.gitignore

@@ -1 +1,2 @@
 watchdog
+generated-version.go

README.md

@@ -16,7 +16,9 @@ Git:
 ```bash
 git clone https://git.coolaj86.com/coolaj86/watchdog.go.git
 pushd watchdog.go/
-go build -o bin/watchdog
+go generate -mod=vendor ./...
+pushd cmd/watchdog
+go build -mod=vendor
 ```
 
 Zip:

cmd/watchdog/watchdog.go

@@ -1,3 +1,6 @@
+//go:generate go run ../../tools/version/version.go
+
+// Watchdog Binary
 package main
 
 import (
@@ -6,15 +9,35 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"strings"
 
 	watchdog "git.rootprojects.org/root/watchdog.go"
 )
 
+var (
+	Version   = "v0.0.0"
+	GitRev    = "00000000"
+	Timestamp = "0000-00-00T00:00:00Z"
+)
+
 func usage() {
 	fmt.Println("Usage: watchdog -c config.json")
 }
 
 func main() {
+	for i := range os.Args {
+		switch {
+		case strings.HasSuffix(os.Args[i], "version"):
+			fmt.Println(Timestamp)
+			fmt.Println(Version)
+			fmt.Println(GitRev)
+			os.Exit(0)
+		case strings.HasSuffix(os.Args[i], "help"):
+			usage()
+			os.Exit(0)
+		}
+	}
+
 	if 3 != len(os.Args) {
 		usage()
 		os.Exit(1)

tools/version/version.go

@@ -0,0 +1,123 @@
+// +build tools
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"os"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+	"text/template"
+	"time"
+)
+
+var exactVer *regexp.Regexp
+var gitVer *regexp.Regexp
+var verFile = "generated-version.go"
+
+func init() {
+	// exactly vX.Y.Z (go-compatible semver)
+	exactVer = regexp.MustCompile(`^v\d+\.\d+\.\d+$`)
+
+	// vX.Y.Z-n-g0000000 git post-release, semver prerelease
+	gitVer = regexp.MustCompile(`^(v\d+\.\d+)\.(\d+)-(\d+)-g`)
+}
+
+// Goal: Either use an exact version like v1.0.0
+//       or translate the git version like v1.0.0-4-g0000000
+//       to a semver like v1.0.1-pre4+g0000000
+//       Don't fail when git repo isn't available.
+func main() {
+	desc := gitDesc()
+	rev := gitRev()
+	ver := semVer(desc)
+	ts := time.Now().Format(time.RFC3339)
+
+	v := struct {
+		Timestamp string
+		Version   string
+		GitRev    string
+	}{
+		Timestamp: ts,
+		Version:   ver,
+		GitRev:    rev,
+	}
+
+	// Create or overwrite the go file from template
+	var buf bytes.Buffer
+	if err := versionTpl.Execute(&buf, v); nil != err {
+		panic(err)
+	}
+
+	// Format
+	src, err := format.Source(buf.Bytes())
+	if nil != err {
+		panic(err)
+	}
+
+	// Write to disk (in the Current Working Directory)
+	f, err := os.Create(verFile)
+	if nil != err {
+		panic(err)
+	}
+	if _, err := f.Write(src); nil != err {
+		panic(err)
+	}
+	if err := f.Close(); nil != err {
+		panic(err)
+	}
+}
+
+func gitDesc() string {
+	args := strings.Split("git describe --tags --dirty --always", " ")
+	cmd := exec.Command(args[0], args[1:]...)
+	out, err := cmd.CombinedOutput()
+	if nil != err {
+		// Don't panic, just carry on
+		out = []byte("v0.0.0-0-g0000000")
+	}
+	return strings.TrimSpace(string(out))
+}
+
+func gitRev() string {
+	args := strings.Split("git rev-parse HEAD", " ")
+	cmd := exec.Command(args[0], args[1:]...)
+	out, err := cmd.CombinedOutput()
+	if nil != err {
+		// Don't panic, just carry on
+		out = []byte("00000000000000000")
+	}
+	return strings.TrimSpace(string(out))
+}
+
+func semVer(desc string) string {
+	var ver string
+	if exactVer.MatchString(desc) {
+		// v1.0.0
+		ver = desc
+	} else if gitVer.MatchString(desc) {
+		// ((v1.0).(0)-(1))
+		vers := gitVer.FindStringSubmatch(desc)
+		patch, err := strconv.Atoi(vers[2])
+		if nil != err {
+			panic(err)
+		}
+		// v1.0.1-pre1
+		ver = fmt.Sprintf("%s.%d-pre%s", vers[1], patch+1, vers[3])
+	}
+	return ver
+}
+
+var versionTpl = template.Must(template.New("").Parse(`// Code generated by go generate; DO NOT EDIT.
+package main
+
+func init() {
+	Timestamp = "{{ .Timestamp }}"
+	Version = "{{ .Version }}"
+	GitRev = "{{ .GitRev }}"
+}
+`))

watchdog.go

@@ -177,14 +177,14 @@ func (d *Dog) notify(hardFail bool) {
 				// because `{{` gets urlencoded
 				//k = strings.Replace(k, "{{ .Name }}", d.Name, -1)
 				v = strings.Replace(v, "{{ .Name }}", d.Name, -1)
-				d.logger <- fmt.Sprintf("[HEADER] %s: %s", k, v)
+				d.Logger <- fmt.Sprintf("[HEADER] %s: %s", k, v)
 				form.Set(k, v)
 			}
 			body = strings.NewReader(form.Encode())
 		} else if 0 != len(h.JSON) {
 			bodyBuf, err := json.Marshal(h.JSON)
 			if nil != err {
-				d.logger <- fmt.Sprintf("[Notify] JSON Marshal Error for '%s': %s", h.Name, err)
+				d.Logger <- fmt.Sprintf("[Notify] JSON Marshal Error for '%s': %s", h.Name, err)
 				continue
 			}
 			// `{{` should be left alone
@@ -194,7 +194,7 @@ func (d *Dog) notify(hardFail bool) {
 		client := NewHTTPClient()
 		req, err := http.NewRequest(h.Method, h.URL, body)
 		if nil != err {
-			d.logger <- fmt.Sprintf("[Notify] HTTP Client Network Error for '%s': %s", h.Name, err)
+			d.Logger <- fmt.Sprintf("[Notify] HTTP Client Network Error for '%s': %s", h.Name, err)
 			continue
 		}