On Wed, Sep 25, 2013 at 11:12:02AM +0200, Jakub Hrozek wrote:
> Hi,
>
> the attached patch fixes
>
https://fedorahosted.org/sssd/ticket/2079
>
>
> I also opened
https://fedorahosted.org/freeipa/ticket/3947 to stop
> setting the dns_discovery_domain parameter from the IPA installer
> completely.
> From e714f3ef180934fa92ca805384ddbf1a510051c8 Mon Sep 17 00:00:00 2001
> From: Jakub Hrozek <jhrozek(a)redhat.com>
> Date: Wed, 25 Sep 2013 11:03:16 +0200
> Subject: [PATCH] IPA: Ignore dns_discovery_domain in server mode
>
>
https://fedorahosted.org/sssd/ticket/2079
> ---
> src/providers/ipa/ipa_init.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/src/providers/ipa/ipa_init.c b/src/providers/ipa/ipa_init.c
> index
a5ab881821c3d169285cb1dca7605a221b4cf604..f5e482344f405abd453bf54ed24110cebc65fb65 100644
> --- a/src/providers/ipa/ipa_init.c
> +++ b/src/providers/ipa/ipa_init.c
> @@ -256,6 +256,18 @@ int sssm_ipa_id_init(struct be_ctx *bectx,
> be_fo_set_srv_lookup_plugin(bectx, ipa_srv_plugin_send,
> ipa_srv_plugin_recv, srv_ctx,
"IPA");
> } else if (server_mode == true) {
> + /* In server mode we need to ignore the dns_discovery_domain if set
> + * and only discover servers based on AD domains
> + */
> + ret = dp_opt_set_string(bectx->be_res->opts, DP_RES_OPT_DNS_DOMAIN,
> + NULL);
In general I agree with the patch mainly because it looks there is no
easy way to only let the AD SRV plugin in ipa_server_mode know to ignore
the option.
But I would suggest to add some extra checks.
The dns_discovery_domain option is only set by ipa-client-install if the
host where ipa-client-install is running is not from the IPA domain.
Because in this case it might not be possible to find IPA server with
DNS SRV lookups where the domain name of the host is used. But since we
are running on a server (server_mode == true) ipa-client-install will by
default not configure any SRV lookups for the IPA server, i.e. there
will be no _srv_ in the ipa_server option.
So with the default everything would work well with the patch. But if
someone modifies sssd.conf manually it might break. I would suggest to
check if the DNS domain of the host is the same as the IPA domain. If
not and ipa_server only contains _srv_ I would not set
DP_RES_OPT_DNS_DOMAIN to NULL but send a log message even to syslog
telling the admin that AD lookups will not work in this setup and
ipa_server should only contain the local hostname.
OK, you're right we should add more checks, see the attached patch.
But I think we should warn anytime the dns_discovery_domain is used. Because
the current failover code would blindly use it for AD discovery, the setup
could only ever work if dns_discovery_domain was set to the AD domain. Then
the SSSD could fail over from SRV to local hostname and AD would use the
DNS domain.