For any problems, comments or feedback please create an issue here on GitHub.
The core types and functions are located under khan. This provides an abstraction
over typical command line usage and a thin layer over Amazon related functionality
in the form of model logic.
khan-cli contains the monolithic interfaces that define top-level commands and subcommands.
This should slowly be reduced to functionality that is related to provisioning with other functionality (such as specifics to development) being moved to separate binaries.
When developing features which are planned to run solely on EC2 instances it is
typically difficult to test the behaviour of logic that is reliant on the underlying
metadata lookup mechanisms that utilise instance-data from http://169.254.169.254.
To that end, two separate utilities are provided to emulate instance-data and
make it easy to test your features locally.
The synchronisation utility needs to be deployed onto the EC2 instance you wish to emulate. (it is part of the resulting debian package by default.)
Running khan-metadata-sync will crawl the local instance-data and will result
in a compressed artifact named metadata.tar.gz in your cwd.
The internal structure of this artifact mirrors the url layout that is available
in the instance-data, and can be used by khan-metadata-server.
A Ruby web server is provided under khan-metadata-server.
For convenience symlinks for the built binaries can be found under
binin the project root.
This server needs to be run with sudo and the name of the network interface to
shape traffic for. On OSX the services can be found by running networksetup -listallnetworkservices.
The server will then remove any DNS servers for the selected interface and inspect
all lookups - modifying the packets to ensure that any requests to http://instance-data
are proxied to localhost.
The compressed metadata.tar.gz artifact from running khan-metadata-sync needs to
be extracted into khan-metadata-server/www.
→ rm -rf khan-metadata-server/www/latest
→ tar -C khan-metadata-server/www -xvf metadata.tar.gz
x ./
x ./latest/
x ./latest/meta-data/
x ./latest/meta-data/network/
x ./latest/meta-data/network/interfaces/
...
Typically, if you are connected to the network on WLAN, the name of the interface on OSX would be Wi-Fi.
→ ./bin/khan-metadata-server Wi-Fi
Password: *****
Adding 169.254.169.254 to lo0
Redirecting http://instance-data to localhost
I, [2014-08-11T10:47:48.247533 #86615] INFO -- : Starting RubyDNS server (v0.8.5)...
I, [2014-08-11T10:47:48.247621 #86615] INFO -- : Listening on tcp:0.0.0.0:53
I, [2014-08-11T10:47:48.247784 #86615] INFO -- : Listening on udp:0.0.0.0:53
Serving metadata on http://169.254.169.254/latest
Thin web server (v1.6.2 codename Doc Brown)
Maximum connections set to 1024
Listening on 169.254.169.254:80, CTRL+C to stop
khan is released under the Mozilla Public License Version 2.0