= Amazon EC2 =
[[TOC]]

Amazon's Cloud provides a flexible platform to deploy Eden scalably.

The costs aren't fixed & can be difficult to predict, despite their [http://aws.amazon.com/calculator calculator], but are competitive, especially in Singapore, which is a good base for the Asia Pacific region.

== Regions & Zones ==
Amazon supports multiple Regions in order to provide a service closest to your users.
* Namespaces of Instances, Volumnes & Snapshots are unique only within a Region.
* Within each Region, there are a couple of Availability Zones to allow spreading the risk across different facilities.
* Volumes are located within a specific Availability Zone
* Bandwidth transfers are free within an Availability Zone

== Instance Size ==
* The free starter 'micro' instance is flexible as it can run both 32-bit & 64-bit Operating Systems.
* The normal production 'small' instance can only run 32-bit.
* Larger production instances can only run 64-bit, so can't have the exact same image used.
* The community Debian Squeeze AMI seems a fine base & attached scripts turn this into an Eden instance

== Instance Persistence ==
* EBS-backed instances have persistent storage even whilst powered down, which is very useful.
 * For DB I/O performance increase can stripe multiple EBS
  * monitoring data available to see if this is the issue
* Each time you start an instance up, it will be assigned a new IP ('Public DNS') although this can be overcome using an Elastic IP
 * Remember to set up Reverse DNS for your Elastic IP to be able to send emails reliably:
  * https://aws-portal.amazon.com/gp/aws/html-forms-controller/contactus/ec2-email-limit-rdns-request
== Authentication ==
=== SSH ===
This can provide an early stumbling block.
* Each instance created needs to start with a unique SSH keypair
* When setting up an instance, be sure to safely download the private key.
* In order to get the public key (needed by SecureCRT for instance) then you need to login using CLI & retrieve it:
{{{
ssh -l root -i private.pem <hostname>
cat ~/.ssh/authorized_keys
}}}
SecureCRT needs the private key storing as <filename> & the public as <filename.pub> (all on one line)

SSH will also need to be enabled in your Firewall policy (restrict the IP source, if possible)

== Using Sahana Eden prebuilt AMIs ==
You will find a prebuilt instance of Sahana Eden in some zones [Current us-west], that can help you in quickly setting up an instance.

* Search for "Sahana Eden" in the AMI's section.
* Launch the instance.
* SSH into the instance by following the steps mentioned in the section above.
* run configure-eden-cherokee-postgis.sh to configure the instance.
{{{

./configure-eden-cherokee-postgis.sh

}}}

* The disk space on the pre-built AMIs is 1GB - Instructions to grow the disk are given below.
* You can add swap from a swap file :
{{{

dd if=/dev/zero of=/swapfile1 bs=1024 count=524288

mkswap /swapfile1
chown root:root /swapfile1
chmod 0600 /swapfile1
swapon /swapfile1
}}}

Make this persistent across reboots by adding the following to your /etc/fstab
{{{
/swapfile1 swap swap defaults 0 0
}}}
== Building AMIs for easier deployment ==
If your region doesn't yet have a Sahana AMI in, then it is easy to create one which allows easier deployment of future instances for both you & others. The only cost to you is a small amount of time to publish it & then using up your 1Gb Snapshot allowance within the free tier.

* Choose a debian AMI in your desired ZONE with 1 GB of EBS storage [This enables AMI registration in AWS free tier.]
* Launch the instance.
* Copy the installation and configuration scripts -> [http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Linux/Server/CherokeePostgreSQL/install-eden-cherokee-postgis.sh install-eden-cherokee-postgis.sh] and [http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Linux/Server/CherokeePostgreSQL/configure-eden-cherokee-postgis.sh configure-eden-cherokee-postgis.sh] into the launched instance.
{{{
wget http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Linux/Server/CherokeePostgreSQL/install-eden-cherokee-postgis.sh
chmod a+x install-eden-cherokee-postgis.sh
wget http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Linux/Server/CherokeePostgreSQL/configure-eden-cherokee-postgis.sh
chmod a+x configure-eden-cherokee-postgis.sh
}}}

* Run the install-eden-cherokee-postgis.sh script and delete it. [Note: This step takes about 10min - grab a coffee]
{{{
./install-eden-cherokee-postgis.sh
rm install-eden-cherokee-postgis.sh
}}}

* Shutdown the EBS instance.
{{{
   shutdown -h now
}}}

* Go to your aws console for the current region at [https://console.aws.amazon.com/ec2/home | EC2 Console]

* Select the debian instance you just prepared in the "Instances"

* Select " Create Image (EBS AMI) " in the "Instance Actions" drop down.


[[Image(http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Amazon/create-image.png, 75%)]]

* Choose a Image name - Lets say - "Sahana Eden" and fill in a description.


[[Image(http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Amazon/create-image-config.png, 75%)]]


* Click "Create this Image"

* Go to the "AMIS" menu and select "Owned by me" and "All Platforms" in the Viewing dropdown.

[[Image(http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Amazon/ami-built.png, 75%)]]

* Wait for about 5 minutes and hit refresh for the AMI you just built to appear.

* Select the AMI and click the Permissions button - Select public, to make the image public.


[[Image(http://eden.sahanafoundation.org/raw-attachment/wiki/InstallationGuidelines/Amazon/ami-permissions.png, 75%)]]

=== CLI ===
To use any of the AWS CLI tools on your own machine to remotely manage instances, then you need to generate a unique X.509 Certificate per account.
This can be done from the 'Security Credentials' page within your account.
== CLI Management ==
There are extensive CLI tools available to manipulate your instances.
* Java CLI for !Windows/Linux
 * http://aws.amazon.com/developertools/351
 * http://serktools.com/2009/05/19/setting-up-ec2-command-line-tools-on-windows/
 * http://docs.amazonwebservices.com/AWSEC2/latest/CommandLineReference/
* Python: http://libcloud.apache.org

== Growing Storage ==
1Gb EBS is too small for Eden - need to grow to 3Gb, which is still within the 10Gb free tier
{{{
# Settings for Instance
set EC2_URL=https://ec2.us-east-1.amazonaws.com
set ZONE=us-east-1c
set DEV=i-950895f1
set OLD=vol-31f5a35d
# Stop Host
ec2stop %DEV%
# Create a snapshot
ec2-create-snapshot %OLD%
# Record the snapshot ID
set SNAPSHOT=snap-63f89d08
# Create new volume from snapshot
ec2-create-volume -z %ZONE% --size 3 --snapshot %SNAPSHOT%
# Record the new Volume ID
set NEW=vol-a9c2a3c4
# Delete Snapshot (if no data in yet)
ec2-delete-snapshot %SNAPSHOT%
# Attach new volume as secondary
ec2-attach-volume -i %DEV% %NEW% -d /dev/sdb1
# Start Host
ec2start %DEV%
# Re-attach the Public IP
# Login
mkdir /mnt/data
echo '/dev/xvdb1 /mnt/data ext3 defaults,noatime 0 0' >> /etc/fstab
mount /mnt/data
resize2fs /dev/xvdb1
umount /mnt/data
# Stop Host
ec2stop %DEV%
# Unattach volumes
ec2-detach-volume -i %DEV% %OLD%
ec2-detach-volume -i %DEV% %NEW%
# Attach volume as boot
ec2-attach-volume -i %DEV% %NEW% -d /dev/sda1
# Attach old volume for /var/log
ec2-attach-volume -i %DEV% %OLD% -d /dev/sdb1
# OR Delete old volume
#ec2-delete-volume %OLD%
# Start Host
ec2start %DEV%
# Re-attach the Public IP
# Login
df -h
# Use the old partition for /var/log (to avoid DoS)
vi /etc/fstab
/dev/xvdb1 /var/log  ext3    noatime 0 0

mv /var/log /var/log_old
mkdir /var/log
mount /var/log
mv /var/log_old/* /var/log
rm -rf /var/log/bin/
rm -rf /var/log/boot/
rm -rf /var/log/dev/
rm -rf /var/log/etc/
rm -rf /var/log/home/
rm -rf /var/log/initrd.img
rm -rf /var/log/lib/
rm -rf /var/log/mnt/
rm -rf /var/log/media/
rm -rf /var/log/opt/
rm -rf /var/log/proc/
rm -rf /var/log/root/
rm -rf /var/log/sbin/
rm -rf /var/log/selinux/
rm -rf /var/log/srv/
rm -rf /var/log/tmp/
rm -rf /var/log/usr/
rm -rf /var/log/var/
rm -rf /var/log/vmlinuz
rm -rf /var/log_old
}}}

Keep Templates as EBS Volumes as this is cheaper than Snapshots

== Next ==
[wiki:UserGuidelines/Admin Administration Guide]