Create automatic AWS EC2 snapshots with limits on the total number of snapshots created and the interval which the snapshots are created., (*1)
For example, you could create a snapshot every day and only keep the last 7 for a running week's worth of snapshots. Or create a snapshot once a week and only keep the last 4 so you would have a running month's worth of snapshots., (*2)
Requirements
- AWS CLI
- AWS IAM snapshot permissions (example policy)
- PHP 5.5+
- Access to crontab (or some other job scheduler)
AWS CLI installation
sudo apt-get install python-pip php5-cli
sudo pip install awscli
// set credentials (Access Key ID, Secret Access Key) and region - ie: us-east-1, us-west-1
aws configure
Setup
This assumes you've already installed and configured AWS CLI and added the correct IAM permissions within your AWS console., (*3)
1. Create a PHP script to use the library
Use composer to autoload all the necessary classes., (*4)
Setup AWS CLI installation directory (using the value from which aws) and
configure your volumes., (*5)
Finally wire the services and test run your cli task. You can also change a description prefix that is used by this library to pick snapshots from the server. This is done via the second argument of Snapshots::run(), (*6)
<?php
$awsCliPath = '/usr/local/bin/aws';
$date = date('Y-m-d');
$volumes = [
new \AwsSnapshots\Options\VolumeIntervalBackupOptions('vol-123af85a', 7, '1 day', 'dev-server-backup'),
new \AwsSnapshots\Options\VolumeIntervalBackupOptions('vol-321bg96c', 4, '1 week', 'image-server-' . $date),
new \AwsSnapshots\Options\VolumeBackupOptions('vol-987ab12a', 10, 'cache-backup-backup'),
];
$awsCliHandler = new \AwsSnapshots\Cli\AwsCliHandler($awsCliPath);
$snapshots = new \AwsSnapshots\Snapshots($awsCliHandler);
$snapshots->run($volumes);
Example wiring in Symfony services.yml:
aws_snapshots.cli.aws_cli_handler:
class: AwsSnapshots\Cli\AwsCliHandler
arguments:
- '%aws.cli_tool.path%'
aws_snapshots.snapshots:
class: AwsSnapshots\Snapshots
arguments:
- '@aws_snapshots.cli.aws_cli_handler'
Volume Configuration
There are two types of volume configurations., (*7)
Both of them maintain a certain number of snapshots (snapshot count limit) of a volume with specified description.
The description is used by this library to select snapshots.
When you create a manual snapshot of a same volume, it will be ignored., (*8)
Interval Backups
You can schedule only one backup within a specified interval by using:, (*9)
new VolumeIntervalBackupOptions(volumeId, snapshotCountLimit, interval, description)
where the arguments are:, (*10)
| Name |
Type |
Description |
| volume id |
string |
AWS EBS volume ID |
| snapshot count limit |
integer |
total number of snapshots to store for a volume |
| interval |
string |
how often to create snapshot (30 minute, 1 day, 7 day, 2 week - full list below) |
| description |
string |
snapshot description that shows in the Snapshot section within AWS console and is used to filter manual backups |
Regular Backups
You can also backup a volume every time you run the PHP task by using:, (*11)
new VolumeBackupOptions(volumeId, snapshotCountLimit, description)
where the arguments are:, (*12)
| Name |
Type |
Description |
| volume id |
string |
AWS EBS volume ID |
| snapshot count limit |
integer |
total number of snapshots to store for a volume |
| description |
string |
snapshot description that shows in the Snapshot section within AWS console and is used to filter manual backups |
Interval Values
The interval format is number type (e.g. 30 minute):, (*13)
- a number is integer
- a type is one of following units:
2. Add a cron job
The cron job schedule will depend on your configuration. You should run the cron command in a period that is as long as the smallest interval of your volume backups., (*14)
In the example you have to run the CRON task at least once a day. It will create snapshot of:
- dev-server-backup every day at 3:00 am,
- image-server-${date} every week on a day you started it for the first time at 3:00 am
- cache-server every time you run the task (if you run it 3× a day it will create 3 snapshots), (*15)
# run the cron job every night at 3:00 am
00 03 * * * /usr/bin/php /root/scripts/run-snapshots.php
Example IAM Policy
This is a minimal policy that includes ONLY the permissions needed to work. You could also limit the "Resources" option to restrict it even further., (*16)
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"ec2:CreateSnapshot",
"ec2:DeleteSnapshot",
"ec2:DescribeSnapshots"
],
"Resource": [
"*"
]
}
]
}
Questions, issues or suggestions
Please use the issues section for any questions or issues you have. Also, suggestions, pull request or any help is most welcome!, (*17)
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