BASIC21 test: added persistent volume checking

Added check on the presence of the persistent volume in Openstack. Created new keywords in openstack_lib.robot for that.
Fix bug in vnf_lib.robot.

Change-Id: I0b4cc8f81d2f1cddcd90d1664a69dafae23e70cb
Signed-off-by: aguilard <e.dah.tid@telefonica.com>
diff --git a/robot-systest/lib/openstack_lib.robot b/robot-systest/lib/openstack_lib.robot
index c72892e..884ec4f 100644
--- a/robot-systest/lib/openstack_lib.robot
+++ b/robot-systest/lib/openstack_lib.robot
@@ -58,3 +58,36 @@
     Should Be Equal As Integers   ${rc}   ${success_return_code}
     [Return]  ${stdout}
 
+
+Get Server Property
+    [Documentation]     Get a field (flavor, image, volumes_attached, etc.) from a server.
+    [Arguments]    ${server_id}   ${field}
+
+    Should Not Be Empty   ${server_id}
+    Should Not Be Empty   ${field}
+    ${rc}   ${stdout}=   Run and Return RC and Output   openstack server show ${server_id} -c ${field} -f value
+    log   ${stdout}
+    Should Be Equal As Integers   ${rc}   ${success_return_code}
+    [Return]  ${stdout}
+
+
+Check If Volume Exists
+    [Documentation]     Checks if a volume id exists
+    [Arguments]    ${volume_id}
+
+    Should Not Be Empty   ${volume_id}
+    ${rc}   ${stdout}=   Run and Return RC and Output   openstack volume list | grep ${volume_id} | wc -l
+    log   ${stdout}
+    Should Be Equal As Integers   ${rc}   ${success_return_code}
+    [Return]  ${stdout}
+
+
+Delete Volume
+    [Documentation]     Delete a volume by its identifier
+    [Arguments]    ${volume_id}
+
+    Should Not Be Empty   ${volume_id}
+    ${rc}   ${stdout}=   Run and Return RC and Output   openstack volume delete ${volume_id}
+    log   ${stdout}
+    Should Be Equal As Integers   ${rc}   ${success_return_code}
+    [Return]  ${stdout}