Running services

Configuration

Service configuration is stored in a JSON file. There is no standard location now, every service should set it manually using pycom.configure(). Nameserver configuration is in: $PREFIX/share/pycom/ns.conf.

Note

easy_install overrides this directory with something complicated, e.g. $PREFIX/lib/python2.7/site-packages/pycom-0.6.0-py2.7.egg/share/pycom/. We are investigating this issue. Use pip when possible.

Configuration top-level objects should contain the following properties:

address

IP and port to listen on. This address will be reported to the nameserver on initialization and should be reachable from other services in your system.

Address is in 0MQ format and looks like: tcp://host:port.

Note

Do not set address to tcp://127.0.0.1:xxxx unless all your services run on localhost.

service

Service name (e.g. /com/example/service/name). Must be unique in your system. If service name is not set, it is generated, e.g. /auto/b42712345bea11e191c9dca97122e60b.

Note

You can get into trouble with generated service names. If you restart such service, for some time (no more than a minute) you’ll have two services with the same interface registered, as old one will not expire (on nameserver) yet.

For all services except nameserver you’ll have to set also:

nameserver

0MQ address of the nameserver (e.g. tcp://127.0.0.1:2012). You can skip this property only if you have nameserver built into your service, e.g.:

import pycom
import pycom.apps.nameserver

# Your service goes here...

As of PyCOM 0.6, you still need external address for such services.

authentication

A dictionary with authentication configuration. The only supported property now is:

policy

Authentication policy, the only meaningful values is string "required" which forces authentication check for all services.

Command-line Interface

For simple cases you can omit creating a configuration file and use command-line interface to set required parameters.

Base command line for starting any number of services is:

python -m pycom [flags] path.to.service1 [path.to.service2 ...]

where

path.to.service

Full qualified module name[s] for service[s] to run

-s *service-name*

This flag sets service name

-a *address*

This flags sets address to listen on

-n *address*

This flag sets nameserver address

-v

This flag increase verbosity

Example for NameServer:

python -m pycom -a tcp://127.0.0.1:2012 -s /org/pycom/nameserver \
    pycom.apps.nameserver

and for some other service:

python -m pycom -a tcp://127.0.0.1:2013 -s /mypkg/svc1 -n tcp://127.0.0.1:2012 \
    mypkg.svc1.iface1 mypkg.svc1.iface2