#!/bin/bash - # Author: Colin Johnson / colin@cloudavail.com # Date: 2013-02-13 # Version 0.9 # License Type: GNU GENERAL PUBLIC LICENSE, Version 3 # #confirms that executables required for succesful script execution are available prerequisite_check() { for prerequisite in basename ec2-create-snapshot ec2-create-tags ec2-describe-snapshots ec2-delete-snapshot date do #use of "hash" chosen as it is a shell builtin and will add programs to hash table, possibly speeding execution. Use of type also considered - open to suggestions. hash $prerequisite &> /dev/null if [[ $? == 1 ]] #has exits with exit status of 70, executable was not found then echo "In order to use `basename $0`, the executable \"$prerequisite\" must be installed." 1>&2 ; exit 70 fi done } #get_EBS_List gets a list of available EBS instances depending upon the selection_method of EBS selection that is provided by user input get_EBS_List() { case $selection_method in volumeid) if [[ -z $volumeid ]] then echo "The selection method \"volumeid\" (which is $app_name's default selection_method of operation or requested by using the -s volumeid parameter) requires a volumeid (-v volumeid) for operation. Correct usage is as follows: \"-v vol-6d6a0527\",\"-s volumeid -v vol-6d6a0527\" or \"-v \"vol-6d6a0527 vol-636a0112\"\" if multiple volumes are to be selected." 1>&2 ; exit 64 fi ebs_selection_string="$volumeid" ;; tag) if [[ -z $tag ]] then echo "The selected selection_method \"tag\" (-s tag) requires a valid tag (-t key=value) for operation. Correct usage is as follows: \"-s tag -t backup=true\" or \"-s tag -t Name=my_tag.\"" 1>&2 ; exit 64 fi ebs_selection_string="--filter tag:$tag" ;; *) echo "If you specify a selection_method (-s selection_method) for selecting EBS volumes you must select either \"volumeid\" (-s volumeid) or \"tag\" (-s tag)." 1>&2 ; exit 64 ;; esac #creates a list of all ebs volumes that match the selection string from above ebs_backup_list_complete=`ec2-describe-volumes --show-empty-fields --region $region $ebs_selection_string 2>&1` #takes the output of the previous command ebs_backup_list_result=`echo $?` if [[ $ebs_backup_list_result -gt 0 ]] then echo -e "An error occured when running ec2-describe-volumes. The error returned is below:\n$ebs_backup_list_complete" 1>&2 ; exit 70 fi ebs_backup_list=`echo "$ebs_backup_list_complete" | grep ^VOLUME | cut -f 2` #code to right will output list of EBS volumes to be backed up: echo -e "Now outputting ebs_backup_list:\n$ebs_backup_list" } create_EBS_Snapshot_Tags() { #snapshot tags holds all tags that need to be applied to a given snapshot - by aggregating tags we ensure that ec2-create-tags is called only onece snapshot_tags="" #if $name_tag_create is true then append ec2ab_${ebs_selected}_$date_current to the variable $snapshot_tags if $name_tag_create then ec2_snapshot_resource_id=`echo "$ec2_create_snapshot_result" | cut -f 2` snapshot_tags="$snapshot_tags --tag Name=ec2ab_${ebs_selected}_$date_current" fi #if $hostname_tag_create is true then append --tag InitiatingHost=`hostname -f` to the variable $snapshot_tags if $hostname_tag_create then snapshot_tags="$snapshot_tags --tag InitiatingHost='`hostname -f`'" fi #if $purge_after_days is true, then append $purge_after_date to the variable $snapshot_tags if [[ -n $purge_after_days ]] then snapshot_tags="$snapshot_tags --tag PurgeAfter=$purge_after_date --tag PurgeAllow=true" fi #if $user_tags is true, then append Volume=$ebs_selected and Created=$current_date to the variable $snapshot_tags if $user_tags then snapshot_tags="$snapshot_tags --tag Volume=${ebs_selected} --tag Created=$date_current" fi #if $snapshot_tags is not zero length then set the tag on the snapshot using ec2-create-tags if [[ -n $snapshot_tags ]] then echo "Tagging Snapshot $ec2_snapshot_resource_id with the following Tags:" ec2-create-tags $ec2_snapshot_resource_id --region $region $snapshot_tags fi } date_binary_get() { #`uname -o (operating system) would be ideal, but OS X / Darwin does not support to -o option` #`uname` on OS X defaults to `uname -s` and `uname` on GNU/Linux defaults to `uname -s` uname_result=`uname` case $uname_result in Darwin) date_binary="osx-posix" ;; Linux) date_binary="linux-gnu" ;; *) date_binary="unknown" ;; esac } get_purge_after_date() { #based on the date_binary variable, the case statement below will determine the method to use to determine "purge_after_days" in the future case $date_binary in linux-gnu) echo `date -d +${purge_after_days}days -u +%Y-%m-%d` ;; osx-posix) echo `date -v+${purge_after_days}d -u +%Y-%m-%d` ;; *) echo `date -d +${purge_after_days}days -u +%Y-%m-%d` ;; esac } get_purge_after_date_epoch() { #based on the date_binary variable, the case statement below will determine the method to use to determine "purge_after_date_epoch" in the future case $date_binary in linux-gnu) echo `date -d $purge_after_date +%s` ;; osx-posix) echo `date -j -f "%Y-%m-%d" $purge_after_date "+%s"` ;; *) echo `date -d $purge_after_date +%s` ;; esac } get_date_current_epoch() { #based on the date_binary variable, the case statement below will determine the method to use to determine "date_current_epoch" in the future case $date_binary in linux-gnu) echo `date -d $date_current +%s` ;; osx-posix) echo `date -j -f "%Y-%m-%d" $date_current "+%s"` ;; *) echo `date -d $date_current +%s` ;; esac } purge_EBS_Snapshots() { #snapshot_tag_list is a string that contains all snapshots with either the key PurgeAllow or PurgeAfter set snapshot_tag_list=`ec2-describe-tags --show-empty-fields --region $region --filter resource-type=snapshot --filter key=PurgeAllow,PurgeAfter` #snapshot_purge_allowed is a list of all snapshot_ids with PurgeAllow=true snapshot_purge_allowed=`echo "$snapshot_tag_list" | grep .*PurgeAllow'\s'true | cut -f 3` for snapshot_id_evaluated in $snapshot_purge_allowed do #gets the "PurgeAfter" date which is in UTC with YYYY-MM-DD format (or %Y-%m-%d) purge_after_date=`echo "$snapshot_tag_list" | grep .*$snapshot_id_evaluated'\s'PurgeAfter.* | cut -f 5` #if purge_after_date is not set then we have a problem. Need to alert user. if [[ -z $purge_after_date ]] #Alerts user to the fact that a Snapshot was found with PurgeAllow=true but with no PurgeAfter date. then echo "A Snapshot with the Snapshot ID $snapshot_id_evaluated has the tag \"PurgeAllow=true\" but does not have a \"PurgeAfter=YYYY-MM-DD\" date. $app_name is unable to determine if $snapshot_id_evaluated should be purged." 1>&2 else #convert both the date_current and purge_after_date into epoch time to allow for comparison date_current_epoch=`get_date_current_epoch` purge_after_date_epoch=`get_purge_after_date_epoch` #perform compparison - if $purge_after_date_epoch is a lower number than $date_current_epoch than the PurgeAfter date is earlier than the current date - and the snapshot can be safely removed if [[ $purge_after_date_epoch < $date_current_epoch ]] then echo "The snapshot \"$snapshot_id_evaluated\" with the Purge After date of $purge_after_date will be deleted." ec2-delete-snapshot --region $region $snapshot_id_evaluated fi fi done } app_name=`basename $0` #sets defaults selection_method="volumeid" #date_binary allows a user to set the "date" binary that is installed on their system and, therefore, the options that will be given to the date binary to perform date calculations date_binary="" #sets the "Name" tag set for a snapshot to false - using "Name" requires that ec2-create-tags be called in addition to ec2-create-snapshot name_tag_create=false #sets the "InitiatingHost" tag set for a snapshot to false hostname_tag_create=false #sets the user_tags feature to false - user_tag creates tags on snapshots - by default each snapshot is tagged with volume_id and current_data timestamp user_tags=false #sets the Purge Snapshot feature to false - this feature will eventually allow the removal of snapshots that have a "PurgeAfter" tag that is earlier than current date purge_snapshots=false #handles options processing while getopts :s:c:r:v:t:k:pnhu opt do case $opt in s) selection_method="$OPTARG";; c) cron_primer="$OPTARG";; r) region="$OPTARG";; v) volumeid="$OPTARG";; t) tag="$OPTARG";; k) purge_after_days="$OPTARG";; n) name_tag_create=true;; h) hostname_tag_create=true;; p) purge_snapshots=true;; u) user_tags=true;; *) echo "Error with Options Input. Cause of failure is most likely that an unsupported parameter was passed or a parameter was passed without a corresponding option." 1>&2 ; exit 64;; esac done #sources "cron_primer" file for running under cron or other restricted environments - this file should contain the variables and environment configuration required for ec2-automate-backup to run correctly if [[ -n $cron_primer ]] then if [[ -f $cron_primer ]] then source $cron_primer else echo "Cron Primer File \"$cron_primer\" Could Not Be Found." 1>&2 ; exit 70 fi fi #if region is not set then: if [[ -z $region ]] #if the environment variable $EC2_REGION is not set set to us-east-1 then if [[ -z $EC2_REGION ]] #if both then region="us-east-1" else region=$EC2_REGION fi fi #calls prerequisitecheck function to ensure that all executables required for script execution are available prerequisite_check #sets date variable date_current=`date -u +%Y-%m-%d` #sets the PurgeAfter tag to the number of days that a snapshot should be retained if [[ -n $purge_after_days ]] then #if the date_binary is not set, call the date_binary_get function if [[ -z $date_binary ]] then date_binary_get fi purge_after_date=`get_purge_after_date` echo "Snapshots taken by $app_name will be eligible for purging after the following date: $purge_after_date." fi #get_EBS_List gets a list of EBS instances for which a snapshot is desired. The list of EBS instances depends upon the selection_method that is provided by user input get_EBS_List #the loop below is called once for each volume in $ebs_backup_list - the currently selected EBS volume is passed in as "ebs_selected" for ebs_selected in $ebs_backup_list do ec2_snapshot_description="ec2ab_${ebs_selected}_$date_current" ec2_create_snapshot_result=`ec2-create-snapshot --region $region -d $ec2_snapshot_description $ebs_selected 2>&1` if [[ $? != 0 ]] then echo -e "An error occured when running ec2-create-snapshot. The error returned is below:\n$ec2_create_snapshot_result" 1>&2 ; exit 70 else ec2_snapshot_resource_id=`echo "$ec2_create_snapshot_result" | cut -f 2` fi create_EBS_Snapshot_Tags done #if purge_snapshots is true, then run purge_EBS_Snapshots function if $purge_snapshots then echo "Snapshot Purging is Starting Now." purge_EBS_Snapshots fi