We have restful api over HTTP. Amongst other clients we have also mobile-device clients (e.g. iphone). The issue is that there are several iphone apps in different versions out there (1.0, 2.0). Because they are distributed we don’t have control which app-version is calling us.
To identify the app-version on server-side I see following options:
- device must append URL parameter (e.g. /foo?iphone-app-version=1.0) : A bit yucky, but good thing is that I can see it always on server-logs (URL is always logged)
- we authenticate api-clients with HTTP digest. We could encode the app-version inside the username (e.g. iphone_1_0): Good thing it is logged in server logs, but only works for resources which are exposed as HTTP digest.
- device must use custom HTTP-header, e.g. X-IPHONE-APP-VERSION: In my view the cleanest approach, but we don’t log HTTP headers in server logs (for log-noise it is switched off). So later analyzation is not possible.
Do you have a preferred approach or any other alternatives?
EDIT: With above versioning I don’t mean api-versioning/content-negotiation. It is the version of the mobile-device.
I decided for custom X-xxx-USER-AGENT one. Main reason to decide against more standard “User-Agent” is that is already “polluted” with http-client library or mobile-device information. A custom X-xxx-USER-AGENT is easier to parse for server and does not intervent http-library which often sets it and could override a custom entry.