Okay, so I messed around with something called a “liberty depth chart” today, and I figured I’d share how it went. It wasn’t super complicated, but it definitely took a little trial and error.
First, I needed to actually get my hands on Open Liberty. I already had Java installed(make sure you get that sorted first), so I went to the Open Liberty website and downloaded the latest version. They’ve got a bunch of different options, but I just grabbed the basic “Web Profile” package. It’s a .zip file, so I unzipped it to a folder on my desktop.
Getting Started
Next, I opened up my command prompt (I’m on Windows). I navigated to the folder where I unzipped Liberty, specifically into the `bin` folder. There’s a bunch of stuff in there, but the one I needed was `*` (it might be `server` on Linux or Mac).
I typed in `server create myServer` and hit enter. This created a new, basic server instance called “myServer”. The command prompt showed a message saying it was successful.
Figuring out the “Depth Chart” Part
Honestly, the phrase “depth chart” kind of threw me off at first. It’s not really an official Liberty term. What I think we’re talking about here is looking at the structure of a running application, seeing what’s inside, and maybe even checking the order of things like filters or servlets.
So, to do that, I needed an actual application running. I grabbed a simple “hello world” WAR file I had lying around from another project. I copied that WAR file into the `dropins` folder inside my server’s directory (that’s `wlp/usr/servers/myServer/dropins`). Liberty is cool because it automatically deploys anything you put in that folder.
Back in the command prompt, I typed `server start myServer` and hit enter. Liberty started up, and you could see in the logs that it deployed my “hello world” application.
Inspecting the Running App
Now, for the “depth chart” part. There are a few ways to peek inside. One of the easiest is to use the Liberty Admin Center, which is a web-based interface. You can enable it with some simple changes into your server’s configuration. I already have experience using the Liberty Admin Center so,
I have already enabled it.
- I opened my web browser and went to: `https://localhost:9443/adminCenter/`.
- I logged in with the default Liberty credentials (which I’d set up earlier).
- I clicked around in the Admin Center. There are sections for exploring deployed applications, seeing their components (like servlets and JSPs), and even looking at runtime details.
Another way, which is more “depth chart”-like, is to use the `server dump` command. In the command prompt, I typed `server dump myServer –include=all` and hit enter. This created a ZIP file in the `wlp/usr/servers/myServer` directory containing a ton of information about the running server and the deployed application.
I unzipped that dump file and started poking around. There’s XML, configuration files, logs, and all sorts of goodies. It’s a bit overwhelming at first, but you can find details about the application’s structure, class loading, and more. It’s like a deep dive into what’s going on under the hood.
That ZIP file is what I think of as the real “depth chart.”It is where all the configuration files are, including the all-important `*` which dictates the setup of your Liberty server.
So, that’s basically it! It’s not a single, magic “depth chart” feature, but rather a combination of tools and techniques for looking inside a running Liberty application. The Admin Center is great for a quick overview, while the `server dump` gives you the full, detailed picture.
