Do I understand correctly that to pass a parameter to a :start lifecycle function I need to specify it inside another defstate? or have the parameters definied in the namespace? no way to pass the argument to the function directly though?

@aleksander is it a command line argument?

no, just a configuration value

a port on which the web server is supposed to listen on

ideally I would like to pass that value when starting

@tolitius

which component starts the app? i.e. is it -main

usually you would create a config state which reads a config file or reaches out to external configuration service (i.e. consul, etcd, ..)

this state becomes a map with all the application configuration

then in other states that need config, such as port, you would do something similar to (config :port)

here is an example: https://github.com/tolitius/hubble

it reads config from consul: https://github.com/tolitius/hubble/blob/master/src/clj/hubble/env.clj#L30 but it could also simply read it from a local config file, since it just becomes a map when started

and here it reads a server port to start a server state: https://github.com/tolitius/hubble/blob/master/src/clj/hubble/server.clj#L44-L49

here is an example of reading a config from a file into a state: https://github.com/tolitius/stater/blob/master/smsio/src/app/conf.clj

and then starting a server with it: https://github.com/tolitius/stater/blob/master/smsio/src/app/www.clj#L20-L27

Thanks, I'll go through the examples tomorrow!

yes, main I was thinking of reading the configuration outside of a mount component

@aleksander > I was thinking of reading the configuration outside of a mount component if you really do not want to have a config component (why?) instead of (mount/start) you could use (mount/start-with-args args) where args is a map with arguments

later anywhere in state / functions you can access it with (mount/args): i.e.

(get-in (mount/args) [:server :port])