How to find EC2 Instance ID from w/i the instance

Victor Farazdagi — Tue, 07 Jul 2009 21:08:12 +0000

When you have several instances running and performing the same job, it’s often very helpful to add tasks into SQS with instance ID attached (that way you can also back-verify that item in queue comes from authorized instance). As it comes out, Amazon has already implemented instance meta-data tool, so no need to implement your own! EC2 Instance Meta-data Query Tool is very simple to install and use, just follow the on-site instructions and you would be done in no time. Here’s how I did it:

$ cd /usr/local/src
$ wget http://s3.amazonaws.com/ec2metadata/ec2-metadata
$ chmod u+x ec2-metadata
$ mv ec2-metadata /usr/bin

and to find out instance ID:

ec2-metadata -i

For other options:

ec2-metadata -help

EC2 Ubuntu – configuring vsftpd

Victor Farazdagi — Fri, 03 Jul 2009 22:18:18 +0000

I am creating custom AMI from very well prepared Ubuntu 9.04 Jaunty (Server) AMI by Eric Hammond. In process, I decided to ship vsftpd (simple and very stable ftp server) by default with my AMI. So, I went on with installing vsftpd:

apt-get install vsftpd

I further configured installed FTP server (/etc/vsftpd.conf):

anonymous_enable=NO # don't want anonymous access
pasv_enable=YES # enable passive mode
pasv_min_port=50000
pasv_max_port=50100
pasv_address=YOUR_INSTANCE_ASSOCIATED_IP
local_enable=YES # enable local users to login into system
write_enable=YES # enable local users to execute FTP write commands

Everything is pretty much simple, probably except for pasv ports. In a nutshell, passive mode means server handles which ports are used for data transfers, and we are using ports in range of 50000-50100. Now any system user should be able to login into your server via ftp. If you need further info regarding laying down the user accounts read my previous post.

One last thing – data ports should be accessible (which is obvious but I have spent half an hour figuring out why I can login via ftp, but cannot execute LIST command), so configure your authorization group accordingly:

ec2-authorize default -p 50000-50100 #open ports for default group

I hope it saves you some time.
Have a nice weekends!

If you need more info on how FTP functions here is good overview.

Victor Farazdagi » EC2

How to find EC2 Instance ID from w/i the instance

EC2 Ubuntu – configuring vsftpd