Use IP addresses for OpenStack nodes

Unlike other cloud providers, OpenStack VMs are not able to resolve each
other by their names. If you try to run the playbooks against nodes
without a pre-created /etc/hosts or a DNS that provides the hostname/ip
resolution, it will fail.

By setting the `openshift_hostname` variable to each node's IP address,
we're able to deploy a functional cluster without running a custom DNS.

It is still possible to provide an external server with nsupdate keys
and have it be populated, but that is no longer a hard requirement.

5 files changed, 44 insertions, 78 deletions

diff --git a/playbooks/openstack/README.md b/playbooks/openstack/README.md
index f3fe13530..c762169eb 100644
--- a/playbooks/openstack/README.md
+++ b/playbooks/openstack/README.md
@@ -6,7 +6,7 @@ etc.). The result is an environment ready for OpenShift installation
 via [openshift-ansible].
 
 We provide everything necessary to be able to install OpenShift on
-OpenStack (including the DNS and load balancer servers when
+OpenStack (including the load balancer servers when
 necessary). In addition, we work on providing integration with the
 OpenStack-native services (storage, lbaas, baremetal as a service,
 dns, etc.).
@@ -38,18 +38,6 @@ Optional:
 * External Neutron network with a floating IP address pool
 
 
-## DNS Requirements
-
-OpenShift requires DNS to operate properly. OpenStack supports DNS-as-a-service
-in the form of the Designate project, but the playbooks here don't support it
-yet. Until we do, you will need to provide a DNS solution yourself (or in case
-you are not running Designate when we do).
-
-If your server supports nsupdate, we will use it to add the necessary records.
-
-TODO(shadower): describe how to build a sample DNS server and how to configure
-our playbooks for nsupdate.
-
 
 ## Installation
 
@@ -57,14 +45,13 @@ There are four main parts to the installation:
 
 1. [Preparing Ansible and dependencies](#1-preparing-ansible-and-dependencies)
 2. [Configuring the desired OpenStack environment and OpenShift cluster](#2-configuring-the-openstack-environment-and-openshift-cluster)
-3. [Creating the OpenStack resources (VMs, networking, etc.)](#3-creating-the-openstack-resources-vms-networking-etc)
-4. [Installing OpenShift](#4-installing-openshift)
+3. [Creating the OpenStack Resources and Installing OpenShift](#3-creating-the-openstack-resources-and-installing-openshift)
 
 This guide is going to install [OpenShift Origin][origin]
 with [CentOS 7][centos7] images with minimal customisation.
 
-We will create the VMs for running OpenShift, in a new Neutron
-network, assign Floating IP addresses and configure DNS.
+We will create the VMs for running OpenShift, in a new Neutron network and
+assign Floating IP addresses.
 
 The OpenShift cluster will have a single Master node that will run
 `etcd`, a single Infra node and two App nodes.
@@ -156,14 +143,6 @@ $ vi inventory/group_vars/all.yml
 4. Set the `openshift_openstack_default_flavor` to the flavor you want your
    OpenShift VMs to use.
    - See `openstack flavor list` for the list of available flavors.
-5. Set the `openshift_openstack_dns_nameservers` to the list of the IP addresses
-   of the DNS servers used for the **private** address resolution.
-
-**NOTE ON DNS**: at minimum, the OpenShift nodes need to be able to access each
-other by their hostname.  OpenStack doesn't provide this by default, so you
-need to provide a DNS server. Put the address of that DNS server in
-`openshift_openstack_dns_nameservers` variable.
-
 
 
 
@@ -191,7 +170,7 @@ the [Sample OpenShift Inventory][sample-openshift-inventory] and
 the [advanced configuration][advanced-configuration].
 
 
-### 3. Creating the OpenStack resources (VMs, networking, etc.)
+### 3. Creating the OpenStack Resources and Installing OpenShift
 
 We provide an `ansible.cfg` file which has some useful defaults -- you should
 copy it to the directory you're going to run `ansible-playbook` from.
@@ -200,11 +179,11 @@ copy it to the directory you're going to run `ansible-playbook` from.
 $ cp openshift-ansible/ansible.cfg ansible.cfg
 ```
 
-Then run the provisioning playbook -- this will create the OpenStack
+Then run the provision + install playbook -- this will create the OpenStack
 resources:
 
 ```bash
-$ ansible-playbook --user openshift -i inventory openshift-ansible/playbooks/openstack/openshift-cluster/provision.yaml
+$ ansible-playbook --user openshift -i inventory openshift-ansible/playbooks/openstack/openshift-cluster/provision_install.yaml
 ```
 
 If you're using multiple inventories, make sure you pass the path to
@@ -214,15 +193,6 @@ If your SSH private key is not in `~/.ssh/id_rsa` use the `--private-key`
 option to specify the correct path.
 
 
-### 4. Installing OpenShift
-
-Run the `byo/config.yml` playbook on top of the OpenStack nodes we have
-prepared.
-
-```bash
-$ ansible-playbook -i inventory openshift-ansible/playbooks/byo/config.yml
-```
-
 
 ### Next Steps
 
diff --git a/playbooks/openstack/advanced-configuration.md b/playbooks/openstack/advanced-configuration.md
index 90cc20b98..03f9c84cc 100644
--- a/playbooks/openstack/advanced-configuration.md
+++ b/playbooks/openstack/advanced-configuration.md
@@ -47,44 +47,42 @@ Otherwise, even if there are differences between the two versions, installation
 
 ## Accessing the OpenShift Cluster
 
-### Use the Cluster DNS
+### Configure DNS
 
-In addition to the OpenShift nodes, we created a DNS server with all
-the necessary entries. We will configure your *Ansible host* to use
-this new DNS and talk to the deployed OpenShift.
+OpenShift requires two DNS records to function fully. The first one poinst to
+the master/load balancer and provides the UI/API access. The other one is a
+wildcard domain that resolves app route requests to the infra node.
 
-First, get the DNS IP address:
+If you followed the default installation from the README section, there is no
+DNS configured.  We can add two entries to your `/etc/hosts` to do a quick
+validation. A real deployment will however require a DNS server with the
+following entries set.
 
-```bash
-$ openstack server show dns-0.openshift.example.com --format value --column addresses
-openshift-ansible-openshift.example.com-net=192.168.99.11, 10.40.128.129
-```
-
-Note the floating IP address (it's `10.40.128.129` in this case) -- if
-you're not sure, try pinging them both -- it's the one that responds
-to pings.
+First, run the `openstack server list` command and note the floating IP
+addresses of the *master* and *infra* nodes (we will use `10.40.128.130` for
+master and `10.40.128.134` for infra here).
 
-Next, edit your `/etc/resolv.conf` as root and put `nameserver DNS_IP` as your
-**first entry**.
-
-If your `/etc/resolv.conf` currently looks like this:
+Then add the following entries to your `/etc/hosts`:
 
 ```
-; generated by /usr/sbin/dhclient-script
-search openstacklocal
-nameserver 192.168.0.3
-nameserver 192.168.0.2
+10.40.128.130 console.openshift.example.com
+10.40.128.134 cakephp-mysql-example-test.apps.openshift.example.com
 ```
 
-Change it to this:
+I.e. point the cluster domain (as defined in the
+`openshift_master_cluster_public_hostname` Ansible variable in `OSEv3`) to the
+master node and any routes for deployed apps to the infra node.
+
+If you deploy another app, it will end up with a different URL (e.g.
+myapp-test.apps.openshift.example.com) and you will need to add that too.  This
+is why a real deployment should always run a DNS where the second entry will be
+a wildcard `*.apps.openshift.example.com).
+
+This will be sufficient to validate the cluster here.
+
+Take a look at the [External DNS](#dns-configuration-variables) section for
+configuring a DNS service.
 
-```
-; generated by /usr/sbin/dhclient-script
-search openstacklocal
-nameserver 10.40.128.129
-nameserver 192.168.0.3
-nameserver 192.168.0.2
-```
 
 ### Get the `oc` Client
 
diff --git a/playbooks/openstack/sample-inventory/group_vars/OSEv3.yml b/playbooks/openstack/sample-inventory/group_vars/OSEv3.yml
index 1e55adb9e..90608bbc0 100644
--- a/playbooks/openstack/sample-inventory/group_vars/OSEv3.yml
+++ b/playbooks/openstack/sample-inventory/group_vars/OSEv3.yml
@@ -5,8 +5,7 @@ openshift_deployment_type: origin
 openshift_master_default_subdomain: "apps.{{ openshift_openstack_clusterid }}.{{ openshift_openstack_public_dns_domain }}"
 
 openshift_master_cluster_method: native
-openshift_master_cluster_hostname: "console.{{ openshift_openstack_clusterid }}.{{ openshift_openstack_public_dns_domain }}"
-openshift_master_cluster_public_hostname: "{{ openshift_master_cluster_hostname }}"
+openshift_master_cluster_public_hostname: "console.{{ openshift_openstack_clusterid }}.{{ openshift_openstack_public_dns_domain }}"
 
 osm_default_node_selector: 'region=primary'
 
diff --git a/playbooks/openstack/sample-inventory/group_vars/all.yml b/playbooks/openstack/sample-inventory/group_vars/all.yml
index 921edb867..ae1528123 100644
--- a/playbooks/openstack/sample-inventory/group_vars/all.yml
+++ b/playbooks/openstack/sample-inventory/group_vars/all.yml
@@ -10,7 +10,6 @@ openshift_openstack_dns_nameservers: []
 #openshift_openstack_node_hostname: "app-node"
 #openshift_openstack_lb_hostname: "lb"
 #openshift_openstack_etcd_hostname: "etcd"
-#openshift_openstack_dns_hostname: "dns"
 
 openshift_openstack_keypair_name: "openshift"
 openshift_openstack_external_network_name: "public"
@@ -34,7 +33,6 @@ openshift_openstack_external_network_name: "public"
 #openshift_openstack_node_image_name: "centos7"
 #openshift_openstack_lb_image_name: "centos7"
 #openshift_openstack_etcd_image_name: "centos7"
-#openshift_openstack_dns_image_name: "centos7"
 openshift_openstack_default_image_name: "centos7"
 
 openshift_openstack_num_masters: 1
@@ -49,7 +47,6 @@ openshift_openstack_num_nodes: 2
 #openshift_openstack_node_flavor: "m1.medium"
 #openshift_openstack_lb_flavor: "m1.medium"
 #openshift_openstack_etcd_flavor: "m1.medium"
-#openshift_openstack_dns_flavor: "m1.medium"
 openshift_openstack_default_flavor: "m1.medium"
 
 # # Numerical index of nodes to remove
@@ -62,7 +59,6 @@ openshift_openstack_default_flavor: "m1.medium"
 #openshift_openstack_docker_infra_volume_size: "15"
 #openshift_openstack_docker_node_volume_size: "15"
 #openshift_openstack_docker_etcd_volume_size: "2"
-#openshift_openstack_docker_dns_volume_size: "1"
 #openshift_openstack_docker_lb_volume_size: "5"
 openshift_openstack_docker_volume_size: "15"
 
@@ -110,7 +106,6 @@ openshift_openstack_subnet_prefix: "192.168.99"
 
 
 # # Roll-your-own DNS
-#openshift_openstack_num_dns: 0
 #openshift_openstack_external_nsupdate_keys:
 #  public:
 #    key_secret: 'SKqKNdpfk7llKxZ57bbxUnUDobaaJp9t8CjXLJPl+fRI5mPcSBuxTAyvJPa6Y9R7vUg9DwCy/6WTpgLNqnV4Hg=='
@@ -121,10 +116,6 @@ openshift_openstack_subnet_prefix: "192.168.99"
 #    key_algorithm: 'hmac-md5'
 #    server: '192.168.1.2'
 
-# # Customize DNS server security options
-#named_public_recursion: 'no'
-#named_private_recursion: 'yes'
-
 
 # NOTE(shadower): Do not change this value. The Ansible user is currently
 # hardcoded to `openshift`.
diff --git a/playbooks/openstack/sample-inventory/inventory.py b/playbooks/openstack/sample-inventory/inventory.py
index 47c56d94d..6fa219f22 100755
--- a/playbooks/openstack/sample-inventory/inventory.py
+++ b/playbooks/openstack/sample-inventory/inventory.py
@@ -79,10 +79,18 @@ def build_inventory():
 
         public_v4 = server.public_v4 or server.private_v4
         if public_v4:
-            hostvars['public_v4'] = public_v4
+            hostvars['public_v4'] = server.public_v4
+            hostvars['openshift_public_ip'] = server.public_v4
         # TODO(shadower): what about multiple networks?
         if server.private_v4:
             hostvars['private_v4'] = server.private_v4
+            # NOTE(shadower): Yes, we set both hostname and IP to the private
+            # IP address for each node. OpenStack doesn't resolve nodes by
+            # name at all, so using a hostname here would require an internal
+            # DNS which would complicate the setup and potentially introduce
+            # performance issues.
+            hostvars['openshift_ip'] = server.private_v4
+            hostvars['openshift_hostname'] = server.private_v4
 
         node_labels = server.metadata.get('node_labels')
         if node_labels: