passt/test, branch 2023_05_09.96f8d55

nstool: Enter holder's cwd when changing mount ns with nstool exec

2023-04-07T23:12:12+00:00

If we enter a mount namespace with nstool exec our working directory will
be changed to / in the new mount ns.  This is surprising if we haven't
actually altered any mounts yet in the new ns.  Instead, change the working
directory to match that of the holder process in this situation.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

nstool: Advertise the holder's cwd (in its mountns) across the socket

2023-04-07T23:12:10+00:00

This is possible useful in nstool info and has further uses for nstool
exec.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

test: Use "nstool exec" to slightly simplify tests

2023-04-07T23:12:08+00:00

Using this, rather than using "nstool info" to get the pid then manually
connecting with nsenter makes things a little simpler.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

test: Initialise ${TRACE} properly

2023-04-07T23:12:05+00:00

Unlike ${DEBUG} we don't initialize ${TRACE} to 0 if not set, which cases
failures when testing it later.  That failure acts as though it is false,
however it emits spurious errors in script.log, which can make it harder to
spot real errors.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

nstool: Add --keep-caps option to nstool exec

2023-04-07T23:12:03+00:00

This allows you to run commands within a user namespace with the
privilege that comes from owning that userns.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

nstool: Add nstool exec command to execute commands in an nstool namespace

2023-04-07T23:12:01+00:00

This combines nstool info -pw  with nsenter with various options for
a more convenient and less verbose of entering existing nstool managed
namespaces.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

nstool: Helpers to iterate through namespace types

2023-04-07T23:11:59+00:00

Will make things a bit less verbose in future.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

nstool: Add magic number to advertized information

2023-04-07T23:11:57+00:00

So that we'll probably give a better error if you point it at something
that's not an nstool hold control socket.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

nstool: Detect what namespaces target is in

2023-04-07T23:11:55+00:00

Give nstool the ability to detect what namespaces the target process is in,
relative to where it's called.  That is, those namespace types for which
the target is not in the same namespace as the caller.  For now, just
print this information with "info", which can be useful for debugging.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

nstool: Replace "pid" subcommand with "info" subcommand

2023-04-07T23:11:52+00:00

The new subcommand gives more information about the holder process and its
namespace, and may be further extended in future.  Add some options which
give the old behaviour for existing scripts.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio