@@ -7,13 +7,13 @@ keywords = ["Examples, Usage, network, docker, documentation, user guide, multih

 parent = "smn_networking"

 weight=-3

 +++

-<![end-metadata]-->     

+<![end-metadata]-->

 # Get started with multi-host networking

 This article uses an example to explain the basics of creating a multi-host

-network. Docker Engine supports multi-host-networking out-of-the-box through the

-`overlay` network driver.  Unlike `bridge` networks overlay networks require

+network. Docker Engine supports multi-host networking out-of-the-box through the

+`overlay` network driver.  Unlike `bridge` networks, overlay networks require

 some pre-existing conditions before you can create one. These conditions are:

 * A host with a 3.16 kernel version or higher.

@@ -22,8 +22,8 @@ some pre-existing conditions before you can create one. These conditions are:

 * A properly configured Engine `daemon` on each host in the cluster.

 Though Docker Machine and Docker Swarm are not mandatory to experience Docker

-multi-host-networking, this example uses them to illustrate how they are

-integrated. You'll use Machine to create both the the key-value store

+multi-host networking, this example uses them to illustrate how they are

+integrated. You'll use Machine to create both the key-value store

 server and the host cluster. This example creates a Swarm cluster.

 ## Prerequisites

@@ -39,10 +39,10 @@ Machine to the latest versions.

 ## Step 1: Set up a key-value store

-An overlay network requires a key-value store. The key-value stores information

-about the network state which includes discovery, networks, endpoints,

-ip-addresses, and more. Docker supports Consul, Etcd, and ZooKeeper (Distributed

-store) key-value stores. This example uses Consul.

+An overlay network requires a key-value store. The key-value store holds

+information about the network state which includes discovery, networks,

+endpoints, IP addresses, and more. Docker supports Consul, Etcd, and ZooKeeper

+key-value stores. This example uses Consul.

 1. Log into a system prepared with the prerequisite Docker Engine, Docker Machine, and VirtualBox software.

@@ -62,9 +62,10 @@ store) key-value stores. This example uses Consul.

 			-h "consul" \

 			progrium/consul -server -bootstrap

-	 You passed the `docker run` command the connection configuration using a bash

-	 expansion `$(docker-machine config mh-keystore)`.  The client started a

-	 `progrium/consul` image running in the `mh-keystore` machine. The server is called `consul`and is listening port `8500`.

+	A bash expansion `$(docker-machine config mh-keystore)` is used to pass the

+	connection configuration to the `docker run` command.  The client starts a

+	`progrium/consul` image running in the `mh-keystore` machine. The server is

+	called `consul` and is listening on port `8500`.

 4. Set your local environment to the `mh-keystore` machine.

@@ -82,7 +83,7 @@ Keep your terminal open and move onto the next step.

 ## Step 2: Create a Swarm cluster

 In this step, you use `docker-machine` to provision the hosts for your network.

-At this point, you won't actually created the network. You'll create several

+At this point, you won't actually create the network. You'll create several

 machines in VirtualBox. One of the machines will act as the Swarm master;

 you'll create that first. As you create each host, you'll pass the Engine on

 that machine options that are needed by the `overlay` network driver.

@@ -91,7 +92,7 @@ that machine options that are needed by the `overlay` network driver.

 		$ docker-machine create \

 		-d virtualbox \

-		--swarm --swarm-image="swarm" --swarm-master \

+		--swarm --swarm-master \

 		--swarm-discovery="consul://$(docker-machine ip mh-keystore):8500" \

 		--engine-opt="cluster-store=consul://$(docker-machine ip mh-keystore):8500" \

 		--engine-opt="cluster-advertise=eth1:2376" \

@@ -102,7 +103,7 @@ that machine options that are needed by the `overlay` network driver.

 2. Create another host and add it to the Swarm cluster.

 		$ docker-machine create -d virtualbox \

-			--swarm --swarm-image="swarm" \

+			--swarm \

 			--swarm-discovery="consul://$(docker-machine ip mh-keystore):8500" \

 			--engine-opt="cluster-store=consul://$(docker-machine ip mh-keystore):8500" \

 			--engine-opt="cluster-advertise=eth1:2376" \

@@ -112,14 +113,13 @@ that machine options that are needed by the `overlay` network driver.

 		$ docker-machine ls

 		NAME         ACTIVE   DRIVER       STATE     URL                         SWARM

-		default               virtualbox   Running   tcp://192.168.99.100:2376   

-		mh-keystore           virtualbox   Running   tcp://192.168.99.103:2376   

-		mhs-demo0             virtualbox   Running   tcp://192.168.99.104:2376   mhs-demo0 (master)

-		mhs-demo1             virtualbox   Running   tcp://192.168.99.105:2376   mhs-demo0

+		default      -        virtualbox   Running   tcp://192.168.99.100:2376

+		mh-keystore  *        virtualbox   Running   tcp://192.168.99.103:2376

+		mhs-demo0    -        virtualbox   Running   tcp://192.168.99.104:2376   mhs-demo0 (master)

+		mhs-demo1    -        virtualbox   Running   tcp://192.168.99.105:2376   mhs-demo0

 At this point you have a set of hosts running on your network. You are ready to create a multi-host network for containers using these hosts.

-

 Leave your terminal open and go onto the next step.

 ## Step 3: Create the overlay Network

@@ -155,7 +155,7 @@ To create an overlay network

 		Total Memory: 2.043 GiB

 		Name: 30438ece0915

-	From this information, you can see that you are running three containers and 2 images on the Master.

+	From this information, you can see that you are running three containers and two images on the Master.

 3. Create your `overlay` network.

@@ -167,54 +167,51 @@ To create an overlay network

 		$ docker network ls

 		NETWORK ID          NAME                DRIVER

-		412c2496d0eb        mhs-demo1/host      host                

-		dd51763e6dd2        mhs-demo0/bridge    bridge              

-		6b07d0be843f        my-net              overlay             

-		b4234109bd9b        mhs-demo0/none      null                

-		1aeead6dd890        mhs-demo0/host      host                

-		d0bb78cbe7bd        mhs-demo1/bridge    bridge              

-		1c0eb8f69ebb        mhs-demo1/none      null     

+		412c2496d0eb        mhs-demo1/host      host

+		dd51763e6dd2        mhs-demo0/bridge    bridge

+		6b07d0be843f        my-net              overlay

+		b4234109bd9b        mhs-demo0/none      null

+		1aeead6dd890        mhs-demo0/host      host

+		d0bb78cbe7bd        mhs-demo1/bridge    bridge

+		1c0eb8f69ebb        mhs-demo1/none      null

-	Because you are in the Swarm master environment, you see all the networks on all Swarm agents. Notice that each `NETWORK ID` is unique.  The default networks on each engine and the single overlay network.  

+	As you are in the Swarm master environment, you see all the networks on all

+	the Swarm agents: the default networks on each engine and the single overlay

+	network. Notice that each `NETWORK ID` is unique.

-5. Switch to each Swarm agent in turn and list the network.

+5. Switch to each Swarm agent in turn and list the networks.

 		$ eval $(docker-machine env mhs-demo0)

 		$ docker network ls

 		NETWORK ID          NAME                DRIVER

-		6b07d0be843f        my-net              overlay             

-		dd51763e6dd2        bridge              bridge              

-		b4234109bd9b        none                null                

-		1aeead6dd890        host                host                

+		6b07d0be843f        my-net              overlay

+		dd51763e6dd2        bridge              bridge

+		b4234109bd9b        none                null

+		1aeead6dd890        host                host

 		$ eval $(docker-machine env mhs-demo1)

 		$ docker network ls

 		NETWORK ID          NAME                DRIVER

-		d0bb78cbe7bd        bridge              bridge              

-		1c0eb8f69ebb        none                null                

-		412c2496d0eb        host                host                

-		6b07d0be843f        my-net              overlay        

+		d0bb78cbe7bd        bridge              bridge

+		1c0eb8f69ebb        none                null

+		412c2496d0eb        host                host

+		6b07d0be843f        my-net              overlay

-  Both agents reports it has the `my-net `network with the `6b07d0be843f` id.  You have a multi-host container network running!

+  Both agents report they have the `my-net` network with the `6b07d0be843f` ID.

+	You now have a multi-host container network running!

 ##  Step 4: Run an application on your Network

 Once your network is created, you can start a container on any of the hosts and it automatically is part of the network.

-1. Point your environment to your `mhs-demo0` instance.

+1. Point your environment to the Swarm master.

-		$ eval $(docker-machine env mhs-demo0)

+		$ eval $(docker-machine env --swarm mhs-demo0)

-2. Start an Nginx server on `mhs-demo0`.

+2. Start an Nginx web server on the `mhs-demo0` instance.

 		$ docker run -itd --name=web --net=my-net --env="constraint:node==mhs-demo0" nginx

-	This command starts a web server on the Swarm master.

-

-3. Point your Machine environment to `mhs-demo1`

-

-		$ eval $(docker-machine env mhs-demo1)

-

-4. Run a Busybox instance and get the contents of the Ngnix server's home page.

+4. Run a BusyBox instance on the `mhs-demo1` instance and get the contents of the Nginx server's home page.

 		$ docker run -it --rm --net=my-net --env="constraint:node==mhs-demo1" busybox wget -O- http://web

 		Unable to find image 'busybox:latest' locally

@@ -284,7 +281,7 @@ to have external connectivity outside of their cluster.

 		412c2496d0eb        host                host

 		97102a22e8d2        docker_gwbridge     bridge

-2. Check the Ngnix container's network interfaces.

+2. Check the Nginx container's network interfaces.

 		$ docker exec web ip addr

 		1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default

@@ -314,9 +311,11 @@ to have external connectivity outside of their cluster.

 You can try starting a second network on your existing Swarm cluster using Docker Compose.

-1. Log into the Swarm master.

+1. If you haven't already, install Docker Compose.

-2. Install Docker Compose.

+2. Change your environment to the Swarm master.

+

+		$ eval $(docker-machine env --swarm mhs-demo0)

 3. Create a `docker-compose.yml` file.

@@ -336,7 +335,15 @@ You can try starting a second network on your existing Swarm cluster using Docke

 6. Start the application with Compose.

-		$ docker-compose --x-networking up -d

+		$ docker-compose --x-networking --project-name=counter up -d

+

+7. Get the Swarm master's IP address.

+

+		$ docker-machine ip mhs-demo0

+

+8. Put the IP address into your web browser.

+

+	Upon success, the browser should display the web application.

 ## Related information