mgr/cephadm: re-use old ip when re-adding hosts if necessary

When a host is re-added without an explicit ip we can default to the old
ip we had stored for the host rather than either keeping the loopback
address or throwing an exception. We only want to actually error when
the only options left are error or use a resolved loopback address

Fixes: https://tracker.ceph.com/issues/53438
Signed-off-by: Adam King <adking@redhat.com>
(cherry picked from commit 7e8d8317bef1b35cddd99950e503f57710002e80)

Conflicts:
	src/pybind/mgr/cephadm/module.py

diff --git a/src/pybind/mgr/cephadm/module.py b/src/pybind/mgr/cephadm/module.py
index 1479d8ca261fd0b19efff2a04783f1fe13c9055b..732eb2eccb971555ac49894973bc9827b1689fe1 100644 (file)
--- a/src/pybind/mgr/cephadm/module.py
+++ b/src/pybind/mgr/cephadm/module.py
@@ -1,5 +1,6 @@
 import json
 import errno
+import ipaddress
 import logging
 import re
 import shlex
@@ -1456,11 +1457,6 @@ class CephadmOrchestrator(orchestrator.Orchestrator, MgrModule,
         ]
 
     def _check_valid_addr(self, host: str, addr: str) -> str:
-        # make sure mgr is not resolving own ip
-        if addr in self.get_mgr_id():
-            raise OrchestratorError(
-                "Can not automatically resolve ip address of host where active mgr is running. Please explicitly provide the address.")
-
         # make sure hostname is resolvable before trying to make a connection
         try:
             ip_addr = utils.resolve_ip(addr)
@@ -1483,6 +1479,15 @@ Then run the following:
 > ssh -F ssh_config -i ~/cephadm_private_key {self.ssh_user}@{addr}'''
             raise OrchestratorError(msg)
 
+        if ipaddress.ip_address(ip_addr).is_loopback and host == addr:
+            # if this is a re-add, use old address. otherwise error
+            if host not in self.inventory or self.inventory.get_addr(host) == host:
+                raise OrchestratorError(
+                    (f'Cannot automatically resolve ip address of host {host}. Ip resolved to loopback address: {ip_addr}\n'
+                     + f'Please explicitly provide the address (ceph orch host add {host} --addr <ip-addr>)'))
+            self.log.debug(
+                f'Received loopback address resolving ip for {host}: {ip_addr}. Falling back to previous address.')
+            ip_addr = self.inventory.get_addr(host)
         out, err, code = CephadmServe(self)._run_cephadm(
             host, cephadmNoImage, 'check-host',
             ['--expect-hostname', host],