Attempt to support backing up commands

backup.nix

@@ -11,30 +11,7 @@ let
     runtimeInputs = [
       pkgs.restic
     ];
-    text = ''
+    text = (builtins.readFile ./backup.sh);
-      if [ -z "$BACKUP_HELPER_DIRS"  ]; then
-        echo "BACKUP_HELPER_DIRS is not set"
-        exit 1;
-      fi
-      exit_code=0;
-      for i in ''${BACKUP_HELPER_DIRS//,/ }; do
-        echo "Starting backup of $i";
-        if ! output=$(restic backup "$i"); then
-          exit_code=1;
-          echo "Backup of $i failed with exit code $?:"
-          echo "$output"
-        else
-          echo "Backup of $i successful:"
-          echo "$output"
-        fi
-      done
-      if [ "$BACKUP_FORGET" -eq 1 ]; then
-        echo "Removing old backups"
-        output=$(restic forget -d 7 -w 4 -m 6 --keep-within 1d --prune)
-        echo "$output"
-      fi
-      exit "$exit_code";
-    '';
   };
 in
 {
@@ -50,6 +27,11 @@ in
       default = [ ];
       description = "Directories to be backed up.";
     };
+    backup-commands = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [ ];
+      description = "Backup the stdout of commands. Format strings like key:command";
+    };
     schedule = lib.mkOption {
       type = lib.types.str;
       default = "*-*-* 00:00:00";
@@ -83,6 +65,9 @@ in
         }
         // lib.attrsets.optionalAttrs (builtins.hasAttr "password-file" cfg) {
           RESTIC_PASSWORD_FILE = cfg.password-file;
+        }
+        // lib.attrsets.optionalAttrs (cfg.backup-commands != [ ]) {
+          BACKUP_HELPER_COMMANDS = lib.strings.concatStringsSep ";" cfg.backup-commands;
         };
       serviceConfig = {
         Type = "oneshot";

backup.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+
+# If neither of BACKUP_HELPER_DIRS and BACKUP_HELPER_COMMANDS not set. Exit
+if [ -z "$BACKUP_HELPER_DIRS" ] && [ -z "$BACKUP_HELPER_COMMANDS" ]; then
+  echo "BACKUP_HELPER_DIRS is not set"
+  exit 1;
+fi
+exit_code=0;
+
+# Backup directories
+if [ -n "$BACKUP_HELPER_DIRS" ]; then
+  for i in ${BACKUP_HELPER_DIRS//,/ }; do
+    echo "Starting backup of $i";
+    if ! output=$(restic backup "$i"); then
+      exit_code=1;
+      echo "Backup of $i failed with exit code $?:"
+      echo "$output"
+    else
+      echo "Backup of $i successful:"
+      echo "$output"
+    fi
+  done
+fi
+
+# Backup command outputs
+if [ -n "$BACKUP_HELPER_COMMANDS" ]; then
+  IFS=";" read -r -a pairs <<< "$BACKUP_HELPER_COMMANDS"
+
+  for pair in "${pairs[@]}"; do
+      IFS=":" read -r key value <<< "$pair"
+
+      if ! output=$(restic backup --stdin-filename "$key" --stdin-from-command -- "$value"); then
+        exit_code=1;
+        echo "Backup of $i failed with exit code $?:"
+        echo "$output"
+      else
+        echo "Backup of $i successful:"
+        echo "$output"
+      fi
+        
+  done
+fi
+
+if [ "$BACKUP_FORGET" -eq 1 ]; then
+  echo "Removing old backups"
+  output=$(restic forget -d 7 -w 4 -m 6 --keep-within 1d --prune)
+  echo "$output"
+fi
+exit "$exit_code"