Merge pull request #21641 from yongtang/21595-discrepancy-on-hostname-validation

API/CLI discrepancy on hostname validation (#21595).

daemon/daemon.go

@@ -13,6 +13,7 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"regexp"
 	"runtime"
 	"strings"
 	"sync"
@@ -1332,6 +1333,18 @@ func (daemon *Daemon) verifyContainerSettings(hostConfig *containertypes.HostCon
 				return nil, err
 			}
 		}
+
+		// Validate if the given hostname is RFC 1123 (https://tools.ietf.org/html/rfc1123) compliant.
+		if len(config.Hostname) > 0 {
+			// RFC1123 specifies that 63 bytes is the maximium length
+			// Windows has the limitation of 63 bytes in length
+			// Linux hostname is limited to HOST_NAME_MAX=64, not not including the terminating null byte.
+			// We limit the length to 63 bytes here to match RFC1035 and RFC1123.
+			matched, _ := regexp.MatchString("^(([[:alnum:]]|[[:alnum:]][[:alnum:]\\-]*[[:alnum:]])\\.)*([[:alnum:]]|[[:alnum:]][[:alnum:]\\-]*[[:alnum:]])$", config.Hostname)
+			if len(config.Hostname) > 63 || !matched {
+				return nil, fmt.Errorf("invalid hostname format: %s", config.Hostname)
+			}
+		}
 	}
 
 	if hostConfig == nil {

integration-cli/docker_cli_run_test.go

@@ -4295,15 +4295,33 @@ func (s *DockerSuite) TestRunTooLongHostname(c *check.C) {
 	hostname1 := "this-is-a-way-too-long-hostname-but-it-should-give-a-nice-error.local"
 	out, _, err := dockerCmdWithError("run", "--hostname", hostname1, "busybox", "echo", "test")
 	c.Assert(err, checker.NotNil, check.Commentf("Expected docker run to fail!"))
-	c.Assert(out, checker.Contains, "invalid hostname format for --hostname:", check.Commentf("Expected to have 'invalid hostname format for --hostname:' in the output, get: %s!", out))
+	c.Assert(out, checker.Contains, "invalid hostname format:", check.Commentf("Expected to have 'invalid hostname format:' in the output, get: %s!", out))
 
-	// HOST_NAME_MAX=64 so 65 bytes will fail
-	hostname2 := "this-is-a-hostname-with-65-bytes-so-it-should-give-an-error.local"
-	out, _, err = dockerCmdWithError("run", "--hostname", hostname2, "busybox", "echo", "test")
-	c.Assert(err, checker.NotNil, check.Commentf("Expected docker run to fail!"))
-	c.Assert(out, checker.Contains, "invalid hostname format for --hostname:", check.Commentf("Expected to have 'invalid hostname format for --hostname:' in the output, get: %s!", out))
+	// Addtional test cases
+	validHostnames := map[string]string{
+		"hostname":    "hostname",
+		"host-name":   "host-name",
+		"hostname123": "hostname123",
+		"123hostname": "123hostname",
+		"hostname-of-63-bytes-long-should-be-valid-and-without-any-error": "hostname-of-63-bytes-long-should-be-valid-and-without-any-error",
+	}
+	for hostname := range validHostnames {
+		dockerCmd(c, "run", "--hostname", hostname, "busybox", "echo", "test")
+	}
 
-	// 64 bytes will be OK
-	hostname3 := "this-is-a-hostname-with-64-bytes-so-will-not-give-an-error.local"
-	dockerCmd(c, "run", "--hostname", hostname3, "busybox", "echo", "test")
+	invalidHostnames := map[string]string{
+		"^hostname": "invalid hostname format: ^hostname",
+		"hostname%": "invalid hostname format: hostname%",
+		"host&name": "invalid hostname format: host&name",
+		"-hostname": "invalid hostname format: -hostname",
+		"host_name": "invalid hostname format: host_name",
+		"hostname-of-64-bytes-long-should-be-invalid-and-be-with-an-error": "invalid hostname format: hostname-of-64-bytes-long-should-be-invalid-and-be-with-an-error",
+	}
+
+	for hostname, expectedError := range invalidHostnames {
+		out, _, err = dockerCmdWithError("run", "--hostname", hostname, "busybox", "echo", "test")
+		c.Assert(err, checker.NotNil, check.Commentf("Expected docker run to fail!"))
+		c.Assert(out, checker.Contains, expectedError, check.Commentf("Expected to have '%s' in the output, get: %s!", expectedError, out))
+
+	}
 }

runconfig/opts/parse.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"path"
-	"regexp"
 	"strconv"
 	"strings"
 
@@ -260,15 +259,6 @@ func Parse(cmd *flag.FlagSet, args []string) (*container.Config, *container.Host
 	if *flEntrypoint != "" {
 		entrypoint = strslice.StrSlice{*flEntrypoint}
 	}
-	// Validate if the given hostname is RFC 1123 (https://tools.ietf.org/html/rfc1123) compliant.
-	hostname := *flHostname
-	if hostname != "" {
-		// Linux hostname is limited to HOST_NAME_MAX=64, not including the terminating null byte.
-		matched, _ := regexp.MatchString("^(([[:alnum:]]|[[:alnum:]][[:alnum:]\\-]*[[:alnum:]])\\.)*([[:alnum:]]|[[:alnum:]][[:alnum:]\\-]*[[:alnum:]])$", hostname)
-		if len(hostname) > 64 || !matched {
-			return nil, nil, nil, cmd, fmt.Errorf("invalid hostname format for --hostname: %s", hostname)
-		}
-	}
 
 	ports, portBindings, err := nat.ParsePortSpecs(flPublish.GetAll())
 	if err != nil {

runconfig/opts/parse_test.go

@@ -390,15 +390,7 @@ func TestParseHostname(t *testing.T) {
 		"host-name":   "host-name",
 		"hostname123": "hostname123",
 		"123hostname": "123hostname",
-		"hostname-of-64-bytes-long-should-be-valid-and-without-any-errors": "hostname-of-64-bytes-long-should-be-valid-and-without-any-errors",
-	}
-	invalidHostnames := map[string]string{
-		"^hostname": "invalid hostname format for --hostname: ^hostname",
-		"hostname%": "invalid hostname format for --hostname: hostname%",
-		"host&name": "invalid hostname format for --hostname: host&name",
-		"-hostname": "invalid hostname format for --hostname: -hostname",
-		"host_name": "invalid hostname format for --hostname: host_name",
-		"hostname-of-65-bytes-long-should-be-invalid-and-be-given-an-error": "invalid hostname format for --hostname: hostname-of-65-bytes-long-should-be-invalid-and-be-given-an-error",
+		"hostname-of-63-bytes-long-should-be-valid-and-without-any-error": "hostname-of-63-bytes-long-should-be-valid-and-without-any-error",
 	}
 	hostnameWithDomain := "--hostname=hostname.domainname"
 	hostnameWithDomainTld := "--hostname=hostname.domainname.tld"
@@ -407,11 +399,6 @@ func TestParseHostname(t *testing.T) {
 			t.Fatalf("Expected the config to have 'hostname' as hostname, got '%v'", config.Hostname)
 		}
 	}
-	for hostname, expectedError := range invalidHostnames {
-		if _, _, err := parse(t, fmt.Sprintf("--hostname=%s", hostname)); err == nil || err.Error() != expectedError {
-			t.Fatalf("Expected error '%v' with '--hostname=%s', got '%s'", expectedError, hostname, err)
-		}
-	}
 	if config, _ := mustParse(t, hostnameWithDomain); config.Hostname != "hostname.domainname" && config.Domainname != "" {
 		t.Fatalf("Expected the config to have 'hostname' as hostname.domainname, got '%v'", config.Hostname)
 	}