Category: Containers

Andrew Pruski shows how to change the default location for Docker containers on Windows:

There’s a switch that you can use when starting up the docker service that will allow you to specify the container/image backend. That switch is -g

Now, I’ve gone the route of not altering the existing service but creating a new one with the -g switch. Mainly because I’m testing and like rollback options but also because I found it easier to do it this way.

Read the whole thing.

Andrew Pruski hows how to copy files into and out from Docker containers:

Last week I was having an issue with a SQL install within a container and to fix I needed to copy the setup log files out of the container onto the host so that I could review.

But how do you copy files out of a container?

Well, thankfully there’s the docker cp command. A really simple command that let’s you copy whatever files you need out of a running container into a specified directory on the host.

I’ll run through a quick demo but I won’t install SQL, I’ll use an existing SQL image and grab its Summary.txt file.

Read on for the demo.

Andrew Pruski shows how to create a Docker container with SQL Server 2014 SP2 installed:

I’m running all of this on my Windows 10 machine but there are a few things you’ll need before we get started: –

Pre-requisites

• The microsoft/windowsservercore image downloaded from the Docker Hub

• Windows Server 2016 installation media extracted toC:\Docker\Builds\Windows

• SQL Server 2014 SP2 Developer Edition installation media extracted to C:\Docker\Builds\SQLServer2014

Or if you prefer, you can just pull his image, but where’s the fun in that?

Elton Stoneman has a five-step process for turning your Windows app into a containerized application:

1. Choose Your Base Image

Docker images for Windows apps need to be based on microsoft/nanoserver or microsoft/windowsservercore, or on another image based on one of those.

Which you use will depend on the application platform, runtime, and installation requirements. For any of the following you need Windows Server Core:

• .NET Framework apps
• MSI installers for apps or dependencies
• 32-bit runtime support

For anything else, you should be able to use Nano Server. I’ve successfully used Nano Server as the base image for Go, Java and Node.js apps.

This is good reading if you’re thinking of offering a containerized version of your product.

Andrew Pruski shows how to save a Docker image:

What I’m going to do now is save my custom image to a location [C:\temp] on my host server. So I’ll run: –

1	docker save -o myfirstimage.tar myfirstimage

N.B. – I’m saving the file as a .tar as this seems to be the format that works best for loading the image. I’ve tried exporting to other formats (.zip) but it always seems to become corrupt. The .tar format has always worked for me so I’ll stick with it.

If I’m understanding Andrew correctly, that’s because docker save will only generate a tar archive.  Keep reading for more details, including how to restore a Docker image to another machine.

Andrew Pruski demos Portainer, a user interface for Docker:

So let’s run through the setup and then look at the system. There’s a couple of pre-requisities to this I’m afraid, the first one is that you must setup remote administration using TLS on the Docker host that you want to manage via Portainer. I’ve detailed how to do this here.

Also, Portainer doesn’t support managing a local Docker Engine running on Windows so the way I’ve set it up is to run Portainer locally on Windows 10 and then point it at a server running the Docker Engine I want to manage. This means that you’ll need to install Docker locally, you can do that here.

Of course you get it in a container.  How else would you get the container interface…?

It looks like a nice UI for getting started with Docker.