Hubble has the capability of providing visibility on L7 protocols such as HTTP or Kafka. This layer 7 protocol visibility feature is opt-in and requires users to either create a L7 policy or to add explicit pod annotations to be enabled. Layer 7 Hubble flows, however, may contain sensitive information, for instance as part of some HTTP headers or in a URL itself.

Hubble should provide an option for users to decide which potentially sensitive L7 data to keep in Hubble flows and it should be finely configurable.

• HTTP URL: sanitize user info part (ie the optional username and password details for a URL), on/off: hubble: Conditionally redact user info present in URLs in (L7) HTTP flows #28848
• HTTP URL: remove query and fragment part of a URL, on/off: Hubble: Add option to remove query from HTTP flows #25746
• HTTP Headers: use a list of allowed HTTP header fields. A default list (e.g. tracing related fields) could be provided. Any header not in the list will have it's value sanitized (the key should be preserved). Add option to redact http headers #26724
• Kafka: redact API key, on/off: Hubble: improve security by adding an option to redact API key in Kafka requests (L7) #25844
• DNS: probably nothing to do.