Initial implementation for epics plugin for collectd 6.0

EPICS is Experimental Physics and Industrial Control System.

Reference: https://epics-controls.org/

Signed-off-by: Matwey V. Kornilov <matwey.kornilov@gmail.com>

Makefile.am

@@ -1122,6 +1122,14 @@ entropy_la_SOURCES = src/entropy.c
 entropy_la_LDFLAGS = $(PLUGIN_LDFLAGS)
 endif
 
+if BUILD_PLUGIN_EPICS
+pkglib_LTLIBRARIES += epics.la
+epics_la_CFLAGS = $(AM_CFLAGS) $(BUILD_WITH_EPICS_BASE_CFLAGS)
+epics_la_SOURCES = src/epics.c
+epics_la_LDFLAGS = $(PLUGIN_LDFLAGS)
+epics_la_LIBADD = -lpthread $(BUILD_WITH_EPICS_BASE_LIBS)
+endif
+
 if BUILD_PLUGIN_EXEC
 pkglib_LTLIBRARIES += exec.la
 exec_la_SOURCES = src/exec.c

README

@@ -133,6 +133,10 @@ Features
     - entropy
       Amount of entropy available to the system.
 
+    - epics
+      Collect data from EPICS message bus.
+      <https://epics-controls.org>
+
     - ethstat
       Network interface card statistics.
 

configure.ac

@@ -2138,6 +2138,34 @@ AC_SUBST([LEVEL_ZERO_CFLAGS])
 AC_SUBST([LEVEL_ZERO_LIBS])
 # }}}
 
+# --with-epics-base {{{
+AC_ARG_WITH([epics-base],
+  [AS_HELP_STRING([--with-epics-base@<:@=PREFIX@:>@], [Path to epics-base.])],
+  [
+    with_epics_base="$withval"
+    if test "x$withval" = "xno"; then
+      with_epics_base="no (disabled on command line)"
+    fi
+  ],
+  [with_epics_base="yes"]
+)
+
+if test "x$with_epics_base" = "xyes"; then
+PKG_CHECK_MODULES([EPICS_BASE], [epics-base],
+  [with_epics_base="yes"],
+  [with_epics_base="no (pkg-config could not find epics-base)"]
+)
+fi
+
+if test "x$with_epics_base" = "xyes"; then
+  BUILD_WITH_EPICS_BASE_CFLAGS="$EPICS_BASE_CFLAGS"
+  BUILD_WITH_EPICS_BASE_LIBS="$EPICS_BASE_LIBS -lca"
+fi
+
+AC_SUBST([BUILD_WITH_EPICS_BASE_CFLAGS])
+AC_SUBST([BUILD_WITH_EPICS_BASE_LIBS])
+# }}}
+
 # --with-libaquaero5 {{{
 AC_ARG_WITH([libaquaero5],
   [AS_HELP_STRING([--with-libaquaero5@<:@=PREFIX@:>@], [Path to aquatools-ng source code.])],
@@ -6747,6 +6775,7 @@ plugin_dpdk_telemetry="no"
 plugin_drbd="no"
 plugin_email="yes"
 plugin_entropy="no"
+plugin_epics="no"
 plugin_ethstat="no"
 plugin_exec="yes"
 plugin_fhcount="no"
@@ -7440,6 +7469,7 @@ AC_PLUGIN([dpdk_telemetry],      [$plugin_dpdk_telemetry],    [Metrics from DPDK
 AC_PLUGIN([drbd],                [$plugin_drbd],              [DRBD statistics])
 AC_PLUGIN([email],               [$plugin_email],             [EMail statistics])
 AC_PLUGIN([entropy],             [$plugin_entropy],           [Entropy statistics])
+AC_PLUGIN([epics],               [$with_epics_base],          [EPICS CA plugin])
 AC_PLUGIN([ethstat],             [$plugin_ethstat],           [Stats from NIC driver])
 AC_PLUGIN([exec],                [$plugin_exec],              [Execution of external programs])
 AC_PLUGIN([fhcount],             [$plugin_fhcount],           [File handles statistics])
@@ -7773,6 +7803,7 @@ AC_MSG_RESULT([    YACC  . . . . . . . . $YACC])
 AC_MSG_RESULT([    YFLAGS  . . . . . . . $YFLAGS])
 AC_MSG_RESULT()
 AC_MSG_RESULT([  Libraries:])
+AC_MSG_RESULT([    epics . . . . . . . . $with_epics_base])
 AC_MSG_RESULT([    intel mic . . . . . . $with_mic])
 AC_MSG_RESULT([    libaquaero5 . . . . . $with_libaquaero5])
 AC_MSG_RESULT([    libatasmart . . . . . $with_libatasmart])
@@ -7889,6 +7920,7 @@ AC_MSG_RESULT([    drbd  . . . . . . . . $enable_drbd])
 AC_MSG_RESULT([    email . . . . . . . . $enable_email])
 AC_MSG_RESULT([    entropy . . . . . . . $enable_entropy])
 AC_MSG_RESULT([    ethstat . . . . . . . $enable_ethstat])
+AC_MSG_RESULT([    epics . . . . . . . . $enable_epics])
 AC_MSG_RESULT([    exec  . . . . . . . . $enable_exec])
 AC_MSG_RESULT([    fhcount . . . . . . . $enable_fhcount])
 AC_MSG_RESULT([    filecount . . . . . . $enable_filecount])

src/collectd.conf.in

@@ -129,6 +129,7 @@
 #@BUILD_PLUGIN_DRBD_TRUE@LoadPlugin drbd
 #@BUILD_PLUGIN_EMAIL_TRUE@LoadPlugin email
 #@BUILD_PLUGIN_ENTROPY_TRUE@LoadPlugin entropy
+#@BUILD_PLUGIN_ENTROPY_TRUE@LoadPlugin epics
 #@BUILD_PLUGIN_ETHSTAT_TRUE@LoadPlugin ethstat
 #@BUILD_PLUGIN_EXEC_TRUE@LoadPlugin exec
 #@BUILD_PLUGIN_FHCOUNT_TRUE@LoadPlugin fhcount
@@ -733,6 +734,15 @@
 #	MaxConns 5
 #</Plugin>
 
+#<Plugin epics>
+#	<Family "cavity.temperature">
+#		Type "gauge"
+#		Unit "Cel"
+#		Label "Cavity1:Name"
+#		Metric "Cavity1:Temp"
+#	</Family>
+#</Plugin>
+
 #<Plugin ethstat>
 #	Interface "eth0"
 #	EthtoolExcludeMetrics "tx_packets"

src/collectd.conf.pod

@@ -3312,6 +3312,51 @@ at most B<16384> to prevent typos and dumb mistakes.
 
 =back
 
+=head2 Plugin C<epics>
+
+The I<epics plugin> collects data from EPICS (Experimental Physics and
+Industrial Control System) message bus.
+
+Note that in addition to the plugin configuration, the host OS has to be
+configured to be part of the message bus: caRepeater daemon is up and running
+and appropriate EPICS environment variables are set, if required. Consult EPICS
+documentation for details.
+
+B<Synopsis:>
+
+ <Plugin epics>
+   <Variable "Cavity1:Temp">
+     Type "gauge"
+   </Variable>
+   Label "Cavity1:Name"
+ </Plugin>
+
+B<Options:>
+
+=over 4
+
+=item E<lt>B<Variable> I<PVName>E<gt>
+
+The plugin configuration consists of multiple E<lt>B<Variable>E<gt> blocks,
+each per monitored EPICS Process Variable (PV). The variables are constantly
+monitored and their values are latched once per I<global Interval>.
+
+=item B<Type> I<Type>
+
+This is mandatory option to specify internal collectd type for this particular
+PV. PV data type announced by EPICS and the I<Type> specified here must be in a
+reasonable agreement.
+
+=item B<Label> I<PVName>
+
+Additionally, string-typed PV can be monitored as a B<Label>. For instance,
+this can potentially be useful for tracking an experiment ID. Note that in
+addition to configuring B<Label> the appropriate label-avare collectd writing
+plugin has to be enabled. For instance, I<write_prometheus plugin>,
+I<write_influxdb_udp plugin>, or I<write_http plugin> with InfluxDB B<Format>.
+
+=back
+
 =head2 Plugin C<ethstat>
 
 The I<ethstat plugin> collects information about network interface cards (NICs)