rabbit_db: Skip reset if the node is already virgin #14768
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[Why] The previous implementation checked if the store was empty. This part is unchanged. However if `is_empty/0` returned an error, typically because the store was stopped, it would consider that the node is also virgin. This is a wrong approximation because an admin could have executed `rabbitmqctl stop_app` before something checks the node is virgin. [How] With this patch, we introduce `rabbit_khepri:is_virgin_node/0`. It will start the store if it is stopped, then it will query if it is empty. It will stop the store again if it was stopped initially. This way, we have a more accurate answer to the question.
[Why]
If we run `reset` again on an already virgin node, it will take
decisions based on the wrong state. In particular, the previous use of
Khepri or Mnesia is lost with the first reset. Therefore, the second
reset wolud delete non-Khepri related files that belong to the
coordination Ra system.
This is particularily problematic with the previously documented way of
joining two nodes using the CLI:
rabbitmqctl stop_app
rabbitmqctl reset
rabbitmqctl join_cluster $REMOTE_NODE
rabbitmqctl start_app
Indeed, `join_cluster` implies a reset. If the admin already reset the
node as documented, `join_cluster` implied reset would delete too many
files, breaking Khepri after the join if Khepri is used by the remote
node.
[How]
In `rabbit_db:reset/0`, we skip the reset if the node is already virgin.
Fixes #14748.
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Why
If we run
resetagain on an already virgin node, it will take decisions based on the wrong state. In particular, the previous use of Khepri or Mnesia is lost with the first reset. Therefore, the second reset wolud delete non-Khepri related files that belong to the coordination Ra system.This is particularily problematic with the previously documented way of joining two nodes using the CLI:
rabbitmqctl stop_app rabbitmqctl reset rabbitmqctl join_cluster $REMOTE_NODE rabbitmqctl start_appIndeed,
join_clusterimplies a reset. If the admin already reset the node as documented,join_clusterimplied reset would delete too many files, breaking Khepri after the join if Khepri is used by the remote node.How
In
rabbit_db:reset/0, we skip the reset if the node is already virgin.Fixes #14748.