Guide for cross compiling using docker

docs/src/SUMMARY.md

@@ -6,6 +6,7 @@
   - [Installing on a Raspberry Pi](./installation/Raspberry-Pi.md)
   - [Installing on Ubuntu (from source)](./installation/Ubuntu.md)
   - [Cross Compiling on Ubuntu](./installation/Cross-Compiling-on-Ubuntu.md)
+  - [Cross Compilation using Docker](./installation/cross-compile-using-docker.md)
   - [Installing with Homebrew on macOS](./installation/MacOS.md)
   - [Installing on FreeBSD](./installation/FreeBSD.md)
   - [Installing on OpenBSD](./installation/OpenBSD.md)

docs/src/installation/cross-compile-using-docker.md

@@ -0,0 +1,41 @@
+# Cross Compilation using Docker
+
+We can also use `docker` to cross compile on every platform and OS that runs `docker` and `qemu`:
+
+1. Setup a docker [custom builder](https://docs.docker.com/build/building/multi-platform/#create-a-custom-builder)
+
+    ```shell
+    docker buildx create \
+      --name container-builder \
+      --driver docker-container \
+      --use --bootstrap
+    ```
+
+    If you are **not** using Docker-Desktop you might have to install [QEMU](https://docs.docker.com/build/building/multi-platform/#install-qemu-manually)
+
+2. Create a docker `compose-file.yml`
+
+    Here we are building a `arm64` binary, so we set `platform: linux/arm64`
+
+    ```yaml
+    services:
+      build-container:
+        image: rust:1.79-bookworm
+        platform: linux/arm64
+        command: bash -c "
+            apt-get update &&
+            apt-get install -y \
+              libasound2-dev \
+              libssl-dev \
+              pkg-config &&
+            curl -sSL https://api.github.com/repos/Spotifyd/spotifyd/tarball/v0.3.5 | tar xz -C /spotifyd --strip-components=1 &&
+            cargo build --release &&
+            cp /spotifyd/target/release/spotifyd /build/"
+        working_dir: /spotifyd
+        volumes:
+          - ./:/build
+    ```
+
+3. Run `docker compose up`
+
+    This will copy the build `spotifyd` binary in the current directory.