Automatically download LKE kubeconfigs and appends/replaces them to the ~/.kube/config files

lke.sh

#!/bin/bash
# Description:
#   This script retrieves the kubeconfig files for all Linode Kubernetes Engine (LKE) clusters
#   associated with the user's Linode account and merges them into a single kubeconfig file.
#   The resulting kubeconfig file is saved as ~/.kube/config.
#
# Usage:
#   ./lke_kubeconfig_merge.sh [--debug] [--op]
#
# Options:
#   --debug   Enable debug mode to print additional information during script execution.
#   --op      Use 1Password CLI (op) to retrieve the Linode CLI token.
#
# Requirements:
#   - linode-cli: Linode CLI tool for interacting with Linode API.
#   - jq: Command-line JSON processor for parsing JSON output.
#   - kubectl: Kubernetes command-line tool for interacting with Kubernetes clusters.
#   - 1Password CLI (op): Optional, required if --op flag is used.
#
# Configuration:
#   - LINODE_CLI_TOKEN: Environment variable containing the Linode CLI token.
#     If --op flag is used, the token is retrieved from 1Password using the specified path.
#
# Script Flow:
#   1. Parse command-line options (--debug and --op).
#   2. Check if required dependencies (linode-cli, jq, kubectl) are installed.
#   3. Create the ~/.kube directory if it doesn't exist.
#   4. Initialize an empty kubeconfig file if ~/.kube/config doesn't exist.
#   5. Retrieve the list of LKE cluster IDs associated with the user's Linode account.
#   6. Create a temporary directory for storing individual kubeconfig files.
#   7. Iterate through each cluster ID:
#      - Retrieve the cluster details (name and region) using linode-cli.
#      - Check if the cluster is already present in the kubeconfig file.
#      - If the cluster is not present, retrieve its kubeconfig and save it as a temporary file.
#      - Update the context and user names in the temporary kubeconfig file.
#      - Append the temporary kubeconfig file path to the KUBECONFIG environment variable.
#   8. Merge all the kubeconfig files using kubectl and the KUBECONFIG environment variable.
#   9. Save the merged kubeconfig to ~/.kube/config.
#  10. Clean up the temporary directory.
#
# Note:
#   - The script requires the Linode CLI token to be set in the LINODE_CLI_TOKEN environment variable
#     or retrieved from 1Password using the --op flag.
#   - The script uses the KUBECONFIG environment variable to specify multiple kubeconfig files for merging.
#   - The script checks if a cluster is already present in the kubeconfig file to avoid duplicates.
#   - Debug mode (--debug) can be enabled to print additional information during script execution.

# Set color variables
RED=$(tput setaf 1)
GREEN=$(tput setaf 2)
YELLOW=$(tput setaf 3)
BLUE=$(tput setaf 4)
CYAN=$(tput setaf 6)
RESET=$(tput sgr0)

# Function to print debug messages
debug() {
  if [ "$DEBUG" = true ]; then
    echo "DEBUG: $1"
  fi
}

# Parse command line options
DEBUG=false
USE_OP=false

while [[ $# -gt 0 ]]; do
  case "$1" in
    --debug)
      DEBUG=true
      debug "Debug mode enabled"
      shift
      ;;
    --op)
      USE_OP=true
      debug "Using op to invoke linode-cli"
      shift
      ;;
    *)
      echo "Invalid option: $1" 1>&2
      exit 1
      ;;
  esac
done

# Function to invoke linode-cli
invoke_linode_cli() {
  if [ "$USE_OP" = true ]; then
    LINODE_CLI_TOKEN_VALUE=$(op read "$LINODE_CLI_TOKEN")
    LINODE_CLI_TOKEN="$LINODE_CLI_TOKEN_VALUE" linode-cli "$@"
  else
    linode-cli "$@"
  fi

  # Check if the command was successful
  if [ $? -ne 0 ]; then
    echo "${RED}Error:${RESET} Failed to invoke linode-cli command."
    exit 1
  fi
}

# Check if required dependencies are installed
dependencies=("linode-cli" "jq" "kubectl")
for dependency in "${dependencies[@]}"; do
  if ! command -v "$dependency" >/dev/null 2>&1; then
    echo "${RED}Error:${RESET} $dependency is not installed. Please install it and try again."
    exit 1
  fi
done

debug "Dependencies checked"

# Create the .kube directory if it doesn't exist
mkdir -p ~/.kube

# Initialize an empty kubeconfig file if it doesn't exist
if [ ! -f ~/.kube/config ]; then
  echo "apiVersion: v1
kind: Config
clusters: []
contexts: []
users: []
current-context: \"\"" > ~/.kube/config
  debug "Empty kubeconfig file created"
else
  debug "Existing kubeconfig file found"
fi

# Get the list of cluster IDs
cluster_ids=$(invoke_linode_cli --json lke clusters-list | jq -r '.[].id' 2>/dev/null)
if [ $? -ne 0 ]; then
  echo -e "${RED}Error:${RESET} Failed to retrieve cluster IDs. Please check your Linode CLI token (${CYAN}\$LINODE_CLI_TOKEN${RESET}) and try again."
  exit 1
fi
debug "Cluster IDs: $cluster_ids"

# Initialize the KUBECONFIG variable with the existing kubeconfig file
KUBECONFIG="$HOME/.kube/config"

# Create a temporary directory for storing kubeconfig files
temp_dir=$(mktemp -d)

# Iterate through each cluster ID
for cluster_id in $cluster_ids; do
  debug "Processing cluster ID: $cluster_id"

  # Get the cluster details
  cluster_details=$(invoke_linode_cli --json lke cluster-view "$cluster_id")
  debug "Cluster details: $cluster_details"

  # Extract the cluster name and region
  cluster_name=$(echo "$cluster_details" | jq -r '.[].label')
  cluster_region=$(echo "$cluster_details" | jq -r '.[].region')
  debug "Cluster name: $cluster_name"
  debug "Cluster region: $cluster_region"

  # Check if the cluster already exists in the kubeconfig
  if kubectl config get-contexts | grep -q "$cluster_name"; then
    echo "Cluster $cluster_name already exists in the kubeconfig. Skipping..."
    debug "Cluster $cluster_name already exists in the kubeconfig"
  else
    # Create a temporary kubeconfig file for the cluster
    temp_kubeconfig="$temp_dir/kubeconfig-$cluster_id"
    invoke_linode_cli --json lke kubeconfig-view "$cluster_id" | jq -r '.[].kubeconfig | @base64d' > "$temp_kubeconfig"

    # Update the context and user names in the temporary kubeconfig file
    sed -i.bak "s/name: lke$cluster_id-ctx/name: $cluster_name/" "$temp_kubeconfig"
    #sed -i.bak "s/user: lke$cluster_id-admin/user: $cluster_name-admin/" "$temp_kubeconfig"

    KUBECONFIG="$KUBECONFIG:$temp_kubeconfig"
    echo "Added cluster $cluster_name (Region: $cluster_region) to the KUBECONFIG"
    debug "Cluster $cluster_name (Region: $cluster_region) added to the KUBECONFIG"
  fi
done

# Merge the kubeconfig files using kubectl and the KUBECONFIG variable
KUBECONFIG="$KUBECONFIG" kubectl config view --flatten > ~/.kube/config.tmp
if [ $? -eq 0 ]; then
  mv ~/.kube/config.tmp ~/.kube/config
  chmod 600 ~/.kube/config
  echo "${GREEN}Success:${RESET} Kubeconfig updated successfully"
else
  echo "${RED}Error:${RESET} Failed to merge kubeconfig files."
  rm -f ~/.kube/config.tmp
  exit 1
fi

# Clean up the temporary directory
rm -rf "$temp_dir"