Update ubuntu-snap.md

snapcraft-options/ubuntu-snap.md

@@ -10,11 +10,17 @@ Run the commands in the root of the repo.
     - `$ ./build/build-snaps.sh agent`
     - `$ ./build/build-snaps.sh sdk-tests`
 
+- By default snapcraft doesn't allow multiple snaps definition in the same code base, so this build-snaps.sh file was created so that we can copy the different snap files into the main snapcraft.yaml file and then build it.
+
 - Subsequent builds of the same component without modifying the corresponding yaml file:
     - `$ snapcraft`
 
 - The build will generate *.snap files in the current working directory. Example: **deliveryoptimization-sdk-tests_0.1_amd64.snap**.
 
+- In the snapcraft.yaml the regular script to build for both the delivery optimization agent and sdk is called (`build.py`), but since there are some different behaviors the code should have when inside a snap, for that we use a flag `--build-for-snap` on the build. Below you can see the usage of this flag, but **is not** necessary to execute them, those lines will be executed inside the snapcraft.yaml file when you call the `build-snaps.sh` file.
+    - `$ python3 ./build/build.py --project agent --build-for-snap`  
+    - `$ python3 ./build/build.py --project sdk --build-for-snap`  
+
 ## Installing
 - `$ sudo snap install --devmode ./deliveryoptimization-sdk-tests_0.1_amd64.snap`
 - `$ sudo snap install --devmode ./deliveryoptimization-client_0.1_amd64.snap`
@@ -24,11 +30,24 @@ It is a fruitful exercise to look around in the host file system and see how sna
 - /snap/<snap-name>
 - /var/snap/<snap-name>
 
-## Connecting plugs and slots
+## Connecting to Other Snaps
+
+- Snapcraft allows communication between different snaps by using a content interface to handle connections with the purpose share code and data between them. These connections are composed by plugs and slots, where a slot is the producer snap and the plug is the consumer snap.
+
 - For the SDK test snap to work, the plugs and slots must be connected. Run the **connect-snaps.sh** script after both snaps are installed.
 - The connections can be listed using this command:
     - `$ snap connections | grep delivery`
 
+```shell
+Interface     Plug                                                      Slot                                         Notes
+content       -                                                         deliveryoptimization-client:do-configs       -
+content       -                                                         deliveryoptimization-client:do-port-numbers  -
+content       deliveryoptimization-client:deviceupdate-agent-downloads  -                                            -
+network       deliveryoptimization-client:network                       :network                                     -
+network-bind  deliveryoptimization-client:network-bind                  :network-bind                                -
+
+```
+
 ## Running or executing
 - Agent
     - The agent is declared as a daemon/service, so it starts running immediately after successful installation.