add dockerfile into template

tools/goctl/docker/template.go

@@ -0,0 +1,44 @@
+package docker
+
+import (
+	"github.com/tal-tech/go-zero/tools/goctl/util"
+	"github.com/urfave/cli"
+)
+
+const (
+	category           = "docker"
+	dockerTemplateFile = "docker.tpl"
+	dockerTemplate     = `FROM golang:alpine AS builder
+
+LABEL stage=gobuilder
+
+ENV CGO_ENABLED 0
+ENV GOOS linux
+ENV GOPROXY https://goproxy.cn,direct
+
+WORKDIR /build/zero
+COPY . .
+COPY {{.goRelPath}}/etc /app/etc
+RUN go build -ldflags="-s -w" -o /app/{{.exeFile}} {{.goRelPath}}/{{.goFile}}
+
+
+FROM alpine
+
+RUN apk update --no-cache
+RUN apk add --no-cache ca-certificates
+RUN apk add --no-cache tzdata
+ENV TZ Asia/Shanghai
+
+WORKDIR /app
+COPY --from=builder /app/{{.exeFile}} /app/{{.exeFile}}
+COPY --from=builder /app/etc /app/etc
+
+CMD ["./{{.exeFile}}"{{.argument}}]
+`
+)
+
+func GenTemplates(_ *cli.Context) error {
+	return util.InitTemplates(category, map[string]string{
+		dockerTemplateFile: dockerTemplate,
+	})
+}