skip test if readline module missing (add it as optional module installs in GHA workflow)

.github/workflows/main.yml

@@ -61,6 +61,8 @@ jobs:
           #sudo apt-get -y install python${F2B_PY/2/}-systemd || echo 'systemd not available'
           sudo apt-get -y install libsystemd-dev || echo 'systemd dependencies seems to be unavailable'
           python -m pip install systemd-python || echo 'systemd not available'
+          #readline if available as module:
+          python -c 'import readline' 2> /dev/null || python -m pip install readline || echo 'readline not available'
 
       - name: Before scripts
         run: |

fail2ban/tests/fail2banclienttestcase.py

@@ -568,6 +568,11 @@ class Fail2banClientTest(Fail2banClientServerBase):
 				os.kill(pid, signal.SIGCONT)
 			self.assertLogged("timed out")
 			self.pruneLog()
+			# check readline module available (expected by interactive client)
+			try:
+				import readline
+			except ImportError as e:
+				raise unittest.SkipTest('Skip test because of import error: %s' % e)
 			# interactive client chat with started server:
 			INTERACT += [
 				"echo INTERACT-ECHO",