On 24.11.2016 16:11, Gabe Alford wrote:
On Thu, Nov 24, 2016 at 1:29 AM, Martin Basti <mba...@redhat.com <mailto:mba...@redhat.com>> wrote:



    On 24.11.2016 07:06, David Kupka wrote:

        On 22/11/16 23:15, Gabe Alford wrote:

            I would say that it is worth keeping in FreeIPA. I know
            myself and some
            customers use its functionality by having the clients sync
            to the IPA
            servers and have the servers sync to the NTP source. This
            way if the NTP
            source ever gets disrupted for long periods of time (which
            has happened in
            my environment) the client time drifts with the
            authentication source. This
            is the way that AD often works and is configured.


        Hello Gabe,
        I agree that it's common practice to synchronize all nodes in
        network with single source in order to have the same time and
        save bandwidth. Also I understand that it's comfortable to let
        FreeIPA installer take care of it.
        But I don't think FreeIPA should do it IMO this is job for
        Ansible or similar tool. Also the problem is that in some
        situations FreeIPA installer makes it worse.

        Example:

        1. Install FreeIPA server (ipa1.example.org
        <http://ipa1.example.org>)
        2. Install FreeIPA client on all nodes in network
        3. Install replica (ipa2.example.org
        <http://ipa2.example.org>) of FreeIPA server to increase
        redundancy


Why not have NTP look at a _srv_records?

Do ntpclients support this natively? I just found some ugly hacks for chrony, i.e extra service that is dynamically changing config file.
But yes this may be way too, but dirty.


        Now all the clients have ipa1.example.org
        <http://ipa1.example.org> as the only server in /etc/ntp.conf.
        If the first FreeIPA server becomes unreachable all clients
        will be able to contact KDC on the other server thanks to DNS
        autodiscovery in libkrb5 but will be unable to synchronize time.


    This can be resolved by DHCP configured NTP. When NTP server
    changed, you just change DHCPd config and hosts conf will be synced.
    We may keep NTP on IPA server side configured, but I'm voting for
    removing it from clients and document+endorse people to use DHCP
    (anyway distros have always enabled some time synchronization so
    it should naturally work without even in small deployments)


If NTP is still configured on the IPA server, this may be less of an issue. Not everyone has/is/will be using ansible. Also in secure environments, DHCP
is not allowed/used at all.

    Also NTP is somehow incompatible with containers, usually
    containers have time synchronized from host, and by default IPA
    client container don't do NTP configuration.


Isn't that what the --no-ntp option in the client is for anyway?


    Let deprecate it in 4.5

    Martin^2




            On Tue, Nov 22, 2016 at 7:05 AM, Jan Cholasta
            <jchol...@redhat.com <mailto:jchol...@redhat.com>> wrote:

                On 22.11.2016 13:06, Petr Spacek wrote:

                    On 22.11.2016 12:15, David Kupka wrote:

                        Hello everyone!

                        Is it worth to keep configuring NTP in FreeIPA?

                        In usual environment there're no special
                        requirements for time
                        synchronization
                        and the distribution default (be it ntpd,
                        chrony or anything else) will
                        just
                        work. Any tampering with the configuration
                        can't make it any better.

                        In environment with special requirements
                        (network disconnected from
                        public
                        internet, nodes disconnected from topology for
                        longer time, ...) time
                        synchronization must be taken care of
                        accordingly by system
                        administrator and
                        FreeIPA simply can't help here.

                        Also there are problems and weird behavior
                        with the current FreeIPA
                        installers:

                        * ipa-client-install replaces all servers in
                        /etc/ntp.conf with the ones
                        specified by user or resolved from DNS. If
                        none were provided nor
                        resolved the
                        FreeIPA server specified/resolved during
                        installation it used. This
                        leads in
                        just single server in the configuration and no
                        time synchronization when
                        this
                        server is down/decommissioned.

                        * ipa-client-install replaces the NTP
                        configuration. If there was any
                        parts
                        previously edited by system administrator it's
                        lost.

                        * ipa-server-install adds
                        {0-4}.$PLATFORM.pool.ntp.org
                        <http://PLATFORM.pool.ntp.org> to /etc/ntp.conf.
                        What's the point in doing that? These
                        servers're already in the
                        configuration
                        file installed with ntp package.

                        I have NTP-related WIP patches that solve some
                        of the issues but in
                        general I
                        would prefer to remove the whole thing
                        together with documenting "Please
                        make
                        sure that time on all FreeIPA servers and
                        clients is synchronized. On
                        most
                        distributions this was already done during
                        system installation."

                        Can we mark NTP options deprecated in 4.5 and
                        remove them and stop
                        touching
                        any time syncing service in 4.6?


                    Considering that default config is just fine for
                    normal cases, and given
                    how
                    poorly integrated it is into FreeIPA, I agree with
                    David. FreeIPA should
                    get
                    out of configuration management business.


                +1

-- Jan Cholasta


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