I wanted to clear my Cloudflare cache during an Azure Pipeline deployment. Cloudflare offers a REST API to do this, but rather than poke around with scripts I decided to see how I could instead write a custom task to do this and publish it on the Visual Studio market place.

Get the extension

The extension is free on Visual Studio Marketplace and it’s open source on github. Here’s a screenshot of how it looks in a Azure DevOps:

Screenshot of Purge Cache for Cloudflare release task

How I built it

I followed a great walk-through on docs.microsoft. I like that the instructions promote typescript and testing, though I’m not going to write tests for such a small task.

Another netizen already pointed out that I would need to query first the Cloudflare REST API to translate a zone name into a zone id, and then request the purge. I turned those instructions into typescript, compiled to javascript, and bundled this javascript as a vsix extensiion using tfx-cli.

Over all the code is very simple. The structure is as follows:

  • /vss-extension.json
    • Extension manifest, defines basic information about what the extenion does. Reference docs.
  • /images/extension-icon.png
    • Icon representing the extension
  • /cloudflarePurge/index.ts
    • The code that the task will execute. I haven’t written TypeScript since before v2 so I suspect the error handling could be more elegantly written with async or similar.
  • /cloudflarePurge/task.json
    • Defines how the task’s configuration options will be rendered and which scripts will execute at build time. Reference docs

If we were just using javascript with no dependencies, that would be it. However we’re using typescript so we also have;

  • /cloudflarePurge/index.js
    • tsc output (generated)
  • /cloudflarePurge/package.json
    • nodejs dependencies
  • /cloudflarePurge/tsconfig.json
    • typescript config

Once this is in place I packaged the extension with:

npx tfx-cli extension create --rev-version --manifest-globs vss-extension.json

Publishing

Publishing was a little odd - to publish publicly your Visual Studio Marketplace account needs to be approved as a publisher by someone at Microsoft. This was accomplished by entering some details about who I was and clicking a Request Approval (or similar) button. I got an approval and a you’re now approved email from someone at Microsoft about two days later.

Prior to being approved, the marketplace will block the uploading of any extension that has public:true set. Post-approval the uploader pointed out I need to include an overview.md on a public extension. However, you can point content/details in your vss-extension.json at, say, README.md to resolve this issue:

"content": {
    "details": {
        "path": "README.md"
    } 
},

That’s it!

Overall it was pretty simple to execute custom code within an Azure Pipeline release and package it into an extension. From here I’d like to look into how such a task can be called by an Azure Pipeline yaml build, and, to auto-deploy updates to this task to the marketplace on commit - a colleague of mine has a post on this.