Add Gunicorn Config For More Fine Grain Control

[gtalarico]

Add gunicorn config for finer control

info ">>> Starting Gunicorn"
# config path will be mounted at root /service/gunicorn_config.py
gunicorn api.wsgi -c gunicorn_config.py

from gunicorn import glogging
from gunicorn.instrument.statsd import Statsd

# TODO config port
bind = f"0.0.0.0:{{ PORT }}"
proc_name = "gunicorn"
preload_app = True
backlog = 2048
workers = 2
worker_class = "sync"
worker_connections = 1000
timeout = 30
keepalive = 2

class CustomGunicornLogger(Statsd):
    # Custom Logger Breaks Statsd
    # https://github.com/benoitc/gunicorn/issues/1564
    def access(self, resp, req, environ, request_time):
        # disable healthcheck logging
        if req.path in ["/health"]:
            return
        super().access(resp, req, environ, request_time)

capture_output = True  # Redirect stdout/stderr to specified file in errorlog.
loglevel = "info"
errorlog = "-"
accesslog = "-"
# access_log_format = '%(h)s %(l)s %(u)s %(t)s "%(r)s" %(s)s %(b)s "%(f)s" "%(a)s"'
# Add Response Time Logging
access_log_format = (
    '%(h)s %(l)s %(u)s %(t)s "%(r)s" %(s)s %(b)s [%(L)s sec] "%(f)s" "%(a)s"'
)
logger_class = CustomGunicornLogger

ps: should benchmark heroku staging with 1/2/3/4 workers and see performance, CPU and memory ps