feat: use os.Getenv() read environment variables for tpl

Dockerfile

@@ -6,6 +6,6 @@ RUN GO111MODULE=on CGO_ENABLED=0 GOOS=linux go build -a -o drone-dingtalk .
 FROM alpine:latest
 RUN apk update && apk add ca-certificates && rm -rf /var/cache/apk/*
 COPY --from=builder /app/drone-dingtalk /bin
-COPY --from=builder /app/tpls /app/tpls
+COPY --from=builder /app/tpls /app/drone/dingtalk/message/tpls
 
 ENTRYPOINT ["/bin/drone-dingtalk"]

main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"time"
 
 	"github.com/joho/godotenv"
 	"github.com/urfave/cli"
@@ -16,7 +17,8 @@ func main() {
 	app := cli.NewApp()
 	app.Name = "Drone DingTalk Message Plugin"
 	app.Usage = "Sending message to DingTalk group by robot using WebHook"
-	app.Copyright = "© 2018 Dee Luo"
+	year := time.Now().Year()
+	app.Copyright = fmt.Sprintf("© 2018-%d Dee Luo", year)
 	app.Authors = []cli.Author{
 		{
 			Name:  "Dee Luo",

plugin.go

@@ -137,6 +137,12 @@ type (
 
 // Exec execute WebHook
 func (p *Plugin) Exec() error {
+	if p.Config.Debug {
+		for _, e := range os.Environ() {
+			log.Println(e)
+		}
+	}
+
 	var err error
 	if "" == p.Config.AccessToken {
 		msg := "missing DingTalk access token"
@@ -194,7 +200,7 @@ func fileExists(filePath string) bool {
 // getTpl get tpl from local file or remote file
 func (p *Plugin) getTpl() (tpl string, err error) {
 	//var tpl string
-	tplDir := "/app/tpls"
+	tplDir := "/app/drone/dingtalk/message/tpls"
 	if "" == p.Custom.Tpl {
 		p.Custom.Tpl = fmt.Sprintf("%s/%s.tpl", tplDir, strings.ToLower(p.Config.MsgType))
 	}
@@ -249,6 +255,11 @@ func (p *Plugin) fillTpl(tpl string) string {
 	reg := regexp.MustCompile(`\[([^\[\]]*)]`)
 	match := reg.FindAllStringSubmatch(tpl, -1)
 	for _, m := range match {
+		// from environment
+		if envStr := os.Getenv(m[1]); envStr != "" {
+			tpl = strings.ReplaceAll(tpl, m[0], envStr)
+		}
+
 		// check if the keyword is legal
 		if _, ok := envs[m[1]]; ok {
 			// replace keyword