Capturing upstream response headers

[Eirik Øverby]

Hi,

I'm trying to move from a shareddict implementation to using a redis store for session tokens. The reason for the move is that I need to collect these tokens from one nginx instance, and validate them in another.

The tokens are generated by the upstream application and returned to nginx as a response header. I've been using header_filter_by_lua_* with the shareddict approach, but this does not work with the redis module (as documented).

I've tried various other approaches, but I cannot seem to capture the response headers. I tried with rewrite_by_lua_*, but then the response headers disappear entirely, for reason I cannot quite understand.

Am I missing something entirely obvious here?

Thanks,

/Eirik

[Aapo Talvensaari]

You can start a timer in the header filter to connect Redis. 

[Eirik Øverby]

....and it's right  there in the docs. Feeling so smart right now.. Thanks!

Presumably also in the docs, but in case it isn't: Is there a best practice for how/where to set up the redis connection? If I'm using redis from the timers and from the rewrite contexts, should I be creating the redis connection somewhere else in order to get connection re-use? I am using the set_keepalive() function at the end of each redis-invoking code block so I should be saving a bit on that.

Take care,

/Eirik

[Aapo Talvensaari]

On Wed, Feb 21, 2024 at 2:53 AM Eirik Øverby <ltn...@gmail.com> wrote:

Presumably also in the docs, but in case it isn't: Is there a best practice for how/where to set up the redis connection? If I'm using redis from the timers and from the rewrite contexts, should I be creating the redis connection somewhere else in order to get connection re-use? I am using the set_keepalive() function at the end of each redis-invoking code block so I should be saving a bit on that.

Just connect and setkeepalive after use. Keepalive pool is shared between different phases.