Module: Locd::Proxy

Includes:
NRSER::Log::Mixin
Defined in:
lib/locd/proxy.rb

Overview

Stuff for running the proxy server, which does "vhost"-style routing of HTTP requests it receives to user-defined sites.

It does this by matching the HTTP Host header against site labels.

Built off proxymachine, which is itself built on eventmachine.

Constant Summary collapse

HOST_RE =

Regexp to match HTTP "Host" header line.

Returns:

  • (Regexp) 
/^Host\:\ /i
ROTATE_LOGS_LABEL =

Label for the Loc'd proxy agent itself

Returns:

  • (String) 
'com.nrser.locd.rotate-logs'

Class Method Summary collapse

Class Method Details

.allocate_port ⇒ Fixnum

Find a port in port_range that is not already used by a Agent::Site to give to a new site.

Returns:

  • (Fixnum) —

    Port number.

Raises:

  • If a port can not be found.



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# File 'lib/locd/proxy.rb', line 190

def self.allocate_port
  allocated_ports = Locd::Agent::Site.ports
  
  port = port_range.find { |port| ! allocated_ports.include? port }
  
  if port.nil?
    raise "Could not allocate port for #{ remote_key }"
  end
  
  port
end

.extract_host(lines) ⇒ String

Get the request host from HTTP header lines.

Parameters:

  • lines (Array<String>)

Returns:

  • (String) 


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# File 'lib/locd/proxy.rb', line 90

def self.extract_host lines
  lines.
    find { |line| line =~ HOST_RE }.
    chomp.
    split( ' ', 2 )[1]
end

.extract_path(lines) ⇒ String

Get the request path from HTTP header lines.

Parameters:

  • lines (Array<String>)

Returns:

  • (String) 


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# File 'lib/locd/proxy.rb', line 103

def self.extract_path lines
  lines[0].split( ' ' )[1]
end

.find_and_start_site(pattern) ⇒ Locd::Agent::Site

Um, find and start a Agent::Site from a pattern.

Parameters:

  • pattern (String | Pattern) —

    Pattern to match against agent.

    When it's a String, passed to Locd::Pattern.from to get the pattern.

Returns:



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# File 'lib/locd/proxy.rb', line 208

def self.find_and_start_site pattern
  logger.debug "Finding and starting site...", pattern: pattern
  
  site = Locd::Agent::Site.find_only! pattern
  
  logger.debug "Found site!", site: site
  
  if site.running?
    logger.debug "Site is RUNNING"
  else
    logger.debug "Site STOPPED, starting..."
    site.start
    logger.debug "Site started."
  end
  
  site
end

.headers_received?(data) ⇒ Boolean

See if the lines include complete HTTP headers.

Looks for the '\r\n\r\n' string that separates the headers from the body.

Parameters:

Returns:

  • (Boolean) —

    true if data contains complete headers.



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# File 'lib/locd/proxy.rb', line 58

def self.headers_received? data
  data.include? "\r\n\r\n"
end

.http_response_for(status, text) ⇒ String

Generate an HTTP text response string.

Parameters:

  • status (String) —

    The HTTP status header.

  • text (String) —

    Text response body.

Returns:

  • (String) —

    Full HTTP response.



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# File 'lib/locd/proxy.rb', line 74

def self.http_response_for status, text
  [
    "HTTP/1.1 #{ status }",
    "Content-Type: text/plain; charset=utf-8",
    "Status: #{ status }",
    "",
    text
  ].join( "\r\n" )
end

.port ⇒ Fixnum

Get the proxy's port from it's .plist if it exists, otherwise from the config setting.

Returns:

  • (Fixnum) —

    Port number.

Raises:

  • (TypeError) —

    If we can't find a suitable config setting when looking for one.



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# File 'lib/locd/proxy.rb', line 236

def self.port
  if proxy = Locd::Agent::Proxy.get
    proxy.port
  else
    Locd.config[:proxy, :port, type: t.pos_int]
  end
end

.port_range ⇒ Range<Fixnum, Fixnum>

Range of ports to allocate to Agent::Site when one is not provided by the user.

Start (inclusive) and end (exclusive) values come from site.ports.start and site.ports.end config values, which default to

55000...56000

Returns:

  • (Range<Fixnum, Fixnum>) 


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# File 'lib/locd/proxy.rb', line 176

def self.port_range
  Locd.config[:site, :ports, :start]...Locd.config[:site, :ports, :end]
end

.route(data) ⇒ Hash<Symbol, (Hash | Boolean)] Command for ProxyMachine.

TODO:

This finds the agent using the host as a pattern, so it will match with unique partial label. I think in the case that the host is not the full label it should probably return a HTTP redirect to the full label so that the user URL is bookmark-abel, etc...?

Route request based on data, see ProxyMachine docs for details.

Parameters:

  • data (String) —

    Data received so far.

Returns:

  • (Hash<Symbol, (Hash | Boolean)] Command for ProxyMachine.) —

    Hash<Symbol, (Hash | Boolean)] Command for ProxyMachine.



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# File 'lib/locd/proxy.rb', line 122

def self.route data
  lines = data.lines
  
  logger.debug "Received data:\n#{ lines.pretty_inspect }"
  
  unless headers_received? data
    logger.debug "Have not yet received HTTP headers, waiting..."
    logger.debug lines: lines
    return {noop: true}
  end
  
  logger.debug "HTTP headers received, processing...\n#{ }"
  logger.debug lines: lines
  
  host = extract_host lines
  logger.debug host: host
  
  path = extract_path lines
  logger.debug path: path
  
  # Label is the domain without the port
  label = if host.include? ':'
    host.split( ':', 2 )[0]
  else
    host
  end
  
  site = find_and_start_site label
  remote_host = "#{ Locd.config[:site, :bind] }:#{ site.port }"
  
  pm_cmd = {remote: remote_host}
  logger.debug "Routing to remote", cmd: pm_cmd
  
  return pm_cmd
  
rescue Locd::RequestError => error
  logger.error error
  error.to_proxy_machine_cmd
rescue Exception => error
  logger.error error
  {close: http_response_for( '500 Server Error', error.message )}
end

.serve(bind: , port: ) ⇒ void

This method returns an undefined value.

Run the proxy server.

Parameters:

  • bind (String) (defaults to: ) —

    Address to bind to.

  • port (Fixnum) (defaults to: ) —

    Port to listen on.



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# File 'lib/locd/proxy.rb', line 256

def self.serve  bind: config[:proxy, :bind],
                port: config[:proxy, :port]
  logger.info "Loc'd is starting ProxyMachine, hang on a sec...",
    bind: bind,
    port: port
  
  require 'locd/proxymachine'
  ProxyMachine.set_router method( :route )
  ProxyMachine.run 'locd', bind, port
end