A Dockerfile that fits
The Dockerfile below listens on $PORT, runs as non-root and writes only to /tmp, the rules the platform checks.
Spring Boot deploy guide · Agent Lab Deploy
Deploy Spring Boot
in one sentence.
Add the Dockerfile below to your Spring Boot project — or tell Claude Code, Codex or Cursor "deploy this". Agent Lab builds it into a web service, gives every version a preview URL with rollback, and checks uploads for leaked keys. Apps and databases run on Google Cloud in Taiwan.
> deploy this Spring Boot app
sites_createmy-spring-boot
sites_deployDockerfile
sites_deploy_statusbuilt · secret scan passed
Live at my-spring-boot--acme.hosting.agentlab.run
Why deploy Spring Boot on Agent Lab
Spring Boot online without running a server yourself
Java project, built from a Dockerfile, deployed as a web service.
Preview, go live, roll back
Every upload is a new version with its own URL. Look first, then go live; switch back to any version in one click.
Leaked keys caught
Uploads are checked for API keys and credentials before they can go live. Secrets go in the console, never in the code.
PostgreSQL in one click
Create a database and connect it; the connection is written into the app's environment and the password is never shown.
Your options
Spring Boot on Agent Lab, or on your own VPS
Scroll the table sideways.
| What you care about | Agent Lab Deploy | Your own VPS |
|---|---|---|
| Setup | Upload with the Dockerfile below, or say one sentence | SSH, a runtime, a process manager, a reverse proxy |
| HTTPS and domains | Automatic, custom domains on paid plans | Certbot and DNS by hand |
| Preview and rollback | Every version has its own URL; roll back in one click | Write your own scripts |
| Before going live | Uploads checked for leaked keys | Nothing unless you set it up |
| Database | PostgreSQL in one click, connection written into the app | Install and back it up yourself |
| Cost to start | Free plan: NT$0, one size-S app (sleeps when idle) | A VPS at roughly NT$200–600 a month, plus your time |
Steps
Deploy Spring Boot in four steps
Prepare
Add the Dockerfile below at the top of the project and replace the placeholder names.
Upload or ask
Drop the folder on a project's Deploy tab, push from GitHub, or ask your AI tool through Agent Lab MCP.
Build and check
The platform builds the version and checks it for leaked keys. Enter any secrets it lists in Settings.
Preview and go live
The first version goes live once it builds. Later ones get a preview URL; go live when you're happy.
Setup
A Spring Boot Dockerfile
The CMD has to be in shell form to expand PORT; or put server.port=${PORT:8080} in application.properties and use the exec form. Temporary files go to java.io.tmpdir (/tmp), which fits the read-only filesystem; never write next to the jar. For Gradle, swap the build stage for gradle:jdk21 and ./gradlew bootJar.
Dockerfile
FROM maven:3-eclipse-temurin-21 AS build
WORKDIR /src
COPY pom.xml .
RUN mvn -q dependency:go-offline
COPY src ./src
RUN mvn -q package -DskipTests
FROM eclipse-temurin:21-jre
WORKDIR /app
COPY --from=build /src/target/*.jar app.jar
USER 10001
EXPOSE 8080
# shell 形式才能展開 PORT / the shell form expands PORT
CMD java -Dserver.port=${PORT:-8080} -jar app.jarPORTthe port the platform gives (8080 by default); the server must listen on it.SPRING_DATASOURCE_URLjdbc:postgresql://… for an Agent Lab PostgreSQL.SPRING_PROFILES_ACTIVEsuch as prod.
Or ask your AI tool
Read https://app.agentlab.cresclab.com/agent/deploy.md and deploy this Spring Boot project to Agent Lab using the Dockerfile at the top. Show me the build plan and the environment variables it needs first, tell me where to enter any secrets, and wait for my OK before it goes live.FAQ
Deploying Spring Boot: questions
Do I need a Dockerfile to deploy Spring Boot?
Yes. Agent Lab builds Spring Boot from the Dockerfile at the top of the project; the one on this page meets the platform's rules (listen on $PORT, linux/amd64, write only to /tmp). Docs →
How much memory does Spring Boot need?
A typical Spring Boot service wants a medium instance or larger. Free's small instance is fine for a trial; for production pick a larger size on Pro.
Where do API keys and other secrets go?
In the project's Settings, under Secrets; the code reads them as environment variables. Random values such as session secrets can be generated in the console without anybody seeing them. A key found in an upload stops it before it goes live.
Can I deploy Spring Boot from Claude Code or Codex?
Yes. Connect Agent Lab MCP once (one command, sign in in the browser, no API key), then say "deploy this Spring Boot app". The tool creates the project, uploads, waits for the build and asks before going live. Connect MCP →
Is there a free way to host Spring Boot?
The Free plan is NT$0: one size-S app that sleeps after 15 idle minutes, one size-S database, three static web pages, 100 build minutes and 5 GB of traffic a month, pausing at the limit instead of charging. Pro (US$29 a month before tax) keeps apps running and adds custom domains. Pricing →