Setup cross compilation

.gitignore

@@ -1,4 +1,6 @@
+# compilation targets
 /target
+/out
 
 # used for tests
 *.tar

README.md

@@ -14,3 +14,8 @@ rl layer dump <image> -l <layer> -o <dir> # dump only this layer
 rl layer dump <image> -l <layer> -o <dir> --stack # include preceding layers into the output
 rl layer extract <image> -l <layer> -p <src> -o <dest> # extract a file or dir from the layer
 ```
+
+## Troubleshooting
+
+- <https://github.com/cross-rs/cross/issues/1184>
+- "version `GLIBC_2.28' not found" -> <https://github.com/cross-rs/cross/issues/724>

flake.nix

@@ -40,12 +40,26 @@
           };
         };
 
-        devShell = mkShell {
+        # should not include c toolchain but use host toolchain.
+        # this seems to be required to cross compile x86_64-apple-darwin on M1
+        # https://github.com/NixOS/nixpkgs/commit/9b3091a94cad63ebd0bd7aafbcfed7c133ef899d
+        devShell = mkShellNoCC {
           packages = [
+            rustup
             cargo-audit
             mask
             goreleaser
+            cargo-cross
+            yq-go
+            ripgrep
+            # required for rust
+            libiconv
           ];
+
+          shellHook = ''
+            # see https://github.com/cross-rs/cross/issues/1241
+            export CROSS_CONTAINER_OPTS="--platform linux/amd64"  
+          '';
         };
       }
     );

maskfile.md

@@ -11,3 +11,29 @@ rm -rf "$out_dir"
 docker build -f test.Dockerfile  -t "$image_name" .
 cargo run -- --image "$image_name" dump -o "$out_dir" --verbose
 ```
+
+## cross
+
+> builds the images for all supported platforms
+
+**OPTIONS**
+
+* filter
+  * flags: --filter -f
+  * type: string
+  * desc: filter all targets with the given string, e.g. "linux", "aarch64"
+
+```sh
+out_dir="out"
+targets=$(yq -o json -p toml -r '.toolchain.targets[]' rust-toolchain)
+if [ "$filter" != "" ]; then
+    targets=$(echo "$targets"|rg "$filter")
+fi
+mkdir -p "$out_dir"/bin
+for target in $targets; do
+    echo "building for $target"
+    # specifying target-dir is a hack for https://github.com/cross-rs/cross/issues/724
+    cross build --release --target "$target" --target-dir "$out_dir/$target"
+    cp "$out_dir/$target/$target/release/rl" "$out_dir/bin/rl-$target"
+done
+```

rust-toolchain

@@ -1,2 +1,8 @@
 [toolchain]
-channel = "1.69"
+channel = "1.69"
+targets = [
+    "x86_64-apple-darwin",
+    "aarch64-apple-darwin",
+    "x86_64-unknown-linux-musl",
+    "aarch64-unknown-linux-musl"
+]