The method of installation that you shall be using for this session would be the 'Advanced Installation' method which uses Ansible playbooks for automating the installation of OpenShift Container Platform cluster (version 3.5). The host preparation and prerequisites needed for the installation have already been done.
Step 1. Examining the provided Ansible inventory file - Let us start by examining the Ansible inventory files which contains the host information. To perform the further steps, you will need to run the commands on the 'master' host.
To get the private key, download from the Qwiklabs page that pops up right after you click on the class and press Start. Store it on the localhost machine and keep note of the path where you have downloaded the .pem key.
The Ip to log into the master host will be in the STACK OUTPUTS: block , under the Additional information section -
example -
MasterIPAddress: 54.164.181.5
Use this command to SSH into the master host -
$ ssh -i <path/private_key.pem> cloud-user@<Public_DNS_IP>
Replace `path`by the path where you have stored the private keyand replace <Public_DNS> by the information shown on instance page.
1) Check the /etc/ansible/hosts to view the configurations done for clouster variables and host variables:
# cat /etc/ansible/hosts
The variables are defined on separate,single lines within the '[OSEv3:vars]' section.
Ensure the deployment_type parameter in your inventory file’s [OSEv3:vars] section is set to openshift-enterprise to install the OpenShift Container Platform variant:
deployment_type=openshift-enterprise
If you want a detailed list of all the cluster variables, you can refer the following page -
This lists all the hosts and the functions and variables for master, 3 nodes and infrastructure node.
2) To configure host variables, indicate the defined variables under [master] or [nodes] section.
3) You can assign labels to node hosts during the Ansible installation. To assign labels to a node host during an Ansible install, use the openshift_node_labels variable with the desired labels added to the desired node host entry in the [nodes] section. In the following example, labels are set for a region called primary and a zone called east:
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
Step 2. Running the Advanced Installation -
# ansible-playbook /usr/share/ansible/openshift-ansible/playbooks/byo/config.yml
The above command runs the ansible playbook to start the advanced installation.
Step 3. Verifying the Installation - 1) Run as 'root' user on the master node :
# oc get nodes
Using the above command verify that the master is started and the nodes are in Ready status. The result should be similar to -
NAME STATUS AGE
{{MASTER_INTERNAL_FQDN}} Ready,SchedulingDisabled 1m
{{NODE1_INTERNAL_FQDN}} Ready 1m
{{NODE2_INTERNAL_FQDN}} Ready 1m
{{NODE3_INTERNAL_FQDN}} Ready 1m
You should be able to see a list of all the hosts mentioned in the inventory file - i.e. 1 master node, 1 infrastructure node and 3 application nodes.
2) Verify that the web console is running: Point your browser to {{WEB_CONSOLE_URL}} in order to reach the management interface.
3) Now that the installation has been verified, run the following command on each master and node host to add the atomic-openshift packages back to the list of yum excludes on the host:
# atomic-openshift-excluder exclude
4) Diagnostics Tool : OpenShift also provides a diagnostics tool to verify the cluster and run a series of checks for any errors in the host or cluster.
The diagnostics were added to the 'openshift' binary so that wherever there is an OpenShift Origin server or client, the diagnostics can run in the exact same environment.
To use the diagnostics tool, run this command on the master host. This runs all the available diagnostics, skipping any that do not apply. -
$ oc adm diagnostics
To run selective diagnostics, you can include names in the command -
$ oc adm diagnostics NodeConfigCheck UnitStatus
To run diagnostics where the master and node configurations are not in the expected locations, use the following command to specify the location -
$ oc adm diagnostics --master-config=<file_path> --node-config=<file_path>