Add a note to deployment page.
@@ -21,6 +21,28 @@ Once your server has been bootstrapped, libcloud.deploy task should be finished
and replaced by other tools such as previously mentioned configuration
management software.
+.. note::
+
+ paramiko v2.9.0 introduced a change to prefer SHA-2 variants of RSA key
+ verification algorithm.
+
+ With this version paramiko would fail to connect to older OpenSSH
+ servers which don't support this algorithm (e.g. default setup on Ubuntu
+ 14.04) and throw authentication error.
+
+ Libcloud code has been updated to be backward compatible. It first tries to
+ connect to the server using default preferred algorithm values and in case
+ that fails, it will fall back to the old approach with SHA-2 variants
+ disabled.
+
+ This functionality can be disabled by setting
+ ``LIBCLOUD_PARAMIKO_SHA2_BACKWARD_COMPATIBILITY`` environment variable to
+ ``false``.
+
+ For security reasons (to prevent possible downgrade attacks and similar) you
+ are encouraged to do that in case you know you won't be connecting to any old
+ OpenSSH servers.
+
Supported private SSH key types
-------------------------------
