M23: automate verified database backups

deploy/unraid/prune-postgres-backups.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+set -eu
+
+destination="${1:-backups/postgres}"
+retention_days="${BACKUP_RETENTION_DAYS:-30}"
+minimum_copies="${BACKUP_MINIMUM_COPIES:-7}"
+
+case "$destination" in ""|"/"|".") echo "Unsafe backup destination: $destination" >&2; exit 1;; esac
+case "$retention_days:$minimum_copies" in *[!0-9:]*|:*|*:) echo "Retention values must be integers" >&2; exit 1;; esac
+[ -d "$destination" ] || exit 0
+
+count=0
+find "$destination" -maxdepth 1 -type f -name 'mobilityops-*.dump' | sort -r | while IFS= read -r file; do
+  count=$((count + 1))
+  if [ "$count" -gt "$minimum_copies" ] && [ -n "$(find "$file" -mtime "+$retention_days" -print)" ]; then
+    rm -f -- "$file" "${file}.sha256"
+  fi
+done