Update docs

Author: danielnelson

.gitignore

@@ -1,2 +1,2 @@
-./openvpn
-dist
+/openvpn
+/dist

LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2020 InfluxData Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

Makefile

@@ -5,6 +5,7 @@ GOARM ?= $(shell go env GOARM)
 .PHONY: all
 all: openvpn
 
+.PHONY: openvpn
 openvpn:
 	go build ./cmd/openvpn
 
@@ -17,16 +18,19 @@ dist-all: openvpn-windows-amd64.zip
 
 openvpn-linux-amd64.tar.gz: GOOS := linux
 openvpn-linux-amd64.tar.gz: GOARCH := amd64
-openvpn-windows-amd64.tar.gz: GOOS := windows
-openvpn-windows-amd64.tar.gz: GOARCH := amd64
+openvpn-windows-amd64.zip: GOOS := windows
+openvpn-windows-amd64.zip: GOARCH := amd64
+openvpn-windows-amd64.zip: EXT := .exe
 openvpn-%.tar.gz:
 	mkdir -p "dist/openvpn-$*"
-	cd "dist/openvpn-$*" && env GOOS=$(GOOS) GOARCH=$(GOARCH) go build -ldflags "-w -s" ../../cmd/openvpn
+	env GOOS=$(GOOS) GOARCH=$(GOARCH) go build -o "dist/openvpn-$*/openvpn$(EXT)" -ldflags "-w -s" ./cmd/openvpn
+	cp openvpn.conf "dist/openvpn-$*"
 	cd dist && tar czf "$@" "openvpn-$*"
 
 openvpn-%.zip:
 	mkdir -p "dist/openvpn-$*"
-	cd "dist/openvpn-$*" && env GOOS=$(GOOS) GOARCH=$(GOARCH) go build -ldflags "-w -s" ../../cmd/openvpn
+	env GOOS=$(GOOS) GOARCH=$(GOARCH) go build -o "dist/openvpn-$*/openvpn$(EXT)" -ldflags "-w -s" ./cmd/openvpn
+	cp openvpn.conf "dist/openvpn-$*"
 	cd dist && zip -r "$@" "openvpn-$*"
 
 .PHONY: clean

README.md

@@ -1 +1,43 @@
+OpenVPN Plugin for Telegraf execd input
+---
 ![](https://github.com/danielnelson/telegraf-execd-plugins/workflows/Build/badge.svg)
+
+
+## Usage
+
+- Download the [latest release package][release] for your platform.
+
+- Unpack the build to your system:
+  ```sh
+  mkdir /var/lib/telegraf
+  chown telegraf:telegraf /var/lib/telegraf
+  tar xf openvpn-linux-amd64.tar.gz -C /var/lib/telegraf
+  ```
+
+- Edit execd plugin configuration as needed:
+  ```sh
+  vi /var/lib/telegraf/openvpn-linux-amd64/openvpn.conf
+  ```
+
+- Add to `/etc/telegraf/telegraf.conf` or into file in `/etc/telegraf/telegraf.d`
+  ```toml
+  [[inputs.execd]]
+    command = ["/var/lib/telegraf/openvpn-linux-amd64/openvpn --config /var/lib/telegraf/openvpn-linux-amd64/openvpn.conf"]
+    signal = "STDIN"
+  ```
+
+- Restart or reload Telegraf.
+
+## Development
+
+When updating the plugin the replace directive in `go.mod` will need updated.
+
+Generally it is expected that no tag will exist and the plugin will reside in a branch.
+```sh
+go mod edit -replace github.com/influxdata/telegraf=github.com/danielnelson/telegraf@openvpn-input
+go mod download
+go mod tidy
+```
+
+
+[releases]: https://github.com/danielnelson/telegraf-execd-openvpn/releases/latest

cmd/openvpn/main.go

@@ -5,15 +5,35 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs/execd/shim"
-	_ "github.com/influxdata/telegraf/plugins/inputs/openvpn"
+	"github.com/influxdata/telegraf/plugins/inputs/openvpn"
 )
 
 var configFile = flag.String("config", "", "path to the config file for this plugin")
+var usage = flag.Bool("usage", false, "print sample configuration")
+
+func printConfig(name string, p telegraf.PluginDescriber) {
+	fmt.Printf("# %s\n", p.Description())
+	fmt.Printf("[[inputs.%s]]", name)
+
+	config := p.SampleConfig()
+	if config != "" {
+		fmt.Printf(config)
+	} else {
+		fmt.Printf("\n  # no configuration\n")
+	}
+}
 
 func main() {
 	flag.Parse()
 
+	if *usage {
+		printConfig("openvpn", &openvpn.OpenVPN{})
+
+		os.Exit(0)
+	}
+
 	shim := shim.New()
 
 	err := shim.LoadConfig(configFile)

openvpn.conf

@@ -1,2 +1,11 @@
+# Gather status from the OpenVPN management interface
 [[inputs.openvpn]]
+  ## Address of the management interface
+  ##   ex: address = "tcp://example.org:1234"
   address = "unix:///var/run/openvpn.sock"
+
+  ## Password to the management interface
+  # password = ""
+
+  ## Timeout for connecting and getting status.
+  # timeout = "5s"