file URI scheme not supported by agent.download.sourceURI

[n0othing]

• Version: Elastic Agent 7.12.1
• Operating System: Windows 10

While not officially supported, the Elastic Agent can be provided a agent.download.sourceURI to download updates. The code [1] seems to suggest you can use http, https, and file URI schemes. However, when the Agent is configured with a file URI (e.g file://<ip_address>) the Agent logs an error about an unsupported protocol:

fetching package failed: Get "file://<ip_address>/elastic-artifacts/beats/elastic-agent/elastic-agent-7.12.1-windows-x86_64.zip": unsupported protocol scheme "file"

[1] https://github.com/elastic/beats/blob/master/x-pack/elastic-agent/pkg/artifact/download/http/downloader.go#L78-L83

[elasticmachine]

Pinging @elastic/agent (Team:Agent)

[botelastic]

Hi!
We just realized that we haven't looked into this issue in a while. We're sorry!

We're labeling this issue as Stale to make it hit our filters and make sure we get back to it as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1.
Thank you for your contribution!