I put together this simple wrapper function for simplifying boot2docker interactions on my Macbook.

Note: I refer to .bashrc as the target as it's the more common shell. However, this has been tested and I personally use it within zsh.

Basic Usage

$ docker reload
# purge current boot2docker environment

$ docker up
# start boot2docker and export environment

$ docker reset|restart|reup
# stop and restart boot2docker

$ docker clean
# remove all orphaned image shards and all containers that aren't running - DANGEROUS

$ docker [etc]
# all other arguements are passed directly passed through to docker

The Functions

# file: ~/.bashrc

#############################################################
# Function -- Docker/Boot2Docker
#############################################################
function docker_shellinit {
  local _shellinit="$(boot2docker shellinit)"
  eval "$(echo ${_shellinit})"
  echo "${_shellinit}" > ~/.boot2dockerrc
}

function docker_reup {
  echo "+ running vpn fix"
  docker_down

  echo "+ resetting vbox route"

  local _iface="$(VBoxManage showvminfo boot2docker-vm --machinereadable | grep hostonlyadapter | cut -d '"' -f 2)"
  echo "++ sudo route -n add -net 192.168.59.0/24 -interface ${_iface}"

  sudo route -n add -net 192.168.59.0/24 -interface ${_iface} && \
    docker_up
}

function docker_reset {
  echo "+ clearing docker variables"
  unset DOCKER_HOST
  unset DOCKER_CERT_PATH
  unset DOCKER_TLS_VERIFY
  docker_shellinit
}

function docker_up {
  echo "+ starting boot2docker"
  boot2docker up
  b2dSTATUS=$?
  docker_reset
  return $b2dSTATUS
}

function docker_down {
  echo "+ stopping boot2docker"
  boot2docker down
  return 0
}

function docker_clean {
  echo "+ clean containers"
  docker ps -a | grep 'Exited ' | awk '{ print $NF }' | xargs docker rm
  docker ps -a | grep -v 'Up ' | awk '{ print $NF }' | xargs docker rm

  echo "+ clean images"
  docker images | grep '^<none>' | awk '{ print $3 }' | xargs docker rmi
}

function b2d {
  case "$@" in
  reload)
    docker_reset
    return 0;;
  reset|fix|reup|fuck)
    docker_reup
    return $?;;
  up)
    docker_up
    return $?;;
  down)
    docker_down
    return $?;;
  clean)
    docker_clean
    return $?;;
  esac
  boot2docker $@
}

docker_exec="$(which docker)"
function docker {
  case "$@" in
  reload)
    docker_reset
    return 0;;
  reset|fix|reup|fuck)
    docker_reup
    return $?;;
  up)
    docker_up
    return $?;;
  down)
    docker_down
    return $?;;
  clean)
    docker_clean
    return $?;;
  esac
  $docker_exec $@
}

Installation

$ curl -s https://gist.githubusercontent.com/jmervine/6713d10ab05fecd6e1aa/raw/5c5f7020696e23dffa6f046816239574f42767ee/boot2dockerrc.sh >> ~/.bashrc

Recently, I've been playing with Python, I thought I would toss up this writeup I found on executing commands via Python I found as a follow up to my Executing BASH Commmands in Ruby post.

$ node -e 'n=0; setInterval(function(){n++;if(n>=20){console.log(".");process.exit(0);}process.stdout.write(".");},1000);'

In this example, I'm finding all files older then 14 days and removing them.

$ find . -type f -mtime +14 | xargs rm

In this example, I'm finding top level directoies in /foo/bar/bah that are more then 30 days old and removing them.

$ find /foo/bar/bah -type d -mtime +30 -maxdepth 0 | xargs rm -rf

I typically use this for removing, which is why I've used that as an example. This type of thing is great for a cronjob...

# remove old files daily at 1am
* 1 * * * find /foo/bar/bah -type d -mtime +30 -maxdepth 0 | xargs rm -rf

Being a Dev Ops guy, I write gems, scripts and hacks that tend to hook in to system binaries. I know, it would probably be better to write C bindings, but heretofore that hasn't been something I really want to tackle. Additionally, I almost always write tests for my stuff. I've come across the problem where my tests pass locally, but not on Travis-CI.

$ curl https://<domain>/path/to.html --insecure

Also see: HTTPS: Creating Slef-signed Certs.

A script to replace script/server in Rails, which runs Unicorn over Webrick, because it's faster. This script is designed for development only!

Thanks to @retr0h:

[[ $(zsh --version | awk '{print $2}') > 4.3.17 ]]

# usage

if [[ $(zsh --version | awk '{print $2}') > 4.3.17 ]]; then
    # do someting that only higher zsh versions support
else
    # do something else for low versions
fi

This was my origitional (not so sexy solution).

The following line will print zsh version information if the version is greater then or equal to 4.3.17, otherwise it will return blank:

zsh --version | awk '{print $2}' | awk -F'.' ' ( $1 > 4 || ( $1 == 4 && $2 > 3 ) || ( $1 == 4 && $2 == 3 && $3 >= 17 ) ) '

An example usage would be something like:

#!/usr/bin/env bash
if test "$( zsh --version | awk '{print $2}' | awk -F'.' ' ( $1 > 4 || ( $1 == 4 && $2 > 3 ) || ( $1 == 4 && $2 == 3 && $3 >= 17 ) ) ' )"
then
    # do someting that only higher zsh versions support
else
    # do something else for low versions
fi

Found this today and thought I would share...

Basic Array handling in BASH, because I always forget.

# basic itteration
items=( a b c d e )

for i in "${items[@]}"
do
    echo -n $i
done

#=> abcde

# update specific array slot
items[1]="foo"

# access specific array slot
echo ${items[1]}

#=> foo

I was looking for a simple way to source and set a bash environment variable from a file, in this specific instance, I can't be 100% sure that the any steps I take to ensure that the file itself is sourced on the host before Rails is started, nor can I impact the format of the file itself (e.g. changing it to YAML).