Distroless builds: Node-something-distroless examples + nginx + mcp server

mcp-server-simple-distroless/Dockerfile

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+FROM python:3.11-slim AS build
+
+WORKDIR /app
+
+RUN set -xe; \
+    /usr/sbin/ldconfig /usr/local/lib
+
+COPY requirements.txt requirements.txt
+RUN pip install -r requirements.txt
+
+
+FROM gcr.io/distroless/python3-debian12
+
+COPY --from=build /usr/local/lib/python3.11/site-packages /usr/local/lib/python3.11/dist-packages
+
+COPY ./server.py /src/server.py

mcp-server-simple-distroless/Kraftfile

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+spec: v0.7
+
+runtime: base-compat:latest
+
+targets:
+  - kraftcloud/x86_64
+
+rootfs:
+  source: ./Dockerfile
+  format: erofs
+
+cmd: [ "/usr/bin/python3", "/src/server.py" ]

mcp-server-simple-distroless/README.md

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+# Simple Distroless MCP Server
+
+This example demonstrates how to build a minimal custom MCP (Model Context Protocol) server from scratch using [FastMCP](https://github.com/jlowin/fastmcp).
+
+This is a great starting point for building your own custom MCP servers with business-specific tools and logic.
+
+## Running on Unikraft Cloud
+
+To run this MCP server on Unikraft Cloud:
+
+1. Install the CLI.
+   Use the [unikraft CLI](https://unikraft.com/docs/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/mcp-server-simple-distroless/` directory:
+
+   ```bash
+   git clone https://github.com/unikraft-cloud/examples
+   cd examples/mcp-server-simple-distroless/
+   ```
+
+Make sure to log into Unikraft Cloud and pick a [metro](https://unikraft.com/docs/platform/metros) close to you.
+This guide uses `fra` (Frankfurt, 🇩🇪):
+
+**Using the unikraft CLI (Recommended)**
+```bash title="unikraft"
+unikraft login
+```
+
+or
+
+**Using the legacy kraft CLI**
+```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:
+
+**Using the unikraft CLI (Recommended)**
+```bash title="unikraft"
+unikraft build . --output <my-org>/mcp-server-simple-distroless:latest
+unikraft run --metro fra \
+  -m 512M \
+  -p 443:8080/tls+http \
+  --scale-to-zero policy=on,cooldown-time=1000,stateful=true \
+  --image <my-org>/mcp-server-simple-distroless:latest
+```
+
+or
+
+**Using the legacy kraft CLI**
+```bash title="kraft"
+kraft cloud deploy \
+  -M 512Mi \
+  -p 443:8080/tls+http \
+  --scale-to-zero on \
+  --scale-to-zero-stateful \
+  --scale-to-zero-cooldown 1s \
+  .
+```
+
+The output shows your instance details:
+
+**Using the unikraft CLI (Recommended)**
+```ansi title="unikraft"
+metro:        fra
+name:         mcp-server-simple-distroless-bbdcb
+uuid:         e87d3591-3497-4f30-bd76-1dc886059647
+state:        starting
+image:        <my-org>/mcp-server-simple-distroless
+resources:
+  memory:     512MiB
+  vcpus:      1
+service:
+  uuid:       3cfc78af-748d-c6ba-5bfb-427b3bd7e9aa
+  name:       cool-paper-b6mht7jv
+  domains:
+  - fqdn:     cool-paper-b6mht7jv.fra.unikraft.app
+networks:
+- uuid:       6a712117-5b67-d89a-7e2e-4a57e1732724
+  private-ip: 10.0.0.193
+  mac:        12:b0:39:2b:a3:15
+timestamps:
+  created:    just now
+```
+
+or
+
+**Using the legacy kraft CLI**
+```ansi title="kraft"
+[●] Deployed successfully!
+ │
+ ├───────── name: mcp-server-simple-distroless-bbdcb
+ ├───────── uuid: e87d3591-3497-4f30-bd76-1dc886059647
+ ├──────── metro: https://api.fra.unikraft.cloud/v1
+ ├──────── state: starting
+ ├─────── domain: https://cool-paper-b6mht7jv.fra.unikraft.app
+ ├──────── image: oci://unikraft.io/<my-org>/mcp-server-simple-distroless@sha256:cbbfb441ee313a6c7c0de571e9002f0f6031312e203ffb6be3b8f4950df3bc20
+ ├─────── memory: 512 MiB
+ ├────── service: cool-paper-b6mht7jv
+ ├─ private fqdn: mcp-server-simple-distroless-bbdcb.internal
+ └─── private ip: 10.0.0.193
+```
+
+In this case, the instance name is `mcp-server-simple-distroless-bbdcb` and the service `cool-paper-b6mht7jv`.
+They're different for each run.
+
+For testing, you can use the example client included in this directory.
+First, [install `uv`](https://docs.astral.sh/uv/getting-started/installation) if you haven't already, then run:
+
+```bash
+export MCP_SERVER_URL=https://cool-paper-b6mht7jv.fra.unikraft.app/mcp
+uv run client.py
+```
+
+```bash
+Connecting to https://cool-paper-b6mht7jv.fra.unikraft.app/mcp...
+
+--- Listing Tools ---
+Name: get_weather
+Description: Get current weather for a city.
+
+Args:
+    city: Name of the city
+
+Returns:
+    Weather information including temperature, conditions, and humidity
+
+Name: get_time
+Description: Get current time in a timezone.
+...
+```
+
+You can list information about the instance by running:
+
+**Using the unikraft CLI (Recommended)**
+```bash title="unikraft"
+unikraft instances list
+```
+
+```ansi title="unikraft"
+METRO  NAME                                STATE    IMAGE                                  ARGS  MEMORY  VCPUS  FQDN
+     CREATED
+fra    mcp-server-simple-distroless-bbdcb  standby  <my-org>/mcp-server-simple-distroless        512MiB  1      cool-paper-b6mht7jv.fra.unikraft.app  2 minutes ago
+```
+
+or
+
+**Using the legacy kraft CLI**
+```bash title="kraft"
+kraft cloud instance list
+```
+
+```ansi title="kraft"
+NAME                                FQDN                                  STATE    STATUS   IMAGE
+                                         MEMORY   VCPUS  ARGS  BOOT TIME
+mcp-server-simple-distroless-bbdcb  cool-paper-b6mht7jv.fra.unikraft.app  standby  standby  oci://unikraft.io/<my-org>/mcp-server-simple-distroless@sha256:...  512 MiB  1            9.15 ms
+```
+
+When done, you can delete the instance with:
+
+```bash
+kraft cloud instance remove mcp-server-simple-distroless-bbdcb
+```
+
+## Available tools
+
+This MCP Server provides the following tools:
+
+* **get_weather**: Get simulated weather for a city
+* **get_time**: Get current time in a timezone
+* **calculate**: Perform basic arithmetic operations (add, subtract, multiply, divide)
+
+## Building your own tools
+
+This example shows the basic structure of an MCP server using FastMCP.
+To add your own tools:
+
+1. **Define the tool** using the `@mcp.tool()` decorator:
+   * Add type hints for parameters
+   * Include a docstring describing what the tool does
+   * Parameters are automatically converted to JSON schema
+
+1. **Write the tool** function:
+   * Process the parameters
+   * Return a string result (or raise an exception for errors)
+
+1. **Test locally** before deploying:
+
+   ```bash
+   pip install -r requirements.txt
+   python server.py
+   ```
+
+Example:
+
+```python
+from fastmcp import FastMCP
+
+mcp = FastMCP("My Custom Server")
+
+@mcp.tool()
+def my_custom_tool(param1: str, param2: int) -> str:
+    """Description of what this tool does.
+
+    Args:
+        param1: Description of first parameter
+        param2: Description of second parameter
+
+    Returns:
+        Result description
+    """
+    # Your implementation here
+    return f"Processed {param1} with {param2}"
+
+if __name__ == "__main__":
+    mcp.run(transport="http", host="0.0.0.0", port=8080)
+```
+
+## Architecture
+
+The server uses FastMCP, a high-level framework for building MCP servers that features:
+
+* **HTTP Transport**: Built-in Streamable HTTP transport
+* **Type-Safe**: Automatic JSON schema generation from Python type hints
+* **Simple API**: Decorator-based tool definitions
+
+This provides:
+
+* Standard MCP protocol support
+* Automatic tool schema generation
+* Built-in HTTP server
+* Easy deployment to any platform
+
+## Learn more
+
+* [MCP Documentation](https://modelcontextprotocol.io/)
+* [FastMCP documentation](https://gofastmcp.com/getting-started/welcome)
+* [Building MCP Servers](https://modelcontextprotocol.io/docs/building-servers)
+* [Unikraft Cloud Documentation](https://unikraft.com/docs/)
+* [Building `Dockerfile` Images with `Buildkit`](https://unikraft.org/guides/building-dockerfile-images-with-buildkit)
+
+Use the `--help` option for detailed information on using Unikraft Cloud:
+
+**Using the unikraft CLI (Recommended)**
+```bash title="unikraft"
+unikraft --help
+```
+
+or
+
+**Using the legacy kraft CLI**
+```bash title="kraft"
+kraft cloud --help
+```
+
+Or visit the [CLI Reference](https://unikraft.com/docs/cli/unikraft) or the [legacy CLI Reference](https://unikraft.com/docs/cli/kraft/overview).

mcp-server-simple-distroless/client.py

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+"""Simple MCP Server Python Client
+-------------------------------
+
+This script demonstrates how to connect to the Simple MCP server deployed on Unikraft Cloud using Streamable HTTP transport.
+It lists available tools and tests each one.
+
+Usage:
+    export MCP_SERVER_URL=https://your-server-url/mcp
+    uv run client.py
+"""
+# /// script
+# requires-python = ">=3.11"
+# dependencies = [
+#     "fastmcp",
+# ]
+# ///
+
+import asyncio
+import os
+from fastmcp import Client
+
+
+async def main():
+    url = os.getenv("MCP_SERVER_URL", None)
+    if url is None:
+        print("Error: MCP_SERVER_URL environment variable is not set.")
+        print("Please set it to the server's MCP endpoint URL (e.g., https://your-server-url/mcp).")
+        return
+
+    print(f"Connecting to {url}...")
+
+    try:
+        async with Client(url) as client:
+            # List available tools
+            print("\n--- Listing Tools ---")
+            tools = await client.list_tools()
+            for tool in tools:
+                print(f"Name: {tool.name}")
+                print(f"Description: {tool.description}")
+                print()
+
+            # Test weather tool
+            print("\n--- Testing Weather Tool ---")
+            try:
+                result = await client.call_tool(
+                    "get_weather",
+                    arguments={"city": "London"}
+                )
+                for content in result.content:
+                    if content.type == "text":
+                        print(content.text)
+
+            except Exception as e:
+                print(f"Error calling weather tool: {e}")
+
+            # Test time tool
+            print("\n--- Testing Time Tool ---")
+            try:
+                result = await client.call_tool(
+                    "get_time",
+                    arguments={"timezone": "America/New_York"}
+                )
+                for content in result.content:
+                    if content.type == "text":
+                        print(content.text)
+
+            except Exception as e:
+                print(f"Error calling time tool: {e}")
+
+            # Test calculate tool
+            print("\n--- Testing Calculate Tool ---")
+            try:
+                result = await client.call_tool(
+                    "calculate",
+                    arguments={"operation": "add", "a": 10, "b": 5}
+                )
+                for content in result.content:
+                    if content.type == "text":
+                        print(content.text)
+
+            except Exception as e:
+                print(f"Error calling calculate tool: {e}")
+
+    except Exception as e:
+        print(f"Connection error: {e}")
+        print("Make sure the URL is correct and the server is running.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())