setup.sh

#!/bin/bash

# The script is set to fail on unbound variables, so take care when checking if they have
# been set. See: https://unix.stackexchange.com/questions/463034/bash-throws-error-line-8-1-unbound-variable
set -euo pipefail

IFS=$'\n\t'

# Check for Kubernetes Nodes
kube_node_check () {
  echo
  echo Checking Kubernetes connection
  output=$(kubectl get nodes)
  [[ $output = "The connection to the server kubernetes.docker.internal:6443 was refused - did you specify the right host or port?" ]] && echo Problem connecting to Kubernetes
  [[ $output != "The connection to the server kubernetes.docker.internal:6443 was refused - did you specify the right host or port?" ]] && echo Connection verified
}

# Lightstep access token
set_ls_credentials () {
  echo
  echo Setting up an lightstep-credentials secret in Kubernetes
  kubectl create secret generic lightstep-credentials --from-literal=accessToken="$LIGHTSTEP_ACCESS_TOKEN" || echo "Secret already present, not updated. If you've changed your access token please run 'make clean' before running 'make setup' again"
  echo
}

# Run skaffold
run_skaffold () {
  echo
  echo Running skaffold to build and deploy the application
  echo If this is you\'re first time building, it could take around ~20 minutes.
  echo Time to grab some coffee!
  skaffold run
}

# Success
success_message () {
  echo
  echo Lightstep mock application is running, happy hacking!
  echo Go to http://localhost to visit the application.
  echo Visit https://app.lightstep.com to see the telemetry data.
}

# Wait for store
wait_for_store () {
  echo -n "Waiting for store to be ready"
  until $(curl --output /dev/null --silent --head --fail http://localhost); do
    printf '.'
    sleep 5
  done
}

# Called if the user is deploying to GKE. Ensures the necessary environment
# variables are set.
gke_steps () {
  echo
  echo Great!
  echo

  if [ -z "${GCP_PROJECT_ID-}" ]  
  then
    echo Please set the GCP_PROJECT_ID environment variable first
    echo so we know where to deploy the cluster! See the README
    echo if you need help!
    echo
    exit
  fi

  set_ls_credentials
  make run
}

# Docker for Desktop steps
docker_for_desktop_steps () {
 echo
 echo Great! Please, launch Docker for Desktop and go to \"Preferences\": 
 echo • choose \"Enable Kubernetes \"
 echo • set CPUs to at least 3, and Memory to at least 6.0 GiB
 echo • on the "Disk" tab, set at least 32 GB disk space
 echo
 read -p "Is Docker for Desktop configured and running? (y/n) " -n 1 -r
 echo    # (optional) move to a new line
 if [[ $REPLY =~ ^[Yy]$ ]]
 then
  kube_node_check #TODO better error handling
  set_ls_credentials
  run_skaffold
  wait_for_store
  success_message
 fi
}

# Minikube steps
minikube_steps () {
 echo
 echo Great! Please, launch Minikube with at least 4 CPU\'s and 4Gib memory
 echo
 read -p "Is Minikube is running? (y/n)" -n 1 -r
 echo    # (optional) move to a new line
 if [[ $REPLY =~ ^[Yy]$ ]]
 then
  echo Starting Minikube
  minikube start --cpus=4 --memory 4096
  kube_node_check #TODO better error handling
  set_ls_credentials
  run_skaffold
  wait_for_store
  success_message
 fi
}

check_env_variables () {  
  if [ -z "${LIGHTSTEP_ACCESS_TOKEN-}" ]
  then
    echo Please set the LIGHTSTEP_ACCESS_TOKEN environment variable to get
    echo started. Check out the README if you need help.
    echo
    exit
  fi
}

# Welcome
echo 
echo Welcome to the Lightstep Mock Application Setup!
echo
check_env_variables
echo Help answer a couple questions about your environment and we\'ll get you up and running.
echo
# What Kubernetes cluster is being used?
echo What kind of Kubernetes cluster are you using?
PS3='Please enter your choice: '
options=("Google Kubernetes Engine (GKE)" "Docker for Desktop" "Minikube" "Quit")
select opt in "${options[@]}"
do
    case $opt in
        "Google Kubernetes Engine (GKE)")
            gke_steps
            break
            ;;
        "Docker for Desktop")
            docker_for_desktop_steps
            break
            ;;
        "Minikube")
            minikube_steps
            break
            ;;
        "Quit")
            break
            ;;
        *) echo "Please enter a number for one of the options above";;
    esac
done