Add custom header to specify fleetapi base url

[tnsetting2023]

Description

Please include a summary of the changes and the related issue.

Fixes # (issue)

Type of change

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• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Bug fix (non-breaking change which fixes an issue)
• Documentation update

Checklist:

Confirm you have completed the following steps:

• My code follows the style of this project.
• I have performed a self-review of my code.
• I have made corresponding updates to the documentation.
• I have added/updated unit tests to cover my changes.

[sethterashima]

What problem are we solving here? If the proxy is trying to hit the wrong hostname, then that's a bug that should be fixed without requiring manually intervention from the operator.

[tnsetting2023]

The issue is that there are some complains about proxy not forwarding request to the right host and getting errors like “user out of region, use base URL: https://fleet-api.prd.eu.vn.cloud.tesla.com, see https://developer.tesla.com/docs/fleet-api/getting-started/base-urls”. The pr is trying to provide some means for operator to force the requests to be forwarded to a specified tesla host.

It looks like we have some retry logic already as from the code base

vehicle-command/pkg/connector/inet/inet.go

Line 142 in e8634aa

func (c *Connection) SendFleetAPICommand(ctx context.Context, endpoint string, command interface{}) ([]byte, error) {

and

vehicle-command/pkg/vehicle/vehicle.go

Line 241 in e8634aa

if !protocol.ShouldRetry(err) {

. It seems we would update the serverURL in the Connection and retry from Vehicle class. So the issue feels like a bug

[tnsetting2023]

It looks like only command got forwards but not other requests like vehicle_data