speedup

#!/bin/bash
: ${1?"Usage: $0 edit"}

set -e
SERVICES="$@"
IFS=''

# Docker for Mac performance improvement
#
# Selectively mount only the volumes you're working on for a 2-5x
# performance improvement, depending on project over-using host mounts
#
# Use in place of docker-compose up -d service1 serviceN
#
# Creates & invokes a temporary, more limited docker-compose yaml 
# and also supports docker-compose.override.yml
#
# Alternative to docker-machine, d4m-nfs, docker-sync.io
#
# This will add "delegated" volume mount mode to the services
# you invoke with the script and will also remove the volume mounts
# to all other services. This means that container file systems will
# not be linked to your source folders, except for the services you
# specify. 
#
# The delegated mode is new as of Docker for Mac 17.06 and
# is highly performant, at the cost of consistency; the container's file
# system is more trusted, and writes made on the container are not
# guaranteed to be sync'd to the host quickly or reliably. If you do
# not want to use "delegated" you can force "cached" or "consistent"
# in your docker-compose.yml.
#
# This has been tested with Docker for Mac 17.06 Stable.
#
# Install:
#
#   Place this script alongside docker-compose.yml, or symlink it to ~/bin
#
# Usage:
# 
#   speedup edit rover
#
# http://github.com/magoon/dockermac-speedup


function remove_unneeded_volumes_from() {

  # Iterate services, removing volumes from those we don't need
  # And adding ":delegated" to those that we do want to keep
  # 
  # Function parameter: docker-compose filename
  #
  # Overview: When a matching service is found after an empty line,
  # matching_service variable becomes set to 1. Then, when "volumes:" is
  # found, any item in that list is conditionally removed or modified.

  FILE=$( IFS='' cat $1 )

  echo $FILE | awk '
    matching_service && volumes {
      # This does the actual skipping of volumes
      if (/\s*-\s*"?[^"]*"?/) 
	next;
    } 

    volumes {
      if (/\s*-\s*"?[^"]*"?/) {
        # Add :delegated mode to volume mount if not exist, 
        # not in quotes, and absolute
        if (!/.*\:.*\:/ && /:/ && !/:(consistent|:delegated|:cached)/ && !/"$/) {   
          print $0":delegated"; 
          next;  
        }
      }
      else 
        volumes=0
    }

    /\volumes:/ {
      volumes=1;
      if (matching_service) {
        next;
      }
    }
    
    empty { 
      matching_service = 1
      split ("'$SERVICES'", servicelist, " ");
      for (i in servicelist)
        if ($1 == servicelist[i]":") 
          matching_service = 0;
    } 
    { 
      # Services are to be preceded by empty lines, sadly
      if (NF) 
        empty = 0; 
      else 
        empty = 1 
    }
    { 
      if (/services:/) 
        empty = 1
    }
    1
  '
}

# Start docker if it's not already running
if ! $(docker info > /dev/null 2>&1); then
  open -a /Applications/Docker.app
  echo -ne "\nWait until Docker for Mac is running."
  while ! $(docker run --rm hello-world > /dev/null 2>&1); do
    echo -n "."
    sleep .5
  done
  echo ""
fi

# Lower the priority of hyperkit
renice -n 19 $(pgrep com.docker.hyperkit) 

# if there's no docker-compose.yml file, exit
if [ ! -f docker-compose.yml ]; then
  echo 'Error: docker-compose.yml: No such file'
  exit 1
fi

# Write out a temporary docker-compose file with modified volume mounts
remove_unneeded_volumes_from docker-compose.yml > .tmp.docker-compose.yml

# Also process your override file if needed
if [ -f docker-compose.override.yml ]; then
  remove_unneeded_volumes_from docker-compose.override.yml > .tmp.docker-compose.override.yml
  docker-compose -f .tmp.docker-compose.yml -f .tmp.docker-compose.override.yml up -d $@
else
  docker-compose -f .tmp.docker-compose.yml up -d $@ 
fi

# Clean up
rm -f .tmp.docker-compose.yml
rm -f .tmp.docker-compose.override.yml

# End the script successfully
exit 0