a8c32c85d5
In our test scripts we need to do some ugly parsing of /proc and/or pstree output in order to get the PIDs of processes running in namespaces so that we can connect to those namespaces with nsenter or pasta. This is actually a pretty tricky problem with standard tools. To determine the PID from the outside of the namespace we need to know how the process of interest is related to the unshare or pasta process (child? one of several children? grandchild?) as well as then parsing /proc or ps output. This is slightly awkward now, and will get worse with future changes I'd like to make to have processes are dispatched. The obvious solution would be to have the process of interest (which we control) report its own PID, but that doesn't work easily, because it is in a PID namepace and sees only its local PID not the global PID we need to address it from outside. To handle this, add a small custom tool, "nsholder". This takes a path and a mode parameter. In "hold" mode it will create a unix domain socket bound to the path and listening. In "pid" mode it will get the "hold"ing process's pid via the unix socket using SO_PEERCRED, which translates between PID namespaces. In "stop" mode it will send a message to the socket causing the "hold"ing process to clean up and exit. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> |
||
|---|---|---|
| .. | ||
| build | ||
| demo | ||
| dhcp | ||
| distro | ||
| env | ||
| icmp | ||
| lib | ||
| ndp | ||
| perf | ||
| shutdown | ||
| tcp | ||
| two_guests | ||
| udp | ||
| .gitignore | ||
| ci | ||
| find-arm64-firmware.sh | ||
| Makefile | ||
| nsholder.c | ||
| passt.mbuto | ||
| prepare-distro-img.sh | ||
| README.md | ||
| run | ||
| run_demo | ||
| valgrind.supp | ||
Scope
This directory contains test cases for passt and pasta and a simple POSIX shell-based framework to define them, and run them as a suite.
These tests can be run as part of a continuous integration workflow, and are also used to provide short usage demos, with video recording, for passt and pasta basic use cases.
Run
Dependencies
Packages
The tests require some package dependencies commonly available in Linux distributions. If some packages are not available, the test groups that need them will be selectively skipped.
This is a non-exhaustive list of packages that might not commonly be installed on a system, i.e. common utilities such as a shell are not included here.
Example for Debian, and possibly most Debian-based distributions:
build-essential git jq strace iperf3 qemu-system-x86 tmux sipcalc bc
clang-tidy cppcheck isc-dhcp-common psmisc linux-cpupower socat
netcat-openbsd fakeroot lz4 lm-sensors qemu-system-arm qemu-system-ppc
qemu-system-misc qemu-system-x86 valgrind
Other tools
Test measuring request-response and connect-request-response latencies use
neper, which is not commonly packaged by distributions and needs to be built
and installed manually:
git clone https://github.com/google/neper
cd neper; make
cp tcp_crr tcp_rr udp_rr /usr/local/bin
Virtual machine images are built during test executions using mbuto, the shell script is sourced via git as needed, so there's no need to actually install it.
Kernel parameters
Performance tests use iperf3 with rather large TCP receiving and sending windows, to decrease the likelihood of iperf3 itself becoming the bottleneck. These values need to be allowed by the kernel of the host running the tests. Example for /etc/sysctl.conf:
net.core.rmem_max = 134217728 net.core.wmem_max = 134217728
Further, the passt demo uses perf(1), relying on hardware events for performance counters, to display syscall overhead. The kernel needs to allow unprivileged users to access these events. Suggested entry for /etc/sysctl.conf:
kernel.perf_event_paranoid = -1
Special requirements for continuous integration and demo modes
Running the test suite as continuous integration or demo modes will record the terminal with the steps being executed, using asciinema(1), and create binary packages.
The following additional packages are commonly needed:
alien asciinema linux-perf tshark
Regular test
Just issue:
./run
from the test directory. Elevated privileges are not needed. Environment
variable settings: DEBUG=1 enables debugging messages, TRACE=1 enables tracing
(further debugging messages), PCAP=1 enables packet captures. Example:
PCAP=1 TRACE=1 ./run
Continuous integration
Issuing:
./ci
will run the whole test suite while recording the execution, and it will also build JavaScript fragments used on http://passt.top/ for performance data tables and links to specific offsets in the captures.
Demo mode
Issuing:
./demo
will run the demo cases under demo, with terminal captures as well.
Framework
The implementation of the testing framework is under lib, and it provides
facilities for terminal and tmux session management, interpretation of test
directives, video recording, and suchlike. Test cases are organised in the
remaining directories.
Test cases can be implemented as POSIX shell scripts, or as a set of directives,
which are not formally documented here, but should be clear enough from the
existing cases. The entry point for interpretation of test directives is
implemented in lib/test.