GitLab

    Infrastructure has been added to kea-dhcp6 such that it can
    now be configured to fetch full and then periodic updates
    from config backends.

    Merging the actual fetched content will be done under subsequent
    issues.

src/bin/dhcp6
    ctrl_dhcp6_srv.*
        - ControlledDhcpv6Srv::processConfig() - added logic to schedule CB update timer
        - ControlledDhcpv6Srv::cbFetchUpdates() - new callback function for CB updates

    dhcp6_lexer.ll
    dhcp6_parser.yy
        -  Added config-fetch-wait-time

    dhcp6_messages.mes
        -  New log messages

    dhcp6_srv.*
        - Dhcpv6Srv::cb_control_  - new member for config backend access
        - Dhcpv6Srv::inTestMode() - new function to test for unit test mode

    json_config_parser.cc
        - configureDhcp6Server() - invokes full fetch from config backend

src/bin/dhcp6/tests
    config_backend_unittest.cc - new file/tests for config backend testing
    config_parser_unittest.cc - updated
    get_config_unittest.cc - rebuild tests
    kea_controller_unittest.cc - added CB control/timer tests

src/lib/dhcpsrv/
    dhcpsrv_messages.mes - added log message
	cb_ctl_dhcp6.* - new files that provide v6 impl of config backend controller

doc/examples/kea6/all-keys-current.json - added config-fetch-wait-time

src/bin/dhcp4/ctrl_dhcp4_srv.*
src/bin/dhcp6/ctrl_dhcp6_srv.*
    Changed dbReconnect() to accept ReconnectCtlPtr
    Added commentary for dbReconnect and dbLostCallback

src/lib/dhcpsrv/database_connection.h
    Removed extraneous typedef

many files:
    Changed DatabaseConnection::Callback to ::DbLostCallback

src/lib/dhcpsrv/tests/database_connection_unittest.cc
    Added commentary to text fixture and tests

    kea-dhcp6
        added support for max-reconnect-tries and reconnect-wait-time
        to lease and host db parsers

        Added a callback for when DB backends detect loss of connectivity

        Added a self-rescheduling method to attempt to reconnect to the
        backends if retries are enabled

    dhcpsrv
        PgSqlConnection::checkStatementError() - Modified "fatal" logic
        to throw after invoking db_lost_callback.

    Misc. cleanup

Added memfile without persistence to set_config unit tests. This eliminates
the tests attempting to create the csv file.

Updated copyrights.

Fixed misspelling.

src/bin/dhcp6/ctrl_dhcp6_srv.h
src/bin/dhcp6/ctrl_dhcp6_srv.cc
    ControlledDhcpv6Srv::commandSetConfigHandler() - new method to process
    the set-config command.

    ControlledDhcpv6Srv::processCommand() - call new set-config handler

    ControlledDhcpv6Srv::processConfig() - added logic to apply logging
    and commit configuration after  successful reconfig

    ControlledDhcpv6Srv::ControlledDhcpv6Srv(uint16_t port) - added registration
    of set-config command

    ControlledDhcpv6Srv::~ControlledDhcpv6Srv() - unregisters set-config command

src/bin/dhcp6/json_config_parser.cc
    configureCommandChannel() - extracted logic to reconfigure command channel
    to its own fucntion

src/bin/dhcp6/kea_controller.cc
    configure() - removed logic to apply logging and commit config, now done
    in ControlledDhcpv6Srv::processConfig()

src/bin/dhcp6/tests/ctrl_dhcp6_srv_unittest.cc
    TEST_F(CtrlChannelDhcpv6SrvTest, set_config) - new test to exercise the
    set-config command

The timers are scheduled in the ControlledDhcpvXSrv instances. The
unit tests are located in the kea_controller_unittest.cc.