how do I get all my rake tasks to write to the same log file? - ruby-on-rails-3

Question

I have two rake tasks that I'd like to run nightly. I'd like them to log to one file. I thought this would do the trick (got it here: Rake: logging any task executing):
application.rb
module Rake
class Task
alias_method :origin_invoke, :invoke if method_defined?(:invoke)
def invoke(*args)
#logger = Logger.new('rake_tasks_log.log')
#logger.info "#{Time.now} -- #{name} -- #{args.inspect}"
origin_invoke(args)
end
end
end
and then in the rakefile:
task :hello do
#logger.warn "Starting Hello task"
puts "Hello World!"
puts "checking connection "
checkConnection
puts "done checking"
#logger.debug "End hello rake task"
end
But when I run the task I get:
private method 'warn' called for nil:NilClass
I've tried a couple of flavors of that call to logging (#, ##, no #) to no avail. Read several threads on here about it. The
rubyonrails.org site doesn't mention logging in rake tasks. The tasks that I'm invoking are fairly complex (about 20-40 mins to complete) so I'll really want to know what went wrong if they fail. I'd prefer for DRY reasons to only create the logger object once.

Answer 1

Unless you're wrapping everything in giant begin/rescue's and catching errors that way, the best way to log errors is to catch all output from stderr and stdout with something like:
rake your:job 2>&1 >> /var/log/rake.log
You could also set your Rails environment to use the system logger as well.

Answer 2

I ended up solving this (or at least well enough) by making a "log" task and depending on that in other tasks. Not really ideal, since that means having to include that dependency in any new task, but I have only a few tasks so this will do fine. I'm aware that there is a "file" task but it didn't seem to want to work in Windows, so I chose this because it seems to be more cross platform and it's more explicit.
I need a logger object because I am passing that object into some method calls in the [...] sections. There's enough begin/rescue/end in there that writing to the output stream wouldn't work (I think).
#log_file = "log/tasks.log"
directory "log"
task :check_log => ["log"] do
log = #log_file
puts 'checking log existence'
if not FileTest.exists? ("./#{log}")
puts 'creating log file'
File.open(log, 'w')
end
end
task :check_connection => [:check_log] do
begin
conn = Mongo::Connection.new
[...]
end
end
task :nightly_tasks => [:check_connection, :environment ] do
for i in 1..2
logger.warn "#########################"
end
[...]
logger.warn "nightly tasks complete"
end
def logger
##logger ||= Logger.new( File.join(Rails.root, #log_file) )
end