I have the following code, where a WEBrick instance is forked, and I want to wait till the webrick is started up, before continuing with the rest of the code:
require 'webrick'
pid = fork do
server = WEBrick::HTTPServer.new({:Port => 3333, :BindAddress => "localhost"})
trap("INT") { server.shutdown }
sleep 10 # here is code that take some time to setup
server.start
end
# here I want to wait till the fork is complete or the WEBrick server is started and accepts connections
puts `curl localhost:3333 --max-time 1` # then I can talk to the webrick
Process.kill('INT', pid) # finally the webrick should be killed
So how can I wait till the fork is complete, or even better till the WEBrick is ready to accept connections? I found a piece of code where they deal with a IO.pipe
and a reader and a writer. But that doesn't wait for webrick to load.
Unfortunately I haven't found anything for this specific case. Hope someone can help.
WEBRick::GenericServer
has some callback hooks which are undocumented (sadly, in fact, the whole webrick library is poorly documented!), such as :StartCallback
, :StopCallback
, :AcceptCallback
. You can provide hooks when initializing a WEBRick::HTTPServer
instance.
So, combined with IO.pipe
, you can write your code like this:
require 'webrick'
PORT = 3333
rd, wt = IO.pipe
pid = fork do
rd.close
server = WEBrick::HTTPServer.new({
:Port => PORT,
:BindAddress => "localhost",
:StartCallback => Proc.new {
wt.write(1) # write "1", signal a server start message
wt.close
}
})
trap("INT") { server.shutdown }
server.start
end
wt.close
rd.read(1) # read a byte for the server start signal
rd.close
puts `curl localhost:#{PORT} --max-time 1` # then I can talk to the webrick
Process.kill('INT', pid) # finally the webrick should be killed
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With