Require listen address and advertise address to be an IP address or an interface name

Hostnames are not supported for now because libnetwork can't use them
for overlay networking yet.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>

api/client/swarm/init.go

@@ -44,8 +44,8 @@ func newInitCommand(dockerCli *client.DockerCli) *cobra.Command {
 	}
 
 	flags := cmd.Flags()
-	flags.Var(&opts.listenAddr, flagListenAddr, "Listen address (format: <ip|hostname|interface>[:port])")
+	flags.Var(&opts.listenAddr, flagListenAddr, "Listen address (format: <ip|interface>[:port])")
-	flags.StringVar(&opts.advertiseAddr, flagAdvertiseAddr, "", "Advertised address (format: <ip|hostname|interface>[:port])")
+	flags.StringVar(&opts.advertiseAddr, flagAdvertiseAddr, "", "Advertised address (format: <ip|interface>[:port])")
 	flags.BoolVar(&opts.forceNewCluster, "force-new-cluster", false, "Force create a new cluster from current state.")
 	addSwarmFlags(flags, &opts.swarmOptions)
 	return cmd

api/client/swarm/join.go

@@ -35,8 +35,8 @@ func newJoinCommand(dockerCli *client.DockerCli) *cobra.Command {
 	}
 
 	flags := cmd.Flags()
-	flags.Var(&opts.listenAddr, flagListenAddr, "Listen address (format: <ip|hostname|interface>[:port])")
+	flags.Var(&opts.listenAddr, flagListenAddr, "Listen address (format: <ip|interface>[:port])")
-	flags.StringVar(&opts.advertiseAddr, flagAdvertiseAddr, "", "Advertised address (format: <ip|hostname|interface>[:port])")
+	flags.StringVar(&opts.advertiseAddr, flagAdvertiseAddr, "", "Advertised address (format: <ip|interface>[:port])")
 	flags.StringVar(&opts.token, flagToken, "", "Token for entry into the swarm")
 	return cmd
 }

daemon/cluster/listen_addr.go

@@ -7,10 +7,13 @@ import (
 )
 
 var (
-	errNoSuchInterface       = errors.New("no such interface")
+	errNoSuchInterface         = errors.New("no such interface")
-	errMultipleIPs           = errors.New("could not choose an IP address to advertise since this system has multiple addresses")
+	errMultipleIPs             = errors.New("could not choose an IP address to advertise since this system has multiple addresses")
-	errNoIP                  = errors.New("could not find the system's IP address")
+	errNoIP                    = errors.New("could not find the system's IP address")
-	errMustSpecifyListenAddr = errors.New("must specify a listening address because the address to advertise is not recognized as a system address")
+	errMustSpecifyListenAddr   = errors.New("must specify a listening address because the address to advertise is not recognized as a system address")
+	errBadListenAddr           = errors.New("listen address must be an IP address or network interface (with optional port number)")
+	errBadAdvertiseAddr        = errors.New("advertise address must be an IP address or network interface (with optional port number)")
+	errBadDefaultAdvertiseAddr = errors.New("default advertise address must be an IP address or network interface (without a port number)")
 )
 
 func resolveListenAddr(specifiedAddr string) (string, string, error) {
@@ -29,6 +32,11 @@ func resolveListenAddr(specifiedAddr string) (string, string, error) {
 		return "", "", err
 	}
 
+	// If it's not an interface, it must be an IP (for now)
+	if net.ParseIP(specifiedHost) == nil {
+		return "", "", errBadListenAddr
+	}
+
 	return specifiedHost, specifiedPort, nil
 }
 
@@ -61,6 +69,11 @@ func (c *Cluster) resolveAdvertiseAddr(advertiseAddr, listenAddrPort string) (st
 			return "", "", err
 		}
 
+		// If it's not an interface, it must be an IP (for now)
+		if net.ParseIP(advertiseHost) == nil {
+			return "", "", errBadAdvertiseAddr
+		}
+
 		return advertiseHost, advertisePort, nil
 	}
 
@@ -76,6 +89,11 @@ func (c *Cluster) resolveAdvertiseAddr(advertiseAddr, listenAddrPort string) (st
 			return "", "", err
 		}
 
+		// If it's not an interface, it must be an IP (for now)
+		if net.ParseIP(c.config.DefaultAdvertiseAddr) == nil {
+			return "", "", errBadDefaultAdvertiseAddr
+		}
+
 		return c.config.DefaultAdvertiseAddr, listenAddrPort, nil
 	}
 

docs/reference/api/docker_remote_api_v1.24.md

@@ -3591,6 +3591,7 @@ Initialize a new Swarm
 
     {
       "ListenAddr": "0.0.0.0:4500",
+      "AdvertiseAddr": "192.168.1.1:4500",
       "ForceNewCluster": false,
       "Spec": {
         "Orchestration": {},
@@ -3619,6 +3620,11 @@ JSON Parameters:
   address/port combination in the form `192.168.1.1:4567`, or an interface followed by a port
   number, like `eth0:4567`. If the port number is omitted, the default swarm listening port is
   used.
+- **AdvertiseAddr** – Externally reachable address advertised to other nodes. This can either be
+  an address/port combination in the form `192.168.1.1:4567`, or an interface followed by a port
+  number, like `eth0:4567`. If the port number is omitted, the port number from the listen
+  address is used. If `AdvertiseAddr` is not specified, it will be automatically detected when
+  possible.
 - **ForceNewCluster** – Force creating a new Swarm even if already part of one.
 - **Spec** – Configuration settings of the new Swarm.
     - **Orchestration** – Configuration settings for the orchestration aspects of the Swarm.
@@ -3659,6 +3665,7 @@ Join an existing new Swarm
 
     {
       "ListenAddr": "0.0.0.0:4500",
+      "AdvertiseAddr: "192.168.1.1:4500",
       "RemoteAddrs": ["node1:4500"],
       "JoinToken": "SWMTKN-1-3pu6hszjas19xyp7ghgosyx9k8atbfcr8p2is99znpy26u2lkl-7p73s1dx5in4tatdymyhg9hu2"
     }
@@ -3679,6 +3686,11 @@ JSON Parameters:
 
 - **ListenAddr** – Listen address used for inter-manager communication if the node gets promoted to
   manager, as well as determining the networking interface used for the VXLAN Tunnel Endpoint (VTEP).
+- **AdvertiseAddr** – Externally reachable address advertised to other nodes. This can either be
+  an address/port combination in the form `192.168.1.1:4567`, or an interface followed by a port
+  number, like `eth0:4567`. If the port number is omitted, the port number from the listen
+  address is used. If `AdvertiseAddr` is not specified, it will be automatically detected when
+  possible.
 - **RemoteAddr** – Address of any manager node already participating in the Swarm to join.
 - **JoinToken** – Secret token for joining this Swarm.
 

docs/reference/api/docker_remote_api_v1.25.md

@@ -3592,6 +3592,7 @@ Initialize a new Swarm
 
     {
       "ListenAddr": "0.0.0.0:4500",
+      "AdvertiseAddr": "192.168.1.1:4500",
       "ForceNewCluster": false,
       "Spec": {
         "Orchestration": {},
@@ -3620,6 +3621,11 @@ JSON Parameters:
   address/port combination in the form `192.168.1.1:4567`, or an interface followed by a port
   number, like `eth0:4567`. If the port number is omitted, the default swarm listening port is
   used.
+- **AdvertiseAddr** – Externally reachable address advertised to other nodes. This can either be
+  an address/port combination in the form `192.168.1.1:4567`, or an interface followed by a port
+  number, like `eth0:4567`. If the port number is omitted, the port number from the listen
+  address is used. If `AdvertiseAddr` is not specified, it will be automatically detected when
+  possible.
 - **ForceNewCluster** – Force creating a new Swarm even if already part of one.
 - **Spec** – Configuration settings of the new Swarm.
     - **Orchestration** – Configuration settings for the orchestration aspects of the Swarm.
@@ -3660,6 +3666,7 @@ Join an existing new Swarm
 
     {
       "ListenAddr": "0.0.0.0:4500",
+      "AdvertiseAddr": "192.168.1.1:4500",
       "RemoteAddrs": ["node1:4500"],
       "JoinToken": "SWMTKN-1-3pu6hszjas19xyp7ghgosyx9k8atbfcr8p2is99znpy26u2lkl-7p73s1dx5in4tatdymyhg9hu2"
     }
@@ -3680,6 +3687,11 @@ JSON Parameters:
 
 - **ListenAddr** – Listen address used for inter-manager communication if the node gets promoted to
   manager, as well as determining the networking interface used for the VXLAN Tunnel Endpoint (VTEP).
+- **AdvertiseAddr** – Externally reachable address advertised to other nodes. This can either be
+  an address/port combination in the form `192.168.1.1:4567`, or an interface followed by a port
+  number, like `eth0:4567`. If the port number is omitted, the port number from the listen
+  address is used. If `AdvertiseAddr` is not specified, it will be automatically detected when
+  possible.
 - **RemoteAddr** – Address of any manager node already participating in the Swarm to join.
 - **JoinToken** – Secret token for joining this Swarm.
 

docs/reference/commandline/swarm_init.md

@@ -17,13 +17,13 @@ Usage:  docker swarm init [OPTIONS]
 Initialize a swarm
 
 Options:
-      --advertise-addr value            Advertised address (format: <ip|hostname|interface>[:port])
+      --advertise-addr value            Advertised address (format: <ip|interface>[:port])
       --cert-expiry duration            Validity period for node certificates (default 2160h0m0s)
       --dispatcher-heartbeat duration   Dispatcher heartbeat period (default 5s)
       --external-ca value               Specifications of one or more certificate signing endpoints
       --force-new-cluster               Force create a new cluster from current state.
       --help                            Print usage
-      --listen-addr value               Listen address (format: <ip|hostname|interface>[:port])
+      --listen-addr value               Listen address (format: <ip|interface>[:port])
       --task-history-limit int          Task history retention limit (default 5)
 ```
 
@@ -79,7 +79,7 @@ The node listens for inbound Swarm manager traffic on this address. The default
 0.0.0.0:2377. It is also possible to specify a network interface to listen on that interface's
 address; for example `--listen-addr eth0:2377`.
 
-Specifying a port is optional. If the value is a bare IP address, hostname, or interface
+Specifying a port is optional. If the value is a bare IP address or interface
 name, the default port 2377 will be used.
 
 ### `--advertise-addr value`
@@ -94,7 +94,7 @@ inter-manager communication and overlay networking.
 It is also possible to specify a network interface to advertise that interface's address;
 for example `--advertise-addr eth0:2377`.
 
-Specifying a port is optional. If the value is a bare IP address, hostname, or interface
+Specifying a port is optional. If the value is a bare IP address or interface
 name, the default port 2377 will be used.
 
 ### `--task-history-limit`

docs/reference/commandline/swarm_join.md

@@ -17,9 +17,9 @@ Usage:  docker swarm join [OPTIONS] HOST:PORT
 Join a swarm as a node and/or manager
 
 Options:
-      --advertise-addr value   Advertised address (format: <ip|hostname|interface>[:port])
+      --advertise-addr value   Advertised address (format: <ip|interface>[:port])
       --help                   Print usage
-      --listen-addr value      Listen address
+      --listen-addr value      Listen address (format: <ip|interface>[:port)
       --token string           Token for entry into the swarm
 ```
 
@@ -64,7 +64,7 @@ If the node is a manager, it will listen for inbound Swarm manager traffic on th
 address. The default is to listen on 0.0.0.0:2377. It is also possible to specify a
 network interface to listen on that interface's address; for example `--listen-addr eth0:2377`.
 
-Specifying a port is optional. If the value is a bare IP address, hostname, or interface
+Specifying a port is optional. If the value is a bare IP address, or interface
 name, the default port 2377 will be used.
 
 This flag is generally not necessary when joining an existing swarm.
@@ -81,7 +81,7 @@ communication and overlay networking.
 It is also possible to specify a network interface to advertise that interface's address;
 for example `--advertise-addr eth0:2377`.
 
-Specifying a port is optional. If the value is a bare IP address, hostname, or interface
+Specifying a port is optional. If the value is a bare IP address, or interface
 name, the default port 2377 will be used.
 
 This flag is generally not necessary when joining an existing swarm.

man/dockerd.8.md

@@ -55,7 +55,7 @@ dockerd - Enable daemon mode
 [**-s**|**--storage-driver**[=*STORAGE-DRIVER*]]
 [**--selinux-enabled**]
 [**--storage-opt**[=*[]*]]
-[**--swarm-default-advertise-addr**[=*IP|HOSTNAME|INTERFACE*]]
+[**--swarm-default-advertise-addr**[=*IP|INTERFACE*]]
 [**--tls**]
 [**--tlscacert**[=*~/.docker/ca.pem*]]
 [**--tlscert**[=*~/.docker/cert.pem*]]
@@ -240,7 +240,7 @@ output otherwise.
 **--storage-opt**=[]
   Set storage driver options. See STORAGE DRIVER OPTIONS.
 
-**--swarm-default-advertise-addr**=*IP|HOSTNAME|INTERFACE*
+**--swarm-default-advertise-addr**=*IP|INTERFACE*
   Set default address or interface for swarm to advertise as its externally-reachable address to other cluster
   members. This can be a hostname, an IP address, or an interface such as `eth0`. A port cannot be specified with
   this option.