Merge ~bjornt/maas:bug-2053033-3.4 into maas:3.4

[Björn Tillenius]

Bug #2053033: Creating MAAS Virsh VM does not work (libvirt: error)

For some reason virsh prints out an error about executing
pkttyagent. This happens only on some machines, and we don't know why.

But the error seems harmless. This patch ignores the error and
lets the connection succeed.

(cherry picked from commit f0005e39bcadfc366c76e713c444739179743c84)

[Björn Tillenius (bjornt)]

Self-approve backport

review: Approve

[MAAS Lander (maas-lander)]

UNIT TESTS
-b bug-2053033-3.4 lp:~bjornt/maas/+git/maas into -b 3.4 lp:~maas-committers/maas

STATUS: SUCCESS
COMMIT: 0e3a8ed6ee2d3cc458b421599ad4224e2f97b515

review: Approve

diff --git a/src/provisioningserver/drivers/pod/tests/test_virsh.py b/src/provisioningserver/drivers/pod/tests/test_virsh.py
index bd1f362..f56ca9b 100644
--- a/src/provisioningserver/drivers/pod/tests/test_virsh.py
+++ b/src/provisioningserver/drivers/pod/tests/test_virsh.py
@@ -575,7 +575,30 @@ class TestVirshSSH(MAASTestCase):
         self.assertFalse(conn.login(poweraddr=factory.make_name("poweraddr")))
         self.assertThat(mock_close, MockCalledOnceWith())
 
+    def test_pkttyagent_permission_denied(self):
+        # Sometimes pkttyagent can't be executed in the snap. The connection
+        # itself still works, though.
+        # See https://bugs.launchpad.net/maas/+bug/2053033
+        virsh_outputs = [
+            "libvirt:  error : cannot execute binary /usr/bin/pkttyagent: Permission denied",
+            "Welcome to virsh, the virtualization interactive terminal.",
+            "",
+            "Type:  'help' for help with commands",
+            "       'quit' to quit",
+            "",
+            "virsh # ",
+        ]
+        conn = self.configure_virshssh_pexpect(virsh_outputs)
+        self.assertTrue(conn.login(poweraddr=factory.make_name("poweraddr")))
+
     def test_login_invalid(self):
+        virsh_outputs = ["Permission denied, please try again."]
+        conn = self.configure_virshssh_pexpect(virsh_outputs)
+        mock_close = self.patch(conn, "close")
+        self.assertFalse(conn.login(poweraddr=factory.make_name("poweraddr")))
+        mock_close.assert_called_once_with()
+
+    def test_unknown(self):
         virsh_outputs = [factory.make_string()]
         conn = self.configure_virshssh_pexpect(virsh_outputs)
         mock_close = self.patch(conn, "close")
diff --git a/src/provisioningserver/drivers/pod/virsh.py b/src/provisioningserver/drivers/pod/virsh.py
index fb2bff3..f357205 100644
--- a/src/provisioningserver/drivers/pod/virsh.py
+++ b/src/provisioningserver/drivers/pod/virsh.py
@@ -286,7 +286,8 @@ class VirshSSH(pexpect.spawn):
     PROMPT = r"virsh \#"
     PROMPT_SSHKEY = "(?i)are you sure you want to continue connecting"
     PROMPT_PASSWORD = "(?i)(?:password)|(?:passphrase for key)"
-    PROMPT_DENIED = "(?i)permission denied"
+    # Credential problems
+    PROMPT_DENIED = "(?i)permission denied, please try again"
     PROMPT_CLOSED = "(?i)connection closed by remote host"
 
     PROMPTS = [