ctr: move resolver to commands package

Signed-off-by: Jess Valarezo <valarezo.jessica@gmail.com>

cmd/ctr/commands/resolver.go

@@ -0,0 +1,92 @@
+package commands
+
+import (
+	"bufio"
+	gocontext "context"
+	"crypto/tls"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/containerd/console"
+	"github.com/containerd/containerd/remotes"
+	"github.com/containerd/containerd/remotes/docker"
+	"github.com/pkg/errors"
+	"github.com/urfave/cli"
+)
+
+// PushTracker returns a new InMemoryTracker which tracks the ref status
+var PushTracker = docker.NewInMemoryTracker()
+
+func passwordPrompt() (string, error) {
+	c := console.Current()
+	defer c.Reset()
+
+	if err := c.DisableEcho(); err != nil {
+		return "", errors.Wrap(err, "failed to disable echo")
+	}
+
+	line, _, err := bufio.NewReader(c).ReadLine()
+	if err != nil {
+		return "", errors.Wrap(err, "failed to read line")
+	}
+	return string(line), nil
+}
+
+// GetResolver prepares the resolver from the environment and options
+func GetResolver(ctx gocontext.Context, clicontext *cli.Context) (remotes.Resolver, error) {
+	username := clicontext.String("user")
+	var secret string
+	if i := strings.IndexByte(username, ':'); i > 0 {
+		secret = username[i+1:]
+		username = username[0:i]
+	}
+	options := docker.ResolverOptions{
+		PlainHTTP: clicontext.Bool("plain-http"),
+		Tracker:   PushTracker,
+	}
+	if username != "" {
+		if secret == "" {
+			fmt.Printf("Password: ")
+
+			var err error
+			secret, err = passwordPrompt()
+			if err != nil {
+				return nil, err
+			}
+
+			fmt.Print("\n")
+		}
+	} else if rt := clicontext.String("refresh"); rt != "" {
+		secret = rt
+	}
+
+	options.Credentials = func(host string) (string, string, error) {
+		// Only one host
+		return username, secret, nil
+	}
+
+	tr := &http.Transport{
+		Proxy: http.ProxyFromEnvironment,
+		DialContext: (&net.Dialer{
+			Timeout:   30 * time.Second,
+			KeepAlive: 30 * time.Second,
+			DualStack: true,
+		}).DialContext,
+		MaxIdleConns:        10,
+		IdleConnTimeout:     30 * time.Second,
+		TLSHandshakeTimeout: 10 * time.Second,
+		TLSClientConfig: &tls.Config{
+			InsecureSkipVerify: clicontext.Bool("insecure"),
+		},
+		ExpectContinueTimeout: 5 * time.Second,
+	}
+
+	options.Client = &http.Client{
+		Transport: tr,
+	}
+
+	return docker.NewResolver(options), nil
+}