fn: rename from fnctl (#321)

* fn: rename from fnctl

* fn: predicting the release version for installer

* fn: predicting the release version for installer

fn/build.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/urfave/cli"
+)
+
+func build() cli.Command {
+	cmd := buildcmd{commoncmd: &commoncmd{}}
+	flags := append([]cli.Flag{}, cmd.flags()...)
+	return cli.Command{
+		Name:   "build",
+		Usage:  "build function version",
+		Flags:  flags,
+		Action: cmd.scan,
+	}
+}
+
+type buildcmd struct {
+	*commoncmd
+}
+
+func (b *buildcmd) scan(c *cli.Context) error {
+	b.commoncmd.scan(b.walker)
+	return nil
+}
+
+func (b *buildcmd) walker(path string, info os.FileInfo, err error) error {
+	walker(path, info, err, b.build)
+	return nil
+}
+
+// build will take the found valid function and build it
+func (b *buildcmd) build(path string) error {
+	fmt.Fprintln(b.verbwriter, "building", path)
+
+	ff, err := b.buildfunc(path)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Function %v built successfully.\n", ff.FullName())
+	return nil
+}