A sample Bash deployment script. This is for a Rails app hosted on an OS X server.

staging_deploy.sh

#!/usr/bin/env bash

# Configuration
SERVER='10.20.30.40'
DEPLOY_TO='/Users/simon/apps/some_app/staging/'
EXCLUDE='*.sqlite3 *.swp .DS_Store .git/ tmp/ log/ public/uploads/ uploads/'
DRY_RUN=false
DEPLOY_GEM_PATH='/Users/simon/.rvm/gems/ruby-1.9.2-p180'
MYSQL2_BUNDLE='/Users/simon/apps/some_app/staging/vendor/bundle/ruby/1.9.1/gems/mysql2-0.2.13/lib/mysql2/mysql2.bundle'

# Map the excluded files to rsync's options
function excludes {
  EXCLUDES=''
  for i in $(echo $EXCLUDE | tr " " "\n")
  do
    EXCLUDES="$EXCLUDES --exclude $i"
  done
}

# Run rsync
function upload_files {
  excludes

  CMD="rsync -avz $EXCLUDES"
  if $DRY_RUN ; then
    CMD="$CMD --dry-run"
  fi

  CMD="$CMD ./ $SERVER:$DEPLOY_TO"
  echo $CMD
  $CMD
}

# run the Rails migrations
function migrate {
  ssh $SERVER "cd $DEPLOY_TO && RAILS_ENV=staging bundle exec rake db:migrate"
}

# Restart the web processes, easy with passenger
function restart_web_processes {
  ssh $SERVER "cd $DEPLOY_TO && touch tmp/restart.txt"
}

# Run bundler
function bundler {
  ssh $SERVER "cd $DEPLOY_TO && GEM_PATH=$DEPLOY_GEM_PATH RAILS_ENV=staging bundle install --deployment --without development test"
  # Patch the mysql2 gem to fix a problem with Snow Leopard (http://freddyandersen.wordpress.com/2010/10/03/mysql-5-5-snow-leopard-and-rails/)
  ssh $SERVER "install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient.18.dylib  $MYSQL2_BUNDLE"
}

# Update cron
function update_cron {
  ssh $SERVER "cd $DEPLOY_TO && whenever --set environment=staging -w"
}

# Run background tasks
function restart_delayed_job {
  ssh $SERVER "cd $DEPLOY_TO && RAILS_ENV=staging script/delayed_job stop"
  ssh $SERVER "cd $DEPLOY_TO && RAILS_ENV=staging nohup script/delayed_job start"
}

# Run deployment
echo "*** Packaging assets ***"
jammit
upload_files

if ! $DRY_RUN ; then
  # copy_settings
  echo "*** Running bundler ***"
  bundler
  echo "*** Migrating the database ***"
  migrate
  echo "*** Updating cron ***"
  update_cron
  echo "*** Restarting delayed_job"
  restart_delayed_job
  echo "*** Restarting Passenger ***"
  restart_web_processes
fi