90DaysOfDevOps/2022/Days/Monitoring/Elastic Stack/setup/helpers.sh

#!/usr/bin/env bash

# Log a message.
function log {
	echo "[+] $1"
}

# Log a message at a sub-level.
function sublog {
	echo "   ⠿ $1"
}

# Log an error.
function err {
	echo "[x] $1" >&2
}

# Poll the 'elasticsearch' service until it responds with HTTP code 200.
function wait_for_elasticsearch {
	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"

	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}' "http://${elasticsearch_host}:9200/" )

	if [[ -n "${ELASTIC_PASSWORD:-}" ]]; then
		args+=( '-u' "elastic:${ELASTIC_PASSWORD}" )
	fi

	local -i result=1
	local output

	# retry for max 300s (60*5s)
	for _ in $(seq 1 60); do
		output="$(curl "${args[@]}" || true)"
		if [[ "${output: -3}" -eq 200 ]]; then
			result=0
			break
		fi

		sleep 5
	done

	if ((result)); then
		echo -e "\n${output::-3}"
	fi

	return $result
}

# Verify that the given Elasticsearch user exists.
function check_user_exists {
	local username=$1

	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"

	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
		"http://${elasticsearch_host}:9200/_security/user/${username}"
		)

	if [[ -n "${ELASTIC_PASSWORD:-}" ]]; then
		args+=( '-u' "elastic:${ELASTIC_PASSWORD}" )
	fi

	local -i result=1
	local -i exists=0
	local output

	output="$(curl "${args[@]}")"
	if [[ "${output: -3}" -eq 200 || "${output: -3}" -eq 404 ]]; then
		result=0
	fi
	if [[ "${output: -3}" -eq 200 ]]; then
		exists=1
	fi

	if ((result)); then
		echo -e "\n${output::-3}"
	else
		echo "$exists"
	fi

	return $result
}

# Set password of a given Elasticsearch user.
function set_user_password {
	local username=$1
	local password=$2

	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"

	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
		"http://${elasticsearch_host}:9200/_security/user/${username}/_password"
		'-X' 'POST'
		'-H' 'Content-Type: application/json'
		'-d' "{\"password\" : \"${password}\"}"
		)

	if [[ -n "${ELASTIC_PASSWORD:-}" ]]; then
		args+=( '-u' "elastic:${ELASTIC_PASSWORD}" )
	fi

	local -i result=1
	local output

	output="$(curl "${args[@]}")"
	if [[ "${output: -3}" -eq 200 ]]; then
		result=0
	fi

	if ((result)); then
		echo -e "\n${output::-3}\n"
	fi

	return $result
}

# Create the given Elasticsearch user.
function create_user {
	local username=$1
	local password=$2
	local role=$3

	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"

	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
		"http://${elasticsearch_host}:9200/_security/user/${username}"
		'-X' 'POST'
		'-H' 'Content-Type: application/json'
		'-d' "{\"password\":\"${password}\",\"roles\":[\"${role}\"]}"
		)

	if [[ -n "${ELASTIC_PASSWORD:-}" ]]; then
		args+=( '-u' "elastic:${ELASTIC_PASSWORD}" )
	fi

	local -i result=1
	local output

	output="$(curl "${args[@]}")"
	if [[ "${output: -3}" -eq 200 ]]; then
		result=0
	fi

	if ((result)); then
		echo -e "\n${output::-3}\n"
	fi

	return $result
}

# Ensure that the given Elasticsearch role is up-to-date, create it if required.
function ensure_role {
	local name=$1
	local body=$2

	local elasticsearch_host="${ELASTICSEARCH_HOST:-elasticsearch}"

	local -a args=( '-s' '-D-' '-m15' '-w' '%{http_code}'
		"http://${elasticsearch_host}:9200/_security/role/${name}"
		'-X' 'POST'
		'-H' 'Content-Type: application/json'
		'-d' "$body"
		)

	if [[ -n "${ELASTIC_PASSWORD:-}" ]]; then
		args+=( '-u' "elastic:${ELASTIC_PASSWORD}" )
	fi

	local -i result=1
	local output

	output="$(curl "${args[@]}")"
	if [[ "${output: -3}" -eq 200 ]]; then
		result=0
	fi

	if ((result)); then
		echo -e "\n${output::-3}\n"
	fi

	return $result
}