AWS CLI ec2-automate-backup：使用卷名称或描述

Question

场合

我使用（AWS Missing Tools）中的 ec2-automate-backup 脚本来创建服务器卷的快照。我想修改脚本以更改快照的描述，因此它具有卷描述（或名称）。这将使基于我们用于服务器名称和功能的描述或名称来识别或过滤快照变得更加容易。

问题

如何在使用ec2-automate-backup脚本创建的快照名称中使用卷描述或名称？

示例和代码

采用以下示例：

• 服务器名称示例：server001
• 示例卷名：data
• volume vol-ab12345c有描述“server001-data”

我使用以下命令创建快照：

sh ec2-automate-backup.sh -v "vol-ab12345c"

此快照在Amazon快照仪表板中具有以下描述：

• ec2ab_vol-ab12345c_1446724865。

我想在快照描述中看到卷名或描述，使其像这样（实际格式并不重要）：

ec2ab_vol-ab12345c_1446724865 (server001-data)

这使得根据服务器名称（或您在卷描述中放置的任何内容）识别和过滤快照变得更加容易。

以下是剧本：

#!/bin/bash -
# Date: 2015-10-26
# Version 0.10
# License Type: GNU GENERAL PUBLIC LICENSE, Version 3
# Author:
# Colin Johnson / https://github.com/colinbjohnson / colin@cloudavail.com
# Contributors:
# Alex Corley / https://github.com/anthroprose
# Jon Higgs / https://github.com/jonhiggs
# Mike / https://github.com/eyesis
# Jeff Vogt / https://github.com/jvogt
# Dave Stern / https://github.com/davestern
# Josef / https://github.com/J0s3f
# buckelij / https://github.com/buckelij
# https://github.com/ccomerImmerge

#confirms that executables required for succesful script execution are available
prerequisite_check() {
  for prerequisite in basename cut date aws; 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 ]]; then #has exits with exit status of 70, executable was not found
      echo "In order to use $app_name, the executable \"$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="--volume-ids $volumeid"
      ;;
    tag)
      if [[ -z $tag ]]; then
        echo "The selected selection_method \"tag\" (-s tag) requires a valid tag (-t Backup,Values=true) for operation. Correct usage is as follows: \"-s tag -t Backup,Values=true.\"" 1>&2 ; exit 64
      fi
      ebs_selection_string="--filters Name=tag:$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=$(aws ec2 describe-volumes --region $region $ebs_selection_string --output text --query 'Volumes[*].VolumeId')
  #takes the output of the previous command 
  ebs_backup_list_result=$(echo $?)
  if [[ $ebs_backup_list_result -gt 0 ]]; then
    echo -e "An error occurred when running ec2-describe-volumes. The error returned is below:\n$ebs_backup_list_complete" 1>&2 ; exit 70
  fi
}

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="Key=CreatedBy,Value=ec2-automate-backup"
  #if $name_tag_create is true then append ec2ab_${ebs_selected}_$current_date to the variable $snapshot_tags
  if $name_tag_create; then
    snapshot_tags="$snapshot_tags Key=Name,Value=ec2ab_${ebs_selected}_$current_date"
  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 Key=InitiatingHost,Value='$(hostname -s)'"
  fi
  #if $purge_after_date_fe is true, then append $purge_after_date_fe to the variable $snapshot_tags
  if [[ -n $purge_after_date_fe ]]; then
    snapshot_tags="$snapshot_tags Key=PurgeAfterFE,Value=$purge_after_date_fe Key=PurgeAllow,Value=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 Key=Volume,Value=${ebs_selected} Key=Created,Value=$current_date"
  fi
  #if $snapshot_tags is not zero length then set the tag on the snapshot using aws ec2 create-tags
  if [[ -n $snapshot_tags ]]; then
    echo "Tagging Snapshot $ec2_snapshot_resource_id with the following Tags: $snapshot_tags"
    tags_argument="--tags $snapshot_tags"
    aws_ec2_create_tag_result=$(aws ec2 create-tags --resources $ec2_snapshot_resource_id --region $region $tags_argument --output text 2>&1)
  fi
}

get_date_binary() {
  #$(uname -o) (operating system) would be ideal, but OS X / Darwin does not support to -o option
  #$(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="posix" ;;
    FreeBSD) date_binary="posix" ;;
    Linux) date_binary="linux-gnu" ;;
    *) date_binary="unknown" ;;
  esac
}

get_purge_after_date_fe() {
case $purge_after_input in
  #any number of numbers followed by a letter "d" or "days" multiplied by 86400 (number of seconds in a day)
  [0-9]*d) purge_after_value_seconds=$(( ${purge_after_input%?} * 86400 )) ;;
  #any number of numbers followed by a letter "h" or "hours" multiplied by 3600 (number of seconds in an hour)
  [0-9]*h) purge_after_value_seconds=$(( ${purge_after_input%?} * 3600 )) ;;
  #any number of numbers followed by a letter "m" or "minutes" multiplied by 60 (number of seconds in a minute)
  [0-9]*m) purge_after_value_seconds=$(( ${purge_after_input%?} * 60 ));;
  #no trailing digits default is days - multiply by 86400 (number of minutes in a day)
  *) purge_after_value_seconds=$(( $purge_after_input * 86400 ));;
esac
#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_value_seconds}sec -u +%s) ;;
  posix) echo $(date -v +${purge_after_value_seconds}S -u +%s) ;;
  *) echo $(date -d +${purge_after_value_seconds}sec -u +%s) ;;
esac
}

purge_EBS_Snapshots() {
  # snapshot_purge_allowed is a string containing the SnapshotIDs of snapshots
  # that contain a tag with the key value/pair PurgeAllow=true
  snapshot_purge_allowed=$(aws ec2 describe-snapshots --region $region --filters Name=tag:PurgeAllow,Values=true --output text --query 'Snapshots[*].SnapshotId')

  for snapshot_id_evaluated in $snapshot_purge_allowed; do
    #gets the "PurgeAfterFE" date which is in UTC with UNIX Time format (or xxxxxxxxxx / %s)
    purge_after_fe=$(aws ec2 describe-snapshots --region $region --snapshot-ids $snapshot_id_evaluated --output text | grep ^TAGS.*PurgeAfterFE | cut -f 3)
    #if purge_after_date is not set then we have a problem. Need to alert user.
    if [[ -z $purge_after_fe ]]; then
      #Alerts user to the fact that a Snapshot was found with PurgeAllow=true but with no PurgeAfterFE date.
      echo "Snapshot with the Snapshot ID \"$snapshot_id_evaluated\" has the tag \"PurgeAllow=true\" but does not have a \"PurgeAfterFE=xxxxxxxxxx\" key/value pair. $app_name is unable to determine if $snapshot_id_evaluated should be purged." 1>&2
    else
      # if $purge_after_fe is less than $current_date then
      # PurgeAfterFE is earlier than the current date
      # and the snapshot can be safely purged
      if [[ $purge_after_fe < $current_date ]]; then
        echo "Snapshot \"$snapshot_id_evaluated\" with the PurgeAfterFE date of \"$purge_after_fe\" will be deleted."
        aws_ec2_delete_snapshot_result=$(aws ec2 delete-snapshot --region $region --snapshot-id $snapshot_id_evaluated --output text 2>&1)
      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_date timestamp
user_tags=false
#sets the Purge Snapshot feature to false - if purge_snapshots=true then snapshots will be purged
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_input="$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 ]]; then
  #if the environment variable $EC2_REGION is not set set to us-east-1
  if [[ -z $EC2_REGION ]]; then
    region="us-east-1"
  else
    region=$EC2_REGION
  fi
fi

#calls prerequisitecheck function to ensure that all executables required for script execution are available
prerequisite_check

#sets date variable
current_date=$(date -u +%s)

#sets the PurgeAfterFE tag to the number of seconds that a snapshot should be retained
if [[ -n $purge_after_input ]]; then
  #if the date_binary is not set, call the get_date_binary function
  if [[ -z $date_binary ]]; then
    get_date_binary
  fi
  purge_after_date_fe=$(get_purge_after_date_fe)
  echo "Snapshots taken by $app_name will be eligible for purging after the following date (the purge after date given in seconds from epoch): $purge_after_date_fe."
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}_$current_date"
  ec2_snapshot_resource_id=$(aws ec2 create-snapshot --region $region --description $ec2_snapshot_description --volume-id $ebs_selected --output text --query SnapshotId 2>&1)
  if [[ $? != 0 ]]; then
    echo -e "An error occurred when running ec2-create-snapshot. The error returned is below:\n$ec2_create_snapshot_result" 1>&2 ; exit 70
  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

Answer 1

脚本中的这两行创建快照：

ec2_snapshot_description="ec2ab_${ebs_selected}_$current_date"
ec2_snapshot_resource_id=$(aws ec2 create-snapshot --region $region --description $ec2_snapshot_description --volume-id $ebs_selected --output text --query SnapshotId 2>&1)

如果您想更改说明，请修改第一行。