Managing Amazon/EC2 NetBSD instances with euca2ools
What and Why
Playing with
ansible,
its "ec2" module came to my attention: it is intended to manage virtual
machines in Amazon's EC2 cloud. The idea is that you describe a system
with the property "needs to run in Amazon's cloud", and ansible then
starts the machine if it isn't there already. In order to get to the point
where this can be played with, a working version of the
euca2ools package was required first.
Packaging was mostly a no-brainer, and a package is currently under review and will end up in pkgsrc eventually.
The more interesting part was to verify if the pkg actually worked as expected.
This proved tricky for two reasons: 1) my overall lack of how to use the
Amazon AWS command line tools (ec2-ami-tools, ec2-api-tools), and 2) the
fact that euca2ools is mostly written for the Eucalyptus Cloud infrastructure,
which just happens to be compatible with Amazon AWS.
To give future parties something to google, here are the steps that to
fire up a NetBSD machine in the Amazon cloud.
How - Prerequirements
A login for Amazon Web Services (AWS) is required, of which the Elastic Cloud Computing (EC2)
Xen infrastructure is a part of. I won't go into details of this, please see
the NetBSD wiki or my article
``NetBSD in der Cloud'' in the German FreeX 5/2012 magazine, pages 58-63, for details.
Before starting, a few environment variables have to be filled
with authentication information.
Log into the Amazon AWS Console,
click on your name in the upper right corner to get to the
"Security Credentials" page, and create an access key if not already present.
Get the acces key ID and the secret key, and put them into environment variables EC2_ACCESS_KEY
and EC2_SECRET_KEY:
% setenv EC2_ACCESS_KEY "AKxxxxxxxxxxxxxxxxxx"
% setenv EC2_SECRET_KEY "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
Next create and download a X.509 certificate - make sure to get both
the file with the private key (pk-XXXX.pem) as well as the file
with the public key (cert-XXX.pem). Set the environment variables
EC2_CERT and EC2_PRIVATE_KEY to thos files, respectively:
% setenv EC2_CERT .../cert-XXX.pem
% setenv EC2_PRIVATE_KEY .../pk-XXX.pem
Last, euca2ools want to know what cloud infrastructure to use for
virtual machines (EC2) and storage (S3). Coming from the
Eucalyptus project, the tools can talk to
cloud servers running Eucalyptus, OpenStack and Amazon AWS.
Communication is via HTTP, and the environment variables
EC2_URL and S3_URL have to be set accordingly:
% setenv EC2_URL http://ec2.amazonaws.com
% setenv S3_URL http://s3.amazonaws.com
Last, make sure your system's time is somewhat in sync with reality,
else you will get funny error messages!
So much for the preparations, let's dive into euca2ools.
List Regions and Availability Zones
Amazon's service offers is spread across many data centers across
different regions of the world. The list of regions is available via
the "euca-describe-regions" command:
% euca-describe-regions
REGION eu-west-1 ec2.eu-west-1.amazonaws.com
REGION sa-east-1 ec2.sa-east-1.amazonaws.com
REGION us-east-1 ec2.us-east-1.amazonaws.com
REGION ap-northeast-1 ec2.ap-northeast-1.amazonaws.com
REGION us-west-2 ec2.us-west-2.amazonaws.com
REGION us-west-1 ec2.us-west-1.amazonaws.com
REGION ap-southeast-1 ec2.ap-southeast-1.amazonaws.com
REGION ap-southeast-2 ec2.ap-southeast-2.amazonaws.com
Inside one region, systems
are grouped together in "availability zones" - usually data centers
or separate security zones within (refer to the Amazon documentation
for details). To list the availability zones in one region, use
the "euca-describe-availability-zones" command:
% euca-describe-availability-zones
AVAILABILITYZONE us-east-1a available
AVAILABILITYZONE us-east-1b available
AVAILABILITYZONE us-east-1c available
AVAILABILITYZONE us-east-1d available
To specify what region to talk to there are two ways. The first is to specify the
region name on any of the following commands with the "--region"
option (yuck):
% euca-describe-availability-zones --region eu-west-1
AVAILABILITYZONE eu-west-1a available
AVAILABILITYZONE eu-west-1b available
AVAILABILITYZONE eu-west-1c available
The second one is to adjust your EC2_URL to point to your preferred
region directly:
% setenv EC2_URL http://ec2.eu-west-1.amazonaws.com
% euca-describe-availability-zones --region eu-west-1
AVAILABILITYZONE eu-west-1a available
AVAILABILITYZONE eu-west-1b available
AVAILABILITYZONE eu-west-1c available
Systems and Listing Available Machine Images
Now that we have a basic overview of the cloud infrastructure
with its regions and availability zones, the next questions are
what hardware is available for running virtual machine instances on,
and what operating systems can be put on.
Amazon lists
available hardware configurations on their "instance types" web
sites. Sizes range from Micro Instances with 613MB RAM, up to two CPU
cores and no local harddisk (t1.micro) to Extra Large (XL) Instances
with 15GB RAM, 8 CPU cores and 1.690 GB local harddisk. Many more
configurations are available for situations that require much memory,
much CPU, much IO, or do cluster computing with CPU and GPU.
As for the operating system and software to put on those virtual
machine instances, there is a VERY wide choice available. The
"euca-describe-images --all" command lists all available optione:
% euca-describe-images --all
...
IMAGE ami-abd0d0df 101367081206/NetBSD-i386-6.0-20121015-1054 \
101367081206 available public i386 machine \
aki-64695810 ebs
IMAGE ami-7fc3c30b 101367081206/NetBSD-x86_64-6.0-20121014-1007 \
101367081206 available public x86_64 machine \
aki-62695816 ebs
...
In the output, the configuration is identified by the Amazon Machine
Identifier (AMI), e.g. "ami-7fc3c30b" for a NetBSD 6.0/amd64
instance. This image ID is required when defining what virtual machine
instance to start.
Note that the "euca-describe-images" command depends on the region
setting, so you will get (and need) different output depending on the
region that you intend your instances to run in.
Setup SSH Access
When starting a NetBSD AMI, access will be via SSH to the root
account. For that, a SSH key pair needs to be created with the
"euca-add-keypair" command. The command can write the private key to a
local file, be sure to protect it properly - it will be the only way
of access to the system! Other interesting commands when managing SSH
keys are "euca-describe-keypairs" and "euca-delete-keypair":
% euca-describe-keypairs
% euca-add-keypair -f key-eucaHF.pem eucaHF
KEYPAIR eucaHF b8:e9:05:7e:3a:df:c7:8e:eb:6e:8d:72:ff:77:68:01:e2:03:7e:3e
% euca-describe-keypairs
KEYPAIR eucaHF b8:e9:05:7e:3a:df:c7:8e:eb:6e:8d:72:ff:77:68:01:e2:03:7e:3e
% euca-delete-keypair eucaHF
KEYPAIR eucaHF
% euca-describe-keypairs
%
Of course we want to keep a key for logging with it, so let's re-run
the important part:
% euca-add-keypair -f key-eucaHF.pem eucaHF
KEYPAIR eucaHF 9b:d4:15:09:bc:51:b1:76:5c:db:a3:93:52:f0:d8:08:87:a4:80:c7
% cat key-eucaHF.pem
-----BEGIN RSA PRIVATE KEY-----
MIIEogIBAAKCAQEAn8rCLhqLyfke+NqeOkqb6BUIbfwBFm/9ddG8ghVt9CUmyKUMRrKFSyaTRreO
...
wA5a3XZuEFw83HdGrhaRgom2ZJ1SEk2889FpAA+yrhveKhDJIe6Zc2rM+crqUWBfnvs=
-----END RSA PRIVATE KEY-----
Manage Virtual Machine Instances
Now that everything is prepared, telling the cloud infrastructure
to find physical hardware, put our preferred operating system
on it, and start it is done with the "euca-run-instance" command:
% euca-run-instances -t t1.micro -k eucaHF ami-7fc3c30b
RESERVATION r-2182506a 749335780469 default
INSTANCE i-2ed60264 ami-7fc3c30b pending \
eucaHF 0 t1.micro 2013-02-03T15:51:49.000Z \
us-east-1b aki-62695816 monitoring-disabled \
ebs
That's actually as complicate as it gets - one command that tells what
hardware to use (t1.micro - can be omitted, a useful default will be
chosen), what SSH key to use for the root account, and what machine
image (AMI) to use are all used here. In return, the command prints a
number of information from the freshly created instance. The one used
in the following commands is the "instance id", "i-2ed60264" in this
example.
When the above command was started, this is a good time to go back to
the Amazon AWS console and have a look at your instances - you will
find the one listed above there now, too!
Instead of the web-based console, the "euca-describe-instances"
command can be used:
% euca-describe-instances
RESERVATION r-2182506a 749335780469 default
INSTANCE i-2ed60264 ami-7fc3c30b ec2-54-228-22-143.compute.amazonaws.com \
ip-10-226-194-20.compute.internal running eucaHF 0 \
t1.micro 2013-02-03T15:51:49.000Z us-east-1b \
aki-62695816 monitoring-disabled \
54.228.22.143 10.226.194.20 ebs
Now this is all nice and dandy, but we have just created a NetBSD
machine in the Amazon cloud. Let's log in!!!1!
To do so, we need the private key file created with the
"euca-add-keypair" command, and the host name. The latter is available
in the list of instances - be sure to use the one within the
"compute.anazonaws.com" domain:
% ssh -i key-eucaHF.pem -l root ec2-54-228-22-143.compute.amazonaws.com
The authenticity of host 'ec2-54-228-22-143.compute.amazonaws.com (54.228.22.143)'
can't be established.
ECDSA key fingerprint is f7:a9:f6:21:fc:d2:0e:46:03:41:f8:d5:c1:72:92:28.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'ec2-54-228-22-143.compute.amazonaws.com,54.228.22.143' (ECDSA)
to the list of known hosts.
NetBSD 6.0 (XEN3_DOMU)
Welcome to NetBSD - Amazon EC2 image!
This system is running a snapshot of a stable branch of the NetBSD
operating system, adapted for running on the Amazon EC2 infrastructure.
The environment is very similar to one provided within a typical Xen domU
installation. It contains a small, autonomous environment (including a
compiler toolchain) that you can run to build your own system.
The file system is lightly populated so you have plenty of space to play with.
Should you need a src or pkgsrc tree, please use the "bootstrap" script found
under /usr to download them. You can also use the script to set up
binary packages using "pkgin":
/usr/bootstrap.sh [src|pkgsrc|binpkg]
This AMI sends email to the maintainer on first boot, to help get
an idea of what is in use at any given time.
You are encouraged to test this image as thoroughly as possible. Should you
encounter any problem, please report it back to the development team using the
send-pr(1) utility (requires a working MTA). If yours is not properly set up,
use the web interface at: http://www.NetBSD.org/support/send-pr.html
Thank you for helping us test and improve NetBSD's quality!
Terminal type is vt220.
We recommend that you create a non-root account and use su(1) for root access.
ip-10-226-194-20# uname -a
NetBSD ip-10-226-194-20.compute.internal 6.0 NetBSD 6.0 (XEN3_DOMU) amd64
ip-10-226-194-20# exit
From here, you are on your own - it's a NetBSD machine, after all.
One word of warning at this point: Amazon AWS is not for free (as you
should be aware from the Preparations step). If you do not need
machines any more, be sure to remove them from the cluster, else this
may drive up your bill for nothing! You can use the
"euca-terminate-instances" command to do just that:
% euca-terminate-instances i-2ed60264
INSTANCE i-2ed60264
When you look at the output of "euca-describe-instances" now, you will
see that the machine's state goes from "running" first to
"shuting-down" then to "terminated" - the cloud infrastructure will
eventually be cleaned up to not list the stale machines any more.
What's next?
As stated above, the whole goal of this exercise is to manage Amazon
EC2 images from ansible. Weekend's mostly over and we will see
where this journey is going. For the time being, I'm happy to hear
about any comments of you using NetBSD on Amazon's EC2, and of
my euca2ools package.
Appendix: euca2ools Cheat Sheet
Environment variables:
setenv EC2_ACCESS_KEY "AKxxxxxxxxxxxxxxxxxx"
setenv EC2_SECRET_KEY "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
setenv EC2_CERT .../cert-XXX.pem
setenv EC2_PRIVATE_KEY .../pk-XXX.pem
setenv EC2_URL http://ec2.amazonaws.com
setenv S3_URL http://s3.amazonaws.com
Regions & availability zones:
euca-describe-regions
euca-describe-availability-zones
euca-describe-availability-zones --region eu-west-1
Change default region:
setenv EC2_URL http://ec2.eu-west-1.amazonaws.com
AMIs:
euca-describe-images --all
SSH Keypairs:
euca-add-keypair -f key-eucaHF.pem eucaHF
euca-describe-keypairs
euca-delete-keypair eucaHF
Instances:
euca-run-instances -k eucaHF ami-7fc3c30b
euca-describe-instances
euca-describe-instances i-96a773dc
ssh -i key-eucaHF.pem ec2-54-328-43-220.compute.amazonaws.com -l root
euca-terminate-instances i-96a773dc
[Tags: amazon, ansible, ec2, euca2ools, eucalyptus]
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