Add multiple listeners and systemd socket listener activation

examples/systemd/README.md

@@ -2,7 +2,7 @@
 
 If you are using distribution packages or the copr repository, you don't need to deal with these files!
 
-The unit file in this directory is to be put into `/etc/systemd/system`.
+The unit files (`*.service` and `*.socket`) in this directory are to be put into `/etc/systemd/system`.
 It needs a user named `node_exporter`, whose shell should be `/sbin/nologin` and should not have any special privileges.
 It needs a sysconfig file in `/etc/sysconfig/node_exporter`.
 It needs a directory named `/var/lib/node_exporter/textfile_collector`, whose owner should be `node_exporter`:`node_exporter`.

examples/systemd/node_exporter.service

@@ -1,10 +1,11 @@
 [Unit]
 Description=Node Exporter
+Requires=node_exporter.socket
 
 [Service]
 User=node_exporter
 EnvironmentFile=/etc/sysconfig/node_exporter
-ExecStart=/usr/sbin/node_exporter $OPTIONS
+ExecStart=/usr/sbin/node_exporter --web.systemd-socket $OPTIONS
 
 [Install]
 WantedBy=multi-user.target

examples/systemd/node_exporter.socket

@@ -0,0 +1,8 @@
+[Unit]
+Description=Node Exporter
+
+[Socket]
+ListenStream=9100
+
+[Install]
+WantedBy=sockets.target

go.mod

@@ -21,7 +21,7 @@ require (
 	github.com/prometheus/client_golang v1.13.0
 	github.com/prometheus/client_model v0.2.0
 	github.com/prometheus/common v0.37.0
-	github.com/prometheus/exporter-toolkit v0.7.1
+	github.com/prometheus/exporter-toolkit v0.8.1
 	github.com/prometheus/procfs v0.8.0
 	github.com/safchain/ethtool v0.2.0
 	github.com/soundcloud/go-runit v0.0.0-20150630195641-06ad41a06c4a
@@ -31,7 +31,7 @@ require (
 
 require (
 	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
-	github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d // indirect
+	github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
@@ -45,16 +45,16 @@ require (
 	github.com/mdlayher/genetlink v1.2.0 // indirect
 	github.com/mdlayher/socket v0.2.3 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
-	github.com/pkg/errors v0.9.1 // indirect
 	github.com/siebenmann/go-kstat v0.0.0-20210513183136-173c9b0a9973 // indirect
 	go.uber.org/atomic v1.7.0 // indirect
 	go.uber.org/multierr v1.6.0 // indirect
-	golang.org/x/crypto v0.0.0-20220314234659-1baeb1ce4c0b // indirect
+	golang.org/x/crypto v0.0.0-20221012134737-56aed061732a // indirect
 	golang.org/x/net v0.0.0-20220923203811-8be639271d50 // indirect
-	golang.org/x/oauth2 v0.0.0-20220223155221-ee480838109b // indirect
-	golang.org/x/sync v0.0.0-20220923202941-7f9b1623fab7 // indirect
+	golang.org/x/oauth2 v0.0.0-20220909003341-f21342109be1 // indirect
+	golang.org/x/sync v0.1.0 // indirect
 	golang.org/x/text v0.3.7 // indirect
-	google.golang.org/appengine v1.6.6 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
 	google.golang.org/protobuf v1.28.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )