

The API creates the web process at S1, where the dashboard’s default is H1. Update process (updateProcessV3) sets the size and adds the readiness probe from Add a health check, with the dashboard’s default timings. Send timeoutSeconds: a probe without it gets 120 seconds, where the dashboard sets 1.

curl -s -X PATCH https://api.sevalla.com/v3/applications/$APP_ID/processes/$WEB_ID \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"resource_type_id":"'"$H1_ID"'","readiness_probe":{"httpGet":{"path":"/health/readiness","port":8080,"scheme":"HTTP"},"initialDelaySeconds":0,"periodSeconds":10,"timeoutSeconds":1,"successThreshold":1,"failureThreshold":3}}' \
  | jq -c '{resource_type_name, readiness_probe}'

CLI: sevalla apps processes update $WEB_ID --app-id $APP_ID --resource-type $H1_ID sets the size; the CLI can’t set probes. MCP: scale_process with size_id for the size, and sevalla_api_update with updateProcessV3 and the same body for the probe.

Turn on auto-deploy

Update application (updateApplicationV3) turns on automatic deployments for every push to the branch:

curl -s -X PATCH https://api.sevalla.com/v3/applications/$APP_ID \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"auto_deploy":true}' | jq .auto_deploy

CLI: sevalla apps update $APP_ID --data '{"auto_deploy":true}'. MCP: sevalla_api_update with updateApplicationV3.

Deploy

Trigger deployment (triggerDeploymentV3) deploys the latest commit on the branch:

DEPLOYMENT_ID=$(curl -s -X POST https://api.sevalla.com/v3/applications/$APP_ID/deployments \
  -H "Authorization: Bearer $SEVALLA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"branch":"main"}' | jq -r .id)

CLI: sevalla apps deployments trigger $APP_ID --branch main. MCP: trigger_deployment.

Wait for the deployment

Get deployment (getDeploymentV3) returns the deployment’s status: waiting and inProgress while it runs, then success, failed, cancelled or skipped. Poll it until the status is final, for up to 30 minutes:

for i in $(seq 1 120); do
  STATUS=$(curl -s "https://api.sevalla.com/v3/applications/$APP_ID/deployments/$DEPLOYMENT_ID" \
    -H "Authorization: Bearer $SEVALLA_API_KEY" | jq -r '.status // empty')
  case $STATUS in success|failed|cancelled|skipped) break ;; esac
  sleep 15
done
echo "$STATUS"

success

CLI: sevalla apps deployments get $DEPLOYMENT_ID --app-id $APP_ID. MCP: get_deployment.

Read the build log

Get application deployment logs (getApplicationDeploymentLogsV3) returns the build log, oldest line first: the build plan from Verify the deployment, the build and the rollout. When the status is failed, the last lines say why.

curl -s https://api.sevalla.com/v3/applications/$APP_ID/deployments/$DEPLOYMENT_ID/logs?limit=5000 \
  -H "Authorization: Bearer $SEVALLA_API_KEY" | jq -r '.[].message'

CLI: sevalla apps deployments logs $DEPLOYMENT_ID --app-id $APP_ID. MCP: get_deployment_logs.

Check the application

Request the home page from the application’s domain:

curl -s -w '\n' https://$HOST/

Hello from Micronaut on Sevalla

Then run the other checks in Verify the deployment.

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Deploy a Micronaut application

At a glance

Environment variables

Before you begin

Create the project

Prepare the project for Sevalla

Deploy to Sevalla

Verify the deployment

Add a health check

Shut down gracefully

Deploy with a Dockerfile

Deploy changes

Use environment variables

Add a custom domain

Deploy with the API

​At a glance

​Environment variables

​Before you begin

​Create the project

​Prepare the project for Sevalla

​Deploy to Sevalla

​Verify the deployment

​Add a health check

​Shut down gracefully

​Deploy with a Dockerfile

​Deploy changes

​Use environment variables

​Add a custom domain

​Deploy with the API

At a glance

Environment variables

Before you begin

Create the project

Prepare the project for Sevalla

Deploy to Sevalla

Verify the deployment

Add a health check

Shut down gracefully

Deploy with a Dockerfile

Deploy changes

Use environment variables

Add a custom domain

Deploy with the API