Added script for building Base Docker CRUX images

Docker-DCO-1.1-Signed-off-by: James Mills <prologic@shortcircuit.net.au> (github: therealprologic)

contrib/mkimage-crux.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+# Generate a minimal filesystem for CRUX/Linux and load it into the local
+# docker as "cruxlinux"
+# requires root and the crux iso (http://crux.nu)
+
+set -e
+
+die () {
+    echo >&2 "$@"
+    exit 1
+}
+
+[ "$#" -eq 1 ] || die "1 argument(s) required, $# provided. Usage: ./mkimage-crux.sh /path/to/iso"
+
+ISO=${1}
+
+ROOTFS=$(mktemp -d /tmp/rootfs-crux-XXXXXXXXXX)
+CRUX=$(mktemp -d /tmp/crux-XXXXXXXXXX)
+TMP=$(mktemp -d /tmp/XXXXXXXXXX)
+
+VERSION=$(basename --suffix=.iso $ISO | sed 's/[^0-9.]*\([0-9.]*\).*/\1/')
+
+# Mount the ISO
+mount -o ro,loop $ISO $CRUX
+
+# Extract pkgutils
+tar -C $TMP -xf $CRUX/tools/pkgutils#*.pkg.tar.gz
+
+# Put pkgadd in the $PATH
+export PATH="$TMP/usr/bin:$PATH"
+
+# Install core packages
+mkdir -p $ROOTFS/var/lib/pkg
+touch $ROOTFS/var/lib/pkg/db
+for pkg in $CRUX/crux/core/*; do
+    pkgadd -r $ROOTFS $pkg
+done
+
+# Remove agetty and inittab config
+if (grep agetty ${ROOTFS}/etc/inittab 2>&1 > /dev/null); then
+    echo "Removing agetty from /etc/inittab ..."
+    chroot ${ROOTFS} sed -i -e "/agetty/d" /etc/inittab
+    chroot ${ROOTFS} sed -i -e "/shutdown/d" /etc/inittab
+    chroot ${ROOTFS} sed -i -e "/^$/N;/^\n$/d" /etc/inittab
+fi
+
+# Remove kernel source
+rm -rf $ROOTFS/usr/src/*
+
+# udev doesn't work in containers, rebuild /dev
+DEV=$ROOTFS/dev
+rm -rf $DEV
+mkdir -p $DEV
+mknod -m 666 $DEV/null c 1 3
+mknod -m 666 $DEV/zero c 1 5
+mknod -m 666 $DEV/random c 1 8
+mknod -m 666 $DEV/urandom c 1 9
+mkdir -m 755 $DEV/pts
+mkdir -m 1777 $DEV/shm
+mknod -m 666 $DEV/tty c 5 0
+mknod -m 600 $DEV/console c 5 1
+mknod -m 666 $DEV/tty0 c 4 0
+mknod -m 666 $DEV/full c 1 7
+mknod -m 600 $DEV/initctl p
+mknod -m 666 $DEV/ptmx c 5 2
+
+IMAGE_ID=$(tar --numeric-owner -C $ROOTFS -c . | docker import - crux:$VERSION)
+docker tag $IMAGE_ID crux:latest
+docker run -i -t crux echo Success.
+
+# Cleanup
+umount $CRUX
+rm -rf $ROOTFS
+rm -rf $CRUX
+rm -rf $TMP