Merge pull request #46 from kscherer/musl

Reduce binary size using musl

Dockerfile

@@ -3,8 +3,8 @@ FROM debian:jessie
 MAINTAINER Chris Kuehl <ckuehl@yelp.com>
 RUN DEBIAN_FRONTEND=noninteractive apt-get update && \
     apt-get install -y --no-install-recommends \
-        build-essential devscripts equivs && \
+        build-essential devscripts equivs musl-tools python python-pytest python-mock && \
-    apt-get clean
+    rm -rf /var/lib/apt/lists/* && apt-get clean
 WORKDIR /mnt
 
 ENTRYPOINT mk-build-deps -i --tool 'apt-get --no-install-recommends -y' && make builddeb

Makefile

@@ -1,4 +1,4 @@
-CFLAGS=-std=gnu99 -static -Wall -Werror -O3
+CFLAGS=-std=gnu99 -static -s -Wall -Werror -O3
 
 TEST_PACKAGE_DEPS := python python-pip
 
@@ -66,7 +66,7 @@ clean-tox:
 
 .PHONY: builddeb
 builddeb:
-	debuild -us -uc -b
+	debuild --set-envvar=CC=musl-gcc -us -uc -b
 	rm -rf dist && mkdir dist
 	mv ../dumb-init_*.deb dist/
 

README.md

@@ -155,6 +155,21 @@ Running this same command without `dumb-init` would result in being unable to
 stop the container without `SIGKILL`, but with `dumb-init`, you can send it
 more humane signals like `SIGTERM`.
 
+## Building dumb-init
+
+Build requires a working compiler and libc headers and defaults to glibc.
+
+    $ make
+
+### Musl
+
+Statically compiled dumb-init is over 700KB due to glibc, but musl is
+now an option. On Debian/Ubuntu `apt-get install musl-tools` to
+install the source and wrappers.
+
+    $ CC=musl-gcc make
+
+When statically compiled with musl the binary size is around 20KB.
 
 ## See also