Add s3-clients section to issues

topics/compute/openstack/docs/additional-information/known-issues.md

@@ -3,8 +3,14 @@
 !!! Information
     This section is meant to list specific problems that we know about including recommended work-arounds.
 
+??? "Problems with S3 Object Storage Clients"
 
+	Some problems were encountered on Brno site while using S3 command-line clients to manage data on Swift Object Storage. Due to misconfiguration, commonly used data operations didn't work (e.g., it wasn't possible to save new data to Swift).
 
+	Swift works best with clients propagated by [OpenStack](https://docs.openstack.org/swift/latest/associated_projects.html#application-bindings), the best one being [python-swiftclient](https://pypi.org/project/python-swiftclient/).
 
+	If You encounter problems, try the following:
 
-
+	* Enforce https instead of http (worked for davix).
+	* Check default values (s3cmd requires overwriting parameter `--host-bucket=object-store.cloud.muni.cz`).
+	* Look into the logs (many tools come with a `--debug` option).