Merge pull request #142747 from helsinki-systems/fix/test-runner-execute

nixos/test-runner: Fix execute() flakiness

Changed files
+45 -17
nixos
+5
nixos/doc/manual/development/writing-nixos-tests.section.md
···
`execute`
: Execute a shell command, returning a list `(status, stdout)`.
+
Takes an optional parameter `check_return` that defaults to `True`.
+
Setting this parameter to `False` will not check for the return code
+
and return -1 instead. This can be used for commands that shut down
+
the VM and would therefore break the pipe that would be used for
+
retrieving the return code.
`succeed`
+7 -1
nixos/doc/manual/from_md/development/writing-nixos-tests.section.xml
···
<listitem>
<para>
Execute a shell command, returning a list
-
<literal>(status, stdout)</literal>.
+
<literal>(status, stdout)</literal>. Takes an optional
+
parameter <literal>check_return</literal> that defaults to
+
<literal>True</literal>. Setting this parameter to
+
<literal>False</literal> will not check for the return code
+
and return -1 instead. This can be used for commands that shut
+
down the VM and would therefore break the pipe that would be
+
used for retrieving the return code.
</para>
</listitem>
</varlistentry>
+28 -12
nixos/lib/test-driver/test-driver.py
···
+ "'{}' but it is in state ‘{}’".format(require_state, state)
)
-
def execute(self, command: str) -> Tuple[int, str]:
+
def _next_newline_closed_block_from_shell(self) -> str:
+
assert self.shell
+
output_buffer = []
+
while True:
+
# This receives up to 4096 bytes from the socket
+
chunk = self.shell.recv(4096)
+
if not chunk:
+
# Probably a broken pipe, return the output we have
+
break
+
+
decoded = chunk.decode()
+
output_buffer += [decoded]
+
if decoded[-1] == "\n":
+
break
+
return "".join(output_buffer)
+
+
def execute(self, command: str, check_return: bool = True) -> Tuple[int, str]:
self.connect()
-
out_command = "( set -euo pipefail; {} ); echo '|!=EOF' $?\n".format(command)
+
out_command = f"( set -euo pipefail; {command} ) | (base64 --wrap 0; echo)\n"
assert self.shell
self.shell.send(out_command.encode())
-
output = ""
-
status_code_pattern = re.compile(r"(.*)\|\!=EOF\s+(\d+)")
+
# Get the output
+
output = base64.b64decode(self._next_newline_closed_block_from_shell())
-
while True:
-
chunk = self.shell.recv(4096).decode(errors="ignore")
-
match = status_code_pattern.match(chunk)
-
if match:
-
output += match[1]
-
status_code = int(match[2])
-
return (status_code, output)
-
output += chunk
+
if not check_return:
+
return (-1, output.decode())
+
+
# Get the return code
+
self.shell.send("echo ${PIPESTATUS[0]}\n".encode())
+
rc = int(self._next_newline_closed_block_from_shell().strip())
+
+
return (rc, output.decode())
def shell_interact(self) -> None:
"""Allows you to interact with the guest shell
+2 -2
nixos/tests/hibernate.nix
···
"mkswap /dev/vda1 -L swap",
# Install onto /mnt
"nix-store --load-db < ${pkgs.closureInfo {rootPaths = [installedSystem];}}/registration",
-
"nixos-install --root /mnt --system ${installedSystem} --no-root-passwd",
+
"nixos-install --root /mnt --system ${installedSystem} --no-root-passwd --no-channel-copy >&2",
)
machine.shutdown()
···
)
# Hibernate machine
-
hibernate.succeed("systemctl hibernate &")
+
hibernate.execute("systemctl hibernate &", check_return=False)
hibernate.wait_for_shutdown()
# Restore machine from hibernation, validate our ramfs file is there.
+1 -1
nixos/tests/kexec.nix
···
testScript =
''
machine.wait_for_unit("multi-user.target")
-
machine.execute("systemctl kexec &")
+
machine.execute("systemctl kexec &", check_return=False)
machine.connected = False
machine.wait_for_unit("multi-user.target")
'';
+2 -1
nixos/tests/switch-test.nix
···
machine.succeed("touch /testpath")
machine.wait_until_succeeds("test -f /testpath-modified")
-
machine.succeed("rm /testpath /testpath-modified")
+
machine.succeed("rm /testpath")
+
machine.succeed("rm /testpath-modified")
switch_to_specialisation("with-path-modified")
machine.succeed("touch /testpath")