Helpers for working with kubernetes

kube_helpers.sh

#!/bin/bash

# A shell function to connect to a running pod for a given application.
#
# Usage:
#   source get_pod_name.sh  # Or add to your .bashrc/.zshrc
#   kubessh <app-name>
#
# Example: kubessh nginx

kubessh() {
  # Check if an application name was provided.
  if [ -z "$1" ]; then
    echo "Usage: kubessh <app-name>"
    return 1
  fi

  local APP_NAME=$1
  
  echo "Attempting to connect to a pod with the 'app=${APP_NAME}' label..."

  # Get the name of a running pod for the specified application label.
  # We use a label selector and JSONPath to filter for the first pod name.
  # The --field-selector is added to only get pods that are "Running".
  local POD=$(kubectl get pods --field-selector=status.phase=Running \
    --selector=app=${APP_NAME} \
    -o=jsonpath='{.items[0].metadata.name}' 2>/dev/null)

  # Check if a pod name was found.
  if [ -z "$POD" ]; then
    echo "Error: No running pod found with label 'app=${APP_NAME}'."
    echo "Please check the application name and try again."
    return 1
  fi

  echo "Found pod: ${POD}"
  
  # Execute a bash shell inside the found pod.
  echo "Connecting to pod..."
  kubectl exec -it ${POD} -- /bin/bash
}

# A shell function to stream the logs from a running pod for a given application.
#
# Usage:
#   kubelogs <app-name>
#
# Example: kubelogs nginx

kubelogs() {
  # Check if an application name was provided.
  if [ -z "$1" ]; then
    echo "Usage: kubelogs <app-name>"
    return 1
  fi

  local APP_NAME=$1
  
  echo "Attempting to get logs for a pod with the 'app=${APP_NAME}' label..."

  # Get the name of a running pod for the specified application label.
  local POD=$(kubectl get pods --field-selector=status.phase=Running \
    --selector=app=${APP_NAME} \
    -o=jsonpath='{.items[0].metadata.name}' 2>/dev/null)

  # Check if a pod name was found.
  if [ -z "$POD" ]; then
    echo "Error: No running pod found with label 'app=${APP_NAME}'."
    echo "Please check the application name and try again."
    return 1
  fi

  echo "Found pod: ${POD}"
  
  # Stream the logs from the found pod using the -f (follow) flag.
  echo "Streaming logs from pod..."
  kubectl logs -f ${POD}
}

Make sure to "source" this from .bashrc.

if [ -f $HOME/local/bin/kube_helpers.sh ]; then
  source $HOME/local/bin/kube_helpers.sh
fi