Sometimes the default 15s is not enough for timeout of ceph commands. For examples,
I encountered that `radosgw-admin` command took dozens of seconds under heavy load.
Signed-off-by: Satoru Takeuchi <satoru.takeuchi@gmail.com>
When the CephCluster is configured with Multus and multiple networks are
used to deploy Ceph some commands are failing to be executed from the
Operator. These commands, in particular, `radosgw-admin` ones need access
to the "ceph public network" to talk to OSDs. Unfortunately, the
Rook-Ceph Operator does not have the network annotations and thus
doesn't have the networks available and cannot reach OSDs. So the commands end
up hanging and eventually time out.
Applying the annotations to the Operator pod is possible but will result
in restarting the operator too and this should be avoided at all costs.
Also, applying the annotations beforehand is not possible since the
Multus declaration is in the CephCluster specification. So we would have
no idea what to do.
So the current approach runs a new sidecar container in the mgr pod to
act as a proxy for "some" ceph commands, only the `radosgw-admin` ones
for multi-site setup. This is a small container with admin access
running idle waiting for commands to be executed. In a sense, it is
similar to the toolbox but we didn't want to clearly expose it, so
running as a sidecar is quite nice.
Proxying command is obviously not always recommended since we add an
extra hop in the network path. Now each request has to go from the
operator pod to the API server to the remote pod to Ceph. Previously,
the command only goes from the operator to Ceph.
It's worth noting that external mode is not impacted since no rgw pod
is configured. This scenario is flexible and allows us to scale
pretty well since any CephCluster with Multus will see its mgr sidecar
deployed and can then talk to Ceph. We are not limited.
Signed-off-by: Sébastien Han <seb@redhat.com>
Satoru Takeuchi
Sébastien Han