Due to the salting being applied to Python's `hash()` (see [1]), the
hash of an object is not stable across different Python processes. As
a result, neither are the topology mappings generated by networkx.
The upside of this is randomness that we get better test coverage over
time, especially on physical devices where the underlying hardware
could differ between ports, for example.
On the other hand, it can be very frustrating to track down a bug when
locial nodes are suffled around between phyical nodes on each
invocation of a test case.
Therefore, use a random seed by default, but allow the user to specify
a fixed value if they so choose. We then add a meta test that logs the
seed being used for the current suite - which means we can simply
copy&paste that value to rerun the suite (or single test) with the
same topology mappings.
[1]: https://docs.python.org/3/reference/datamodel.html#object.__hash__
- Present the topologies to networkx as multigraphs, rather than
expaning each port of the record shape as a separate node.
- Create a topology mapping by locating a subgraph monomorphism of the
logical topology in the physical ditto.
This cuts down the time of finding a mapping by several orders of
magnitude. Example:
Before:
time python3 test/infamy/topology.py \
test/virt/quad/topology.dot.in \
test/infamy/topologies/ring-4-duts.dot >/dev/null
real 13m1,213s
user 13m0,112s
sys 0m0,732s
After:
time python3 test/infamy/topology.py \
test/virt/quad/topology.dot.in \
test/infamy/topologies/ring-4-duts.dot >/dev/null
real 0m0,153s
user 0m0,128s
sys 0m0,024s
Launches an interactive ipython environment, attached to Infix nodes.
This can be used as a playground for developing tests, testing out
NETCONF operations, etc.
When running in the cloud, without KVM emulation, together with many
other tenants, it can take a very long time to boot the instances.
Therefore, add a meta test that will wait for all devices in the
physical topology to come up before exiting. This means that the
actual test cases that follow can assume that devices will answer
NETCONF requests.
