[PATCH v2 05/14] tests/vm: Set UseDNS=no in the sshd configuration

From: Ilya Leoshkevich <iii(a)linux.ibm.com&gt; make vm-build-freebsd sometimes fails with "Connection timed out during banner exchange". The client strace shows: 13:59:30 write(3, "SSH-2.0-OpenSSH_9.3\r\n", 21) = 21 13:59:30 getpid() = 252655 13:59:30 poll([{fd=3, events=POLLIN}], 1, 5000) = 1 ([{fd=3, revents=POLLIN}]) 13:59:32 read(3, "S", 1) = 1 13:59:32 poll([{fd=3, events=POLLIN}], 1, 3625) = 1 ([{fd=3, revents=POLLIN}]) 13:59:32 read(3, "S", 1) = 1 13:59:32 poll([{fd=3, events=POLLIN}], 1, 3625) = 1 ([{fd=3, revents=POLLIN}]) 13:59:32 read(3, "H", 1) = 1 There is a 2s delay during connection, and ConnectTimeout is set to 1. Raising it makes the issue go away, but we can do better. The server truss shows: 888: 27.811414714 socket(PF_INET,SOCK_DGRAM|SOCK_CLOEXEC,0) = 5 (0x5) 888: 27.811765030 connect(5,{ AF_INET 10.0.2.3:53 },16) = 0 (0x0) 888: 27.812166941 sendto(5,"\^Z/\^A\0\0\^A\0\0\0\0\0\0\^A2"...,39,0,NULL,0) = 39 (0x27) 888: 29.363970743 poll({ 5/POLLRDNORM },1,5000) = 1 (0x1) So the delay is due to a DNS query. Disable DNS queries in the server config. Reviewed-by: Thomas Huth <thuth(a)redhat.com&gt; Signed-off-by: Ilya Leoshkevich <iii(a)linux.ibm.com&gt; Message-Id: <20240206002344.12372-2-iii(a)linux.ibm.com&gt; Signed-off-by: Alex Bennée <alex.bennee(a)linaro.org&gt; --- tests/vm/basevm.py | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tests/vm/basevm.py b/tests/vm/basevm.py index 61725b83254..c0d62c08031 100644 --- a/tests/vm/basevm.py +++ b/tests/vm/basevm.py @@ -423,6 +423,8 @@ def console_ssh_init(self, prompt, user, pw): def console_sshd_config(self, prompt): self.console_wait(prompt) self.console_send("echo 'PermitRootLogin yes' >> /etc/ssh/sshd_config\n") + self.console_wait(prompt) + self.console_send("echo 'UseDNS no' >> /etc/ssh/sshd_config\n") for var in self.envvars: self.console_wait(prompt) self.console_send("echo 'AcceptEnv %s' >> /etc/ssh/sshd_config\n" % var) -- 2.39.2