Add PodDisruptionBudget support

[timflannagan]

Tracker for adding PDB support for both the control plane & data plane components. See #12173 for some prior art in this scenario. We need to determine our approach on how to handle this in both 1.) the control plane given our current stance on how HA works and how it will evolve in 2.x release cadence, and 2.) how PDB applies to our data plane components.

Related Issues

• PDB Support for ExtAuth #8056
• https://github.com/solo-io/solo-projects/issues/7465
• https://github.com/solo-io/gloo-gateway/issues/975

[DuncanDoyle]

See my comment here: https://github.com/solo-io/solo-projects/issues/7465#issuecomment-2557050966

Playing devil's advocate here: Wrt PDB support for the actual proxy deployments, since these deployments are dynamic and controlled by the deployment of a Gateway CR, why would we need to create an entire "PodDisruptionBudget" abstraction in our GatewayParameters? The name of the generated Deployment is deterministic, so a user can simply create a PDB and add the correct selectors to select the Deployment of the deployed Gateway, and the deploy the PodDisruptionBudget CR alongside the Gateway CR.

This is "Bring Your Own" approach is basically what we've done for the initial support of HPA: #10697 (comment)

[korjek]

See my comment here: https://github.com/solo-io/solo-projects/issues/7465#issuecomment-2557050966

Playing devil's advocate here: Wrt PDB support for the actual proxy deployments, since these deployments are dynamic and controlled by the deployment of a Gateway CR, why would we need to create an entire "PodDisruptionBudget" abstraction in our GatewayParameters? The name of the generated Deployment is deterministic, so a user can simply create a PDB and add the correct selectors to select the Deployment of the deployed Gateway, and the deploy the PodDisruptionBudget CR alongside the Gateway CR.

This is "Bring Your Own" approach is basically what we've done for the initial support of HPA: #10697 (comment)

@DuncanDoyle could we get PDB support for control plane at least?

[chandler-solo]

@korjek #13238 is in review for the control planes' PDBs.