6. The first network

6.1. Two containers

cloonix start nemo
cloonix cli nemo demo cloonix/cnt.py

cloonix start stays in the foreground: the demo goes in a second terminal. The demo needs the container image trixie in /var/lib/cloonix/bulk; without it, its first line says so and how to build it. What it prints is the nine lines of the chapter First run, run one after the other, and the answer of the ping:

$ cloonix cli nemo add cnt cnt1 eth=1 trixie
$ cloonix cli nemo add cnt cnt2 eth=1 trixie
$ cloonix cli nemo plug cnt1 eth0 lan1
$ cloonix cli nemo plug cnt2 eth0 lan1
$ cloonix cli nemo ssh cnt1 "ip addr add dev eth0 1.1.1.1/24"
$ cloonix cli nemo ssh cnt1 "ip link set dev eth0 up"
$ cloonix cli nemo ssh cnt2 "ip addr add dev eth0 1.1.1.2/24"
$ cloonix cli nemo ssh cnt2 "ip link set dev eth0 up"
$ cloonix cli nemo ssh cnt1 "ping -c 5 1.1.1.2"
64 bytes from 1.1.1.2: icmp_seq=1 ttl=64 time=0.1 ms
...
cnt1 pings cnt2. Erase everything, the server stays:
$ cloonix cli nemo del all

Each line after a $ can be typed as it is. Between the add lines and the ssh lines the demo waits for the two containers to answer, which is what a hand-typed run does by retrying the first ssh.

6.2. Two virtual machines

cloonix cli nemo demo cloonix/kvm.py

Same shape, with kvm1 and kvm2 on image trixie.qcow2, 1000 MB of ram and two cpus each:

$ cloonix cli nemo add kvm kvm1 ram=1000 cpu=2 eth=1 trixie.qcow2
$ cloonix cli nemo add kvm kvm2 ram=1000 cpu=2 eth=1 trixie.qcow2
$ cloonix cli nemo plug kvm1 eth0 lan1
$ cloonix cli nemo plug kvm2 eth0 lan1

then the same four ip lines and the same ping. A virtual machine boots a kernel, so the wait before the first ssh is longer than for a container.

6.3. From the canvas

The Demo panel of the canvas lists the same two files under cloonix, and Play runs them on the machine of the server. The commands appear in the log of the panel as they run; beside it the History popup tells the four steps, why each is there and what the ping proved, and its About view holds the drawing of the network. In the toy, this panel is the way to play them.

Both demos leave their machines in place, so the canvas shows them and a double-click on one opens its shell. cloonix cli nemo del all clears the net for the next one.

6.4. Where they are

/usr/share/cloonix/demos/cloonix/cnt.py
/usr/share/cloonix/demos/cloonix/kvm.py

Each is a short python file using the standard library only; the chapter Demos describes what every demo of the tree does.