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 >>>> >>> >>
