Docker 17.06.0-ce-RC5 got announced 5 days back and is available for testing. It brings numerous new features & enablements under this new upcoming release. Few of my favourites includes support for Secrets on Windows, allows specifying a secret location within the container, adds
--format option to docker system df command, adds support for placement preference to docker stack deploy, adds monitored resource type metadata for GCP logging driver and adding build & engine info prometheus metrics to list a few. But one of the notable and most awaited feature include support of swarm-mode services with node-local networks such as macvlan, ipvlan, bridge and host.
Under the new upcoming 17.06 release, Docker provides support for local scope networks in Swarm. This includes any local scope network driver. Some examples of these are
macvlan though any local scope network driver, built-in or plug-in, will work with Swarm. Previously only swarm scope networks like
overlay were supported. This is a great news for all Docker Networking enthusiasts.
A Brief Intro to MacVLAN:
In case you’re new , the MACVLAN driver provides direct access between containers and the physical network. It also allows containers to receive routable IP addresses that are on the subnet of the physical network.
MACVLAN offers a number of unique features and capabilities. It has positive performance implications by virtue of having a very simple and lightweight architecture. It’s use cases includes very low latency applications and networking design that requires containers be on the same subnet as and using IPs as the external host network.The
macvlan driver uses the concept of a parent interface. This interface can be a physical interface such as
eth0, a sub-interface for 802.1q VLAN tagging like
VLAN 10), or even a bonded host adaptor which bundles two Ethernet interfaces into a single logical interface.
To test-drive MacVLAN under Swarm Mode, I will leverage the existing 3 node Swarm Mode clusters on my VMware ESXi system. I have tested it on bare metal system and VirtualBox and it works equally great.[Updated: 9/27/2017 – I have added docker-stack.yml at the end of this guide to show you how to build services out of docker-compose.yml file. DO NOT FORGET TO CHECK IT OUT]
Installing Docker 17.06 on all the Nodes:[simterm]
$curl -fsSL https://test.docker.com > install-docker.sh
Verifying the latest Docker version:
Setting up 2 Node Swarm Mode Cluster:
Attention VirtualBox Users: – In case you are using VirtualBox, the MACVLAN driver requires the network and interfaces to be in promiscuous mode.
A local network config is created on each host. The config holds host-specific information, such as the subnet allocated for this host’s containers.
--ip-range is used to specify a pool of IP addresses that is a subset of IPs from the subnet. This is one method of IPAM to guarantee unique IP allocations.
manager1==>sudo docker network create --config-only --subnet 100.98.26.0/24 -o parent=ens160.60 --ip-range 100.98.26.100/24 collabnet[/simterm]
worker1==>sudo docker network create --config-only --subnet 100.98.26.0/24 -o parent=ens160.60 --ip-range 100.98.26.100/24 collabnet[/simterm]
Instantiating the macvlan network globally
manager1==> $sudo docker network create -d macvlan --scope swarm --config-from collabnet swarm-macvlan[/simterm]
Deploying a service to the swarm-macvlan network:
Let us go ahead and deploy WordPress application. We will be creating 2 services – wordpressapp and wordpressdb1 and attach it to “swarm-macvlan” network as shown below:
Creating Backend Service:[simterm]
$docker service create –replicas 1 –name wordpressdb1 –network swarm-macvlan –env MYSQL_ROOT_PASSWORD=collab123 –env MYSQL_DATABASE=wordpress mysql[/simterm]
Let us verify if MacVLAN network scope holds this container:
Creating Frontend Service
Next, it’s time to create wordpress application i.e. wordpressapp[simterm]
#docker service create –env WORDPRESS_DB_HOST=wordpressdb1 –env WORDPRESS_DB_PASSWORD=collab123 –network swarm-macvlan –replicas 4 –name wordpressapp –publish 80:80/tcp wordpress:latest[/simterm]
Verify if both the services are up and running:
Verifying if all the containers on the master node picks up desired IP address from the subnet:
Docker Compose File showcasing MacVLAN Configuration
Ensure that you run the below commands to setup MacVLAN configuration for your services before you execute the above docker stack deploy CLI:[simterm]
root@ubuntu-1610:~# docker network create –config-only –subnet 100.98.26.0/24 –gateway 100.98.26.1 -o parent=ens160.60 –ip-range 100.98.26.120/24 collabnet
root@ubuntu-1610:~#docker network create -d macvlan –scope swarm –config-from collabnet swarm-macvlan
Verify that the containers inspection shows the correct information:[simterm]
root@ubuntu-1610:~/docker101/play-with-docker/wordpress/example1# docker network inspect swarm-macvlan
Docker Stack Deploy CLI:[simterm]
$docker stack deploy -c docker-stack.yml myapp2
Ignoring unsupported options: restart
Creating service myapp2_db
Creating service myapp2_wordpress
Verifying if the services are up and running:[simterm]
root@ubuntu-1610:~/# docker stack ls
root@ubuntu-1610:~/# docker stack ps myapp2
ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS
nd2m62alxmpo myapp2_wordpress.1 wordpress:latest ubuntu-1610 Running Running 15 minutes ago
cxz3y1cg1m6u myapp2_db.1 mysql:5.7 ubuntu-1610 Running Running 15 minutes ago
Looking for Docker Compose file for Single Node?
Cool..I am going to leverage this for my Apache JMeter Setup so that I can push loads from different IPs using Docker containers.
Did you find this blog helpful? Feel free to share your experience. Get in touch @ajeetsraina.
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Know more what’s new upcoming under Docker 17.06 CE release by clicking on this link.