run.sh

#!/usr/bin/env bash

# This file inspired by this piece of art at
# https://github.com/nickjj/docker-django-example#run
# and when I say inspired, I mean large chunks were copied.

set -euo pipefail

DC="${DC:-exec}"
APP_NAME="${APP_NAME:-influxdb}"

# If we're running in CI we need to disable TTY allocation for docker-compose
# commands that enable it by default, such as exec and run.
TTY=""
if [[ ! -t 1 ]]; then
  TTY="-T"
fi

# Volume names required for this repo.
volumes=("influxdb2-data" "grafana-data" "metrics-caddy-data" "metrics-caddy-config")

post_influx_services=("telegraf" "grafana" "caddy" "renderer")
# -----------------------------------------------------------------------------
# Helper functions start with _ and aren't listed in this script's help menu.
# -----------------------------------------------------------------------------

function _dc {
  docker-compose "${DC}" ${TTY} "${@}"
}

# -----------------------------------------------------------------------------

function cmd {
  # Run any command you want in the influx container
  _dc influxdb "${@}"
}

function up() {
  check_volumes
  echo "Raising docker containers..."
  docker-compose up -d influxdb
  echo "Setting up influx..."
  influx_setup
  echo "Running Telegraf and Grafana containers..."
  docker-compose up -d ${post_influx_services[@]}
  docker cp metrics-caddy:/data/caddy/pki/authorities/local/root.crt ./caddy
}

function check_volumes() {
  for i in ${volumes[@]}
    do
      local vol_name=$(docker volume ls | grep "$i" | awk -F $' +' '{print $2}')
      if [ "$vol_name" == '' ]; then
        echo "Creating $i volume"
        docker volume create "$i" > /dev/null 2>&1
      fi
    done
}

function influx_setup() {
  . .env
  . ./influxdb/influxdb.env
  . ./grafana/grafana.env
  . ./telegraf/telegraf.env

  wait_on_influx

  cmd influx setup \
    -u "$INFLUX_USERNAME" \
    -p "$INFLUX_PASSWORD" \
    -o "$INFLUX_ORG" \
    -b "$INFLUX_BUCKET" \
    -r "$INFLUX_RETENTION" \
    -f
  # Create admin config
  create_admin_config

  # Create write token
  bucket_id="$(get_influxdb_bucket)"
  telegraf_token="$(create_write_token $bucket_id)"
  sed_replacement 'TELEGRAF_WRITE_TOKEN=.*' "TELEGRAF_WRITE_TOKEN=$telegraf_token" '/telegraf/telegraf.env'

  # Create read token
  grafana_token="$(create_read_token)"
  sed_replacement 'GRAFANA_READ_TOKEN=.*' "GRAFANA_READ_TOKEN=$grafana_token" '/grafana/grafana.env'
}

function sed_replacement() {
  local blank_token_text="$1"
  local full_token_text="$2"
  local file="$3"
  if [[ "$OSTYPE" == "darwin"* ]]; then
    sed -i '' "s/$blank_token_text/$full_token_text/" "$PWD/$file"
  else
    sed -i "s/$blank_token_text/$full_token_text/" "$PWD/$file"
  fi
}

function wait_on_influx() {
  # The influx db is not ready when the container is up,
  # wait until health checks are good and then run the setup
  until cmd influx ping > /dev/null 2>&1; do
  >&2 echo "InfluxDB not ready yet - sleeping"
  sleep 1
  done
}

function create_admin_config() {
  local admin_token="$(cmd influx auth list | grep $INFLUX_USERNAME | awk -F $'\t' '{print $3}')"
  cmd influx config create --config-name administrator --host-url "$INFLUX_HOST" --org "$INFLUX_ORG" --token "$admin_token" --active
}

function get_influxdb_bucket() {
  local bucket_id="$(cmd influx bucket list | grep $INFLUX_BUCKET | awk '{print $1}')"
  echo "$bucket_id"
}

function create_write_token() {
  # use this function with a parameter which is the bucket id
  local token="$(cmd influx auth create --write-bucket "$1" -d "Telegraf write token" | grep "$INFLUX_USERNAME" | awk -F $'\t' '{print $3}')"
  echo "$token"
}

function create_read_token() {
  local token="$(cmd influx auth create \
    -d "Grafana read token" \
    --read-buckets \
    --read-checks \
    --read-dashboards \
    --read-dbrps \
    --read-notificationEndpoints \
    --read-notificationRules \
    --read-orgs \
    --read-tasks \
    --read-telegrafs \
    --read-user | grep "$INFLUX_USERNAME" | awk -F $'\t' '{print $3}')"
  echo "$token"
}

function wipe_telegraf() {
  local container_name="metrics-telegraf"
  docker-compose stop telegraf
  if [ "$(docker ps -q -f name="$container_name")" ]; then
    docker rm "$container_name"
  fi
}

function start_over() {
  # Delete all containers and reset volumes
  # but DO NOT DELETE the caddy volumes!
  docker-compose down
  for i in "${volumes[@]:0:2}"
  do
    docker volume rm "$i"
    docker volume create "$i"
  done
}

function help() {
  printf "%s <task> [args]\n\nTasks:\n" "${0}"

  compgen -A function | grep -v "^_" | cat -n

  printf "\nExtended help:\n  Each task has comments for general usage\n"
}

# This idea is heavily inspired by: https://github.com/adriancooney/Taskfile
TIMEFORMAT=$'\nTask completed in %3lR'
time "${@:-help}"