Feature/ allow ulimits parameters configuration of the devices

[g4br-i]

I've introduced the possibility to set ulimits in the devices via lab.conf file

-Changed files The following files have been modified:

• src/Kathara/manager/docker/DockerMachine.py:
  • to be able to support the ulimits instances upon container creation.
  • _create_ulimit_instances method was introduced to parse a ulimits dictionary to ulimit instances following the docker sdk requirements
• src/Kathara/model/Machine.py:
  • the add_meta method is now able to parse strings like yourdevice[ulimit]="ulimit=softlimit:hardlimit" or yourdevice[ulimit]="ulimit=softlimit" in the second case hardlimit will be set to be equal to softlimit
  • get_ulimits method was introduced to retrieve the dictionary of ulimits
• tests/model/machine_test.py, added tests to verify correct parsing
• docs/kathara-lab.conf.5.ronn, added some lines to explain how to set ulimits

- How to verify it

• Create a lab.conf with a some devices then set yourdevice[ulimit]="nofile=1000:1000" or yourdevice[ulimit]="memlock=-1"
• start the lab
• in the terminal of the device run ulimit -a
• check that ulimit you've set in lab conf matches printed value in the teminal

- Description for the changelog Lab.conf now supports ulimits configuration at device creation, this solves cases where specific containers need to be run with custom values as in "docker run --ulimit memlock=819200000:819200000 ..."

[g4br-i]

with the latest commit i've added:

https://github.com/KatharaFramework/Kathara/blob/c9f7d13a5a1ec7a4e12a84ee07841488d9b4b3cf/src/Kathara/model/Machine.py#L212-L223 this addresses some edge case that i did not consider initially, like setting ulimit less the -1 and fixing a wrong behaviour i've introduced by imposing only that hard must be bigger than soft ( i was not considering the case hard=-1 which is equal to unlimited and soft being a value like 1024).

i've also added the warning for kubernets

https://github.com/KatharaFramework/Kathara/blob/c9f7d13a5a1ec7a4e12a84ee07841488d9b4b3cf/src/Kathara/manager/kubernetes/KubernetesMachine.py#L306-L308

also a bunch of new tests:

https://github.com/KatharaFramework/Kathara/blob/c9f7d13a5a1ec7a4e12a84ee07841488d9b4b3cf/tests/model/machine_test.py#L306C1-L324C60