Backup given sources via restic to AWS S3 at regularity using AWS SNS to notify of result

s3-b2-cronjob.sh

#!/bin/bash

# Requires:
# - restic (system package)
# - AWS account with SNS topic configured, S3 bucket created, and API keys created
# - awscli (pip) with API keys configured (aws configure)
# - cron implementation (system package)

ResticBinaryPath=`which restic`
AwsCliBinaryPath=`which aws`
ScriptWorkingPath=''
UploadLimit=0 #KiB/s
RepositoryPasswordFile="${ScriptWorkingPath}/s3-encryption-pass"
AwsSnsRegion=''
AwsS3Region=''
RepositoryEngine='s3'
RepositoryPath="s3.${AwsS3Region}.amazonaws.com/bucket/repo"
SnsTopic="arn:aws:sns:${AwsSnsRegion}:id:topic_name"

export AWS_CONFIG_FILE=/path/to/.aws/config
export AWS_SHARED_CREDENTIAL_FILE=/path/to/.aws/credentials
export AWS_PROFILE=
export AWS_DEFAULT_REGION=$AwsS3Region

# Path exclusions from objects within SourcePaths
ExcludedPaths=( \
	'/path/within/sources/to/exclude'
)

# Do not leave trailing slash on the end of directory sources
SourcePaths=()

# Path to a text file containing further source paths to include
SourceFileList="${ScriptWorkingPath}/s3-files.list"

[ ! -d "${ScriptWorkingPath}/logs" ] && ( mkdir "${ScriptWorkingPath}/logs" )
LogFile="${ScriptWorkingPath}/logs/s3-`date '+%Y%m%d'`.log"

function SnsPublication () {
	local ErrorCode=$1

	if [ $ErrorCode -gt 0 ] ; then
		local ScriptResultCode='Failure'
		local ScriptPostMessage="Something went wrong executing the restic backup job. See $LogFile for summary details."
	else
		local ScriptResultCode='Success'
		local ScriptPostMessage="Successfully executed restic backup job. See $LogFile for summary details."
	fi

	# Publish to SNS topic to notify admin
	$AwsCliBinaryPath sns publish \
		--region $AwsSnsRegion \
		--topic-arn $SnsTopic \
		--subject "Workstation restic backup job notification ($ScriptResultCode)" \
		--message "$ScriptPostMessage" \
		2>&1 >> $LogFile
}

# Assemble the one-liner
CommandPrefix="$ResticBinaryPath -r ${RepositoryEngine}:${RepositoryPath} backup -v -v --limit-upload $UploadLimit --password-file $RepositoryPasswordFile"

for e in "${ExcludedPaths[@]}" ; do
	CommandExclusions="${CommandExclusions} --exclude $e"
done
for i in "${SourcePaths[@]}" ; do
	CommandSources="${CommandSources} $i"
done
Command="$CommandPrefix $CommandExclusions $CommandSources --files-from $SourceFileList"

# Execute backup job
$Command 2>&1 >> $LogFile
ReturnCode=$?

# Generate email with outcome of job
if [ $ReturnCode -ne 0 ] ; then
	SnsPublication 1
else
	SnsPublication 0
fi