Shell command line expansion from kubernetes aliases; even complete in system namespace if bash alias uses that

bashrc_kubernetes_alias_completions.sh

# source kubectl bash completions
if hash kubectl 2>/dev/null; then
    source <(kubectl completion bash)
fi

# the magic via https://github.com/cykerway/complete-alias
# seems to require BASH 4; install bash from Homebrew and make its BASH 4 the default user shell in macOS
# mkdir ~/.bash_completion.d
# curl -o ~/.bash_completion.d/bash_complete-alias.sh  https://raw.githubusercontent.com/cykerway/complete-alias/master/completions/bash_completion.sh
if [ -f ~/.bash_completion.d/bash_complete-alias.sh ] ; then
    . ~/.bash_completion.d/bash_complete-alias.sh
fi

# in ~/.bash_aliases (that gets sourced by ~/.bashrc)
# kubernetes
alias kbk="kubectl"
alias kbn="kubectl --namespace=kube-system"

# _complete_alias requires https://github.com/cykerway/complete-alias to be loaded
complete -F _complete_alias kbk
complete -F _complete_alias kbn

To see this in action, you can use the kubectl completions on an alias that specifies kube-system namespace.

kbn logs <TAB>
# completions shows pods in '--namespace=kube-system' as "kbn" alias has that