I am a newbie in Kubernetes.
I have 19 LAN servers with 190 machines.
Each of the 19 LANs has 10 machines and 1 exposed IP.
I have different websites/apps and their environments that are assigned to each LAN.
how do I manage my Kubernetes cluster and do setup/housekeeping.
Would like to have a single portal or manager to manage the websites and environment(dev, QA, prod) and keep isolation.
Is that possible?
I only got a vague idea of what you want to achieve so here goes nothing.
Since Kubernetes has a lot of convenience tools for setting a cluster on a public cloud platform, I'd suggest to start by going through "kubernetes-the-hard-way". It is a guide to setup a cluster on Google Cloud Platform without any additional scripts or tools, but the instructions can be applied to local setup as well.
Once you have an operational cluster, next step should be to setup an Ingress Controller. This gives you the ability to use one or more exposed machines (with public IPs) as gateways for the services running in the cluster. I'd personally recommend Traefik. It has great support for HTTP and Kubernetes.
Once you have the ingress controller setup, your cluster is pretty much ready to use. Process for deploying a service is really specific to service requirements but the right hand rule is to use a Deployment and a Service for stateless loads, and StatefulSet and headless services for stateful workloads that need peer discovery. This is obviously too generalized and have many exceptions.
For managing different environments, you could split your resources into different namespaces.
As for the single portal to manage it all, I don't think that anything as such exists, but I might be wrong. Besides, depending on your workflow, you can create your own portal using the Kubernetes API but it requires a good understanding of Kubernetes itself.
Related
I am looking at some strategies how to make bidirectional communication of applications hosted on seperate clusters. Some of them are hosted in Service Fabric and the others are in Kubernetes. One of the options is to use a DNS service on the Service Fabric and the counterpart on Kubernetes. On the other hand the Reverse Proxy seems to be a way to go. After going through the options I was thinking...what is actually the best way to create microservices that can be deployed either in SF or in K8s without worrying about the communication model which requires least changes if we wish suddenly to migrate one app from SF to K8s but still making it avaiable to the SF apps and vice versa?
I am learning Kubernetes and have developed good knowledge about it. however I am not able to understand why and in which case one would use the service discovery tools when infra is on Kubernetes.
This was asked to me during the interview like which service discovery software will you use for microservices. I am not sure why one would need service discovery when in Kubernetes we have services objects which can be referenced by name.
Has anyone come across a case, where they are developing microservices on Kubernetes and needed the service discovery tool to say like etcd ?
Yes, there could be many more cases for setting up your own service discovery. One, in particular, is a multi-cluster setup with k8s. You can look at how Submariner (a tool for connecting several k8s clusters with an l3/4 tunnel) utilize CoreDNS to add a cross-cluster DNS Service Discovery).
I have recently been reading more about infrastructure as a service (IaaS) and platform as a service (PaaS) and had some questions. I see when we opt for a PaaS solution, it is generally very easy to create the infrastructure as the cloud providers handle that for us and we can even automate the deployment using an infrastructure as code solution like Terraform.
But if we use an IaaS solution or even a local on premise cluster, we lose a lot of the automation it seems that PaaS allows. So I was curious, are there any good tools out there for automating infrastructure deployment on a local cluster that is not in the cloud?
The best thing I could think of was to run a local Kubernetes cluster and then Dockerize each of the infrastructure components, but this seems difficult as each node in the cluster will need its own specific configuration files.
From my basic Googling, it seems like there is not a good solution to this.
Edit:
I was not clear enough with my original intentions. I have two problems I am trying to solve.
How do I automate infrastructure deployment locally? For example, suppose I wanted to create a Hadoop HDFS cluster. I would need to configure one node to be the namenode with an accessible IP, and the other nodes to be datanodes that are aware of the namenode's IP. At the moment, I have to do this manually by logging into each node, checking it's IP, and then configuring each one. How would I automate this? If I were to use a Kubernetes approach, how do I specify that one of the running pods needs to be the namenode and the others are datanodes? How do I find the pods' IPs and have them be aware of the namenode IP?
The next problem I have is very similar to the first, but a slight modification. How would I deploy specific configuration files to each node. For instance in Kafka, the configuration file for one node, requires the IPs of the Zookeeper nodes, as well as the IP it should listen on. This may be different for every node in the cluster. Is there a good way to make these config files pod specific, so that I do not have to do bash text processing to insert the correct contents into each pod's config files?
You can use Terraform for all of your on-premise Infra. Automation, and Ansible for configuration management.
Let's say you have three HPE servers, Install K8s or VMware on them using Ansible, then you can treat them as three Avvaliabilty zones in one region, same as AWS. from this you can start deploying dockerize apps, or helm charts using Terraform.
Summary:
Ansbile for installing and configuration K8s.
Terraform for provisioning K8s.
Helm for installing apps on K8s.
After this you gonna have a base automated on-premise Infra.
My company mostly specialize in web and mobile development. Some of our clients want to have backend or web applications hosted and managed by us, because of that we have several apps and server to manage. I'm looking for a solution to have all these servers under one panel and most of all deploy all this application in High Availability. Moreover, we have servers in many different cloud providers and it would be nice if it would be possible to use them.
I've already found and tested few solutions. Maybe someone had the same problem and found a better solution or maybe can you advise which one of these are the best?
1. Rancher + DNS Round Robin
It would be setting up Rancher in HA mode with use of cattle or Kubernetes. Then set up few host just for loadBalancer and achieve HA by using DNS Round Robin. Put ip of all LoadBalancer in DNS records for every web application.
Pros:
Easy to setup
Multiple environments. One panel to administrate development, production infrastructure.
No single point of failure
Very cheap
Cons:
Leaves failover to the client-side application
Not reliable
When one node down high response times for some clients (he needs to wait for request to timeout)
2. Rancher + Cloudflare Load Balancer
As the previous set up Rancher in HA mode with use of cattle or Kubernetes. Then set up few host just for LoadBalancer and achieve HA by using Cloudflare LoadBancer pointing to rancher nodes used for LoadBalancers.
Pros:
Easy to setup
Multiple environments. One panel to administrate development, production infrastructure.
Theoretically, Cloudflare LB has 100% SLA
Cons:
The biggest problem is that Cloudflare LB uses DNS records for LoadBalancing. So our clients would need to redirect their domain to our DNS servers on Cloudflare or add CNAME record for our domain. Both of them are not ideal solutions :/ CNAME would be bad for SEO I think.
With many domains and many requests can get expensive.
Notes: I've tested this solution and it's working quite well, after shutting down node with LoadBalancer or with application downtime was about 20s-60s, so just time needed to spin new container.
3. Rancher + Floating IP + Keep alive
As the previous set up Rancher in HA mode with use of cattle or Kubernetes. Then set up few host just for LoadBalancer. Then setting up keepalive and (DigitalOcean) floating IP for nodes that are for LoadBalancers.
DigitalOcean floating ip diagram
Pros:
Easy to setup
Multiple environments. One panel to administrate development, production infrastructure.
No single point of failer
Cons:
LoadBalancers nodes needs to be on DigitalOcean
4. Kubernets on Google Cloud Platform with Kubernetes Engine
Setting up Kubernetes in HA mode on GCP.
Pros:
Super easy to setup on GCP. Just one click
Cons:
I couldn't find SLA of GCP Load Balancers. But probably single point of failer and SLA is not 100%
We would be attached with this Kubernetes cluster to one cloud provider
Having LB for every application, even if it's small could get expensive.
Worse web panel than the Rancher
5. Rancher 2.0 use all from above depending on environment
With Rancher 2.0 we could use all of above solutions it allows to add existing Kubernetes clusters to Rancher. So it would work with Kubernetes engine on GCP. However, it's in alpha version and doesn't have HA deployment yet.
Mostly I'm thinking about setting up option 3. Then if the rancher 2.0 will be released change for it and for larger applications use GCP with Kubernetes Engine. Have someone better solution? or maybe should I use other solutions from provided?
In my company we have few public websites and many internal webapps. Currently they are are running in different AWS security groups.
Is it possible to run both kind of services on the same OpenShift cluster and make sure internal services are not accessible from the Internet?
Thanks!
The traditional(?) way that is solved is through Internet-facing ELB/ALBs pointed to the NodePorts on the cluster. I personally haven't tried Service of kind: LoadBalancer since 1.2 to be able to speak to its functionality, but I do know kubernetes has a lot of users on AWS, so it's plausible it works fine by now.
You can also run your own Ingress Controller, several of which have support for ip white/black listing, authentication, SSL/TLS, all the fancy toys, if you'd prefer not to deal with the ELB headache.
If you're not already considering it, Calico SDN has support for in-cluster networking policies, so you could also apply an extra level of locked-down-ness to ensure no Internet app breaks out of its allowed network path; thus, security-groups moving down into the cluster.