Is it plan to support backend configuration with stats socket ? 2016-04-13 16:09 GMT+02:00 Smain Kahlouch <smain...@gmail.com>:
> Ok thank you, > I'll have a look to SmartStack. > > 2016-04-13 16:03 GMT+02:00 B. Heath Robinson <he...@midnighthour.org>: > >> SmartStack was mentioned earlier in the thread. It does a VERY good job >> of doing this. It rewrites the haproxy configuration and performs a reload >> based on changes in a source database by a polling service on each >> instance. The canonical DB is zookeeper. >> >> We have been using this in production for over 2 years and have had very >> little trouble with it. In the next year we will be moving to docker >> containers and plan to make some changes to our configuration and move >> forward with SmartStack. >> >> That said, your polling application could write instructions to the stats >> socket; however, it currently does not allow adding/removing servers but >> only enabling/disabling. See >> https://cbonte.github.io/haproxy-dconv/configuration-1.5.html#9.2 for >> more info. BTW, this section is missing from the 1.6 manual. You might >> also see https://github.com/flores/haproxyctl. >> >> On Wed, Apr 13, 2016 at 7:42 AM Smain Kahlouch <smain...@gmail.com> >> wrote: >> >>> Sorry to answer to this thread so late :p >>> >>> >>> due to the fact that this will be changed when the pod is recreated! >>>> >>> >>> Alexis, as i mentionned earlier the idea is to detect these changes by >>> polling in a regular basis the API and change the backend configuration >>> automatically. >>> Using the DNS (addon) is not what i would like to achieve because it >>> still uses kubernetes internal loadbalancing system. >>> Furthermore it seems to me easier to use the NodePort, >>> <http://kubernetes.io/docs/user-guide/services/#type-nodeport>This is >>> what i use today. >>> >>> Nginx Plus has now such feature : >>> >>>> With APIs – This method uses the NGINX Plus on-the-fly reconfiguration >>>> API >>>> <https://www.nginx.com/resources/admin-guide/load-balancer/#upstream_conf> >>>> to add and remove entries for Kubernetes pods in the NGINX Plus >>>> configuration, and the Kubernetes API to retrieve the IP addresses of the >>>> pods. This method requires us to write some code, and we won’t discuss it >>>> in depth here. For details, watch Kelsey Hightower’s webinar, Bringing >>>> Kubernetes to the Edge with NGINX Plus >>>> <https://www.nginx.com/resources/webinars/bringing-kubernetes-to-the-edge-with-nginx-plus/>, >>>> in which he explores the APIs and creates an application that utilizes >>>> them. >>>> >>> >>> Please let me know if you are considering this feature in the future. >>> Alternatively perhaps you can guide me to propose a plugin. Actually >>> python is the language i used to play with but maybe that's not possible. >>> >>> Regards, >>> Smana >>> >>> 2016-02-25 18:29 GMT+01:00 Aleksandar Lazic <al-hapr...@none.at>: >>> >>>> Hi. >>>> >>>> Am 25-02-2016 16:15, schrieb Smain Kahlouch: >>>> >>>>> Hi ! >>>>> >>>>> Sorry to bother you again with this question, but still i think it >>>>> would >>>>> be a great feature to loadbalance directly to pods from haproxy :) >>>>> Is there any news on the roadmap about that ? >>>>> >>>> >>>> How about DNS as mentioned below? >>>> >>>> >>>> https://github.com/kubernetes/kubernetes/blob/v1.0.6/cluster/addons/dns/README.md >>>> http://cbonte.github.io/haproxy-dconv/configuration-1.6.html#5.3 >>>> >>>> ### oc rsh -c ng-socklog nginx-test-2-6em5w >>>> cat /etc/resolv.conf >>>> nameserver 172.30.0.1 >>>> nameserver 172.31.31.227 >>>> search nginx-test.svc.cluster.local svc.cluster.local cluster.local >>>> options ndots:5 >>>> >>>> ping docker-registry.default.svc.cluster.local >>>> #### >>>> >>>> #### >>>> oc describe svc docker-registry -n default >>>> Name: docker-registry >>>> Namespace: default >>>> Labels: docker-registry=default >>>> Selector: docker-registry=default >>>> Type: ClusterIP >>>> IP: 172.30.38.182 >>>> Port: 5000-tcp 5000/TCP >>>> Endpoints: 10.1.5.52:5000 >>>> Session Affinity: None >>>> No events. >>>> #### >>>> >>>> Another option is that you startup script adds the A record into skydns >>>> >>>> https://github.com/skynetservices/skydns >>>> >>>> But I don't see benefit to conncect directly to the endpoint, due to >>>> the fact that this will be changed when the pod is recreated! >>>> >>>> BR Aleks >>>> >>>> Regards, >>>>> Smana >>>>> >>>>> 2015-09-22 20:21 GMT+02:00 Joseph Lynch <joe.e.ly...@gmail.com>: >>>>> >>>>> Disclaimer: I help maintain SmartStack and this is a shameless plug >>>>>> >>>>>> You can also achieve a fast and reliable dynamic backend system by >>>>>> using something off the shelf like airbnb/Yelp SmartStack >>>>>> (http://nerds.airbnb.com/smartstack-service-discovery-cloud/). >>>>>> >>>>>> Basically there is nerve that runs on every machine healthchecking >>>>>> services, and once they pass healthchecks they get registered in a >>>>>> centralized registration system which is pluggable (zookeeper is the >>>>>> default but DNS is another option, and we're working on DNS SRV >>>>>> support). Then there is synapse which runs on every client machine and >>>>>> handles re-configuring HAProxy for you automatically, handling details >>>>>> like doing socket updates vs reloading HAProxy correctly. To make this >>>>>> truly reliable on some systems you have to do some tricks to >>>>>> gracefully reload HAProxy for picking up new backends; search for zero >>>>>> downtime haproxy reloads to see how we solved it, but there are lots >>>>>> of solutions. >>>>>> >>>>>> We use this stack at Yelp to achieve the same kind of dynamic load >>>>>> balancing you're talking about except instead of kubernetes we use >>>>>> mesos and marathon. The one real trick here is to use a link local IP >>>>>> address and run the HAProxy/Synapse instances on the machines >>>>>> themselves but have containers talk over the link local IP address. I >>>>>> haven't tried it with kubernetes but given my understanding you'd end >>>>>> up with the same problem. >>>>>> >>>>>> We plan to automatically support whichever DNS or stats socket based >>>>>> solution the HAProxy devs go with for dynamic backend changes. >>>>>> >>>>>> -Joey >>>>>> >>>>>> On Fri, Sep 18, 2015 at 8:34 AM, Eduard Martinescu >>>>>> <emartine...@salsalabs.com> wrote: >>>>>> >>>>>>> I have implemented something similar to allow use to dynamically >>>>>>> load-balance between multiple backends that are all joined to each >>>>>>> >>>>>> other as >>>>>> >>>>>>> part of a Hazelcast cluster. All of which is running in an AWS VPC, >>>>>>> >>>>>> with >>>>>> >>>>>>> autoscaling groups to control spin up and down of new members of the >>>>>>> >>>>>> cluster >>>>>> >>>>>>> based on load, etc. >>>>>>> >>>>>>> What we ended up doing is righting custom code that attached to the >>>>>>> hazelcast cluster as a client, and periodically queried the cluster >>>>>>> >>>>>> for the >>>>>> >>>>>>> current list of servers, and their IP addresses. The coded would >>>>>>> >>>>>> then >>>>>> >>>>>>> rewrite the HAProxy configuration, filling in the correct backend >>>>>>> >>>>>> list. >>>>>> >>>>>>> Then via a shell call (sadly, Java can't do Unix domain sockets to >>>>>>> >>>>>> write >>>>>> >>>>>>> directly to the server), it would tell HAProxy to restart >>>>>>> >>>>>> gracefully. >>>>>> >>>>>>> >>>>>>> In our use case, this works great, as we don't have long-running TCP >>>>>>> connections (these servers typically serve REST API calls or static >>>>>>> >>>>>> HTML >>>>>> >>>>>>> content with no keep-alive.) >>>>>>> >>>>>>> I'm also open to suggestions on how this could be improved too, >>>>>>> >>>>>> especially >>>>>> >>>>>>> with 1.6 possibly. >>>>>>> >>>>>>> Ed >>>>>>> >>>>>>> ________________________________ >>>>>>> ✉ Eduard Martinescu | ✆ (585) 708-9685 [1] | - ignite action. >>>>>>> >>>>>> fuel change. >>>>>> >>>>>> >>>>>>> On Fri, Sep 18, 2015 at 9:21 AM, Baptiste <bed...@gmail.com> wrote: >>>>>>> >>>>>>>> >>>>>>>> On Fri, Sep 18, 2015 at 3:18 PM, Smain Kahlouch >>>>>>>> >>>>>>> <smain...@gmail.com> >>>>>> >>>>>>> wrote: >>>>>>>> >>>>>>>>> If I may chime in here: Kubernetes supports service discovery >>>>>>>>>> >>>>>>>>> through >>>>>> >>>>>>> DNS >>>>>>>>>> SRV records for most use-cases, so the dynamic DNS support that >>>>>>>>>> Baptiste >>>>>>>>>> is >>>>>>>>>> currently working on would be a perfect fit. No special API >>>>>>>>>> >>>>>>>>> support >>>>>> >>>>>>> required. >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Well dns would be great but, as far as i know, kubernetes uses >>>>>>>>> >>>>>>>> dns only >>>>>> >>>>>>> for >>>>>>>>> services name, not for pods. >>>>>>>>> A pod can be seen as a server in a backend, the number of servers >>>>>>>>> >>>>>>>> and >>>>>> >>>>>>> their >>>>>>>>> ip addresses can change frequently. >>>>>>>>> I'll dig further... >>>>>>>>> >>>>>>>>> Thanks, >>>>>>>>> Smana >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> That's usually the purpose of DNS SRV records ;) >>>>>>>> >>>>>>>> Baptiste >>>>>>>> >>>>>>>> >>>>>>> >>>>> >>>>> >>>>> Links: >>>>> ------ >>>>> [1] tel:%28585%29%20708-9685 >>>>> >>>> >>> >
