Postfix

[Simon0Harms]

General information

Affected plugin: agents/plugins/mk_sap.py (SAP R/3 monitoring via RFC/CCMS).
The plugin emits piggyback blocks keyed by the SAP SID. It already supports a
host_prefix option; this change adds a symmetric host_postfix.

Depends on #937 . That PR fixes the logwatch header to honor
host_prefix; this PR builds on the same two header lines. Please merge the
prefix fix first.

Proposed changes

• What it does: adds an optional host_postfix config key. If set, it is appended
  to the SID in the piggyback host name (mirroring the existing host_prefix).
  It is applied to both the sap and the logwatch section headers, so both stay
  on the same piggyback host.
• Motivation: when several systems share a SID (e.g. an ECC and an S/4HANA system
  both called SB1), their piggyback data must be routed to distinct hosts. A
  suffix (SB1_S4H, SB1_ECC) is often preferable to a prefix for grouping and
  sorting by SID. Doing this in the plugin avoids needing a per-source-host
  "Host name translation for piggybacked hosts" rule on the server side, and it
  also works when two systems are monitored from the same agent host (where a
  source-host-based translation rule cannot separate them).
• Change: the header is written as
  "<<<<%s%s%s>>>>\n" % (cfg_entry.get("host_prefix", ""), host, cfg_entry.get("host_postfix", ""))
  for both sections.
• Backward compatibility: host_postfix defaults to "" via .get(), so existing
  configurations are unaffected. The new option is documented in the sample config.
• What made you submit this? Monitoring two SAP systems that share a SID from
  related agent hosts; a suffix-based naming scheme was needed for clean host
  naming.
• Unit test: a test that sets host_postfix (and optionally host_prefix) and
  asserts both the sap and logwatch headers render as <prefix><SID><postfix>.

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[Simon0Harms]

I have read the CLA Document and I hereby sign the CLA or my organization already has a signed CLA.