fn: rename from fnctl (#321)

* fn: rename from fnctl

* fn: predicting the release version for installer

* fn: predicting the release version for installer

fn/run.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/urfave/cli"
+)
+
+func run() cli.Command {
+	r := runCmd{}
+
+	return cli.Command{
+		Name:      "run",
+		Usage:     "run a function locally",
+		ArgsUsage: "USERNAME/image:tag",
+		Flags:     append(runflags(), []cli.Flag{}...),
+		Action:    r.run,
+	}
+}
+
+type runCmd struct{}
+
+func runflags() []cli.Flag {
+	return []cli.Flag{
+		cli.StringSliceFlag{
+			Name:  "e",
+			Usage: "limit the environment variables sent to function, if ommited then all are sent.",
+		},
+	}
+}
+
+func (r *runCmd) run(c *cli.Context) error {
+	image := c.Args().First()
+	if image == "" {
+		ff, err := findFuncfile()
+		if err != nil {
+			if _, ok := err.(*notFoundError); ok {
+				return errors.New("error: image name is missing or no function file found")
+			}
+			return err
+		}
+		image = ff.FullName()
+	}
+
+	sh := []string{"docker", "run", "--rm", "-i"}
+
+	var env []string
+	detectedEnv := os.Environ()
+	if se := c.StringSlice("e"); len(se) > 0 {
+		detectedEnv = se
+	}
+
+	for _, e := range detectedEnv {
+		shellvar, envvar := extractEnvVar(e)
+		sh = append(sh, shellvar...)
+		env = append(env, envvar)
+	}
+
+	dockerenv := []string{"DOCKER_TLS_VERIFY", "DOCKER_HOST", "DOCKER_CERT_PATH", "DOCKER_MACHINE_NAME"}
+	for _, e := range dockerenv {
+		env = append(env, fmt.Sprint(e, "=", os.Getenv(e)))
+	}
+
+	sh = append(sh, image)
+	cmd := exec.Command(sh[0], sh[1:]...)
+	// Check if stdin is being piped, and if not, create our own pipe with nothing in it
+	// http://stackoverflow.com/questions/22744443/check-if-there-is-something-to-read-on-stdin-in-golang
+	stat, err := os.Stdin.Stat()
+	if err != nil {
+		// On Windows, this gets an error if nothing is piped in.
+		// If something is piped in, it works fine.
+		// Turns out, this works just fine in our case as the piped stuff works properly and the non-piped doesn't hang either.
+		// See: https://github.com/golang/go/issues/14853#issuecomment-260170423
+		// log.Println("Warning: couldn't stat stdin, you are probably on Windows. Be sure to pipe something into this command, eg: 'echo \"hello\" | fn run'")
+	} else {
+		if (stat.Mode() & os.ModeCharDevice) == 0 {
+			// log.Println("data is being piped to stdin")
+			cmd.Stdin = os.Stdin
+		} else {
+			// log.Println("stdin is from a terminal")
+			cmd.Stdin = strings.NewReader("")
+		}
+	}
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Env = env
+	return cmd.Run()
+}
+
+func extractEnvVar(e string) ([]string, string) {
+	kv := strings.Split(e, "=")
+	name := toEnvName("HEADER", kv[0])
+	sh := []string{"-e", name}
+	env := fmt.Sprintf("%s=%s", name, os.Getenv(kv[0]))
+	return sh, env
+}
+
+// From server.toEnvName()
+func toEnvName(envtype, name string) string {
+	name = strings.ToUpper(strings.Replace(name, "-", "_", -1))
+	return fmt.Sprintf("%s_%s", envtype, name)
+}