Add BABASHKA_MUSL build variable (#834)

This allows building a Babashka binary using musl C libraries instead,
instead of hardcoding this accordingly to the CPU arch.

.circleci/config.yml

@@ -155,6 +155,7 @@ jobs:
       BABASHKA_PLATFORM: linux # used in release script
       BABASHKA_TEST_ENV: native
       BABASHKA_STATIC: "true"
+      BABASHKA_MUSL: "true"
       BABASHKA_XMX: "-J-Xmx6500m"
     resource_class: large
     steps:

.circleci/script/setup-musl

@@ -1,62 +0,0 @@
-#!/usr/bin/env bash
-
-# This script sets up the latest available musl-tools using apt pinning from debian unstable.
-# The one available in stable and testing are quite outdated and this ensures we get the latest improvements
-# This explictly installs musl from unstable and keeps the others at a higher priority
-
-if [ "$BABASHKA_STATIC" != "true" ]
-then
-    echo "BABASHKA_STATIC wasn't set, skipping musl installation."
-    exit 0
-fi
-
-if [ "$BABASHKA_ARCH" = "aarch64" ]
-then
-    echo "GraalVM only supports musl on x86_64"
-    exit 0
-fi
-
-cat >> /etc/apt/sources.list <<eof
-deb http://ftp.us.debian.org/debian unstable main non-free contrib
-deb http://non-us.debian.org/debian-non-us unstable/non-us main contrib non-free
-eof
-
-cat >> /etc/apt/preferences <<eof
-Package: *
-Pin: release a=stable
-Pin-Priority: 700
-Package: *
-Pin: release a=testing
-Pin-Priority: 650
-Package: *
-pin: release a=unstable
-pin-priority: 600
-eof
-
-apt-get update -y && apt-get install musl-tools/unstable -y
-
-ZLIB_VERSION="1.2.11"
-
-curl -O -sL "https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz"
-
-echo "c3e5e9fdd5004dcb542feda5ee4f0ff0744628baf8ed2dd5d66f8ca1197cb1a1 zlib-${ZLIB_VERSION}.tar.gz" |
-    sha256sum --check
-tar xf "zlib-${ZLIB_VERSION}.tar.gz"
-
-arch=${BABASHKA_ARCH:-"x86_64"}
-echo "ARCH: $arch"
-
-cd "zlib-${ZLIB_VERSION}"
-CC=musl-gcc ./configure --static --prefix=/usr/lib/$arch-linux-musl/
-make CC=musl-gcc
-sudo make install
-export CC=gcc
-cd ..
-
-# depending on GCC version, we will have different directories here.
-# for example, for GCC 6.3.0 we will have:
-# - /usr/lib/gcc/x86_64-linux-gnu/6
-# - /usr/lib/gcc/x86_64-linux-gnu/6.3.0
-for dest_dir in /usr/lib/gcc/$arch-linux-gnu/*; do
-    sudo cp -f /usr/lib/$arch-linux-musl/lib/libz.a "$dest_dir"
-done

Dockerfile

@@ -17,6 +17,7 @@ ENV BABASHKA_XMX=$BABASHKA_XMX
 # Make it possible to use Docker to build bb with a particular set of features
 # by setting them at build time via `docker build --build-arg ARG_NAME=true ...`
 ARG BABASHKA_LEAN=
+ARG BABASHKA_MUSL=
 ARG BABASHKA_FEATURE_CORE_ASYNC=
 ARG BABASHKA_FEATURE_CSV=
 ARG BABASHKA_FEATURE_JAVA_NIO=
@@ -50,6 +51,7 @@ ENV BABASHKA_FEATURE_ORACLEDB=$BABASHKA_FEATURE_ORACLEDB
 ENV BABASHKA_FEATURE_DATASCRIPT=$BABASHKA_FEATURE_DATASCRIPT
 ENV BABASHKA_FEATURE_LANTERNA=$BABASHKA_FEATURE_LANTERNA
 ENV BABASHKA_STATIC=$BABASHKA_STATIC
+ENV BABASHKA_MUSL=$BABASHKA_MUSL
 
 COPY . .
 RUN ./script/uberjar

script/compile

@@ -74,11 +74,11 @@ args=( "-jar" "$BABASHKA_JAR"
        "$BABASHKA_XMX" )
 
 BABASHKA_STATIC=${BABASHKA_STATIC:-}
-BABASHKA_ARCH=${BABASHKA_ARCH:-}
+BABASHKA_MUSL=${BABASHKA_MUSL:-}
 
 if [ "$BABASHKA_STATIC" = "true" ]; then
     args+=("--static")
-    if [ "$BABASHKA_ARCH" != "aarch64" ]; then
+    if [ "$BABASHKA_MUSL" = "true" ]; then
         args+=("--libc=musl"
                # see https://github.com/oracle/graal/issues/3398
                "-H:CCompilerOption=-Wl,-z,stack-size=2097152")

script/setup-musl

@@ -1,5 +1,17 @@
 #!/usr/bin/env bash
 
+set -euo pipefail
+
+if  [[ -z "${BABASHKA_STATIC:-}" ]]; then
+    echo "BABASHKA_STATIC wasn't set, skipping musl installation."
+    exit 0
+fi
+
+if [[ -z "${BABASHKA_MUSL:-}" ]]; then
+    echo "BABASHKA_MUSL wasn't set, skipping musl installation."
+    exit 0
+fi
+
 # This script sets up the latest available musl-tools using apt pinning from debian unstable.
 # The one available in stable and testing are quite outdated and this ensures we get the latest improvements
 # This explictly installs musl from unstable and keeps the others at a higher priority

src/babashka/main.clj

@@ -865,9 +865,9 @@ Use bb run --help to show this help output.
 
 (def musl?
   "Captured at compile time, to know if we are running inside a
-  statically compiled executable."
+  statically compiled executable with musl."
   (and (= "true" (System/getenv "BABASHKA_STATIC"))
-       (not= "aarch64" (System/getenv "BABASHKA_ARCH"))))
+       (= "true" (System/getenv "BABASHKA_MUSL"))))
 
 (defmacro run [args]
   (if musl?