Merge pull request #42 from dyweb/example/udash/docker-log-exec

[Partial][example][ui] Udash docker log and exec

- implemented docker log in client and dk cli #40 , it has a package for deduplex stream (stdout, stderr)
- implemented docker exec in client and dk cli #41 , need to create a new connection manually and read the response (I actually don't need to get http client's transport, I can keep the original addr and dial it directly, need a dedicated tcp connection anyway)
- implemented web terminal using xterm and gorillawebsocket #46 , it's tricky if you don't understand all the pty stuff, most examples didn't say that (maybe it's too obvious?), when use pty, you have echo for what you type, so you won't see anything when type in xterm and when it attach to socket it will send each character as a single message, and you don't need to do any buffering on server side (pty will do that), same applies to stdout, you just copy what you read and write to websocket connection (I xterm might did some buffer on that). The gorilla example was for some one off command and submit the entire command in a web form so it adds `\n` when write to pty stdin and buffer output using bufio

Gopkg.toml

@@ -31,7 +31,7 @@ ignored = [
 # NOTE: we lock gommon version because dep will use lastest release but gommon is adding new features when go.ice need it ...
 [[constraint]]
   name = "github.com/dyweb/gommon"
-  branch = "master"
+  branch = "errors/types"
 
 [[constraint]]
   name = "github.com/go-sql-driver/mysql"

cli/pkg.go

@@ -1,2 +1,5 @@
 // Package cli provides wrapper around spf13/cobra so test is easier
 package cli
+
+type Command interface {
+}

cmd/dk/main.go

@@ -3,25 +3,32 @@ package main
 
 import (
 	"context"
-	"log"
+	"io"
+	"os"
+	"strconv"
 
 	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/pkg/stdcopy"
+	dlog "github.com/dyweb/gommon/log"
+	"github.com/olekukonko/tablewriter"
 
 	"github.com/dyweb/go.ice/lib/dockerclient"
 )
 
 // TODO: start using cobra for handling sub commands
+// TODO: support output like kubectl
+var log, logReg = dlog.NewApplicationLoggerAndRegistry("dk")
 
 func main() {
 	//version()
-	images()
+	//images()
+	//containers()
+	//containerLog(os.Args[1])
+	containerExec(os.Args[1])
 }
 
 func ping() {
-	c, err := dockerclient.New("/var/run/docker.sock")
-	if err != nil {
-		log.Fatal(err)
-	}
+	c := cli()
 	p, err := c.Ping()
 	if err != nil {
 		log.Fatal(err)
@@ -30,10 +37,7 @@ func ping() {
 }
 
 func version() {
-	c, err := dockerclient.New("/var/run/docker.sock")
-	if err != nil {
-		log.Fatal(err)
-	}
+	c := cli()
 	p, err := c.Version()
 	if err != nil {
 		log.Fatal(err)
@@ -53,6 +57,86 @@ func images() {
 	log.Printf("%d images", len(images))
 }
 
+func containers() {
+	c := cli()
+	containers, err := c.ContainerList(context.Background(), types.ContainerListOptions{
+		All: true,
+	})
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
+	log.Infof("total %d containers", len(containers))
+	// TODO: print as table
+	table := tablewriter.NewWriter(os.Stdout)
+	table.SetHeader([]string{"#", "id", "status", "image"})
+	for i, c := range containers {
+		table.Append([]string{
+			strconv.Itoa(i),
+			c.ID,
+			c.Status,
+			c.Image,
+		})
+	}
+	table.Render()
+}
+
+// https://docs.docker.com/engine/reference/commandline/logs/#options
+func containerLog(container string) {
+	c := cli()
+	res, err := c.ContainerLog(context.Background(), container, types.ContainerLogsOptions{
+		ShowStdout: true,
+		ShowStderr: true,
+		Timestamps: true,
+		Follow:     true,
+		Tail:       "100",
+		Details:    true,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	// https://github.com/docker/cli/blob/master/cli/command/container/logs.go
+	// NOTE: using StdCopy will remove the 8 bytes multiplex header ...
+	// TODO: the time in container is in different timezone by default, also docker timestamp seems to be using UTC?
+	// actually it's not supported https://github.com/moby/moby/issues/33778
+	stdcopy.StdCopy(os.Stdout, os.Stderr, res)
+	//io.Copy(os.Stdout, res)
+}
+
+func containerExec(container string) {
+	cfg := types.ExecConfig{
+		Tty:          true,
+		Cmd:          []string{"/bin/sh"},
+		Detach:       false,
+		AttachStdout: true,
+		AttachStderr: true,
+		AttachStdin:  true,
+	}
+	c := cli()
+	res, err := c.ContainerExecCreate(context.Background(), container, cfg)
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
+	log.Infof("exec id is %s", res.ID)
+	conn, err := c.ContainerExecAttach(context.Background(), res.ID, types.ExecStartCheck{
+		Detach: false,
+		Tty:    true,
+	})
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
+	go func() {
+		if _, err := io.Copy(os.Stdout, conn); err != nil {
+			log.Warnf("err copy conn to stdout: %s", err)
+		}
+	}()
+	if _, err := io.Copy(conn, os.Stdin); err != nil {
+		log.Fatalf("err copy stdin to conn: %s", err)
+	}
+}
+
 func cli() *dockerclient.Client {
 	c, err := dockerclient.New("/var/run/docker.sock")
 	if err != nil {

doc/design/cli.md

@@ -0,0 +1 @@
+# Cli