app-metrics/node_exporter: Add systemd-patched ebuild fpr version 0.18.1.

Package-Manager: Portage-2.3.76, Repoman-2.3.16

app-metrics/node_exporter/files/node_exporter-0.18.1-systemd.patch

@@ -0,0 +1,15 @@
+Index: node_exporter-0.18.1/src/github.com/prometheus/node_exporter/examples/systemd/node_exporter.service
+===================================================================
+--- node_exporter-0.18.1.orig/src/github.com/prometheus/node_exporter/examples/systemd/node_exporter.service
++++ node_exporter-0.18.1/src/github.com/prometheus/node_exporter/examples/systemd/node_exporter.service
+@@ -3,8 +3,8 @@ Description=Node Exporter
+ 
+ [Service]
+ User=node_exporter
+-EnvironmentFile=/etc/sysconfig/node_exporter
+-ExecStart=/usr/sbin/node_exporter $OPTIONS
++EnvironmentFile=/etc/sysconfig/node_exporter/sysconfig.node_exporter
++ExecStart=/usr/bin/node_exporter $OPTIONS
+ 
+ [Install]
+ WantedBy=multi-user.target

app-metrics/node_exporter/files/node_exporter-1.initd

@@ -0,0 +1,23 @@
+#!/sbin/openrc-run
+# Copyright 2016-2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+description="Prometheus machine metrics exporter"
+pidfile=${pidfile:-"/run/${RC_SVCNAME}.pid"}
+user=${user:-${RC_SVCNAME}}
+group=${group:-${RC_SVCNAME}}
+
+command="/usr/bin/node_exporter"
+command_args="${command_args:---collector.textfile.directory=/var/lib/node_exporter/}"
+command_background="true"
+start_stop_daemon_args="--user ${user} --group ${group} \
+	--stdout /var/log/node_exporter/${RC_SVCNAME}.log \
+	--stderr /var/log/node_exporter/${RC_SVCNAME}.log"
+
+depend() {
+	after net
+}
+
+start_pre() {
+	checkpath -q -d -m 0755 -o ${user}:${group} /var/log/node_exporter
+}

app-metrics/node_exporter/files/node_exporter.confd

@@ -0,0 +1,2 @@
+# arguments for prometheus node exporter
+command_args="--collector.textfile.directory=/var/lib/node_exporter/"