# Lua 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 simple Lua-based HTTP 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-lua5.1/` directory:

   ```bash
   git clone https://github.com/unikraft-cloud/examples
   cd examples/httpserver-lua5.1/
   ```

Make sure to log into Unikraft Cloud and pick a [metro](/platform/metros) close to you.
This guide uses `fra` (Frankfurt, 🇩🇪):

<CodeTabs syncKey="cli">

```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
```

</CodeTabs>

When done, invoke the following command to deploy this app on Unikraft Cloud:

<CodeTabs syncKey="cli">

```bash title="unikraft"
unikraft build . --output <my-org>/httpserver-lua51:latest
unikraft run --scale-to-zero policy=on,cooldown-time=1000 --metro fra -p 443:8080/tls+http -m 256M --image <my-org>/httpserver-lua51:latest
```

```bash title="kraft"
kraft cloud deploy --scale-to-zero on --scale-to-zero-cooldown 1s -p 443:8080/tls+http -M 256Mi .
```

</CodeTabs>

The output shows the instance address and other details:

<CodeTabs syncKey="cli">

```ansi title="unikraft"
metro:        fra
name:         httpserver-lua51-ma2i9
uuid:         e7389eee-9808-4152-b2ec-1f3c0541fd05
state:        starting
image:        <my-org>/httpserver-lua51
resources:
  memory:     256MiB
  vcpus:      1
service:
  uuid:       51a41f63-7e88-c443-b9bf-83cd7c04d975
  name:       young-night-5fpf0jj8
  domains:
  - fqdn:     young-night-5fpf0jj8.fra.unikraft.app
networks:
- uuid:       afcc149e-cd07-a4b6-905a-6d498e251e14
  private-ip: 10.0.3.3
  mac:        12:b0:fe:e4:63:48
timestamps:
  created:    just now
```

```ansi title="kraft"
[●] Deployed successfully!
 │
 ├───────── name: httpserver-lua51-ma2i9
 ├───────── uuid: e7389eee-9808-4152-b2ec-1f3c0541fd05
 ├──────── metro: https://api.fra.unikraft.cloud/v1
 ├──────── state: starting
 ├─────── domain: https://young-night-5fpf0jj8.fra.unikraft.app
 ├──────── image: oci://unikraft.io/<my-org>/httpserver-lua51@sha256:278cb8b14f9faf9c2702dddd8bfb6124912d82c11b4a2c6590b6e32fc4049472
 ├─────── memory: 256 MiB
 ├────── service: young-night-5fpf0jj8
 ├─ private fqdn: httpserver-lua51-ma2i9.internal
 └─── private ip: 10.0.3.3
```

</CodeTabs>

In this case, the instance name is `httpserver-lua51-ma2i9` and the address is `https://young-night-5fpf0jj8.fra.unikraft.app`.
They're different for each run.

Use `curl` to query the Unikraft Cloud instance of the Lua-based HTTP web server:

```bash
curl https://young-night-5fpf0jj8.fra.unikraft.app
```

```text
Hello, World!
```

You can list information about the instance by running:

<CodeTabs syncKey="cli">

```bash title="unikraft"
unikraft instances list
```

```bash title="kraft"
kraft cloud instance list
```

</CodeTabs>

<div style={{ marginTop: '0.8em' }} />

<CodeTabs syncKey="cli">

```ansi title="unikraft"
METRO  NAME                    STATE    IMAGE                      ARGS  MEMORY  VCPUS  FQDN                                   CREATED
fra    httpserver-lua51-ma2i9  running  <my-org>/httpserver-lua51        256MiB  1      young-night-5fpf0jj8.fra.unikraft.app  2 minutes ago
```

```ansi title="kraft"
NAME                    FQDN                                   STATE    STATUS        IMAGE                                                   MEMORY   VCPUS  ARGS  BOOT TIME
httpserver-lua51-ma2i9  young-night-5fpf0jj8.fra.unikraft.app  running  1 minute ago  oci://unikraft.io/<my-org>/httpserver-lua51@sha256:...  256 MiB  1            15.09 ms
```

</CodeTabs>

When done, you can remove the instance:

<CodeTabs syncKey="cli">

```bash title="unikraft"
unikraft instances delete httpserver-lua51-ma2i9
```

```bash title="kraft"
kraft cloud instance remove httpserver-lua51-ma2i9
```

</CodeTabs>

## Customize your app

To customize the app, update the files in the repository, listed below:

* `http_server.lua`: the actual Lua HTTP server implementation
* `Kraftfile`: the Unikraft Cloud specification
* `Dockerfile`: the Docker-specified app filesystem

The following options are available for customizing the app:

* If you only update the implementation in the `http_server.lua` 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/)).

## Learn more

Use the `--help` option for detailed information on using Unikraft Cloud:

<CodeTabs syncKey="cli">

```bash title="unikraft"
unikraft --help
```

```bash title="kraft"
kraft cloud --help
```

</CodeTabs>

Or visit the [CLI Reference](/cli/unikraft) or the [legacy CLI Reference](/cli/kraft/overview).
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