Openshift stable release install centos 7

Question

Please can someone let me know which latest version of openshift-ansible (origin) is stable enough to install on Centos 7?

I am looking for successful multi-node install experience and any tips that was used.

Thanks

Answer 1

the latest stable release is 3.9

git clone https://github.com/openshift/openshift-ansible
cd openshift-ansible
git checkout release-3.9

and follow the Advanced Installation guide

https://docs.openshift.org/latest/install_config/install/advanced_install.html

Answer 2

It is now working.

After enabling openshift_repos_enable_testing=true, I did not run the pre-requisite playbook before the deploy_cluster playbook, which was why it was still giving the error of not finding the packages.

Answer 3

I believe that v3.11.0 version of OpenShift OKD/Origin (latest 3.x release at time) meets your needs. In this answer is a complete roadmap for installing OpenShift OKD/Origin as a single node cluster service.

Some information transposed from the OKD website about OpenShift OKD/Origin...

The Community Distribution of Kubernetes that powers Red Hat OpenShift. Built around a core of OCI container packaging and Kubernetes container cluster management, OKD is also augmented by application lifecycle management functionality and DevOps tooling. OKD provides a complete open source container application platform.

OKD is a distribution of Kubernetes optimized for continuous application development and multi-tenant deployment. OKD adds developer and operations-centric tools on top of Kubernetes to enable rapid application development, easy deployment and scaling, and long-term lifecycle maintenance for small and large teams. OKD is a sibling Kubernetes distribution to Red Hat OpenShift.

OKD embeds Kubernetes and extends it with security and other integrated concepts. OKD is also referred to as Origin in github and in the documentation.

If you are looking for enterprise-level support, or information on partner certification, Red Hat also offers Red Hat OpenShift Container Platform.

So I recommend starting with OpenShift OKD/Origin using the roadmap below to install on CentOS 7. Then you can explore other possibilities ("multi-node", for example).

However, if you want to test the OpenShift (OKD) 4.X application the guide and the right way to do this is at this link Install the OpenShift (OKD) 4.X cluster (UPI/"bare-metal"). It is a long way and with a reasonable level of complexity.

PLUS:

• Informations about OpenShift Ansible on GitHub and RedHat Ansible;
• You can take a look at the OpenShift Installer (NOT OKD/Origin!).

---

• OpenShift Origin (OKD) - Open source container application platform:

OpenShift is a family of containerization software products developed by Red Hat. Its flagship product is the OpenShift Container Platform - an on-premises platform as a service built around Docker containers orchestrated and managed by Kubernetes on a foundation of Red Hat Enterprise Linux. The family's other products provide this platform through different environments: OKD serves as the community-driven upstream (akin to the way that Fedora is upstream of Red Hat Enterprise Linux), OpenShift Online is the platform offered as software as a service, and Openshift Dedicated is the platform offered as a managed service.

The OpenShift Console has developer and administrator oriented views. Administrator views allow one to monitor container resources and container health, manage users, work with operators, etc. Developer views are oriented around working with application resources within a namespace. OpenShift also provides a CLI that supports a superset of the actions that the Kubernetes CLI provides.

The OpenShift Origin (OKD) is the comunity driven version of OpenShift (non-enterprise-level). That means you can host your own PaaS (Platform as a service) for free and almost with no hassle.

[Ref(s).: https://en.wikipedia.org/wiki/OpenShift , https://www.openshift.com/blog/openshift-ecosystem-get-started-openshift-origin-gitlab ]

• Setup Local OpenShift Origin (OKD) Cluster on CentOS 7

All commands in this setup must be performed with the "root" user.

• Update CentOS 7

Updating your CentOS 7 server...

yum -y update

• Install and Configure Docker

OpenShift required docker engine on the host machine for running containers. Install Docker and other dependencies on CentOS 7 using the commands below...

yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
yum -y install git-core
yum -y install wget
yum -y install yum-utils
yum -y install device-mapper-persistent-data
yum -y install lvm2
yum -y install docker-ce
yum -y install docker-ce-cli
yum -y install containerd.io

Add logged in user account to docker group...

usermod -aG docker $USER
newgrp docker

Create necessary folders...

mkdir "/etc/docker"
mkdir "/etc/containers"

Create "registries.conf" file with an insecure registry parameter ("172.30.0.0/16") to the Docker daemon...

tee "/etc/containers/registries.conf" << EOF
[registries.insecure]
registries = ['172.30.0.0/16']
EOF

Create "daemon.json" file with configurations...

tee "/etc/docker/daemon.json" << EOF
{
   "insecure-registries": [
     "172.30.0.0/16"
   ]
}
EOF

We need to reload systemd and restart the Docker daemon after editing the config...

systemctl daemon-reload
systemctl restart docker

Enable Docker to start at boot...

systemctl enable docker

Then enable "IP forwarding" on your system...

tee "/etc/sysctl.d/ip_forward.conf" << EOF
net.ipv4.ip_forward=1
EOF
sysctl -w net.ipv4.ip_forward=1

• Configure Firewalld.

Add the necessary firewall permissions...

firewall-cmd --zone=public --add-port=80/tcp --permanent
firewall-cmd --zone=public --add-port=443/tcp --permanent
firewall-cmd --zone=public --add-port=8443/tcp --permanent
firewall-cmd --zone=public --add-port=53/udp --permanent
firewall-cmd --zone=public --add-port=8053/udp --permanent
firewall-cmd --reload

NOTE: Allows containers access to the OpenShift master API (8443/tcp), DNS (53/udp) endpoints and add others permissions.

• Download OpenShift

Download the OpenShift binaries from GitHub and move them to the "/usr/local/bin/" folder...

wget https://github.com/openshift/origin/releases/download/v3.11.0/openshift-origin-client-tools-v3.11.0-0cbc58b-linux-64bit.tar.gz
tar -zxvf openshift-origin-client-tools-v3.11.0-0cbc58b-linux-64bit.tar.gz
cd ./openshift-origin-client-tools-v3.11.0-0cbc58b-linux-64bit
mv ./oc /usr/local/bin/
mv ./kubectl /usr/local/bin/
rm -rf ./openshift-origin-client-tools-v3.11.0-0cbc58b-linux-64bit*

Verify installation of OpenShift client utility...

oc version

• Start OpenShift Origin (OKD) Local Cluster

Now bootstrap a local single server OpenShift Origin cluster by running the following command...

oc cluster up --public-hostname="<YOUR_SERVER_IP_OR_NAME>"

... or...

oc cluster up --public-hostname="$(ip route get 1 | awk '{print $NF;exit}')"

This one above will get the primary IP address of the local machine dynamically.

[Ref(s).: https://stackoverflow.com/a/25851186/3223785 ]

TIP: In case of error, try perform the command oc cluster down and repeat the command above.

NOTE: Insufficient hardware configuration (mainly CPU and RAM) will cause timeout on the command above.

IMPORTANT: If the parameter --public-hostname="<YOUR_SERVER_IP_OR_NAME>" is not informed, then calls to the web service ("web console") at URL <YOUR_SERVER_IP_OR_NAME> will be redirected to the local IP "127.0 .0.1".

[Ref(s).: https://github.com/openshift/origin/issues/19699 , https://github.com/openshift/origin/issues/19699#issuecomment-854069124 , https://github.com/openshift/origin/issues/20726 , https://github.com/openshift/origin/issues/20726#issuecomment-498078849 , https://hayardillasenlared.blogspot.com/2020/06/instalar-openshift-origin-ubuntu.html , https://www.a5idc.net/helpview_526.html , https://thecodeshell.wordpress.com/ , https://www.techrepublic.com/article/how-to-install-openshift-origin-on-ubuntu-18-04/ ]

The command above will...

1. Start OKD Cluster listening on the interface informed (<YOUR_SERVER_IP_OR_NAME>:8443);
2. Start a web console listening on all interfaces at "/console" (<YOUR_SERVER_IP_OR_NAME>:8443);
3. Launch Kubernetes system components;
4. Provisions registry, router, initial templates and a default project;
5. The OpenShift cluster will run as an all-in-one container on a Docker host.

On a successful installation, you should get output similar to below...

[...]
Login to server ...
Creating initial project "myproject" ...
Server Information ...
OpenShift server started.

The server is accessible via web console at:
    https://<YOUR_SERVER_IP_OR_NAME>:8443

You are logged in as:
    User:     developer
    Password: <any value>

To login as administrator:
    oc login -u system:admin

TIPS:

1. There are a number of options which can be applied when setting up Openshift Origin. View them with oc cluster up --help;
2. Command model using custom options...

MODEL

oc cluster up --public-hostname="<PUBLIC_HOSTNAME_OR_IP>" --routing-suffix="<PUBLIC_HOSTNAME_OR_IP>.<SUFFIX>"

EXAMPLE

oc cluster up --public-hostname="192.168.56.124" --routing-suffix="192.168.56.124.nip.io"

;

3. The OpenShift Origin cluster configuration files will be located inside the "~/openshift.local.clusterup" directory. The "~" is the logged in user home directory.

If your cluster setup was successful the command...

oc cluster status

... will give you a positive output like this...

Web console URL: https://<YOUR_SERVER_IP_OR_NAME>:8443/console/

Config is at host directory 
Volumes are at host directory 
Persistent volumes are at host directory /root/openshift.local.clusterup/openshift.local.pv
Data will be discarded when cluster is destroyed

• Run OpenShift as a single node cluster service on system startup

Create OpenShift service file...

read -r -d '' FILE_CONTENT << 'HEREDOC'
BEGIN
[Unit]
Description=OpenShift oc cluster up service
After=docker.service
Requires=docker.service

[Service]
ExecStart=/usr/bin/bash -c "/usr/local/bin/oc cluster up --public-hostname=\"$(ip route get 1 | awk '{print $NF;exit}')\""
ExecStop=/usr/bin/bash -c "/usr/local/bin/oc cluster down"
Restart=no
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=occlusterup
User=root
Type=oneshot
RemainAfterExit=yes
TimeoutSec=300

[Install]
WantedBy=multi-user.target

END
HEREDOC
echo -n "${FILE_CONTENT:6:-3}" > '/etc/systemd/system/openshift.service'

NOTE: For some reason without the workaround /usr/bin/bash -c "<SOME_COMMAND>" we were unable to start the OpenShift cluster. Additional information about parameters for the oc cluster up command can be seen in the references immediately below.

[Ref(s).: https://avinetworks.com/docs/18.1/avi-vantage-openshift-installation-guide/ , https://github.com/openshift/origin/issues/7177#issuecomment-391478549 , https://github.com/minishift/minishift/issues/1910#issuecomment-375031172 ]

[Ref(s).: https://tobru.ch/openshift-oc-cluster-up-as-systemd-service/ , https://eenfach.de/gitblit/blob/RedHatTraining!agnosticd.git/af831991c7c752a1215cfc4cff6a028e31f410d7/ansible!configs!rhte-oc-cluster-vms!files!oc-cluster.service.j2 ]

Start and enable (start at boot) the OpenShift service and see the log output in sequence...

systemctl enable openshift.service
systemctl start openshift.service
journalctl -u openshift.service -f --no-pager | less

• Using OpenShift OKD/Origin Admin Console

OKD includes a web console which you can use for creation and other management actions. This web console is accessible on server IP/hostname on the port 8443 via https...

https://<IP_OR_HOSTNAME>:8443/console

NOTE: You should see an OpenShift Origin page with username and password form (USERNAME: developer / PASSWORD: developer ).

• Deploy a test application in the Cluster

Login to Openshift cluster as "regular developer" user (USERNAME: developer / PASSWORD: developer )...

oc login

TIP: You begin logged in as "developer".

Create a test project using oc "new-project" command...

MODEL

oc new-project <PROJECT_NAME> --display-name="<PROJECT_DISPLAY_NAME>" --description="<PROJECT_DESCRIPTION>"

EXAMPLE

oc new-project test-project --display-name="Test Project" --description="My cool Test Project."

NOTE: All commands below involving the "deployment-example" parameter value will be linked to the "test-project" because after create this project it will be selected as the project for the subsequent settings. To confirm this login as administrator using the oc login -u system:admin command and see the output of the oc status command. For more information, see the oc project <PROJECT_NAME> command in the "Some OpenShift Origin Cluster Useful Commands" section.

Tag an application image from Docker Hub registry...

oc tag --source=docker openshift/deployment-example:v2 deployment-example:latest

Deploy application to OpenShift...

MODEL

oc new-app <DEPLOYMENT_NAME>

EXAMPLE

oc new-app "deployment-example"

Allow external access to the deployed application...

MODEL

oc expose "svc/<DEPLOYMENT_NAME>"

EXAMPLE

oc expose "svc/deployment-example"

Show application deployment status...

oc status

Show pods status...

oc get pods

Get service detailed information...

oc get svc

Test Application local access...

NOTE: See <CLUSTER_IP> on command oc get svc output above.

curl http://<CLUSTER_IP>:8080

See external access route to the deployed application...

oc get routes

Test external access to the application...

Open the URL <HOST_PORT> on your browser.

MODEL

http://<HOST_PORT>

EXAMPLE

http://deployment-example-test-project.192.168.56.124.nip.io

NOTES:

1. See <HOST_PORT> on oc get routes output;
2. The wildcard DNS record *.<IP_OR_HOSTNAME>.nip.io points to OpenShift Origin server IP address.

Delete test project...

MODEL

oc delete project "<PROJECT_NAME>"

EXAMPLE

oc delete project "test-project"

[Ref(s).: https://docs.openshift.com/container-platform/4.2/applications/projects/working-with-projects.html#deleting-a-project-using-the-CLIprojects ]

Delete test deployment...

MODEL

oc delete all -l app="<DEPLOYMENT_NAME>"

EXAMPLE

oc delete all -l app="deployment-example"

Check pods status after deleting the project and the deployment...

oc get pods

TIP: Completely recreate the cluster...

oc cluster down
rm -rf ~/openshift.local.clusterup

. May be necessary reboot the server to delete the above folder;
. The "~" is the logged in user home directory.

• Some OpenShift Origin Cluster Useful Commands

To login as an administrator use...

oc login -u system:admin

As administrator ("system:admin") user you can see informations such as node status...

oc get nodes

To get more detailed information about a specific node, including the reason for the current condition...

MODEL

oc describe node "<NODE_NAME>"

EXAMPLE

oc describe node "localhost"

To display a summary of the resources you created...

oc status

Select a project to perform CLI operations...

oc project "<PROJECT_NAME>"

NOTE: The selected project will be used in all subsequent operations that manipulate project-scoped content.

[Ref(s).: https://docs.openshift.com/container-platform/4.2/applications/projects/working-with-projects.html#viewing-a-project-using-the-CLI_projects ]

To return to the "regular developer" user (USERNAME: developer / PASSWORD: developer )...

oc login

To check who is the logged in user...

oc whoami

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Thanks! =D