I have a virtual machine with Kubernetes (minikube) installed. I have a couple of docker images running a .net 6 web-api app. Now I would like to setup RabbitMQ to allow the apps to talk to each other. How do configure RabbitMQ into the environment. Does RabbitMQ need to run in a docker container, or do I need to install it on the VM to run with Kubernetes. Not sure how to integrate RabbitMQ into the environment so the api's can use the RabbitMQ exchange. Thanks for the help
You can install it both ways either run it as the container or run it on VM outside of the Kubernetes cluster.
If you will run it as the container it would be easy to manage, install and services can directly connect to it, no need to take care of firewall, port security, etc. Microservices will be able to connect to it using the service name.
If you will install it on VM and services running on Kubernetes you have to set up network connectivity so from K8s to VM service can connect to RabbitMQ.
You can checkout the RabbitMQ operator to install the RabbitMQ on Kubernetes : https://www.rabbitmq.com/kubernetes/operator/operator-overview.html
You can setup HA RabbitMQ on Kubernetes and the application will be easily able to connect it to.
Related
I built two docker applications that communicate with each other using the docker network, but when I tried to run those applications using nomad. The problem within nomad is that the container name is not configurable and gives the container a random name. So I can't add those containers to the docker network and have them know each other with their specific names.
So how can I run two or more docker containers in the same docker network using nomad?
I'm aware of few approaches. First one works with nomad only, the others assume that consul is deployed as well.
Place both containers in the same task group. Nomad will locate them always on the same node and you can access address via Nomad env variables NOMAD_IP_<label>, NOMAD_PORT_<label> or NOMAD_ADDR_<label>.
Register the server application (docker container) in the consul service registry with nomad service stanza. You can then use nomad template stanza in "client" application to render config. Example/doc is here.
Setup consul connect (service mesh) in your deployment.
You could use consul DNS interface. Consul can work as a DNS server and every service is resolvable at <service_name>.service.<dc>.consul (doc). But you have to configure your servers to use consul DNS (doc).
Approach 1 is the easiest but has huge limitation (the same node). Approach 2 worked for me well for several years. Nomad is that intelligent that it will reload/restart your client IP should the server IP/port change.
I'm currently working on making a game where the servers need to be replicated on pods inside the Minikube cluster (I'm using Minikube since it's just a school project). However, I cannot seem to figure out how to make these game servers accessible from other networks. I have tried making a NodePort service, that points to the deployment of my server image, and when using the Minikube cluster IP + my service's port I can connect fine.
What would be the best approach to solve this issue?
By default, the Pod is only accessible by its internal IP address within the Kubernetes cluster. To make the your container accessible from outside the Kubernetes virtual network, you have to expose the Pod as a Kubernetes Service in this example as a type LoadBalancer.
On cloud providers that support load balancers, an external IP address would be provisioned to access the Service. On Minikube, the LoadBalancer type makes the Service accessible through the minikube service command.
Minikube is great for local setups but not for real clusters. It spins up only a one-node cluster for development and testing. It is useless if you want to use multiple servers environment.
Taking under consideration that you want to play fast with scalability across the nodes it is useful to create Kubernetes cluster - using Kubespray or Kubeadm.
If you want to run an actual local Kubernetes, use a local VM and then create K8s cluster using these tools for automated deployment.
Kubeadm
The kubeadm tool is good if you are new in cloud technologies -run k8s cluster for the first time. You can install and use kubeadm on various machines: your laptop, a set of cloud servers and more. Whether you’re deploying into the cloud or on-premises, you can integrate kubeadm into provisioning systems such as Ansible or Terraform.
Kubeadm provides domain Knowledge of Kubernetes clusters' life cycle management, including self-hosted layouts, dynamic discovery services and so on.
Kubespray
Kubespray supports deployments on AWS, Google Compute Engine, Microsoft Azure, OpenStack, and bare metal. It enables deployment of Kubernetes highly available clusters. It supports a variety of Linux distributions and CI. Kubespray supports kubeadm.
There isn't really a good way to do this. Minikube is for local development. If you want to run an actual local Kubernetes, start a local VM directly and use something like kubeadm and kubespray.
I have a docker container which has Flask application running.
I want to use this API for connection. I am very new to Kerberos and I have very little practical knowledge on it.
My host system will have a Kerberos client installed which can connect to hadoop successfully. Can I somehow use the host system TGT to connect to Hadoop? I have looked at almost all the resources available online and I understand how Kerberos and Hadoop interact. I would just like to know how do I make it work from inside the docker container.
I installed Nginx ECS Docker container service through AWS ECS, which is running without any issue. However, every other container services such as centos, ubuntu, mongodb or postgres installed through AWS ECS keeps restarting (de-registering, re-registering or in pending state) in a loop. Is there a way to install these container services using AWS ECS without any issue on AMI Optimized Linux? Also, is there a way to register Docker containers in AWS ECS that was manually pulled and ran from Docker Hub?
Usually if a container is restarting over and over again its because its not passing the health check that you setup. MongoDB for example does not use the HTTP protocol so if you set it up as a service in ECS with an HTTP healthcheck it will not be able to pass the healthcheck and will get killed off by ECS for failing to pass the healthcheck.
My recommendation would be to launch such services without using a healthcheck, either as standalone tasks, or with your own healthcheck mechanism.
If the service you are trying to run does in fact have an HTTP interface and its still not passing the healthcheck and its getting killed then you should do some debugging to verify that the instance has the right security group rules to accept traffic from the load balancer. Additionally you should verify that the ports you define in your task definition match up with the port of the healthcheck.
We are currently moving towards microservices with Docker from a monolith application running in JBoss. I want to know the platform/tools/frameworks to be used to test these Docker containers in developer environment. Also what tools should be used to deploy these containers to this developer test environment.
Is it a good option to use some thing like Kubernetes with chef/puppet/vagrant?
I think so. Make sure to get service discovery, logging and virtual networking right. For the former you can check out skydns. Docker now has a few logging plugins you can use for log management. For virtual networking you can look for Flannel and Weave.
You want service discovery because Kubernetes will schedule the containers the way it sees fit and you need some way of telling what IP/port your microservice will be at. Virtual networking make it so each container has it's own subnet thus preventing port clashes in case you have two containers with the same ports exposed in the same host (kubernetes won't let it clash, it will schedule containers to run until you have hosts with ports available, if you try to create more it just won't run).
Also, you can try the built-in cluster tools in Docker itself, like docker service, docker network commands and Docker Swarm.
Docker-machine helps in case you already have a VM infrastructure in place.
We have created and open-sourced a platform to develop and deploy docker based microservices.
It supports service discovery, clustering, load balancing, health checks, configuration management, diagnosing and mini-DNS.
We are using it in our local development environment and production environment on AWS. We have a Vagrant box with everything prepared so you can give it a try:
http://armada.sh
https://github.com/armadaplatform/armada