add preliminary documentation in the README, add the script

2 files changed, 487 insertions, 0 deletions

diff --git a/README.md b/README.md
index aa36238..3cda65c 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,187 @@ freebsd-unicorn
 ===============
 
 A robust init script for running unicorn on FreeBSD
+
+This rc script works with either RVM and RBENV installed in your deploy user's directory, or with a globally installed ruby. It correctly handle's Unicorn+Bundler [idiosyncrasies][unicorn-sandboxing].
+
+Simply place the `unicorn` script in your `/usr/local/etc/rc.d` directory, modify it if necessary, and configure your application via variables in `/etc/rc.conf`
+
+This has been tested on **FreeBSD 9.0 and 9.1**
+
+Making sure unicorn starts after your database launches
+-------------------------------------------------------
+
+The only thing you might need to configure in the rc script is to change the `REQUIRES` line to specify your database (I use PostreSQL so that's what's in the repo)
+
+For example, if you were using MySQL, you would change
+
+    # REQUIRE: LOGIN postgresql
+
+to
+
+    # REQUIRE: LOGIN mysql-server
+
+You might need to add other services to this list if your Rails application requires them.
+
+### Quick Setup
+
+To get up and running quickly, adjust the `REQUIRES` line like above, and add edit your `/etc/rc.conf`:
+
+For Capistrano or Capistrano-like directory layouts:
+
+    unicorn_enable="YES"
+
+    # this is the path to where your application is deployed in Capistrano,
+    # the parent directory of the `current` directory
+    unicorn_directory="/u/application"
+
+
+For Non-Capistrano-like layouts:
+
+    unicorn_enable="YES"
+    unicorn_command="/u/application/bin/unicorn_rails"
+    unicorn_command_args="/u/application/config.ru"
+    unicorn_pidfile="/u/application/tmp/pids/unicorn.pid"
+    unicorn_old_pidfile="/u/application/tmp/pids/unicorn.oldbin"
+    unicorn_listen="/u/application/tmp/sockets/unicorn.sock"
+    unicorn_config="/u/application/config/unicorn.rb"
+    unicorn_chdir="/u/application"
+    unicorn_user="deploy"
+
+    # Uncomment this if using a different RAILS_ENV/RACK_ENV than production
+    #unicorn_env="production"
+    
+
+Edit `/etc/rc.conf` to meet your needs
+-------------------------------------------
+
+### Using a Capistrano directory layout
+
+The rc script does as much as possible to help you out. If you are using capistrano, or a capistrano-like directory structure, then you can just specify the directory of your application (the parent directory of `current`):
+
+    unicorn_enable="YES"
+    unicorn_directory="/u/application"
+
+This infers all sorts of information about your app (you can always run `/usr/local/etc/rc.d/unicorn show` to see what your configuration is. **Note** the variable names listed here are without the leading `unicorn_` prefix that you would need to specify in `/etc/rc.conf`):
+
+    #
+    # Unicorn Configuration for application
+    #
+
+    command:        /u/application/current/bin/unicorn_rails
+    command_args:   /u/application/current/config.ru
+    pidfile:        /u/application/shared/pids/unicorn.pid
+    old_pidfile:    /u/application/shared/pids/unicorn.pid.oldbin
+    listen:         
+    config:         /u/application/current/config/unicorn.conf.rb
+    init_config:    
+    bundle_gemfile: /u/application/current/Gemfile
+    chdir:          /u/application/current
+    user:           deploy
+    nice:           
+    env:            production
+    flags:          -E production -c /u/application/current/config/unicorn.conf.rb -D
+    
+    start_command:
+    
+    su -l deploy -c "export BUNDLE_GEMFILE=/u/application/current/Gemfile && cd /u/application && /u/application/current/bin/unicorn_rails -E production -c /u/application/current/config/unicorn.conf.rb -D /u/application/current/config.ru"
+
+Let's look at these settings one by one:
+
+`command`: By default, it uses the `current/bin/unicorn_rails` [bundler binstub][binstub] located in your project to ensure your gems are loaded. `command` comes from FreeBSD's `rc.subr` init system functions.
+
+`command_args`: This is the standard FreeBSD's `rc.subr` variable that holds the arguments to the above `command`
+
+`pidfile`: This is also part of FreeBSD's `rc.subr` system. This is where the built in functions will look for the pid of the process. By default, this rc script looks in the `shared/pids/unicorn.pid` file.
+
+`old_pidfile`: This is the pidfile used by unicorn to perform zero-downtime upgrades. [Procedure to replace a running unicorn executable][unicorn-0-downtime]. This rc script uses Unicorn's default convention of appending `.oldbin` to the end of the `pidfile`
+
+`listen`: This is the port or socket for Unicorn to listen on. This rc script assumes that you will specify it in your project's Unicorn config file (see the next variable).
+
+e.g.
+
+    listen "#{app}/shared/sockets/unicorn.sock", :backlog => 64
+
+`config`: This is the path to Unicorn's config file where unicorn will find it's settings. By default this rc script looks for a file called `current/conf/unicorn.conf.rb`
+
+`init_config`: This is a shell script file that is included in the environment before Unicorn is executed. In this file you can include `export VAR=value` statements to pass environment variables into your rails app. By default, this init script looks for a file called `current/.env` and uses that. If that file doesn't exist, this rc script will skip this functionality (as seen in the above example).
+
+This could be used in conjunction with [dotenv][dotenv] in development since dotenv accepts lines beginning with `export`
+
+
+`bundle_gemfile`: This is the path to the `Gemfile` of your project. This rc script sets the `BUNDLE_GEMFILE` environment variable to this value. By default it looks to `current/Gemfile`. This is required so that Unicorn uses the most current `Gemfile` (rather than the one in the specific deployment directory) when an upgrade is performed. See [Unicorn Sandboxing][unicorn-sandboxing]. This is a safeguard, you should really put this in your unicorn.conf.rb:
+
+    before_exec do |server|
+      ENV["BUNDLE_GEMFILE"] = "/path/to/app/current/Gemfile"
+    end
+
+`chdir`: This is the directory we `cd` into before running Unicorn. By default it's the currently deployed version of your application "`current/`"
+
+`user`: This is the user that Unicorn will be run as. By default we do like [Passenger][passenger] and use the owner of the `unicorn_directory`.
+
+`nice`: The `nice` level to run unicorn at. Usually you'll leave this alone.
+
+`flags`: This is a variable defined by FreeBSD's `/etc/rc.subr` init system, and contains the flags passed to the command (Unicorn in this case) when run. This variable is built up from the variables above, but you could manually specify `unicorn_flags` in your `/etc/rc.conf` to override them.
+
+`start_command`: Here you can see the full command that will be run when you start this service. It's a beaut' isn't it?
+
+You can override any of these parameter in your `/etc/rc.conf` by simply specifying the variables like you see below (you can pick and choose which to override).
+
+
+### Using a custom directory layout
+
+Using your own layout is easy, you can just leave the `unicorn_directory` variable out of your `/etc/rc.conf` and specify all of the above variables manually. Here's a list of those variables for your convenience:
+
+    unicorn_command:      The path to the unicorn command
+    unicorn_command_args: The non-flag arguments passed to the above command. This is usually the path to the Rack config.ru file
+    unicorn_pidfile:      The path where Unicorn will put its pid file
+    unicorn_old_pidfile:  The path where Unicorn will put its `old` pid file (usually the same as the sbove with `.oldbin` appended)
+    unicorn_listen:       The path to the socket or port to listen on. You can leave this blank to specify where to listen in the Unicorn config
+    unicorn_config:       The path to the Unicorn config file
+    unicorn_chdir:        The path where this script will `cd` to before starting unicorn
+    unicorn_user:         The user to run Unicorn as
+    unicorn_nice:         The `nice` level to run Unicorn as. Leave blank to run un-niced
+    unicorn_env:          The RAILS_ENV (or RACK_ENV) to run your application as. (default: production)
+    unicorn_flags:        The flags passed in to Unicorn when starting (not counting the unicorn_command_args specified above). Override this for complete control of how to start Unicorn.
+    
+
+### Deploying multiple applications
+
+This is all find and dandy, but some of you might have multiple applications running on the same server (even if it's just a staging and production version of your app).
+
+This rc script can work with multiple applications. It works similarly to how postgresql's rc script works on FreeBSD.
+
+You simply specify your profiles in your `/etc/rc.conf` with the `unicorn_profiles` variable. This is a space separated list of application names.
+
+Then you can customize each application by specifying variables in this form:
+
+    unicorn_<application-name>_variable=VALUE
+
+Here's a simple example (I can leave the _env variable out of the production declaration since it's the default value)
+
+    unicorn_enable="YES"
+    unicorn_profiles="application_staging application_production"
+
+    unicorn_application_staging_enable="YES"
+    unicorn_application_staging_directory="/u/application_staging"
+    unicorn_application_staging_env="staging"
+
+    unicorn_application_production_enable="YES"
+    unicorn_application_production_directory="/u/application_production"
+
+You can use the simplified Capistrano `directory`-based configuration like above, or you can specify all of the variable's separately, for a fully custom setup
+
+### Customizing the script
+
+If you want to customize the default, calculated values you want to look in the `_setup_directory()` function. This is what is called when you specify that you want to use a Capistrano-like directory layout by specifying `unicorn_directory` or `unicorn_<application-name>_directory` in your `/etc/rc.conf`.
+
+If you use a different deployment strategy than Capistrano, you could adjust the default values to work with your system.
+
+
+
+
+passenger: https://www.phusionpassenger.com
+unicorn-sandboxing: http://unicorn.bogomips.org/Sandbox.html
+dotenv: https://github.com/bkeepers/dotenv
+unicorn-0-downtime: http://unicorn.bogomips.org/SIGNALS.html
+binstub: https://github.com/sstephenson/rbenv/wiki/Understanding-binstubs
\ No newline at end of file
diff --git a/unicorn b/unicorn
new file mode 100644
index 0000000..0817fbd
--- /dev/null
+++ b/unicorn
@@ -0,0 +1,303 @@
+#!/bin/sh
+
+# PROVIDE: unicorn
+# REQUIRE: LOGIN postgresql
+# KEYWORD: shutdown
+
+. /etc/rc.subr
+
+name="unicorn"
+rcvar=`set_rcvar`
+procname="ruby"
+
+extra_commands="upgrade show reopenlogs"
+start_cmd="unicorn_start_command"
+upgrade_cmd="unicorn_upgrade_command"
+show_cmd="unicorn_show_command"
+reopenlogs_cmd="unicorn_reopenlogs_command"
+
+load_rc_config "${name}"
+
+: ${unicorn_enable:="NO"}
+: ${unicorn_flags:="-D"}
+: ${unicorn_env:="production"}
+: ${unicorn_init_config:=""}
+: ${unicorn_bundle_gemfile:=""}
+: ${unicorn_profiles:=""}
+: ${unicorn_upgrade_timeout:="60"}
+: ${unicorn_rc_script:="/usr/local/etc/rc.d/unicorn"}
+
+#
+# Convenience function to read a profile's environment variable, or fall back to a default
+#
+# e.x. _read_profile_var my_app pidfile '/u/my_app/shard/pids/unicorn.pid'
+#
+_read_profile_var()
+{
+  profile=$1
+  var=$2
+  default=$3
+  default2=$4
+  eval value="\${unicorn_${profile}_${var}:-${default}}"
+  eval value="\${value:-${default2}}"
+  echo "${value}"
+}
+
+#
+# Takes a directory and sets up some default environement variables based on a capistrano layout
+#
+_setup_directory()
+{
+  local directory
+  directory=$1
+  
+  directory_command="${directory}/current/bin/unicorn_rails"
+  directory_pidfile="${directory}/shared/pids/unicorn.pid"
+  directory_old_pidfile="${directory_pidfile}.oldbin"
+  directory_config="${directory}/current/config/unicorn.conf.rb"
+  directory_rackup="${directory}/current/config.ru"
+  directory_init_config="${directory}/current/.env"
+  directory_bundle_gemfile="${directory}/current/Gemfile"
+  directory_chdir="${directory}/current"
+
+  # only use the directory_init_config if it exists
+  if [ ! -f "${directory_init_config}" ]; then
+    unset directory_init_config
+  fi
+
+  # only use the bundle_gemfile if it exists
+  if [ ! -f "${directory_bundle_gemfile}" ]; then
+    unset directory_bundle_gemfile
+  fi
+
+  if [ -f "${directory_config}" ]; then
+    directory_user=`stat -f "%Su" "${directory_config}"` # default to the owner of the config file
+  fi
+}
+
+#
+# If we have a profile, set up the environment for that profile
+#
+if [ -n "$2" ]; then
+  profile="$2"
+
+  # set the rcvar for this specific profile
+  rcvar=`set_rcvar "${name}_${profile}"`
+  # if the user provides a directory, we can infer some default configuration
+  directory=`_read_profile_var "${profile}" "directory"`
+
+  if [ -n "${directory}" ]; then
+    _setup_directory "${directory}"
+  fi
+
+  unicorn_rackup=`        _read_profile_var "${profile}" "rackup"         "${directory_rackup}"`
+  unicorn_old_pidfile=`   _read_profile_var "${profile}" "old_pidfile"    "${directory_old_pidfile}"`
+  unicorn_config=`        _read_profile_var "${profile}" "config"         "${directory_config}"`
+  unicorn_init_config=`   _read_profile_var "${profile}" "init_config"    "${directory_init_config}"`
+  unicorn_bundle_gemfile=`_read_profile_var "${profile}" "bundle_gemfile" "${directory_bundle_gemfile}"`
+  unicorn_chdir=`         _read_profile_var "${profile}" "chdir"          "${directory_chdir}"`
+  unicorn_listen=`        _read_profile_var "${profile}" "listen"         "${unicorn_listen}"`
+  unicorn_user=`          _read_profile_var "${profile}" "user"           "${unicorn_user}"           "${directory_user}"`
+  unicorn_nice=`          _read_profile_var "${profile}" "nice"           "${unicorn_nice}"`
+  unicorn_env=`           _read_profile_var "${profile}" "env"            "${unicorn_env}"`
+  unicorn_flags=`         _read_profile_var "${profile}" "flags"          "${unicorn_flags}"`
+
+  command=`_read_profile_var "${profile}" "command"     "${unicorn_command}"       "${directory_command}"`
+  pidfile=`_read_profile_var "${profile}" "pidfile"     "${directory_pidfile}"`
+else
+  if [ "x${unicorn_profiles}" != "x" -a "x$1" != "x" ]; then
+    # If we weren't started with a profile, run the command on all available profiles
+    for profile in ${unicorn_profiles}; do
+      # By default set the profile rcvar to no to suppress warnings by checkyesno
+      profile_rcvar=`set_rcvar "${name}_${profile}"`
+      eval "${profile_rcvar}=\${${profile_rcvar}:-'NO'}"
+
+      if checkyesno ${profile_rcvar}; then
+        echo "Running ${1} on ${profile}"
+        ${unicorn_rc_script} $1 $profile
+      else
+        echo "Skipping ${profile}"
+
+        # Unset the variable and then checkyesno again to print the warning
+        eval "unset ${profile_rcvar}"
+        checkyesno ${profile_rcvar}
+      fi
+      echo
+    done
+    exit 0
+  else
+    # look for a profile-less configuration
+
+    # if the user provides a directory, we can infer some default configuration
+    directory=${unicorn_directory:-}
+
+    if [ -n "${directory}" ]; then
+      _setup_directory "${directory}"
+    fi
+
+    unicorn_rackup=${unicorn_rackup:-$directory_rackup}
+    unicorn_old_pidfile=${unicorn_old_pidfile:-$directory_old_pidfile}
+    unicorn_chdir=${unicorn_chdir:-$directory_chdir}
+    unicorn_user=${unicorn_user:-$directory_user}
+    unicorn_config=${unicorn_config:-$directory_config}
+    unicorn_init_config=${unicorn_init_config:-$directory_init_config}
+    unicorn_bundle_gemfile=${unicorn_bundle_gemfile:-$directory_bundle_gemfile}
+
+    command=${unicorn_command:-$directory_command}
+    pidfile=${unicorn_pidfile:-$directory_pidfile}
+  fi
+fi
+
+# add the directory as a required directory, if it's specified
+required_dirs="${directory:-}"
+
+# if we have a config file or rackup file specified, make sure it exists
+required_files="${unicorn_config:-} ${unicorn_rackup:-}"
+
+#
+# Build up the flags based on the environment variables
+#
+[ -n "${unicorn_listen}" ] && unicorn_flags="-l ${unicorn_listen} ${unicorn_flags}"
+[ -n "${unicorn_config}" ] && unicorn_flags="-c ${unicorn_config} ${unicorn_flags}"
+[ -n "${unicorn_env}" ] && unicorn_flags="-E ${unicorn_env} ${unicorn_flags}"
+
+# Add our rackup file to the unicorn command_args
+[ -n "${unicorn_rackup:-}" ] && command_args="${unicorn_rackup:-}"
+
+# This function builds the command to start unicorn. This is split out so we can
+# print it from the "show" command
+_unicorn_start_command()
+{
+  local shell_command
+  shell_command="${unicorn_bundle_gemfile:+export BUNDLE_GEMFILE=$unicorn_bundle_gemfile && }"\
+"${unicorn_init_config:+. $unicorn_init_config && }"\
+"${unicorn_chdir:+cd $unicorn_chdir && }"\
+"${unicorn_nice:+nice -n $unicorn_nice }"\
+"${command} ${rc_flags} ${command_args}"
+
+  if [ -n "${unicorn_user}" ]; then
+    echo "su -l ${unicorn_user} -c \"${shell_command}\""
+  else
+    echo "sh -c \"${shell_command}\""
+  fi
+}
+
+#
+# The start command
+#
+unicorn_start_command()
+{
+  # ensure unicorn isn't already running
+  if [ -z "$rc_fast" -a -n "$rc_pid" ]; then
+    echo 1>&2 "${name} already running? (pid=$rc_pid)."
+    return 1
+  fi
+
+  # ensure that the command exists and is executable
+  if [ ! -x ${_chroot}${_chroot:+"/"}${command} ]; then
+    warn "run_rc_command: cannot run $command"
+    return 1
+  fi
+
+  check_startmsgs && echo "Starting ${name}: ${profile}."
+
+  eval "$(_unicorn_start_command)"
+  _return=$?
+
+  if [ $_return -ne 0 ] && [ -z "${rc_force}" ]; then
+    return 1
+  fi
+
+  return 0
+}
+
+unicorn_upgrade_command()
+{
+  if [ -n "${rc_pid}" ]; then
+    # Tell the master to spawn a new version of itself
+    if kill -USR2 "${rc_pid}"; then
+      n=$unicorn_upgrade_timeout
+
+      # Wait until the unicorn_old_pidfile and pidfile both exist and are non-empty
+      echo -n >&2 "Waiting for the new master to spawn"
+      while [ \( ! -s "${unicorn_old_pidfile}" -o ! -s "${pidfile}" \) -a $n -ge 0 ]; do
+        printf >&2 '.' && sleep 1 && n=$(( $n-1 ))
+      done
+      echo
+
+      # if the pidfile or unicorn_old_pidfile still don't exist, quit
+      if [ ! -s "${pidfile}" -o ! -s "${unicorn_old_pidfile}" ]; then
+        [ ! -s "${pidfile}" ]              && echo >&2 "${pidfile} doesn't exist after ${unicorn_upgrade_timeout} seconds"
+        [ ! -s "${punicorn_old_pidfile}" ] && echo >&2 "${unicorn_old_pidfile} doesn't exist after ${unicorn_upgrade_timeout} seconds"
+        return 1
+      fi
+
+      # make sure the new master can receive signals, and then QUIT the old one
+      echo >&2 "Killing the old master"
+      kill -0 `check_pidfile "${pidfile}" "${procname}"` && kill -QUIT `check_pidfile "${unicorn_old_pidfile}" "${procname}"`
+
+      # Wait for the old master to die
+      echo -n >&2 "Waiting for the old master to cleanup"
+      while [ -s "${unicorn_old_pidfile}" -a $n -ge 0 ]; do
+        printf >&2 '.' && sleep 1 && n=$(( $n-1 ))
+      done
+      echo
+
+      # If the old master is still around, print that fact and exit with an error
+      if [ -s "${unicorn_old_pidfile}" -a $n -lt 0 ]; then
+        echo >&2 "${unicorn_old_pidfile} still exists after ${unicorn_upgrade_timeout} seconds"
+        return 1
+      fi
+
+      # everything worked, return success
+      return 0
+    fi
+
+    # If there isn't a pid in rc_pid, just run the start command
+    echo >&2 "Couldn't upgrade, running `start` instead"
+    $0 start "${2}"
+  fi
+}
+
+#
+# Prints the configuration for the given profile
+#
+unicorn_show_command()
+{
+  if [ -n "${profile}" ]; then
+    banner="Unicorn Configuration for ${profile}"
+  else
+    banner="Unicorn Configuration"
+  fi
+
+  echo "
+#
+# ${banner}
+#
+
+command:        ${command}
+command_args:   ${command_args}
+pidfile:        ${pidfile}
+old_pidfile:    ${unicorn_old_pidfile}
+listen:         ${unicorn_listen}
+config:         ${unicorn_config}
+init_config:    ${unicorn_init_config}
+bundle_gemfile: ${unicorn_bundle_gemfile}
+chdir:          ${unicorn_chdir}
+user:           ${unicorn_user}
+nice:           ${unicorn_nice}
+env:            ${unicorn_env}
+flags:          ${unicorn_flags}
+
+start_command:
+
+$(_unicorn_start_command)
+"
+}
+
+unicorn_reopenlogs_command()
+{
+  [ -n "${rc_pid}" ] && kill -USR1 $rc_pid
+}
+
+run_rc_command "${1}"