# Spring Boot HTTP Server
import { Tabs, TabsContent, TabsList, TabsTrigger } from "zudoku/ui/Tabs"
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{/* THIS FILE WAS AUTOGENERATED FROM THE PUBLIC EXAMPLE REPOSITORY. DO NOT EDIT THIS FILE DIRECTLY. */}
This guide explains how to create and deploy a Spring Boot web server.
To run this example, follow these steps:
1. Install the CLI.
Use the [unikraft CLI](/cli/unikraft) or the legacy [kraft CLI](https://unikraft.org/docs/cli/install).
You need a [BuildKit](https://github.com/moby/buildkit) builder. The easiest way to get one is via [Docker](https://docs.docker.com/engine/install/).
Alternatively, you can also directly set up and use BuildKit, see the [quick start](https://github.com/moby/buildkit#quick-start).
:::note
The unikraft CLI is the current standard, while kraft is the legacy version.
Choose one of the CLIs below and only run the commands associated with it for the rest of this guide.
:::
2. Clone the [`examples` repository](https://github.com/unikraft-cloud/examples) and `cd` into the `examples/httpserver-java17-springboot/` directory:
```bash
git clone https://github.com/unikraft-cloud/examples
cd examples/httpserver-java17-springboot/
```
Make sure to log into Unikraft Cloud and pick a [metro](/platform/metros) close to you.
This guide uses `fra` (Frankfurt, 🇩🇪):
```bash title="unikraft"
unikraft login
```
```bash title="kraft"
# Set Unikraft Cloud access token
export UKC_TOKEN=token
# Set metro to Frankfurt, DE
export UKC_METRO=fra
```
When done, invoke the following command to deploy this app on Unikraft Cloud:
```bash title="unikraft"
unikraft build . --output /httpserver-java17-springboot:latest
unikraft run --metro fra \
-m 1G \
-p 443:8080/tls+http \
--scale-to-zero policy=idle,cooldown-time=1000,stateful=true \
--image /httpserver-java17-springboot:latest
```
```bash title="kraft"
kraft cloud deploy \
-M 1Gi \
-p 443:8080/tls+http \
--scale-to-zero idle \
--scale-to-zero-stateful \
--scale-to-zero-cooldown 1s \
.
```
The output shows the instance address and other details:
```ansi title="unikraft"
[1mmetro[22m: fra
[1mname[22m: httpserver-java17-springboot-qseeo
[1muuid[22m: b081166d-a2a0-43af-982d-1aa17f06b5c4
[1mstate[22m: [38;2;144;161;185mstarting[0m
[1mimage[22m: /httpserver-java17-springboot
[1mresources[22m:
[3m memory[23m: 1024MiB
[3m vcpus[23m: 1
[1mservice[22m:
[3m uuid[23m: 04f5b3ce-0aae-a50a-9d58-e6fa618b2cdc
[3m name[23m: long-dust-si7xsngk
[3m domains[23m:
[3m - fqdn[23m: long-dust-si7xsngk.fra.unikraft.app
[1mnetworks[22m:
[3m- uuid[23m: 4bde3abf-faf8-3a14-ceb9-bc05e646dfac
[3m private-ip[23m: 10.0.6.2
[3m mac[23m: 12:b0:eb:ad:60:a2
[1mtimestamps[22m:
[3m created[23m: just now
```
```ansi title="kraft"
[38;5;245m[[0m[92m●[0m[38;5;245m][0m Deployed successfully!
[38;5;245m│[0m
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mname[0m: httpserver-java17-springboot-qseeo
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245muuid[0m: b081166d-a2a0-43af-982d-1aa17f06b5c4
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mmetro[0m: https://api.fra.unikraft.cloud/v1
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mstate[0m: [92mstarting[0m
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mdomain[0m: https://long-dust-si7xsngk.fra.unikraft.app
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mimage[0m: oci://unikraft.io//httpserver-java17-springboot@sha256:cc2f2ad18ce8e36b8e8f4debee096fef7b0bb8b47762575a2ba5a9de8199c64a
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mmemory[0m: 1024 MiB
[38;5;245m├[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mservice[0m: long-dust-si7xsngk
[38;5;245m├[0m[38;5;245m─[0m [38;5;245mprivate fqdn[0m: httpserver-java17-springboot-qseeo.internal
[38;5;245m└[0m[38;5;245m─[0m[38;5;245m─[0m[38;5;245m─[0m [38;5;245mprivate ip[0m: 10.0.6.2
```
In this case, the instance name is `httpserver-java17-springboot-qseeo` and the address is `https://long-dust-si7xsngk.fra.unikraft.app`.
They're different for each run.
Use `curl` to query the Spring Boot server's `hello` endpoint:
```bash
curl https://long-dust-si7xsngk.fra.unikraft.app/hello
```
```text
Hello World!
```
When done, you can remove the instance:
```bash title="unikraft"
unikraft instances delete httpserver-java17-springboot-qseeo
```
```bash title="kraft"
kraft cloud instance remove httpserver-java17-springboot-qseeo
```
## Customize your app
To customize the app, update the files in the repository, listed below:
* `DemoApplication.java`: the server
* `Kraftfile`: the Unikraft Cloud specification
* `Dockerfile`: the Docker-specified app filesystem
Lines in the `Kraftfile` have the following roles:
* `spec: v0.7`: The current `Kraftfile` specification version is `0.7`.
* `runtime: base-compat:latest`: The runtime kernel to use is the base compatibility kernel.
* `rootfs`: Build the app root filesystem.
`source: ./Dockerfile` means the filesystem is built using the `Dockerfile`.
`format: erofs` means the filesystem type is [EROFS](https://erofs.docs.kernel.org/).
* `cmd: ["/usr/lib/jvm/java-17-openjdk-amd64/bin/java", "-jar", "/usr/src/demo-0.0.1-SNAPSHOT.jar"]`: Use as the starting command of the instance.
Lines in the `Dockerfile` have the following roles:
* `FROM scratch`: Build the filesystem from the [`scratch` container image](https://hub.docker.com/_/scratch/), to [create a base image](https://docs.docker.com/build/building/base-images/).
* `COPY DemoApplication.java src/main/java/com/example/demo/`: Copy the server implementation file in the Docker filesystem.
The following options are available for customizing the app:
* If you only update the implementation in the `DemoApplication.java` source file, you don't need to make any other changes.
* If you create any new source files, copy them into the app filesystem by using the `COPY` command in the `Dockerfile`.
* More extensive changes may require extending the `Dockerfile` ([see `Dockerfile` syntax reference](https://docs.docker.com/engine/reference/builder/)).
You can list information about the instance by running:
```bash title="unikraft"
unikraft instances list
```
```bash title="kraft"
kraft cloud instance list
```
```ansi title="unikraft"
[1mMETRO[22m [1mNAME[22m [1mSTATE[22m [1mIMAGE[22m [1mARGS[22m [1mMEMORY[22m [1mVCPUS[22m [1mFQDN[22m [1mCREATED[22m
fra httpserver-java17-springboot-qseeo [38;2;0;188;125mrunning[0m /httpserver-java17-springboot 1024MiB 1 long-dust-si7xsngk.fra.unikraft.app 2 minutes ago
```
```ansi title="kraft"
[0;1;39mNAME[0m [0;1;39mFQDN[0m [0;1;39mSTATE[0m [0;1;39mSTATUS[0m [0;1;39mIMAGE[0m [0;1;39mMEMORY[0m [0;1;39mVCPUS[0m [0;1;39mARGS[0m [0;1;39mBOOT TIME[0m
httpserver-java17-springboot-qseeo long-dust-si7xsngk.fra.unikraft.app [0;32mrunning[0m 1 minute ago oci://unikraft.io//httpserver-java17-springboot@sha256:... 1.0 GiB 1 421.30 ms
```
When done, you can remove the instance:
```bash title="unikraft"
unikraft instances delete httpserver-java17-springboot-qseeo
```
```bash title="kraft"
kraft cloud instance remove httpserver-java17-springboot-qseeo
```
## Learn more
Use the `--help` option for detailed information on using Unikraft Cloud:
```bash title="unikraft"
unikraft --help
```
```bash title="kraft"
kraft cloud --help
```
Or visit the [CLI Reference](/cli/unikraft) or the [legacy CLI Reference](/cli/kraft/overview).
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