VSTS (Visual Studio Team Services) continues to grow and change over time. It seems every few months I see some new features and changes, which are good and bad. Good in that usually things improve. Bad in that I get confused and lost at times, and sometimes have to re-acquaint myself with the system.

One of the changes I noticed recently was the Deployment phases, which come as Server and Agent phases. I won’t cover server here, but I wanted to make a quick note on Agent Phases because I think they’re handy and a nice packaging concept.

Agents

There are agents that run for VSTS to do work. I’ve written about how to download an agent so tasks run inside of your network (on a server or client).  This post will look at the other side, how do I control an agent from the release process.

Once I get a new release definition, I’ll see something like this:

This is a blank deployment definition. To the left I see the environment I’m working with, in this case, just the generic Environment 1 name. For each environment, I can set up tasks. On the right I have the Add Tasks button, but also the “Run on Agent” item. This is the container where I will add tasks.

I used to just add tasks with VSTS 2015 here, expecting that everything would run on an agent. VSTS has hosted agents that contain a set list of software, and also downloadable agents that you run on your servers or workstations. Things changed recently to include phases.

Phases

The phases are place of execution, which allow a series of tasks to be grouped together. VSTS and TFS 2017 give you two choices. We now have Agent or Server phases. The difference between these is that I can choose where items execute, on an agent or on the server (VSTS or TFS). In addition, I can set these to execute in parallel if need be.

If I click the down arrow next to the Add Tasks, I’ll get this dialog. This allows me to set up a process that can run on the VSTS server, or one that can run on the Agent.

I haven’t played with server phases, but when I add an agent phase, this gives me a section under which I add tasks. Note that when I click the “Agent phase” item, I get a new blade to the right. Note that the pool for these agents is the default.

This threw me early on because I have a separate pool of agents for mobile development. As I upgraded some deployment definitions, I couldn’t figure out why I didn’t have any agents available to execute my tasks. It turns out I needed to change the agent pool here.

There are options here, but I haven’t really played with parallelism or demands since I typically deploy to one system at a time.

Once I’ve selected an agent, I can click Add Tasks and then add a series of tasks to that agent. If you look below, I have added a couple tasks to each of the two agent phases. These will run one phase, then the other.

Each of these phases is independent, and as of the time I wrote this, there’s no way to copy a phase and duplicate it.

I’ve used this to upgrade my release definitions by adding new tasks, and then copying settings between one phase and the other. This is a manual, copy/paste operation, but I can easily see if I’ve duplicated everything by going back and forth quickly.

Once I’m done, I can just click the “x” to the right of the agent phase and delete the entire phase. I have to confirm this action, and then I’ve removed a complete phase.

Right now I haven’t see any benefit outside of the upgrade scenario, but that’s useful. I will duplicate my tasks, disable all the ones in one phase and then see if the other one runs. If it doesn’t, I can always enable the old tasks and disable the new ones.

I expect as I look to perform more complex deployments I will use these to logically separate things, and also perhaps use the server to do some things when I don’t need an agent.

Filed under: Blog Tagged: continuous delivery, DevOps, syndicated, vsts