Add support for latest backup symlink

Author: prodrigestivill

.github/workflows/ci.yml

@@ -50,6 +50,7 @@ jobs:
           POSTGRES_PASSFILE_STORE: "**None**"
           POSTGRES_CLUSTER: "FALSE"
           BACKUP_SUFFIX: ".sql.gz"
+          BACKUP_LATEST_TYPE: "symlink"
           BACKUP_KEEP_DAYS: 7
           BACKUP_KEEP_WEEKS: 4
           BACKUP_KEEP_MONTHS: 6
@@ -72,6 +73,7 @@ jobs:
           POSTGRES_PORT: 5432
           POSTGRES_EXTRA_OPTS: "-Z0 -Fd"
           BACKUP_SUFFIX: ""
+          BACKUP_LATEST_TYPE: "symlink"
           BACKUP_DIR: ".data"
           # Defaults
           POSTGRES_DB_FILE: "**None**"
@@ -108,6 +110,7 @@ jobs:
           POSTGRES_PASSWORD_FILE: "**None**"
           POSTGRES_PASSFILE_STORE: "**None**"
           BACKUP_SUFFIX: ".sql.gz"
+          BACKUP_LATEST_TYPE: "symlink"
           BACKUP_KEEP_DAYS: 7
           BACKUP_KEEP_WEEKS: 4
           BACKUP_KEEP_MONTHS: 6

README.md

@@ -79,6 +79,7 @@ Most variables are the same as in the [official postgres image](https://hub.dock
 | BACKUP_KEEP_WEEKS | Number of weekly backups to keep before removal. Defaults to `4`. |
 | BACKUP_KEEP_MONTHS | Number of monthly backups to keep before removal. Defaults to `6`. |
 | BACKUP_KEEP_MINS | Number of minutes for `last` folder backups to keep before removal. Defaults to `1440`. |
+| BACKUP_LATEST_TYPE | Type of `latest` pointer (`symlink`,`hardlink`,`none`). Defaults to `symlink`. |
 | HEALTHCHECK_PORT | Port listening for cron-schedule health check. Defaults to `8080`. |
 | POSTGRES_DB | Comma or space separated list of postgres databases to backup. If POSTGRES_CLUSTER is set this refers to the database to connect to for dumping global objects and discovering what other databases should be dumped (typically is either `postgres` or `template1`). Required. |
 | POSTGRES_DB_FILE | Alternative to POSTGRES_DB, but with one database per line, for usage with docker secrets. |

alpine.Dockerfile

@@ -23,6 +23,7 @@ ENV POSTGRES_DB="**None**" \
     SCHEDULE="@daily" \
     BACKUP_DIR="/backups" \
     BACKUP_SUFFIX=".sql.gz" \
+    BACKUP_LATEST_TYPE="symlink" \
     BACKUP_KEEP_DAYS=7 \
     BACKUP_KEEP_WEEKS=4 \
     BACKUP_KEEP_MONTHS=6 \

backup.sh

@@ -121,14 +121,22 @@ for DB in ${POSTGRES_DBS}; do
     ln -vf "${FILE}" "${MFILE}"
   fi
   # Update latest symlinks
-  echo "Point last backup file to this last backup..."
-  ln -svf "${LAST_FILENAME}" "${BACKUP_DIR}/last/${DB}-latest${BACKUP_SUFFIX}"
-  echo "Point latest daily backup to this last backup..."
-  ln -svf "${DAILY_FILENAME}" "${BACKUP_DIR}/daily/${DB}-latest${BACKUP_SUFFIX}"
-  echo "Point latest weekly backup to this last backup..."
-  ln -svf "${WEEKLY_FILENAME}" "${BACKUP_DIR}/weekly/${DB}-latest${BACKUP_SUFFIX}"
-  echo "Point latest monthly backup to this last backup..."
-  ln -svf "${MONTHY_FILENAME}" "${BACKUP_DIR}/monthly/${DB}-latest${BACKUP_SUFFIX}"
+  LATEST_LN_ARG=""
+  if [ "${BACKUP_LATEST_TYPE}" = "symlink" ]; then
+    LATEST_LN_ARG="-s"
+  fi
+  if [ "${BACKUP_LATEST_TYPE}" = "symlink" -o "${BACKUP_LATEST_TYPE}" = "hardlink"  ]; then
+    echo "Point last backup file to this last backup..."
+    ln "${LATEST_LN_ARG}" -vf "${LAST_FILENAME}" "${BACKUP_DIR}/last/${DB}-latest${BACKUP_SUFFIX}"
+    echo "Point latest daily backup to this last backup..."
+    ln "${LATEST_LN_ARG}" -vf "${DAILY_FILENAME}" "${BACKUP_DIR}/daily/${DB}-latest${BACKUP_SUFFIX}"
+    echo "Point latest weekly backup to this last backup..."
+    ln "${LATEST_LN_ARG}" -vf "${WEEKLY_FILENAME}" "${BACKUP_DIR}/weekly/${DB}-latest${BACKUP_SUFFIX}"
+    echo "Point latest monthly backup to this last backup..."
+    ln "${LATEST_LN_ARG}" -vf "${MONTHY_FILENAME}" "${BACKUP_DIR}/monthly/${DB}-latest${BACKUP_SUFFIX}"
+  else # [ "${BACKUP_LATEST_TYPE}" = "none"  ]
+    echo "Not updating lastest backup."
+  fi
   #Clean old files
   echo "Cleaning older files for ${DB} database from ${POSTGRES_HOST}..."
   find "${BACKUP_DIR}/last" -maxdepth 1 -mmin "+${KEEP_MINS}" -name "${DB}-*${BACKUP_SUFFIX}" -exec rm -rvf '{}' ';'

debian.Dockerfile

@@ -37,6 +37,7 @@ ENV POSTGRES_DB="**None**" \
     SCHEDULE="@daily" \
     BACKUP_DIR="/backups" \
     BACKUP_SUFFIX=".sql.gz" \
+    BACKUP_LATEST_TYPE="symlink" \
     BACKUP_KEEP_DAYS=7 \
     BACKUP_KEEP_WEEKS=4 \
     BACKUP_KEEP_MONTHS=6 \