composeless

#!/usr/bin/env python3
#
# Composeless - compose hybrid container/function applications

import yaml
import sys
import os
import copy
import subprocess
import json
import signal

configfile = "docker-composeless.yaml"
functionhub = "http://snafu-control-zhaw-prod-demos.appuioapp.ch/"
# web interface: http://functionhub-zhaw-prod-demos.appuioapp.ch/

def printless(*s):
	yellow = "\033[1;33m"
	reset = "\033[0;0m"
	s += (reset,)
	print(yellow, "»» Composeless:", *s)

def prepare():
	if not os.path.isdir("_snafu"):
		printless("setting up functions environment...")
		cp = subprocess.run("git clone https://github.com/serviceprototypinglab/snafu.git _snafu", shell=True)
		if cp.returncode:
			printless("error retrieving functions environment")
			return

def deploy(service, args, fdir):
	if args:
		printless("treat...", service, "with", args)
		if "up" in args:
			cmd = "aws --endpoint-url {} lambda get-function --function-name {}".format(functionhub, service)
			cp = subprocess.run(cmd, stdout=subprocess.PIPE, shell=True)
			if not cp.returncode:
				#print(cp)
				s = json.loads(cp.stdout.decode("utf-8"))
				download = s["Code"]["Location"]
				# FIXME snafu-control might figure out route internally one day
				download = download.replace("http://localhost:10000/", functionhub)
				if os.path.isfile(os.path.join(fdir, os.path.basename(download))):
					printless("- assuming cached copy")
				else:
					printless("- download", download)
					os.makedirs(fdir, exist_ok=True)
					cp = subprocess.run("wget -q {} -O {}/{}".format(download, fdir, os.path.basename(download)), shell=True)
					if cp.returncode:
						printless("error retrieving function implementation")
						return
					cp = subprocess.run("unzip -d {} {}/{}".format(fdir, fdir, os.path.basename(download)), shell=True)
			else:
				printless("error retrieving function information")
				return
		elif "down" in args:
			printless("- operation not yet supported")
		else:
			printless("- no relevant operation")
	else:
		printless("skip functions processing")

prepare()

idx = None
for i, arg in enumerate(sys.argv):
	if arg in ("-f", "--file"):
		idx = i + 1
		configfile = sys.argv[idx]
		break

conf = yaml.load(open(configfile).read())
confout = copy.deepcopy(conf)
cpsnafu = None
if "services" in conf:
	services = conf["services"]
	fdir = "_" + os.path.basename(configfile).replace(".yaml", ".functions")
	needed = False
	for service in services:
		if "function" in services[service]:
			deploy(services[service]["function"], sys.argv[1:], fdir)
			needed = True
			del confout["services"][service]
	if needed:
		if "up" in sys.argv[1:]:
			cmd = "./_snafu/snafu-control {}".format(fdir)
			printless("launch functions environment...", cmd)
			cpsnafu = subprocess.Popen(cmd, shell=True)
			printless("launched [pid={}]".format(cpsnafu.pid))
		elif "down" in sys.argv[1:]:
			printless("do nothing")
		else:
			printless("do nothing")

ediblefile = "_composeless.yaml"

f = open(ediblefile, "w")
f.write(yaml.dump(confout))
f.close()

args = sys.argv[:]
if idx:
	args[idx] = ediblefile
else:
	args = [args[0]] + ["-f", ediblefile] + args[1:]

cmd = "docker-compose {}".format(" ".join(args[1:]))
printless("invoke containers environment...", cmd)
cpcompose = subprocess.Popen(cmd, shell=True)
printless("launched [pid={}]".format(cpcompose.pid))

if "up" in sys.argv[1:]:
	try:
		while True:
			pass
	except KeyboardInterrupt:
		pass

	print()
	printless("interrupt!")

	if cpsnafu:
		os.kill(cpsnafu.pid, signal.SIGTERM)
	# FIXME hacky
	cmd = cmd.replace("up", "down")
	os.system(cmd)