dbus: enable user sessions

[ddstreet]

While most distros have migrated over to dbus-broker, we still provide dbus-daemon, and we do not enable user sessions, so each user login does not have any dbus that can be used to communicate with the user session's systemd manager. This leads to frequent error messages while upgrading packages, and at other times, similar to:

Failed to connect to bus: No medium found
Reload daemon failed: Transport endpoint is not connected

Those errors also mean that while the systemd system manager (pid1) can be reloaded or reexeced, systemd user managers will not be reexeced on a package upgrade, nor can any other package that provides user session services cause their user services to reload/reexec on upgrade. This may leave user processes running old code after some package updates.

Note that the user can still communicate with the user session systemd manager, via systemctl, because it will use the private systemd bus. However, the root user (including scripts run during package updates) cannot connect to any user's private systemd bus and so must use the public user dbus, which is not provided by our dbus package currently.

This changes the dbus build to include support for user sessions.

Merge Checklist

All boxes should be checked before merging the PR (just tick any boxes which don't apply to this PR)

• The toolchain has been rebuilt successfully (or no changes were made to it)
• The toolchain/worker package manifests are up-to-date
• Any updated packages successfully build (or no packages were changed)
• Packages depending on static components modified in this PR (Golang, *-static subpackages, etc.) have had their Release tag incremented.
• Package tests (%check section) have been verified with RUN_CHECK=y for existing SPEC files, or added to new SPEC files
• All package sources are available
• cgmanifest files are up-to-date and sorted (./cgmanifest.json, ./toolkit/scripts/toolchain/cgmanifest.json, .github/workflows/cgmanifest.json)
• LICENSE-MAP files are up-to-date (./LICENSES-AND-NOTICES/SPECS/data/licenses.json, ./LICENSES-AND-NOTICES/SPECS/LICENSES-MAP.md, ./LICENSES-AND-NOTICES/SPECS/LICENSE-EXCEPTIONS.PHOTON)
• All source files have up-to-date hashes in the *.signatures.json files
• sudo make go-tidy-all and sudo make go-test-coverage pass
• Documentation has been updated to match any changes to the build system
• Ready to merge

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Summary

enable user dbus support

Change Log

enables user dbus support

Does this affect the toolchain?

n

Associated issues

• #xxxx

Links to CVEs

• https://nvd.nist.gov/vuln/detail/CVE-YYYY-XXXX

Test Methodology

• Pipeline build id: xxxx