Month: November 2020

Browse Files in Docker

Use the Docker VSCode extension to browse files in your container

If you struggle using the command prompt to figure out where the files are in your Docker container, this post is for you. I will show you how easy it is to actually browse around the files inside your container.

The Struggle is Real

The first time that I sat behind a PC was in high school in the early 80s. At the time, the only way to ‘communicate’ with your computer was through a DOS prompt. If you were REALLY fancy, you had a .bat file that provided a menu, and you had to type the number and then hit enter to execute what was behind the number. We read how to do the cool things in paper magazines, because the only other resource was books at the library.

The command prompt was not my favorite, and I never really got into computers as much as you’d expect. Not until years later did I find myself working ‘in computers’, and at that time I tried to stick to GUI based tools. For some reason, CLE based tools are back in vogue (or I’m just recently discovering that this is where it’s at) and I find myself struggling to navigate. I kind of know how it works, but it’s difficult for me to keep straight where I am and where the connections are.

Finding Files in my Container

Up until now, the only way that I know of to find files inside a Docker container is to use the command prompt. Using the BCContainerHelper module, you can connect to the container by using the Enter-BCContainer <ContainerName> command. You can tell by the prompt when you are in the container.

The container has its own file system, with folders, just like your host computer. To make things easy, there are two Very Important Folders:

  • The ‘C:\run\my’ folder in the container is mapped to the ‘C:\ProgramData\BcContainerHelper\Extensions\<ContainerName>\my’ folder. This means that the files in those folders are shared by the host and the container, but the path in the container is NOT the same as the path on the host
    • NOTE: this is a container specific folder, so anything that you put into this folder will be deleted when you destroy the container
  • The ‘C:\programdata\bccontainerhelper’ folder is mapped to the same folder on the host. This means that the folder is also shared between the host and the container, PLUS the path is the same in both contexts
    • NOTE: As long as you have BcContainerHelper installed, any files (and additional folders) that you put into this folder will remain there, even when you remove containers. This is a perfect folder for sharing purposes.

This is important to understand, because you will probably use PowerShell scripts to do all sorts of things with containers, and you will need to read and/or write files to folders within the proper context.

A Better Way

The Docker extension for VSCode was updated this week, and it has a new feature that enables you to browse the files from inside VSCode.

This shot shows the folder structure inside my container

For me, this is a MUCH better way, because I find it very hard to keep track of where I am in the folder structure, and this gives me a bit more context. What I am missing is an easy way to tell which folders are shared, and what the path on the host is.

If you don’t have the Docker extension for VSCode yet, you can find it here. You can also search for it in the VSCode marketplace.

SQL Server and Docker

Learn how to use SQL Server to access the databases in your Docker container

This post is for you if you want to be able to access the SQL Server database inside your Docker container, without having to write the query.

For one of my projects, I needed to be able to see the apps that were uninstalled but still had their schema in the tenant database. That information is in the $ndo$navappuninstalledapp table, and with SQL Server Management Studio (SSMS) it is super easy to look at table data. In my container I assumed that I would have to figure out a way to write the actual query (something I am not very good at). As it turns out, I was wrong. In this post I will explain two very easy ways to access the SQL Server database inside your Docker container.

SQL Server Management Studio

The first, most obvious, option is to do a complete install of SQL Server in whatever edition you have access to. If you want to keep things lean though, you can also install a standalone SSMS. You can download SQL Server Management Studio here.

Connecting to a Docker container could not be easier. In the connection dialog, simply enter the name of your container as the server name, and SSMS will connect to it for you. I always use NavUserPassword authentication in my containers, and by default your container password will also work as the sa password inside the container.

My container is called ‘densterdev’, and you can see the default app and tenant databases inside the container.

All I needed to do was look at some table data, and that works just fine. I did not try to do anything more advanced than that.

SQL Server Extension in VSCode

The second option is even easier than installing SSMS, because you are already using VSCode to do your AL development. Microsoft has created a ‘SQL Server’ extension, which works very similar to SSMS. In the extensions search box in VSCode, type ‘SQL’ and select the one made by Microsoft.

After installing you may need to reload VSCode to enable the extension. You will see a new tab on the left navigation pane that will show you the tooltip ‘SQL Server’ when you hover over it. When you click this tab, you will see a heading that says ‘Connections’ at the top, with a + sign next to it. Click this + and follow the prompts. Just like SSMS, you enter the container name as the server name, and it should connect to it with no problem.

The same app and tenant databases are shown inside VSCode

I still did not need to do anything more complex than looking at some data, so I really can’t say what features are available beyond that. My guess is that it is less capable than SSMS, so this may not be an option if you need more advanced capabilities.