We started using Kubernetes, a few time ago, and now we have deployed a fair amount of services. It's becoming more and more difficult to know exactly what is deployed. I suppose many people are facing the same issue, so is there already a solution to handle this issue?
I'm talking of a solution that when connected to kubernetes (via kubectl for example) can generate a kind of map off the cluster.
In order to display one or many resources you need to use kubectl get command.
To show details of a specific resource or group of resources you can use kubectl describe command.
Please check the links I provided for more details and examples.
You may also want to use Web UI (Dashboard)
Dashboard is a web-based Kubernetes user interface. You can use
Dashboard to deploy containerized applications to a Kubernetes
cluster, troubleshoot your containerized application, and manage the
cluster resources. You can use Dashboard to get an overview of
applications running on your cluster, as well as for creating or
modifying individual Kubernetes resources (such as Deployments, Jobs,
DaemonSets, etc). For example, you can scale a Deployment, initiate a
rolling update, restart a pod or deploy new applications using a
deploy wizard.
Let me know if that helped.
Related
we are using k8s cluster for one of our application, cluster is owned by other team and we dont have full control over there… We are trying to find out metrics around resource utilization (CPU and memory), detail about running containers/pods/nodes etc. Need to find out how many parallel containers are running. Problem is they have exposed monitoring of cluster via Prometheus but with Prometheus we are not getting live data, it does not have info about running containers.
My query is , what is that API which is by default available in k8s cluster and can give all what we need. We dont want to read data form another client like Prometheus or anything else, we want to read metrics directly from cluster so that data is not stale. Any suggestions?
As you mentioned you will need metrics-server (or heapster) to get those information.
You can confirm if your metrics server is running kubectl top nodes/pods or just by checking if there is a heapster or metrics-server pod present in kube-system namespace.
Also the provided command would be able to show you the information you are looking for. I wont go into details as here you can find a lot of clues and ways of looking at cluster resource usage. You should probably take a look at cadvisor too which should be already present in the cluster. It exposes a web UI which exports live information about all the containers on the machine.
Other than that there are probably commercial ways of acheiving what you are looking for, for example SignalFx and other similar projects - but this will probably require the cluster administrator involvement.
I would like to know if it is possible for multiple pods in the same Kubernetes cluster to access a database which is configured using persistent volumes on a Google cloud persistent disk.
Currently I am building a microservices achitecture web app which has 3 node apis in different pods all accessing the same database. So how do I achieve this with kubernetes.
Kindly let me know if my architecture is right as well
You can certainly connect multiple node-based app pods to the same database. It is sometimes said that microservices shouldn't share a database but this depends on what your apps are doing, the project history and the extent to which you want the parts to be worked on separately.
There are questions you have to answer about running databases at scale, such as your future load and whether you want to use relational databases if you're going to try to span availability zones. And there are
some specific to kubernetes, especially around how you associate DB Pods to data. See https://stackoverflow.com/a/53980021/9705485. Another popular option is to use a managed DB service from a cloud provider. If you do run the DB in k8s then I'd suggest looking for a helm chart or looking at an operator, such as the kubeDB operator, to avoid crafting the kubernetes descriptors yourself and to get more guidance on running the DB and setting it up.
If it's a new project and you've not used k8s before then you'll also have to decide where to host your code, your docker images and your deployment descriptors and how to setup your CI pipelines. If you've not got answers to these questions already then I'd suggest looking at Jenkins-X as it will provide you with out of the box defaults for a whole cluster and CI setup and a template ('build pack') for building node apps and deploying them to staging and prod environments through a pipeline.
Requirement - New Relic monitoring for an application running in pods as part of a kubernetes cluster.
I have installed Kube-state-metrics on my cluster and able to see kubernetes dashboard using newrelic insights.
Also, need to configure the Application monitoring for the same. Following https://blog.newrelic.com/2017/11/27/monitoring-application-performance-in-kubernetes/ for the same.
Have some questions for the same -
Can this be achieved using kube-state-metrics ?
Do I need to have separate yaml file for each pod containing license key?
Do I need to make changes in my application also or adding the information in spec will work?
Do I need to install Java agent in every pod? If yes, will it eat resources?
Somehow, Installation of application monitoring is becoming complex. Please explain the exact requirement of installation
You didn't mention your stack, you should follow instructions on their site for your language. Typically you just pull in their agent library and configure credentials to get started. You should not have a reason to tell your pods apart, so the agent credentials should be the same for all pods
Installing agents at infrastructure will let you have infrastructure data. So you'll get alerts if you're running out of memory/space/cpu and such. Infrastructure agent cannot possibly know about application data. If you want application performance data (apm) you need to install the agent at the application level too and you'll get data such as http request rates, error rates and response times if it's a webserver. You can also annotate current transaction with data which is all application specific. They have a bunch of client agents, see if there's one for your stack. For example all you need for a nodejs service is require('newrelic') at the top of your app and configuration
Long time I did not come here and I hope you're fine :)
So for now, i have the pleasure of working with kubernetes ! So let's start ! :)
[THE EXISTING]
I have an operationnal kubernetes cluster with which I work every day.it consists of several applications, one of which is of particular interest to us, which is the web management interface.
I currently own one master and four nodes in my cluster.
For my web application, pod contain 3 containers : web / mongo /filebeat, and for technical reasons, we decided to assign 5 users max for each web pod.
[WHAT I WANT]
I want to deploy a web pod on each nodes (web0,web1,web2,web3), what I can already do, and that each session (1 session = 1 user) is distributed as follows:
For now, all HTTP requests are processed by web0.
[QUESTIONS]
Am I forced to go through an external loadbalancer (haproxy)?
Can I use an internal loadbalancer, configuring a service?
Does anyone have experience on the implementation described above?
I thank in advance those who can help me in this process :)
This generally depends how and where you've deployed your Kubernetes infrastructure, but you can do this natively with a few options.
Firstly, you'll need to scale your web deployment. This is very simple to do:
kubectl scale --current-replicas=2 --replicas=3 deployment/web
If you're deployed into a cloud provider (such as AWS using kops, or GKE) you can use a service. Just specify the type as LoadBalancer. Services will spread the sessions for your users.
Another option is to use an Ingress. In order to do this, you'll need to use an Ingress Controller, such as the nginx-ingress-controller which is the most featureful and widely deployed.
Both of these options will automatically loadbalance your incoming application sessions, but they may not necessarily do it in the order you've described in your image, it'll be random across the available web deployments
I am trying to deploy my Docker images using Kubernetes orchestration tools.When I am reading about Kubernetes, I am seeing documentation and many YouTube video tutorial of working with Kubernetes. In there I only found that creation of pods, services and creation of that .yml files. Here I have doubts and I am adding below section,
When I am using Kubernetes, how I can create clusters and nodes ?
Can I deploy my current docker-compose build image directly using pods only? Why I need to create services yml file?
I new to containerizing, Docker and Kubernetes world.
My favorite way to create clusters is kubespray because I find ansible very easy to read and troubleshoot, unlike more monolithic "run this binary" mechanisms for creating clusters. The kubespray repo has a vagrant configuration file, so you can even try out a full cluster on your local machine, to see what it will do "for real"
But with the popularity of kubernetes, I'd bet if you ask 5 people you'll get 10 answers to that question, so ultimately pick the one you find easiest to reason about, because almost without fail you will need to debug those mechanisms when something inevitably goes wrong
The short version, as Hitesh said, is "yes," but the long version is that one will need to be careful because local docker containers and kubernetes clusters are trying to solve different problems, and (as a general rule) one could not easily swap one in place of the other.
As for the second part of your question, a Service in kubernetes is designed to decouple the current provider of some networked functionality from the long-lived "promise" that such functionality will exist and work. That's because in kubernetes, the Pods (and Nodes, for that matter) are disposable and subject to termination at almost any time. It would be severely problematic if the consumer of a networked service needed to constantly update its IP address/ports/etc to account for the coming-and-going of Pods. This is actually the exact same problem that AWS's Elastic Load Balancers are trying to solve, and kubernetes will cheerfully provision an ELB to represent a Service if you indicate that is what you would like (and similar behavior for other cloud providers)
If you are not yet comfortable with containers and docker as concepts, then I would strongly recommend starting with those topics, and moving on to understanding how kubernetes interacts with those two things after you have a solid foundation. Else, a lot of the terminology -- and even the problems kubernetes is trying to solve -- may continue to seem opaque