Merge ~bjornt/maas:bug-2073731-3.4 into maas:3.4

[Björn Tillenius]

fix: don't fail commissioning if no suitable IPMI ciphers can be detected

Some BMCs (like HPE ILO 5 3.05) seems to not report all the ciphers
that actually are enabled.

Instead of failing commissioning, we now only print out a warning.

Resolves LP:2073731

(cherry picked from commit b2d55fd8c55b36139547e6b1306a7b96286d7875)
(cherry picked from commit 60fbad31927d726ae9d3098e0aedb7aa9a874f11)

[Björn Tillenius (bjornt)]

Self-approve backport.

review: Approve

diff --git a/src/metadataserver/builtin_scripts/commissioning_scripts/bmc_config.py b/src/metadataserver/builtin_scripts/commissioning_scripts/bmc_config.py
index cfaa80d..cea099f 100755
--- a/src/metadataserver/builtin_scripts/commissioning_scripts/bmc_config.py
+++ b/src/metadataserver/builtin_scripts/commissioning_scripts/bmc_config.py
@@ -553,8 +553,10 @@ class IPMI(IPMIBase):
         # this one.
 
         if not self._check_ciphers_enabled():
-            print("ERROR: No cipher enabled!", file=sys.stderr)
-            sys.exit(1)
+            # We can't detect any suitable cipher. We still continue,
+            # since we don't trust that the BMC reports all the
+            # ciphers that actually are usable.
+            print("WARNING: No cipher enabled!", file=sys.stderr)
 
         self._config_ipmi_lan_channel_settings()
         self._config_lan_conf_auth()