Command line tool usage
Rahti can be used via the command line either with OpenShift's oc tool or with the kubectl tool from Kubernetes. Certain features specific to OpenShift are only available when using the oc tool.
How to install the
The oc tool is a single binary that only needs to be included in your path. You may download it from the latest release page in GitHub. The detailed instructions are:
- Go to the aforementioned release page (https://github.com/openshift/origin/releases/latest). In the bottom you will see the list of clients. Download the "Openshift origin client" corresponding to your OS (Windows, Mac or Linux).
- Once downloaded, extract the
- Copy the file to a folder in your
$PATHand make it executable. For Mac and Linux the steps are similar to the following:
$ echo $PATH /usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:~/bin $ mkdir -p ~/bin $ cp oc ~/bin/ $ chmod +x ~/bin/oc
In the example above, we are displaying the contents of the
$PATH variable, choosing the bin folder in the home (~) folder, using
mkdir just to be sure that the folder exist, copy the oc command (of course, we have to be in the folder
oc was downloaded), and finally adding executable (
+x) permissions to the
oc binary. That is all.
In order to test that it was properly installed, open a new terminal, go to any folder, and run:
$ oc --help
It should show the list of all available commands.
The "Command Line Tools" page in the OpenShift web UI
Instructions for downloading the oc tool and logging in via the command line can be found in the "Command Line Tools" page in the web interface:
How to login with
The oc login command to login can be found in one of the fields on the page. There is a button next to it for copying the command to the clipboard:
Copy the command and paste it in a terminal to start using OpenShift via the command line.
If you open multiple terminals, the login session for oc will be active in all of them.
How to login in the registry?
In order to use Rahti internal container registry, it is necessary to login separately. Once you login, it is possible to use the client docker to
push from Rahti's registry.
Using personal account
After login with
oc, it is possible to use the command to generate a token (
oc whoami -t):
docker login -p $(oc whoami -t ) -u unused docker-registry.rahti.csc.fi
Using a service account token
Rahti also offers the opportunity of using an internal service account to interact with the registry. This is recommended for automated procedures like a CI pipeline. Even though by default 3 internal service accounts are created in every Rahti namespace: builder, default and deployer, it is recommended to create a dedicated internal service account and assign to it the
oc create serviceaccount pusher oc policy add-role-to-user system:image-pusher pusher docker login -p $(oc sa get-token pusher) -u unused docker-registry.rahti.csc.fi
This service account token, the one you get with
oc sa get-token pusher does not expire.
CLI cheat sheet
oc <command> <--flags> oc help <command>
Authorize the CLI tool to the cluster:
oc login https://rahti.csc.fi:8443 --token=<secret access token>
This command can be obtained by clicking your usename and "Copy Login Command" in the web console:
Switch to project
oc project my-project
Show all pods in the current namespace:
oc get pods
Show all pods in the namespace
oc get pods -n <my-other-namespace>
Show all pods that have the key-value pair
app: myapp in
oc get pods --selector app=myapp
Print the specifications of the pod
oc get pod mypod -o yaml
Other useful commands
oc createcreates an object. Example:
oc create -f file.yaml
oc replacereplaces an object. Example:
oc replace -f file.yaml
oc deletedeletes an object in OpenShift. Example:
oc delete rc myreplicationcontroller
oc applymodifies an object according to the input. Example
oc apply -f file.yaml
oc explainprints out the API documentation. Example:
oc explain dc.spec
oc editloads an object from the API to the local editor chosen by the
$EDITORenvironment variable. Example:
oc edit DeploymentConfig mydc
Object types have abbreviations that are recognized in the CLI:
See the official documentation for more information about using the command line interface:
Last edited Thu Apr 15 2021