Add the initial version of the script

backup.sh

@@ -0,0 +1,104 @@
+#!/usr/bin/env bash
+
+__CONFIG_FILE="/etc/backups.conf"
+
+# A simple wrapper for a Gentoo ebuild-like `die`.
+die() {
+    echo "$*" 1>&2
+    exit 1
+}
+
+# Source the configuration file.
+[[ -f ${__CONFIG_FILE} ]] || die "Cannot find ${__CONFIG_FILE}. Exiting."
+source ${__CONFIG_FILE}
+# Check the required / optional variables.
+[[ -z ${__BACKUP_DIR} ]] && die "__BACKUP_DIR is not set."
+[[ -z ${__BACKUP_EXT} ]] && __BACKUP_EXT=".tar.gz" # default compression format
+[[ -z ${__BACKUP_AGE} ]] && __BACKUP_AGE=2 # 2 day-old backups stored by default
+# Set the date to be inserted to tarball names.
+__DATE="$(date +%Y-%m-%d-%H-%M)"
+
+# Create the backup directory if it does not exist yet.
+[[ ! -d ${__BACKUP_DIR} ]] && mkdir -p ${__BACKUP_DIR} && \
+    echo "Created ${__BACKUP_DIR} for you."
+
+# Creates an empty tar archive. Accepts a single parameter, the filename.
+empty_archive() {
+    /usr/bin/env tar -cf "${1}" -T /dev/null --xattrs || \
+        die "Creating ${1} failed!"
+    # This works on BSD and Linux. Not tested with others.
+}
+# Accepts two parameters, the archive filename and the file to be added.
+add_to_archive() {
+    /usr/bin/env tar --xattrs --append -pvf 2>/dev/null "${1}" "${2}" || \
+        die "Adding ${2} to ${1} failed!"
+}
+
+clean_up() {
+    /usr/bin/env find "${__BACKUP_DIR}" -ctime +${__BACKUP_AGE} -delete || \
+        die "Cleanup failed!"
+}
+
+backup_docker() {
+    echo "Running a Docker volumes backup..."
+    __FILENAME="${__BACKUP_DIR}/${__DATE}-docker${__BACKUP_EXT}"
+    # Check the presence of the Docker directory.
+    [[ -d /var/lib/docker ]] || die "Docker is likely to not be installed."
+    empty_archive ${__FILENAME}
+    add_to_archive ${__FILENAME} /var/lib/docker/volumes
+}
+
+backup_postgres() {
+    echo "Running a PostgreSQL databases backup..."
+    __FILENAME="${__BACKUP_DIR}/${__DATE}-postgres${__BACKUP_EXT}"
+    # The databases need to be listed in a special variable.
+    [[ -z ${__BACKUP_DATABASES} ]] && die "The databases list is not specified."
+    for database in "${__BACKUP_DATABASES[@]}"; do
+        __DUMP_NAME="${__FILENAME}-$database"
+        pg_dump -Fc $database > ${__DUMP_NAME} || \
+            die "Failed backing up database $database."
+        add_to_archive ${__FILENAME} ${__DUMP_NAME}
+        rm ${__DUMP_NAME}
+    done
+}
+
+backup_configs() {
+    echo "Running config files backups..."
+    __FILENAME="${__BACKUP_DIR}/${__DATE}-configs${__BACKUP_EXT}"
+    # The files to be saved need to be listed in a special variable.
+    [[ -z ${__BACKUP_FILES} ]] && \
+        die "The files to be backed up are not specified."
+    for file in "${__BACKUP_FILES[@]}"; do
+        add_to_archive ${__FILENAME} $file
+    done
+}
+
+# Check if the first command-line flag is `-a` and run all of the options if
+# applicable, check for the other flags otherwise.
+if [[ "${1}" != "-a" ]]; then
+    for arg in "$*"; do
+        case $arg in
+            "-d" | "--docker")
+                backup_docker
+                ;;
+            "-p" | "--postgres")
+                backup_postgres
+                ;;
+            "-c" | "--configs")
+                backup_configs
+                ;;
+            "-a")
+                die "-a cannot be specified after any other flags."
+                ;;
+            "$0")
+                # This is only hit when listing through the basename.
+                # Do nothing.
+                ;;
+        esac
+    done
+else
+    backup_configs
+    backup_docker
+    # backup_postgres
+fi
+clean_up