Docker compose name resolution

So to my understanding the name resolution inside the containers simply uses the entries from the hosts file of the docker host. How to reach docker containers by name. And there you go, the end. This is the newest version.

By default, when you create a container, it does not publish any of its ports to the outside world. My issue can be pinpointed to docker network trying to open a socket on an existing ip:port(53) for DNS. After some iterations the newly created docker network will try to use an existing socket and this will fail. On my laptop, docker deamon always stops name resolution after suspending. When I wake up the laptop again I always need to restart the deamon to get it back to work.

Using the docker - compose CLI comman you can create and start one or more containers for each dependency with a single command ( docker - compose up). In some networks, like Canonical’s London office network where I work, the administrators intentionally block the use of public DNS servers to encourage people. The docker - compose.

From an elevated PowerShell session, navigate to the top level of the Blog Application directory. If I have a docker - compose which defines various containers on one or more (internal) networks, processes inside the containers can resolve the IPvaddresses of other containers using the names defined in the docker - compose. Name :IP mappings are shared between hosts using a distributed key-value store (e.g. etc zookeeper).

It also runs through a VPN container. But, you can force docker-compose not to stop and recreate the containers, you can use –no-recreate option as shown below during the docker-compose up. Docker is a bit like a virtual machine. Troubleshooting a User-Defined Network. Look up all backend IP addresses by DNS name : DNS.

For example, suppose you had an application which required NGNIX and MySQL, you could create one file which would start both the containers as a service without the need to start each one separately. We’ll see later in this post how you can change the name of the Compose file, or use multiple Compose files that extend each other. Now use the following commands to rebuild webapp container and relaunch using docker - compose. Check the output of the command. You can see that mysql_db container is showing unchanged as nothing changed there.

If the above docker - compose. WordPress service that connects to a MySQL database service. You can now give memorable names to your containers using the new - name flag for docker run. When you link one container to another you will have to provide the name and alias of the child that you want to link to via -link child_ name :alias.

After the first time, however, we can simply use start to start the services: docker - compose start. Red Hat will continue to evaluate docker-compose and ansible-container but there are no plans to include either in RHEL at this time. So we are on our own….

However, it has a (in my opinion) huge drawback. It is related to security. Let’s take a glance at the docker-compose.