42 layer image test

make-dockerfile.sh

#!/bin/bash

# Test 42-layer image on EC2.
#
# Relevant info:
#
#   ubuntu@domU-12-31-38-04-C2-78:~/layer-test$ docker info
#   Containers: 145
#   Images: 798
#   Storage Driver: aufs
#   Root Dir: /mnt/docker/aufs
#   Dirs: 1088
#   Execution Driver: native-0.1
#   Kernel Version: 3.11.0-15-generic
#   WARNING: No swap limit support
#
#   ubuntu@domU-12-31-38-04-C2-78:~/layer-test$ mount | grep /mnt
#   /dev/xvdb on /mnt type ext3 (rw,_netdev)
#
# Run like this:
#
#  ./make-dockerfile.sh && docker build -t test .
#
# The final layer outputs something like:
#
#   Step 42 : RUN echo layer=42
#    ---> Running in e1575d3b71f7
#   2014/04/14 01:33:04 exec: "/bin/sh": stat /bin/sh: no such file or directory
#   2014/04/14 01:33:04 The command [/bin/sh -c echo 42] returned a non-zero code: 1

echo "FROM ubuntu:13.10" >Dockerfile
for i in $(seq 1 42); do
  echo "RUN echo layer=$i" >>Dockerfile
done