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Glint
Fires arbitrary TCP servers
http://www.flickr.com/photos/tjblackwell/3107540997/
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@kentaro
Software engineer to
build technical basis
Rubyist / Perl Monger
Kentaro Kuribayashi
paperboy&co.
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No content
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Problem
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Applications often consists
of various components
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• Cache servers
• Storage servers
• Job queue/workers
• Other applications
(e.g. external APIs)
• etc.
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• Launch servers in advance
(e.g mysql/pg with Rails)
• Stub out connections to
the servers
(e.g. stub/mock in RSpec)
To deal with it, you may:
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Launching Servers
• We don’t always need
such many servers
• It can be waste of limited
resources of our daily-
used local machine
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Stubbing out Connections
• Efficient way to test apps that
depends on external
components
• But we can’t tell whether or
not our apps work well indeed
against real servers
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Solution
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Glint
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Glint is a library which allows
you to fire arbitrary TCP
servers to help you test your
codes against those real
servers without stubbing
out.
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1. Fork a child process for a
TCP server
2. Find an empty port for the
server
3. Exec the server program
using the port
4. Destroy the child process
when it’s no longer needed
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1. Fork a child process for a
TCP server
2. Find an empty port for the
server
3. Exec the server program
using the port
4. Destroy the child process
when it’s no longer needed
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Basic usage
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With RSpec
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servers/memcached.rb
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spec_helper.rb
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**_spec.rb
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App + External App
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initializer/**.rb
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**_spec.rb
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TCP server
+
TCP server
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Fluentd::Integration
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How Glint Cleans up
the Servers
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http://ruby-doc.org/core-2.0/ObjectSpace.html
“ObjectSpace also provides support
for object finalizers, procs that will
be called when a specific object is
about to be destroyed by garbage
collection.”
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glint/server.rb
Glint::Server#stop
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• Stubbing out external
connection may cause
some problems
• Glint allows you to easily
fire up TCP servers as you
need
• Patches are welcome!
Recap