Add support for elastic-agent-complete to Elastic Package

[dominiqueclarke]

The elastic-package stack up command currently enrolls a standard agent using the mainline elastic-agent image.

We should configure the command to also enroll a complete agent using the elastic-agent-complete image, or provide a flag to determine which type of agent to enroll.

[mtojek]

@dominiqueclarke Thank you for the reference PR, but we need to rethink how to support it. Adding an extra container with agent might be a performance overkill here, so maybe it's valid to replace/extend the original elastic-agent image instead.

The "elastic-agent-complete" means that it includes "heartbeat", right? Could you please share image details? How much is that image heavier than standard one. Maybe we can just switch it to complete.

[dominiqueclarke]

Thanks @mtojek. The elastic-agent-complete image contains all the binaries necessary to run beats, plus additional dependencies required to run the synthetics agent via heartbeat. This includes node, chromium, playwright, the synthetics agent itself and more.

Reference ticket: elastic/beats#26398
Agent image (~400MB bigger than the original): https://container-library.elastic.co/r/beats/elastic-agent-complete?show_snapshots=true

The complete image will indeed cover the scope of existing capabilities of the mainline Elastic Agent, so it would make sense to switch the agent over to complete.

[mtojek]

We can try to replace the agent with "complete" variant and observe. Let's first wait until the issue with faulty elastic-agent is solved (waiting for new snapshots get published) and then we'll try.

If everything goes well, we'll leave just the "complete" one.

[mtojek]

Version bump for elastic/integrations: elastic/integrations#1748

[mtojek]

Ok, I see that we need a small workaround for stacks < 7.15.0, where elastic-agent-complete wasn't available.

[mtojek]

I guess we can close this issue as it's deployed in elastic/integrations.