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#! /bin/bash
#
# s3backup.sh
# General-purpose, Ansible-managed backup script to push directories, DBs, and
# more up to an S3 bucket
#
# NOTICE: THIS FILE CONTAINS SECRETS
# This file may contain the following secrets depending on configuration:
# * An AWS access key
# * An AWS session token
# These are NOT things you want arbitrary readers to access! Ansible will
# attempt to ensure this file has 0700 permissions, but that won't stop you
# from changing that yourself
# DO NOT ALLOW THIS FILE TO BE READ BY NON-ROOT USERS
# NOTICE: DO NOT MODIFY THIS FILE
# Any changes made will be clobbered by Ansible
# Please make any configuration changes in the main repo
set -e
# AWS S3 configuration
# NOTE: THIS IS SECRET INFORMATION
export AWS_ACCESS_KEY_ID="{{ backup_s3_aws_access_key_id }}"
export AWS_SECRET_ACCESS_KEY="{{ backup_s3_aws_secret_access_key }}"
# Directories to backup
# Ansible will determine the entries here
# We use a bash array because it affords us some level of sanitization, enough
# to let us back up items whose paths contain spaces
declare -a DIRS
{% for item in backup_s3backup_list + backup_s3backup_list_extra %}
DIRS+=("{{ item }}")
{% endfor %}
# End directory manual configuration
# Helper functions
backup() {
# Takes a file or directory to backup and backs it up
[ -z "$*" ] && return 1
for dir in "$@"; do
echo "- $dir"
done
# First, we remove stale locks. This command will only remove locks that have not been
# updated in the last half hour. By default, restic updates them during an ongoing
# operation every 5 minutes, so this should be perfectly fine to do.
# What I'm not sure of (but should be fine because we auto-restart if need be) is if two
# processes doing this concurrently will cause issues. I'd hope not but you never know.
# restic-unlock(1)
/opt/restic-wrapper \
--verbose \
unlock
# Back up everything in the $DIRS array (which was passed as args)
# This results in some level of pollution with regard to what paths are backed up
# (especially on ostree systems where we do the etc diff) but that's syntactic and
# we can script around it.
/opt/restic-wrapper \
--verbose \
{% for item in backup_s3backup_exclude_list + backup_s3backup_exclude_list_extra %}
--exclude="{{ item }}" \
{% endfor %}
--exclude="/data/**/backup" \
--exclude="/data/**/backups" \
--exclude="*.bak" \
--exclude="*.tmp" \
--exclude="*.swp" \
backup \
"$@"
# In addition, we should also prune our backups
# https://restic.readthedocs.io/en/stable/060_forget.html
# --keep-daily n Keeps daily backups for the last n days
# --keep-weekly n Keeps weekly backups for the last n weeks
# --keep-montly n Keeps monthly backups for the last n months
# --keep-tag foo Keeps all snapshots tagged with "foo"
# --host "$HOSTNAME" Only act on *our* snapshots. We assume other machines are taking
# care of their own houses.
/opt/restic-wrapper \
--verbose \
forget \
--keep-daily 7 \
--keep-weekly 4 \
--keep-monthly 6 \
--keep-tag noremove \
--host "$HOSTNAME"
}
# Dump Postgres DBs, if possible
if command -v psql > /dev/null 2>&1; then
# Put down a place for us to store backups, if we don't have it already
backupdir="/opt/postgres-backups"
mkdir -p "$backupdir"
# Populate a list of databases
declare -a DATABASES
while read line; do
DATABASES+=("$line")
done < <(sudo -u postgres psql -t -A -c "SELECT datname FROM pg_database where datname not in ('template0', 'template1', 'postgres');" 2>/dev/null)
# pgdump all DBs, compress them, and pipe straight up to S3
echo "Commencing backup on the following databases:"
for dir in "${DATABASES[@]}"; do
echo "- $dir"
done
echo "Will upload resultant backups to {{ backup_s3_bucket }}"
for db in "${DATABASES[@]}"; do
echo "Backing up $db"
path="$backupdir/$db.pgsql.gz"
sudo -u postgres pg_dump "$db" \
| gzip -v9 \
> "$path"
DIRS+=("$path")
done
fi
# Tar up all items in the backup list, recursively, and pipe them straight
# up to S3
if [ -n "${DIRS[*]}" ]; then
echo "Commencing backup on the following items:"
for dir in "${DIRS[@]}"; do
echo "- $dir"
done
echo "Will ignore the following items:"
{% for item in backup_s3backup_exclude_list + backup_s3backup_exclude_list_extra %}
echo "- {{ item }}"
{% endfor %}
echo "Will upload resultant backups to {{ backup_s3_bucket }}"
backup ${DIRS[*]}
fi