Remove FIPS noise from SSHd

When a system is in FIPS mode, SSHd can prints some noise to stderr:

    FIPS mode initialized\r\n

This noise causes interference and breakage of some tests. Remove the
noise from stderr_bytes, which automatically fixes stderr_text, too.

Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Francisco Trivino <ftrivino@redhat.com>

ipatests/pytest_ipa/integration/host.py

@@ -18,6 +18,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 """Host class for integration testing"""
+import re
 import subprocess
 import tempfile
 
@@ -31,6 +32,8 @@ from .fips import (
     is_fips_enabled, enable_userspace_fips, disable_userspace_fips
 )
 
+FIPS_NOISE_RE = re.compile(br"FIPS mode initialized\r?\n?")
+
 
 class LDAPClientWithoutCertCheck(ipaldap.LDAPClient):
     """Adds an option to disable certificate check for TLS connection
@@ -176,6 +179,9 @@ class Host(pytest_multihost.host.Host):
             log_stdout=log_stdout, raiseonerr=False, cwd=cwd, bg=bg,
             encoding=encoding
         )
+        # in FIPS mode SSH may print noise to stderr, remove the string
+        # "FIPS mode initialized" + optional newline.
+        result.stderr_bytes = FIPS_NOISE_RE.sub(b'', result.stderr_bytes)
         try:
             result_ok = result.returncode in ok_returncode
         except TypeError: