Expected behavior docker run --net=host. Should connect to local. I also tried this with pinata set network nat and pinata set network hostnet. Unfortunately Docker for Desktop doesn't currently support the 'host' network_mode where containers are able to freely bind host ports without being managed by docker. Instead, ports must be explicitly whitelisted in the docker run or the docker-compose.yml.
In this lab you will learn about key Docker Networking concepts. You will get your hands dirty by going through examples of a few basic networking concepts, learn about Bridge networking, and finally Overlay networking. Difficulty: Beginner to Intermediate Time: Approximately 45 minutes Tasks:. Section #1 - Networking Basics Step 1: The Docker Network Command The docker network command is the main command for configuring and managing container networks. Run the docker network command from the first terminal. Docker network.
Usage: docker network COMMAND Manage networks Options: -help Print usage Commands: connect Connect a container to a network create Create a network disconnect Disconnect a container from a network inspect Display detailed information on one or more networks ls List networks prune Remove all unused networks rm Remove one or more networks Run 'docker network COMMAND -help' for more information on a command. The command output shows how to use the command as well as all of the docker network sub-commands. As you can see from the output, the docker network command allows you to create new networks, list existing networks, inspect networks, and remove networks. It also allows you to connect and disconnect containers from networks.
Step 2: List networks Run a docker network ls command to view existing container networks on the current Docker host. Docker network ls. NETWORK ID NAME DRIVER SCOPE 3430ad6f20bf bridge bridge local a7449465c379 host host local 06c349b9cc77 none null local The output above shows the container networks that are created as part of a standard installation of Docker. New networks that you create will also show up in the output of the docker network ls command. You can see that each network gets a unique ID and NAME. Each network is also associated with a single driver. Notice that the “bridge” network and the “host” network have the same name as their respective drivers.
Step 3: Inspect a network The docker network inspect command is used to view network configuration details. These details include; name, ID, driver, IPAM driver, subnet info, connected containers, and more. Use docker network inspect to view configuration details of the container networks on your Docker host. The command below shows the details of the network called bridge. Docker network inspect bridge. NETWORK ID NAME DRIVER SCOPE 3430ad6f20bf bridge bridge local a7449465c379 host host local 06c349b9cc77 none null local The output above shows that the bridge network is associated with the bridge driver. It’s important to note that the network and the driver are connected, but they are not the same.
In this example the network and the driver have the same name - but they are not the same thing! The output above also shows that the bridge network is scoped locally. This means that the network only exists on this Docker host. This is true of all networks using the bridge driver - the bridge driver provides single-host networking. All networks created with the bridge driver are based on a Linux bridge (a.k.a.
A virtual switch). Install the brctl command and use it to list the Linux bridges on your Docker host. You can do this by running sudo apt-get install bridge-utils.
Apk update apk add bridge Then, list the bridges on your Docker host, by running brctl show. 3: docker0: mtu 1500 qdisc noqueue state DOWN group default link/ether 02:42:52:ed:52:f7 brd ff:ff:ff:ff:ff:ff inet 172.17.0.1/16 scope global docker0 validlft forever preferredlft forever Step 2: Connect a container The bridge network is the default network for new containers. This means that unless you specify a different network, all new containers will be connected to the bridge network. Create a new container by running docker run -dt ubuntu sleep infinity.
Docker run -dt ubuntu sleep infinity. Unable to find image 'ubuntu:latest' locally latest: Pulling from library/ubuntu d54efb8db41d: Pull complete f8b845f45a87: Pull complete e8db7bf7c39f: Pull complete 96: Pull complete 6d9ef359eaaa: Pull complete Digest: sha256:dd7808d8792c9841d0b460122f1acf0a2dd1f56404f8d1e5e45535 Status: Downloaded newer image for ubuntu:latest 846af8443c90a39cba68373c619d1feaa932719260a5f5afddbf71 This command will create a new container based on the ubuntu:latest image and will run the sleep command to keep the container running in the background. You can verify our example container is up by running docker ps.
Ping -c5 172.17.0.2 PING 172.17.0.2 (172.17.0.2) 56(84) bytes of data. 64 bytes from 172.17.0.2: icmpseq=1 ttl=64 time=0.055 ms 64 bytes from 172.17.0.2: icmpseq=2 ttl=64 time=0.031 ms 64 bytes from 172.17.0.2: icmpseq=3 ttl=64 time=0.034 ms 64 bytes from 172.17.0.2: icmpseq=4 ttl=64 time=0.041 ms 64 bytes from 172.17.0.2: icmpseq=5 ttl=64 time=0.047 ms - 172.17.0.2 ping statistics - 5 packets transmitted, 5 received, 0% packet loss, time 4075ms rtt min/avg/max/mdev = 0.031/0.041/0.055/0.011 ms The replies above show that the Docker host can ping the container over the bridge network. But, we can also verify the container can connect to the outside world too. Lets log into the container, install the ping program, and then ping www.github.com. First, we need to get the ID of the container started in the previous step. You can run docker ps to get that. PING www.docker.com (104.239.220.248) 56(84) bytes of data.
64 bytes from 104.239.220.248: icmpseq=1 ttl=45 time=38.1 ms 64 bytes from 104.239.220.248: icmpseq=2 ttl=45 time=37.3 ms 64 bytes from 104.239.220.248: icmpseq=3 ttl=45 time=37.5 ms 64 bytes from 104.239.220.248: icmpseq=4 ttl=45 time=37.5 ms 64 bytes from 104.239.220.248: icmpseq=5 ttl=45 time=37.5 ms - www.docker.com ping statistics - 5 packets transmitted, 5 received, 0% packet loss, time 4003ms rtt min/avg/max/mdev = 37.372/37.641/38.143/0.314 ms Finally, lets disconnect our shell from the container, by running exit. Exit We should also stop this container so we clean things up from this test, by running docker stop. Docker stop yourcontainerid This shows that the new container can ping the internet and therefore has a valid and working network configuration. Step 4: Configure NAT for external connectivity In this step we’ll start a new NGINX container and map port 8080 on the Docker host to port 80 inside of the container. This means that traffic that hits the Docker host on port 8080 will be passed on to port 80 inside the container. NOTE: If you start a new container from the official NGINX image without specifying a command to run, the container will run a basic web server on port 80. Start a new container based off the official NGINX image by running docker run -name web1 -d -p 8080:80 nginx.
Docker run -name web1 -d -p 8080:80 nginx. CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 4e0da45b0f16 nginx 'nginx -g 'daemon.' 2 minutes ago Up 2 minutes 443/tcp, 0.0.0.0:8080-80/tcp web1 The top line shows the new web1 container running NGINX. Take note of the command the container is running as well as the port mapping - 0.0.0.0:8080-80/tcp maps port 8080 on all host interfaces to port 80 inside the web1 container. This port mapping is what effectively makes the containers web service accessible from external sources (via the Docker hosts IP address on port 8080).
Now that the container is running and mapped to a port on a host interface you can test connectivity to the NGINX web server. To complete the following task you will need the IP address of your Docker host. This will need to be an IP address that you can reach (e.g.
Your lab is hosted in Azure so this will be the instance’s Public IP - the one you SSH’d into). Just point your web browser to the IP and port 8080 of your Docker host. Also, if you try connecting to the same IP address on a different port number it will fail. If for some reason you cannot open a session from a web broswer, you can connect from your Docker host using the curl 127.0.0.1:8080 command. Curl 127.0.0.1:8080.
Docker swarm init -advertise-addr $(hostname -i). Swarm initialized: current node (rzyy572arjko2w0j82zvjkc6u) is now a manager. To add a worker to this swarm, run the following command: docker swarm join -token SWMTKN-1-69b2x1u2wtjdmot0oqxjw1r2d27f0lbmhfxhvj83chln1l6es5-37ykdpul0vylenefe2439cqpf 10.0.0.5:2377 To add a manager to this swarm, run 'docker swarm join-token manager' and follow the instructions. In the first terminal copy the entire docker swarm join. Command that is displayed as part of the output from your terminal output. Then, paste the copied command into the second terminal.
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS ijjmqthkdya65h9rjzyngdn48 node2 Ready Active rzyy572arjko2w0j82zvjkc6u. node1 Ready Active Leader The ID and HOSTNAME values may be different in your lab. The important thing to check is that both nodes have joined the Swarm and are ready and active. Step 2: Create an overlay network Now that you have a Swarm initialized it’s time to create an overlay network. Create a new overlay network called “overnet” by running docker network create -d overlay overnet. Docker network create -d overlay overnet.
NETWORK ID NAME DRIVER SCOPE 3430ad6f20bf bridge bridge local a4d584350f09 dockergwbridge bridge local a7449465c379 host host local 8hq1n8nak54x ingress overlay swarm 06c349b9cc77 none null local wlqnvajmmzsk overnet overlay swarm The new “overnet” network is shown on the last line of the output above. Notice how it is associated with the overlay driver and is scoped to the entire Swarm. NOTE: The other new networks (ingress and dockergwbridge) were created automatically when the Swarm cluster was created.
Run the same docker network ls command from the second terminal. Docker network ls. NETWORK ID NAME DRIVER SCOPE 55f10b3fb8ed bridge bridge local b7b30433a639 dockergwbridge bridge local a7449465c379 host host local 8hq1n8nak54x ingress overlay swarm 06c349b9cc77 none null local Notice that the “overnet” network does not appear in the list.
This is because Docker only extends overlay networks to hosts when they are needed. This is usually when a host runs a task from a service that is created on the network. We will see this shortly. Use the docker network inspect command to view more detailed information about the “overnet” network.
You will need to run this command from the first terminal. Docker network inspect overnet. ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS riicggj5tuta myservice.1 ubuntu:latest node2 Running Running about a minute ago nlozn82wsttv myservice.2 ubuntu:latest node1 Running Running about a minute ago The ID and NODE values might be different in your output. The important thing to note is that each task/replica is running on a different node. Now that the second node is running a task on the “overnet” network it will be able to see the “overnet” network. Lets run docker network ls from the second terminal to verify this.
Docker network ls. Root@d676496d18f7:/# ping -c5 10.0.0.3 PING 10.0.0.3 (10.0.0.3) 56(84) bytes of data.
^C - 10.0.0.3 ping statistics - 4 packets transmitted, 0 received, 100% packet loss, time 2998ms The output above shows that both tasks from the myservice service are on the same overlay network spanning both nodes and that they can use this network to communicate. Step 5: Test service discovery Now that you have a working service using an overlay network, let’s test service discovery. If you are not still inside of the container, log back into it with the docker exec -it /bin/bash command. Run cat /etc/resolv.conf form inside of the container. Docker exec -it yourcontainerid /bin/bash cat /etc/resolv.conf search ivaf2i2atqouppoxund0tvddsa.jx.internal.cloudapp.net nameserver 127.0.0.11 options ndots:0 The value that we are interested in is the nameserver 127.0.0.11.
This value sends all DNS queries from the container to an embedded DNS resolver running inside the container listening on 127.0.0.11:53. All Docker container run an embedded DNS server at this address. NOTE: Some of the other values in your file may be different to those shown in this guide. Try and ping the “myservice” name from within the container by running ping -c5 myservice. Root@d676496d18f7:/# ping -c5 myservice PING myservice (10.0.0.2) 56(84) bytes of data.
64 bytes from 10.0.0.2: icmpseq=1 ttl=64 time=0.020 ms 64 bytes from 10.0.0.2: icmpseq=2 ttl=64 time=0.052 ms 64 bytes from 10.0.0.2: icmpseq=3 ttl=64 time=0.044 ms 64 bytes from 10.0.0.2: icmpseq=4 ttl=64 time=0.042 ms 64 bytes from 10.0.0.2: icmpseq=5 ttl=64 time=0.056 ms - myservice ping statistics - 5 packets transmitted, 5 received, 0% packet loss, time 4001ms rtt min/avg/max/mdev = 0.020/0.042/0.056/0.015 ms The output clearly shows that the container can ping the myservice service by name. Notice that the IP address returned is 10.0.0.2.
In the next few steps we’ll verify that this address is the virtual IP (VIP) assigned to the myservice service. Type the exit command to leave the exec container session and return to the shell prompt of your Docker host.
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