Consider adding WatchConfig and automatic reload for CA secrets

[jansobczak]

Preflight Checklist

• I have searched the issue tracker for an issue that matches the one I want to file, without success.
• I agree to follow the Code of Conduct.

Problem Description

When using cert-manager as CA provider for webhook in line

vault-secrets-webhook/main.go

Line 175 in 5c5715a

tlsCertFile := viper.GetString("tls_cert_file")

this CA is read but when CA rotates this require a rollout of the webhook deployment

Proposed Solution

Use the WatchConfig() in viper library to detect change in the file and reload vault-secrets-webhook

Alternatives Considered

No response

Additional Information

No response

[ramizpolic]

Thanks for raising this @jansobczak! If you have some time to assist on this, would be quite helpful. Let us know so we can plan ahead.