D-Bus API for registration

[joseivanlopez]

Problem

Agama needs to know the repositories of the product to install. But for some products (e.g., SLE, ALP), the repositories are unknown until the product is registered.

Solution

Export a new D-Bus object /org/opensuse/Agama/Software1/Product to manage the product selection and registration. Note that methods for selecting a product were moved from /org/opensuse/Agama/Software1 object.

# busctl --address unix:path=/run/agama/bus introspect org.opensuse.Agama.Software1 /org/opensuse/Agama/Software1/Product
NAME                                 TYPE      SIGNATURE  RESULT/VALUE                             FLAGS
org.opensuse.Agama.Software1.Product interface -          -                                        -
.SelectProduct                       method    s          (us)                                     -
.AvailableProducts                   property  a(ssa{sv}) 3 "ALP-Dolomite" "SUSE ALP Dolomite" 1 … emits-change
.SelectedProduct                     property  s          "Tumbleweed"                             emits-change
org.opensuse.Agama1.Issues           interface -          -                                        -
.All                                 property  a(ssuu)    0                                        emits-change
org.opensuse.Agama1.Registration     interface -          -                                        -
.Deregister                          method    -          (us)                                     -
.Register                            method    sa{sv}     (us)                                     -
.Email                               property  s          ""                                       emits-change
.RegCode                             property  s          ""                                       emits-change
.Requirement                         property  u          0                                        emits-change

Note 1: the current code still uses the libsuseconnect ruby bindings to communicate to SCC. That bindings only exist because of YaST, and it should not be used for new projects. The plan is to directly use SUSEConnect CLI in Agama instead. But for that, SUSEConnect needs some improvements in order to avoid applying changes on the running system. SCC team is already working on it, see https://github.com/SUSE/scc-docs/pull/287.

Note 2: the current implementation works similar to YaST, that is, the service, repositories, SCC credentials, etc are directly added to the running system (e.g., TW running on agama-live) and then they are copied to the target system. Changes altering the running system should be avoided. This will be improved in a follow-up task, see https://trello.com/c/jqcFar3M/243-agama-registration-avoid-changes-in-running-system.

Note 3: RMT and SSL certificates are not covered yet. This will come in a next iteration.

Note 4: the target of this PR is the registration feature branch. It will be merged into master once the registration UI is implemented.

Note 5: changelog will be added later at the time of merging into master.

Testing

• Added unit tests
• Tested manually

[coveralls]

coverage: 75.536% (+0.4%) from 75.13% when pulling aa32a97 on registration-dbus-api into 18d7a88 on registration.

[jreidinger]

when we touch it we probably also need to solve issue with version...as there can be two products with same name and different version like it happen with micro based on some SP. And registration need version....maybe product should be tuple of strings with name and version?

[jreidinger]

LGTM now. manual test passed