changing telemetry_secret key results in loss of messages in message queue

[Abhishek Sharma M]

telemetry_secret holds a secret password/key and is present under [publisher] section of ceilometer.conf file. This telemetry_secret is used to sign ceilometer messages which flow through a messaging queue. When we change this secret key, the messages already present in the message queue which were signed by the previous telemetry_secret cannot be validated/unsigned by ceilometer and they will be lost.

Many customers of openstack would want this functionality where in telemetry_secret gets changed every few months for security reasons & in those cases the messages in message queue should not be lost.