I am setting up a multi container application on mesos cluster on Azure using azure container service and currently stuck in linking containers.
My setup brief info:
- Mesos cluster is deployed on Azure using Azure container service
- It's a 3 container application - A, B and C
- B is dependent on A and C is dependent on A & B-
- A is deployed currently
How can I link the above containers?
Thanks,
Suraj
If by linking you mean Docker's --link then thats deprecated practice and inter-container communication should be done using Docker networks and port mappings.
For DC/OS - you have some different ways to achieve this (also called Service Discovery). I have written a blog post explaining these different tools by examples: http://blog.itaysk.com/2017/04/28/dcos-service-discovery-and-load-balancing-by-example
If you don't want to read through that long post and looking for a recommendation: Try using VIPs.
When creating the application (either from Marathon or DC/OS UI), look for the 'VIP' setting. Enter an IP there (it can be a made up IP) and port. Your service will be discoverable under this IP:Port.
More on VIPs: https://dcos.io/docs/1.9/networking/load-balancing-vips/virtual-ip-addresses/
Related
I'm trying to deploy a simple API into an AKS and want to show it off to the internet using an ingress controller. I want to know if I'm using cloud do I need to install minikube?
Minikube is designed for local Kubernetes development and testing. It supports one node by default. So it is not related to your AKS setup, i.e you don't need minikute for AKS.
To be able to demo your setup on the Internet, you can set up an AKS but be mindful of securities and make sure that you are not exposing your entire cluster on the Internet.
I have created an Azure Service Fabric Cluster using "Windows 2016 DataCenter with Containers" OS and enabled Reverse Proxy listening on Port 80 on the cluster. We intend to deploy our legacy ASP.NET MVC & WCF applications on this cluster.
In our existing deployment model we have services co-located on same host communicating to each other because of chatty communication and low latency requirements. Is it possible for apps hosted in windows container to communicate with other windows container apps on the same Node? Basically I would like to have Node affinity between two windows container apps on the same Service Fabric Node.
I tried it with a sample application and it looks like the only option is to use Private IP of container which is getting dynamically assigned. Is it possible to pass --ip-address parameter while instantiating containers on Service Fabric cluster?
[Update: 04/05/2017]
Service Fabric Cluster Version: 5.5.219.0
Total NodeTypes: 1
Total Nodes: 3
Both containers are deployed on all three nodes. Azure internet load balancer is used to expose Service Fabric Reverse Proxy. All services are accessing internally as well as externally via reverse proxy.
Gaurav
There is what you can do now in the v5.5 release and what is coming in the next release.
For v5.5 Release
This GitHub repo https://github.com/Azure-Samples/service-fabric-dotnet-containers shows how to communicate between Windows Containers where you can map a host port to the private port on the container using PortBinding policy in the Application manifest.
You can then communicate either called the Naming Service over REST (this is what this sample does) or as you say and is easier, with the ReverseProxy which has a URL format. If both containers are deployed on the same machine then the communication is via the local ReverseProxy and you get local calls between the containers. See https://learn.microsoft.com/en-us/azure/service-fabric/service-fabric-reverseproxy. As Mikkel points out, you have to tell Service Fabric that you want the containers on the same VM, through placement constraints.
Note: for the GitHub sample above to work on your local machine you need to update the local dev manifest ClusterManifestTemplate.xml in the C:\Program Files\Microsoft SDKs\Service Fabric\ClusterSetup\NonSecure\FiveNode folder and change the IPAddressOrFQDN attribute from "localhost" to the actual IP of the machine it is running on. This is due to a Windows Server Network bug, documentated in the git repo above. i.e
<Node NodeName="_Node_0" IPAddressOrFQDN="ComputerFullName" IsSeedNode="true" NodeTypeRef="NodeType0" FaultDomain="fd:/0" UpgradeDomain="0" />
becomes
<Node NodeName="_Node_0" IPAddressOrFQDN="192.1.3.50" IsSeedNode="true" NodeTypeRef="NodeType0" FaultDomain="fd:/0" UpgradeDomain="0" />
Coming for v5.6 Release
In the next release we have added a DNS server layered on top of the Naming Service, so that you can use DNS names in place of fabric:/ names used by the reverse proxy. This means that within the Service Fabric cluster you can call between the containers with http://[domainname]/path calls instead. Same rules apply for the calls between local containers on the same machine as for the reverse proxy.
Using Service affinity would be an option: https://learn.microsoft.com/en-us/azure/service-fabric/service-fabric-cluster-resource-manager-advanced-placement-rules-affinity
I'm using Azure for the first time to deploy a web app. More specifically, I'm using the Docker Container Service to do this. I already have one instance of it deployed. But, I want to also deploy 2 more instances of the same web app. I want each instance to have a different URL. What is the best way of doing this? Do I have to add a new container service for each new instance and repeat the steps I did for deploying the first instance?
As in case of Azure Container Service (ACS),
You choose a container orchestrator i.e. Swarm, DC\OS and Kubernetes (Because creating replicas works differently in each of them).
In case of Swarm then either create a separate application container for the same application with a different end point and use automatic discovery feature for different URL(s) or choose a reverse-proxy load-balancer such as Nginx which will work on the same URL but on a different port (My blog here might help you).
Creating replicas across a cluster are used for Load Balancing, Routing Mesh, Scaling and Rolling updates etc.
In our organization, we are currently trying out the Azure Container Service with Docker Swarm. We have developed a Web API project based on .NET Core and created containers out of it. We have exposed the web api on Container’s Private Port (3000). We want to scale this to say 15 containers on three agent nodes while still accessing the web api through one single Azure load balancer url on public port 8080.
I believe we would need an Internal Load Balancer to do this but there is no documentation around it. I have seen this article on DC\OS but we are using Docker Swarm here. Any help?
Azure Container Service use vanilla Docker Swarm so any load balancing solution for Swarm will work in ACS, e.g. https://botleg.com/stories/load-balancing-with-docker-swarm
Same is true for DC/OS, but in this case it is documented in "Load balance containers in an Azure Container Service cluster" - https://azure.microsoft.com/en-us/documentation/articles/container-service-load-balancing/
I'm trying to deploy a simple WordPress example (WordPress & MySQL DB) on Microsofts new Azure Container Service with Mesos & Marathon as the underlying orchestration platform. I already ran this on the services offered by Google (Kubernetes) and Amazon (ECS) and thought it would be an easy task on ACS as well.
I have my Mesos cluster deployed and everything is up and running. Deploying the MySQL container isn't a problem either, but when I deploy my WordPress container I can't get a connection to my MySQL container. I think this might be because MySQL runs on a different Mesos agent?
What I tried so far:
Using the Mesos DNS to get ahold of the MySQL container host (for now I don't really care which container I get ahold of). I set the WORDPRESS_DB_HOST environment var to mysql.marathon.mesos and specified the host of MySQL container as suggested here.
I created a new rule for the Agent Load Balancer and a Probe for port 3306 in Azure itself, this worked but seems like a very complicated way to achieve something so simple. In Kubernetes and ECS links can be simply defined by using the container name as hostname.
An other question that came up, what difference is their in Marathon between setting the Port in the Port Mappings Section and in the Optional Settings section. (See screenshot attached)
Update: If I ssh into the master node than I can dig by using mysql.marathon.mesos, how ever I can't get a connection to work from within an other container (in my case the wordpress container).
So there are essentially two questions here: one around stateful services on Marathon, the other around port management. Let me first clarify that neither has to do anything with Azure or ACS in the first place, they are both Marathon-related.
Q1: Stateful services
Depending on your requirements (development/testing or prod) you can either use Marathon's persistent volumes feature (simple but no automatic failover/HA for the data) or, since you are on Azure, a robust solution like I showed here (essentially mounting a file share).
Q2: Ports
The port mapping you see in the Marathon UI screen shot is only relevant if you launch a Docker image and want to explicitly map container ports to host ports in BRIDGE mode, see the docs for details.