17237 FIX check_mk_agent.openwrt: resolve issue when hostname command…

… unavailable

Built-in BusyBox shell in OpenWRT has no `hostname` command available per default.
While it can be added with additional packages in custom images there are alternative
ways to determine the machine's hostname without introducing an additional dependency.
This werk uses one of those alternatives.

Closes: #721

Change-Id: Ib05f837151f02942077a5b405dab966e7f4f9318

.werks/17237.md

@@ -0,0 +1,17 @@
+[//]: # (werk v2)
+# check_mk_agent.openwrt: resolve issue when hostname command unavailable
+
+key        | value
+---------- | ---
+date       | 2024-11-08T07:14:01+00:00
+version    | 2.4.0b1
+class      | fix
+edition    | cre
+component  | checks
+level      | 1
+compatible | yes
+
+Built-in BusyBox shell in OpenWRT has no `hostname` command available per default.
+While it can be added with additional packages in custom images there are alternative
+ways to determine the machine's hostname without introducing an additional dependency.
+This werk uses one of those alternatives.

agents/check_mk_agent.openwrt

@@ -354,7 +354,7 @@ section_checkmk() {
     echo "<<<check_mk>>>"
     echo "Version: 2.4.0b1"
     echo "AgentOS: openwrt"
-    echo "Hostname: $(hostname)"
+    echo "Hostname: $(cat /proc/sys/kernel/hostname)"
     echo "AgentDirectory: ${MK_CONFDIR}"
     echo "DataDirectory: ${MK_VARDIR}"
     echo "SpoolDirectory: ${SPOOLDIR}"
@@ -948,7 +948,7 @@ section_veritas_vcs() {
     # Secure mode must be off to allow root to execute commands
     if [ -x /opt/VRTSvcs/bin/haclus ]; then
         echo "<<<veritas_vcs>>>"
-        vcshost=$(hostname | cut -d. -f1)
+        vcshost=$(cut -d. -f1 </proc/sys/kernel/hostname)
         waitmax -s 9 2 /opt/VRTSvcs/bin/haclus -display -localclus | grep -e ClusterName -e ClusState
         waitmax -s 9 2 /opt/VRTSvcs/bin/hasys -display -attribute SysState
         waitmax -s 9 2 /opt/VRTSvcs/bin/hagrp -display -sys "${vcshost}" -attribute State -localclus