ec2dns is a set of command line tools that makes it easy to resolve public hostnames of EC2 instances and ssh into them via their tag name.
Usage of ec2dns
ec2dns provides DNS resolution of ec2 tag names under the ".ec2" TLD. If a servers tag name is
appserver-1, it can be resolved as
ec2dns allows working with ec2 tag names like with normal domain names as shown in the following examples.
ssh firstname.lastname@example.org ubuntu@ip-1-11-11-11:~$
$ scp email@example.com:/etc/nginx/nginx.conf . nginx.conf 100% 221 0.2KB/s 00:00
$ mysql --host=appserver-1.ec2 --user=someUser --password=somePassword someDatabase Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 348 Server version: 5.5.25a Source distribution Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
ec2dns also includes wrappers around ssh and scp (if you can't or don't want to set up the DNS feature on your machine), as well as a tool to lookup hostnames and a tool to update your /etc/hosts file.
You won't need these wrapper tools if you have set up the DNS feature as shown in the installation instructions below.
Get a list of ec2 instances
$ ec2host i-12345678: appserver-1 ec9-99-99-99-99.compute-1.amazonaws.com i-87654321: appserver-2 ec1-11-11-11-11.compute-1.amazonaws.com
Get the hostname of an ec2 instance by its name tag
$ ec2host appserver-1 ec9-99-99-99-99.compute-1.amazonaws.com
combine ec2host with other commands by using backticks
$ mysql --host=`ec2host appserver-1` --user=someUser --password=somePassword someDatabase Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 348 Server version: 5.5.25a Source distribution Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
ssh into an instance via its name tag
$ ec2ssh ubuntu@appserver-2 ubuntu@ip-1-11-11-11:~$
ssh into an instance via its name tag and execute commands
$ ec2ssh appserver-1 uptime 13:09:10 up 1 day, 14:23, 0 users, load average: 0.35, 0.36, 0.35 $ ec2ssh appserver-1 'uname -a' Linux ip-10-140-78-75 3.2.0-23-virtual #36-Ubuntu SMP Tue Apr 10 22:29:03 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
copy a file from an ec2 instance onto your machine
$ ec2scp ubuntu@appserver-1:/etc/nginx/nginx.conf . nginx.conf 100% 221 0.2KB/s 00:00
update /etc/hosts with your ec2 instances
$ sudo -E ec2updatehostsfile Updated/Added 2 hosts.
Your machine is now able to resolve your ec2 instances by tags directly, so for example the following will just work
$ ping appserver-1
- Obviously an AWS account and at least one running EC2 instance.
- Correctly set
- You need Composer to install the dependencies - you should install it globally, as described here.
- You should have a
~/bindirectory and it should be included in your
- The following command installs ec2dns via Composer.
composer global require "fruux/ec2dns=~2.0.0"
- Make sure you have
~/.composer/vendor/bin/in your path.
These instructions are for OS X.
- Add the configuration for the DNS resolver by creating the file
/etc/resolver/ec2and pasting the following content.
nameserver 127.0.0.1 port 57005
- Create the LaunchAgent configuration that starts the DNS server by creating the file
~/Library/LaunchAgents/com.fruux.ec2dns.plistwith the following command.
tee ~/Library/LaunchAgents/com.fruux.ec2dns.plist <<EOF <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>Label</key> <string>com.fruux.ec2dns</string> <key>ProgramArguments</key> <array> <string>/bin/bash</string> <string>-i</string> <string>-l</string> <string>-c</string> <string>$HOME/.composer/vendor/bin/ec2dns</string> </array> <key>RunAtLoad</key> <true/> <key>StandardErrorPath</key> <string>/usr/local/var/log/ec2dns.log</string> <key>StandardOutPath</key> <string>/usr/local/var/log/ec2dns.log</string> </dict> </plist> EOF
- Finally activate the LaunchAgent config by pasting the following into the terminal.
launchctl load ~/Library/LaunchAgents/com.fruux.ec2dns.plist
composer global update fruux/ec2dns launchctl unload ~/Library/LaunchAgents/com.fruux.ec2dns.plist launchctl load ~/Library/LaunchAgents/com.fruux.ec2dns.plist
Please submit all pull requests against the master branch. Code accompanied with phpunit tests is highly appreciated. Thanks!
Copyright and license
Copyright (c) fruux GmbH. All rights reserved.
fruux is a free service that takes care of your contacts, calendars and more so you don't have to (powered by CardDAV and CalDAV).
Check the license.