Build Linux binaries with musl

When I tried to build with "normal" glibc, I got weird errors on old/new glibc.

Instead of building with glibc, which limits us with compatibility and weird issues, let's build with
musl, which will always produce 100% static library.

(Musl is a libc alternative. The good thing is musl is statically linked
and can cross-compile relatively easily.)

The actual hard work is building all these musl cross-compilers;
luckily, Rust people already did that for Rust :) we can steal that and reuse.

Note that this all works on both AMD and ARM hosts, as both the musl cross-compilers images
and the go images are published for both.

release/linux/Dockerfile.build

@@ -0,0 +1,11 @@
+FROM messense/rust-musl-cross:aarch64-musl AS go-arm64-musl
+COPY --from=golang:1.19.1 /usr/local/go/ /usr/local/go/
+ENV TREZORD_BUILD=go-arm64-musl
+
+FROM messense/rust-musl-cross:i686-musl AS go-386-musl
+COPY --from=golang:1.19.1 /usr/local/go/ /usr/local/go/
+ENV TREZORD_BUILD=go-386-musl
+
+FROM messense/rust-musl-cross:x86_64-musl AS go-amd64-musl
+COPY --from=golang:1.19.1 /usr/local/go/ /usr/local/go/
+ENV TREZORD_BUILD=go-amd64-musl

release/linux/Dockerfile → release/linux/Dockerfile.package

@@ -1,6 +1,6 @@
 # initialize from the image
 
-FROM fedora:32
+FROM fedora:36
 
 # update package repositories
 

release/linux/Makefile

@@ -1,33 +1,40 @@
 PLATFORM = linux
 VOL_MOUNT = -v $(shell pwd):/release
-IMAGETAG = trezord-go-build-env-$(PLATFORM)
 
-IMPORT_PATH = ../..
+IMAGETAG_PACKAGE = trezord-go-package-env-$(PLATFORM)
+IMAGETAG_BUILD = trezord-go-build-env-$(PLATFORM)
+
+IMPORT_PATH = $(shell realpath ../..)
 
 all: clean .package
 
 clean:
  $(info Cleaning...)
  rm -rf build
 
-.binary:
- $(info Building with xgo ...)
+.binary: .docker-image-build
+ $(info Building with musl crosbuild ...)
  mkdir -p build
- xgo -targets=linux/386,linux/amd64,linux/arm64 $(IMPORT_PATH)
- mv -f trezord-go-linux-386 build/trezord-linux-386
- mv -f trezord-go-linux-amd64 build/trezord-linux-amd64
- mv -f trezord-go-linux-arm64 build/trezord-linux-arm64
+ docker run -it --rm -v $(IMPORT_PATH):/trezord -w /trezord $(IMAGETAG_BUILD)-arm64 /trezord/release/linux/build.sh
+ docker run -it --rm -v $(IMPORT_PATH):/trezord -w /trezord $(IMAGETAG_BUILD)-386 /trezord/release/linux/build.sh
+ docker run -it --rm -v $(IMPORT_PATH):/trezord -w /trezord $(IMAGETAG_BUILD)-amd64 /trezord/release/linux/build.sh
  cp ../../VERSION build
 
-.package: .binary .docker-image
+.package: .binary .docker-image-package
  $(info Packaging ...)
- docker run -i -t $(VOL_MOUNT) $(IMAGETAG) /release/release.sh linux-386
- docker run -i -t $(VOL_MOUNT) $(IMAGETAG) /release/release.sh linux-amd64
- docker run -i -t $(VOL_MOUNT) $(IMAGETAG) /release/release.sh linux-arm64
+ docker run -i -t $(VOL_MOUNT) $(IMAGETAG_PACKAGE) /release/release.sh linux-386
+ docker run -i -t $(VOL_MOUNT) $(IMAGETAG_PACKAGE) /release/release.sh linux-amd64
+ docker run -i -t $(VOL_MOUNT) $(IMAGETAG_PACKAGE) /release/release.sh linux-arm64
+
+.docker-image-build:
+ $(info Preparing docker images for build ...)
+ docker build -t $(IMAGETAG_BUILD)-arm64 . -f Dockerfile.build --target go-arm64-musl
+ docker build -t $(IMAGETAG_BUILD)-amd64 . -f Dockerfile.build --target go-amd64-musl
+ docker build -t $(IMAGETAG_BUILD)-386 . -f Dockerfile.build --target go-386-musl
 
-.docker-image:
+.docker-image-package:
  $(info Preparing docker image ...)
- docker build -t $(IMAGETAG) .
+ docker build -t $(IMAGETAG_PACKAGE) . -f Dockerfile.package
 
 shell: .docker-image
  docker run -i -t $(VOL_MOUNT) $(IMAGETAG) /bin/bash

release/linux/build.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+
+set -ex
+PATH=$PATH:/usr/local/go/bin
+
+case $TREZORD_BUILD in
+ "go-arm64-musl")
+ CGO_ENABLED=1 CC="/usr/local/musl/bin/aarch64-unknown-linux-musl-gcc" GOARCH=arm64 \
+ go build --ldflags '-linkmode external -extldflags "-static" -extld /usr/local/musl/bin/aarch64-unknown-linux-musl-gcc' \
+ -o release/linux/build/trezord-linux-arm64
+ ;;
+
+ "go-386-musl")
+ CGO_ENABLED=1 CC="/usr/local/musl/bin/i686-unknown-linux-musl-gcc" GOARCH=386 \
+ go build --ldflags '-linkmode external -extldflags "-static" -extld /usr/local/musl/bin/i686-unknown-linux-musl-gcc' \
+ -o release/linux/build/trezord-linux-386
+ ;;
+
+ "go-amd64-musl")
+ CGO_ENABLED=1 CC="/usr/local/musl/bin/x86_64-unknown-linux-musl-gcc" GOARCH=amd64 \
+ go build --ldflags '-linkmode external -extldflags "-static" -extld /usr/local/musl/bin/x86_64-unknown-linux-musl-gcc' \
+ -o release/linux/build/trezord-linux-amd64
+ ;;
+
+ *)
+ echo -n "unknown build"
+ exit 1
+ ;;
+esac