.. _tips:

Tips and tricks
================

Namespace switching
---------------------

The CoCalc OnPrem deployment is namespace-agnostic, but this documentation assumes it has been installed in the ``cocalc`` namespace and hence you find ``-n cocalc`` added to some kubectl/helm commands.
If you issue these commands, you have to explicitly specify the namespace all the time.

However, it's possible to switch the default namespace configuration of your current kubectl context by running:

.. code-block:: bash

    kubectl config set-context --current --namespace=cocalc

This will allow you to run commands without the ``-n cocalc`` flag.

More general, here is a simple bash function, called ``ns``, to either list all available namespaces, or it lets you select a namespace to switch to, by providing the start of the namespace's name (it matches based on the beginning of the string):

.. code-block:: bash

    ns() {
        NSs=$(kubectl get namespaces -o json | jq -r '.items[].metadata.name')
        if [[ -z "$1" ]]; then
            echo "Select one of these namespaces (first substring that matches is enough):"
            echo "$NSs"
            return
        fi
        for n in $NSs; do
            if [[ "$n" =~ ^.*$1.*$ ]]; then
                echo "switching to $n"
                kubectl config set-context --current --namespace=$n
                return
            fi
        done
        echo "NO MATCH FOR '$1'"
    }

.. note::

    Then use it like ``ns coc`` to switch to the ``cocalc`` namespace or ``ns def`` to go back to the default namespace.

Additionally, you can adjust your ``$PS1`` prompt to show the context and current namespace.
This gives you a visual indication of the current namespace and context, which is very helpful when working with multiple clusters and namespaces:

.. code-block:: bash

    _context() {
        command kubectl config current-context
    }

    _namespace() {
        command kubectl config view --minify --output 'jsonpath={..namespace}'
    }

    export PS1='[`_context`/`_namespace`] \[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]> '

How to use this? Put all of the above into a file, let's call it ``activate.sh``, and then source it in your shell:

.. code-block:: bash

    . activate.sh

Now you can use the ``ns`` function to switch namespaces and your prompt will show the current context and namespace.