Yeah. That's right. It won't work the way you intended. you probably need an external source of truth as your trigger. e.g. a local redis store. So you have some cron to keep checking some URL and update a key in the local redis store. And then you have lua script to check the key in the local redis store and make decision based on that.
Thanks. On Fri, Dec 9, 2016 at 2:18 PM, Di Li <di...@apple.com> wrote: > looks like so far only thing that’s not request lifetime is that > ts.stat_create and find > > > Thanks, > Di Li > > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > + SHIELD :: Self-Service Load-Balancer (LB) and Web App Firewall (WAF) > + http://shield.apple.com > + > + SHIELD classes: > + > http://shield.apple.com/FAQ/doku.php?id=start#shield_classes_trainings_tutorials > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > > On Dec 9, 2016, at 11:21 AM, Di Li <di...@apple.com> wrote: > > I just did a quick test with counter = counter + 1 , and seems that global > lua table has the same lifetime as the request. > > is there any way I can store data beyond the request lifetime ? > > > > Thanks, > Di Li > > > > > On Dec 9, 2016, at 10:23 AM, Di Li <di...@apple.com> wrote: > > Hey Kit, > > > Thanks for taking time to respond my emails, I still have some confusions, > hopefully you can help me understand more about those pieces. > > The background here is we are trying to do a forward proxy, the reason I was > thinking about using ts.schedule is that it can keep get the latest our > control data from a external end point like whatever NOSQL family solution > via ts.fetch, so that we don’t have to depends on the __init__ function with > which we have to restart the traffic server to get latest data. The __init__ > function can be used to serve the first fetch of data, this is what in my > mind at beginning. > > Looks like the pieces I missed here is a shared_lua_dict part, that other > lua script won’t be able to access whatever that scheduler fetched. > > Now I’m thinking a different path to make this happen, maybe not ideal, but > maybe gonna work, what if I have a do_global_read_request (we are forward > proxy, we don’t have remap rules) and checks where the a request being > called, and where I can match our control fetch, and then that will fetch > the data from a external point that has our control data and update the > GLOBAL variable, which will be used in the same script. > > ============================ > > local control_data = {} > > function __init__() > -- do whatever the logic to fetch a external endpoint, and update lua table > control_data, > -- maybe use luasocket to do that > end > > > > function control_request() > > local url_host = ts.client_request.get_url_host() > > if url_host == '127.0.0.1' then > -- for example this is our local cron call to update the control_data > table, could match with IP or whatever make sense. > -- ts.fetch our endpoint to get control_data > > local res = ts.fetch(url, {method = 'GET', header=hdr}) > if res.status == 200 then > -- parse result, and update the contorl_data > end > > else > -- this is client normal call, check if our control_data has logic on it, > for example simple allow or not > if control_data[url_host] == 'allow' then > return 0 > else > -- this is not allow > ts.http.set_resp(403) > return 0 > end > return 0 > end > > > function do_global_read_request() > ts.hook(TS_LUA_HOOK_READ_REQUEST_HDR, control_request) > return 0 > end > =============================== > > If I understand this correctly, the init will only be called once at traffic > server start up, and then all the rest request will go through > do_global_read_request logic (we are forward proxy). > > two questions here: > > 1. with this work flow, after init, I will have a control_data table, and if > I update it by local calls from 127.0.0.1 and update that control_data > table, does the following requests check the control_data with new data or > still the initialized data by init ? > > 2. ts.fetch’s context is after_do_remap, you mentioned that yesterday, I > don’t have the do_remap(), but do_global_read_request(), I call the fetch > inside a Hook, I should be OK ? > > > > Thanks, > Di Li > > > > > On Dec 8, 2016, at 4:27 PM, Shu Kit Chan <chanshu...@gmail.com> wrote: > > 1) No. you don't need to do anything in txn close hook. > > 2) See the example in the documentation. I think we can definitely > improve the text a bit. What it means is that you need to add a hook > inside do_remap and ts.schedule() can only be called inside that hook > function. > It is similar to > https://docs.trafficserver.apache.org/en/latest/developer-guide/api/functions/TSContSchedule.en.html > However, inside ts_lua we only support net and task. > > 3) There is an example (the second one) close to the beginning of the > doc - > https://docs.trafficserver.apache.org/en/latest/admin-guide/plugins/ts_lua.en.html > > 4) we don't have this for now. Suggestions/patches are welcome. > > IMHO, you don't need to use ts.schedule() . You can directly use > luasocket inside __init__ function since this is run inside > TSPluginInit(). You can use global variable to store the results you > want similar to the __init__ example in the document . > However, pls be aware that we instantiate multiple lua state and thus > we run __init__ for each of those state so it may result in a slow > startup time for you. See jira - > https://issues.apache.org/jira/browse/TS-4994 for a patch for this. > > Thanks. Let me know if i can provide any more help. > > Kit > > > > On Thu, Dec 8, 2016 at 3:52 PM, Di Li <di...@apple.com> wrote: > > Hey Guys, > > Several questions about the ts-lua , just start to use it, so some question > may seem very simple > > 1. question about log part “[globalHookHandler] has txn hook -> adding txn > close hook handler to release resources” > > for example I’m using the following code, and the debug log shows above log > , do I need to do anything to handle a txt close hook to release the > resource, or I should just ignore the log > > > function do_some_work() > - - do some logic > return 0 > end > > > function do_global_read_request() > ts.debug('this is do_global_read_request') > ts.hook(TS_LUA_HOOK_READ_REQUEST_HDR, do_some_work) > return 0 > end > > > 2. question for ts.schedule > > what does “after do_remap” means, is that after hook TS_HTTP_POST_REMAP_HOOK > ? > what are the types in “ THREAD_TYPE” other than the one in the example > "TS_LUA_THREAD_POOL_NET”, and what’s the different between those types. > > > ts.schedule > syntax: ts.schedule(THREAD_TYPE, sec, FUNCTION, param1?, param2?, ...) > context: after do_remap > > > 3. init function being called when traffic_server starts > > is there a init function being called when traffic_server starts, like the > following in nginx > > https://github.com/openresty/lua-nginx-module#init_worker_by_lua > > > 4. Global shared lua dict > > is there a global shared lua dict, that will not has the lift time as > ts.ctx, something like lua_shared_dict in nginx ? > > > What I’m trying to do here is that when traffic server starts up, it will > try to call a init script, which will init a scheduler to fetch a url either > internal or external and get that response store to a shared_lua_dict as > key/value pairs, and later on each of the request comes to the ATS will try > to check the key/values use that shared_lua_dict. With that in mind, I need > to understand those 4 questions above. > > > > Thanks, > Di Li > > > > >
