Merge pull request #2117 from jimklimov/issue-2063

Follow-up for `apc_modbus` driver

Author: jimklimov

NEWS.adoc

@@ -195,6 +195,28 @@ as part of https://github.com/networkupstools/nut/issues/1410 solution.
    * fix to clean obsoleted readings (if any) AFTER getting new info from an
      `apcupsd` daemon, to avoid the gap when NUT driver knows nothing [#2007]
 
+ - apc_modbus driver was introduced, to cover the feature gap between existing
+   NUT drivers for APC hardware and the actual USB-connected devices (or their
+   firmwares) released since roughly 2010, which deprecated standard USB HID
+   support in favor of Modbus-based protocol which is used across the board
+   (also with their network management cards). The new driver can monitor APC
+   UPS devices over TCP and Serial connections, as well as USB with a patched
+   libmodbus (check https://github.com/EchterAgo/libmodbus/commits/rtu_usb
+   for now, PR pending). [#139, #2063]
+   * For a decade until this driver got introduced, people were advised to
+     use apcupsd project as the actual program which talks to a device, and
+     NUT apcupsd-ups driver to relay information back and forth. This was a
+     limited solution due to lack of command and variable setting support,
+     as well as relaying of just some readings (just whatever apcupsd exposes,
+     further constrained by what our driver knows to re-translate), with
+     little leverage for NUT to tap into everything the device has to offer.
+     There were also issues on some systems due to packaging (e.g. marking
+     NUT and apcupsd as competing implementations of the same features) which
+     required clumsy workarounds to get both installed and running. Finally,
+     there is a small matter of long-term viability of that approach: last
+     commits to apcupsd sources were in 2017 (with last release 3.14.14 in
+     May 2016): https://sourceforge.net/p/apcupsd/svn/HEAD/tree/
+
  - NUT for Windows:
    * Ability to build NUT for Windows, last tackled with a branch based on
      NUT v2.6.5 a decade ago, has been revived with the 2.8.x era codebase [#5].

scripts/upsdrvsvcctl/nut-driver-enumerator.sh.in

@@ -9,7 +9,7 @@
 #       is to just pick out some strings relevant for tracking config changes.
 #
 # Copyright (C) 2016-2020 Eaton
-# Copyright (C) 2020-2022 Jim Klimov <jimklimov+nut@gmail.com>
+# Copyright (C) 2020-2023 Jim Klimov <jimklimov+nut@gmail.com>
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -171,7 +171,7 @@ fi
 # Cache needed bits of ups.conf to speed up later parsing. Note that these
 # data are needed for most operations, and populated by upslist_readFile()
 UPSCONF_DATA=""
-# Subset of normalized data above that only has sections, drivers and ports
+# Subset of normalized data above that only has sections, drivers and ports (SDP)
 UPSCONF_DATA_SDP=""
 
 # List of configured UPSes in the config-file
@@ -479,8 +479,45 @@ upsconf_getDriverMedia() {
     # particular system's physics, both serial and network media may need USB).
     CURR_DRV="`upsconf_getDriver "$1"`" || return $?
     case "$CURR_DRV" in
-        *netxml*|*snmp*|*ipmi*|*powerman*|*-mib*|*avahi*|*apcupsd*)
+        *netxml*|*snmp*|*ipmi*|*powerman*|*-mib*|*avahi*)
             printf '%s\n%s\n' "$CURR_DRV" "network" ; return ;;
+        *apcupsd-ups*)
+            # Relay from a nearby apcupsd network server into NUT ecosystem:
+            CURR_PORT="`upsconf_getPort "$1"`" || CURR_PORT=""
+            case "$CURR_PORT" in
+                *localhost*|*127.0.0.1*|*::1*)
+                    printf '%s\n%s\n' "$CURR_DRV" "network-localhost" ; return ;;
+                *)
+                    printf '%s\n%s\n' "$CURR_DRV" "network" ; return ;;
+            esac
+            ;;
+        *apc_modbus*)
+            CURR_PORT="`upsconf_getPort "$1"`" || CURR_PORT=""
+            CURR_PORTTYPE="`upsconf_getValue "$1" 'porttype'`" || CURR_PORTTYPE=""
+            case "$CURR_PORTTYPE" in
+                *usb*)
+                    printf '%s\n%s\n' "$CURR_DRV" "usb" ; return ;;
+                *serial*)
+                    printf '%s\n%s\n' "$CURR_DRV" "serial" ; return ;;
+                *)  # default depends on driver build (against libmodbus
+                    # version with or without support for usb)
+                    # TOTHINK: Check for presence of config values like
+                    # vendorid (USB) or baud (Serial)? They are optional
+                    # with reasonable defaults anyway...
+                    case "$CURR_PORT" in
+                        *auto*)
+                            printf '%s\n%s\n' "$CURR_DRV" "usb" ; return ;;
+                        /*)
+                            printf '%s\n%s\n' "$CURR_DRV" "serial" ; return ;;
+                        *localhost*|*127.0.0.1*|*::1*)
+                            printf '%s\n%s\n' "$CURR_DRV" "network-localhost" ; return ;;
+                        *)
+                            printf '%s\n%s\n' "$CURR_DRV" "network" ; return ;;
+                    esac
+                    # returns are above, but just in case - have a fallback:
+                    printf '%s\n%s\n' "$CURR_DRV" "" ; return ;;
+            esac
+            ;;
         *usb*)
             printf '%s\n%s\n' "$CURR_DRV" "usb" ; return ;;
         nutdrv_qx) # May be direct serial or USB