Script to fix pty default for SSH connections

fix-knife-pty-default.sh

#!/bin/bash

# Common functions
function log_prefix { date +%Y-%m-%d\ %H:%M:%S; }
function info { echo "[$(log_prefix)] Info: ${1}"; }
function error { >&2 echo "[$(log_prefix)] Error: ${1}"; }
function fatal { >&2 echo "[$(log_prefix)] Fatal: ${1}"; exit ${2:1}; }

# Detect if we're on OS-X
if [[ "${OSTYPE}" != darwin* ]]; then
  fatal 'Chef knife fixer can only run on OS-X!'
fi

# Because OS-X is BSD based, we need to template the conflicting options
sed --version >/dev/null 2>&1 && sed_opts='--in-place' || sed_opts='-i ""'
stat -c %U "$(pwd)" >/dev/null 2>/dev/null && stat_opts='-c %U' || stat_opts='-f %Su'

# Try to find the file we need to fix
info 'Searching for knife scripts we need to fix'
search='/opt/chef-workstation/embedded/lib/ruby/gems/*/gems/chef-*/lib/chef/knife/ssh.rb'
ls ${search} >/dev/null 2>&1
if [ $? -gt 0 ]; then
  fatal 'No files to fix found, is chef workstation installed?' 2
fi

found=0
fixed=0
correct=0

# Fix each found file
for path in $(ls ${search}); do
  found=$(( ${found} + 1))

  egrep 'def.*open_session.*pty ?= ?false' "${path}" >/dev/null 2>/dev/null
  if [ $? -eq 0 ]; then
    info "Need to fix ${path}"

    owner="$(stat ${stat_opts} "${path}")"
    [[ "${owner}" != "${USER}" ]] \
      && sudo='sudo' \
      && info 'Elevated permissions required to edit this file' \
      || sudo=''

    ${sudo} sed -E ${sed_opts} \
      's/^( *def open_session.*,) ?pty ?= ?false(.*)$/\1 pty = true\2/' \
      "${path}"

    [ $? -eq 0 ] \
      && info 'Fixed pty default' \
      && fixed=$(( ${fixed} + 1)) \
      || error 'Failed to alter file...'
  else
    info "No need to fix ${path}"
    correct=$(( ${correct} + 1 ))
  fi
done

if [ ${found} -eq 0 ]; then
  info 'No files found to be fixed, is this expected?'
else
  info "Found ${found} files that might needed fixing"
  [ ${fixed} -gt 0 ] && info "- ${fixed} fixed"
  [ ${correct} -gt 0 ] && info "- ${correct} did not need fixing"

  incorrect=$(( ${found} - ${fixed} - ${correct} ))
  if [ ${incorrect} -gt 0 ]; then
    error "Not all found files could be fixed (${incorrect}), please check the log above."
  else
    info "Happy knifing!"
  fi
fi