GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together.What Exactly is CNI (Container Network Interface)?
If nothing happens, download GitHub Desktop and try again. If nothing happens, download Xcode and try again. If nothing happens, download the GitHub extension for Visual Studio and try again. The output will probably be much longer as the agent will spew a lot of logs. By default the server will register itself as a node run the agent. It is common and almost required these days that the control plane be part of the cluster.
Deploy Lightweight Kubernetes Cluster in 5 minutes with K3s
To not run the agent by default use the --disable-agent flag. If you encounter an error like "stream server error: listen tcp: lookup some-host on X. For example:. Then replace "localhost" with the IP or name of your k3s server. It is also possible to deploy Helm charts. Keep in mind that namespace in your HelmChart resource metadata section should always be kube-systembecause k3s deploy controller is configured to watch this namespace for new HelmChart resources.
If you want to specify the namespace for the actual helm release, you can do that using targetNamespace key in the spec section:. Also note that besides set you can use valuesContent in the spec section. And it's okay to use both of them. As of version 0. This command will attempt to connect to MySQL on host The above command will use these certificates to generate the tls config to communicate with mysql securely.
By default the server will attempt to connect to postgres on localhost with using the postgres user and with postgres password, k3s will also create a database with the name kubernetes if the database is not specified in the DSN. This command will attempt to connect to Postgres on host The above command will use these certificates to generate the tls config to communicate with postgres securely, note that the sslmode in the example is verify-full which verify that the certification presented by the server was signed by a trusted CA and the server host name matches the one in the certificate.
The above command will attempt to connect insecurely to etcd on localhost with portyou can connect securely to etcd using the following command:. This will create the main executable, but it does not include the dependencies like containerd, CNI, etc.
To run a server and agent with all the dependencies for development run the following helper scripts. To build the full release binary run make and that will create. If you installed your k3s server with the help of install. The server needs port to be accessible by the nodes.
The nodes need to be able to reach other nodes over UDP port If you don't use flannel and provide your own custom CNI, then is not needed by k3s. The node should not listen on any other port. The VXLAN port on nodes should not be exposed to the world, it opens up your cluster network to accessed by anyone.
I wouldn't be me if I couldn't run my cluster in Docker. A docker-compose. To run from docker-compose from this repo run. To run the agent only in Docker use the following docker-compose-agent.Please reference that page for details on Flannel and the various flannel backend options or how to set up your own CNI.
Please reference the Installation Requirements page for port information. CoreDNS is deployed on start of the agent. To disable, run each server with the --disable coredns option. Traefik is a modern HTTP reverse proxy and load balancer made to deploy microservices with ease. It simplifies networking complexity while designing, deploying, and running applications. Traefik is deployed by default when starting the server.
For more information see Auto Deploying Manifests. The Traefik ingress controller will use ports 80,and on the host i. You can tweak traefik to meet your needs by setting options in the traefik. Refer to the official Traefik for Helm Configuration Parameters readme for more information.
K3s includes a basic service load balancer that uses available host ports. If you try to create a load balancer that listens on port 80, for example, it will try to find a free host in the cluster for port If no port is available, the load balancer will stay in Pending. To disable the embedded load balancer, run the server with the --disable servicelb option. This is necessary if you wish to run a different load balancer, such as MetalLB.
This can cause problems with domain name resolution. Need Help?
Open Ports Please reference the Installation Requirements page for port information. To disable it, start each server with the --disable traefik option. Service Load Balancer K3s includes a basic service load balancer that uses available host ports.
Edit this page.There are many choices available which can be used as CNI plug-ins with a large variation in the sophistication of functionality provided. In the most common setup of Kubernetes clusters, it is desirable that every node is reachable from every other node in the cluster. This enables the seamless deployment of applications and services across the nodes within the cluster.
The CNI is responsible for ensuring that the containers created are reachable from every node and can use a range of technologies to enable this, for example building an overlay network using VXLAN.
In our use-case, we have chosen a different network organization from the Kubernetes norm, as we are looking to enable Edge Compute for IoT. In the simplest case, the Edge Gateway acts as a relay, passing on data from the endpoints for example, data from a temperature sensor to a cloud-based application and passing back commands from that cloud application.
In this setup, many endpoints may be connected to a single Edge Gateway. This combination of endpoints plus gateway is then the unit of deployment that can be instantiated in many different locations.
This can also have benefits in terms of privacy and data-security as we also can reduce the amount of raw data being sent to the cloud. We chose to use Kubernetes to manage the deployment of applications to the Edge Gateways in our system.
Each of our deployed Edge Gateways becomes a node in our Kubernetes cluster, but unlike a normal cluster we have no requirement for each node to be reachable from every other node. In this typical IoT edge computing implementation, the system is segmented with the control plane master running in the cloud, while the Edge Gateways the worker nodes themselves are scattered geographically and are probably located behind a firewall or behind a NAT in a private network.
In this model, the connectivity between nodes and that between a node and the cloud are limited. We assume that nodes have an outbound internet connectivity and they can initiate a connection to the hosted Kubernetes master in the cloud.
When using smarter-cni, only pods containers running on the same node can communicate directly with each other. Kubernetes source repository. This plugin is no longer maintained and so we have made the smarter-cni plugin.
Smarter-cni plugin. The networking configuration for a node Edge Gateway using smarter-cni can be viewed in two ways:. Smarter-cni provides a simpler implementation that is less expensive and more distributed, it also alleviates the need for Service objects by providing a DNS entry for each pod. Docker provides an automatically enabled, embedded DNS resolver Each node also runs a containerized dnsmasq connected to the user-defined network with a static address.
To install smarter-cni on a node, check out the latest tagged version currently v0. Smarter-cni repository. Once smarter-cni is installed on a node, it can be used as the CNI when the node is joined to a Kubernetes cluster. Here is an example of using smarter-cni with k3s with docker as the container runtime engine we assume that docker is already present. Download the latest k3s binary. Both bit and bit Arm platforms are supported as well as x This command also prevents coredns and traefik being deployed as we do not use that functionality.
This command will generate logging information so it's best to redirect standard error and standard output to file as shown. Note that in this setup the master node is not running the k3s agent and will therefore not run any applications that are deployed into the cluster. Find the token that a worker will need to join the cluster.
Run the k3s agent on the worker node filling in the IP of the master node and providing the token:. This will start the k3s agent and join the worker to the cluster. This command will also generate logging information so it's best to redirect standard error and standard output to file as shown. The same k3s agent command can be run on other nodes on which smarter-cni and k3s have been installed to add more nodes to the cluster.
Here is a YAML description for an example application that can be deployed to the cluster. It's described as a Kubernetes dameonset and will be deployed on each node in the cluster:. This application consists of a shell command running in an Alpine Linux image. It prints the current date and time onto standard out every five seconds.You want to deploy a Lightweight Kubernetes Cluster with ease and less memory footprint? Kubernetes has been a game changer in how containerized workloads are deployed and managed at immense scale.
The main challenge for Developers revolve around setup process and resource requirements to have a working Kubernetes Cluster. For Development and test impetus, a user should be able to deploy Kubernetes with least resource utilization and low hardware specs.
Since K3s is optimized to use less resources, some Kubernetes features are stripped off. These include:. One of the servers will be used as master and other two as worker nodes. There are many ways to run k3s.
The quickest method is installation via provided bash script. This script provides a convenient way for installing to systemd or openrc. The k3s installer script will install k3s and additional utilities, such as kubectlcrictlk3s-killall. To uninstall K3s, run the command:.
Check K3s documentation for advanced configurations. How To run Local Kubernetes clusters in Docker. Sign in. Log into your account. Forgot your password? Password recovery. Recover your password. Get help. You can support us by downloading this article as PDF from the Link below. Download the guide as PDF Close. Kubernetes for the Absolute Beginners - Hands-on. Buy Now. Install Kubernetes Cluster on Ubuntu Ceph Persistent Storage for Kubernetes with Cephfs.
K3s - Lightweight Kubernetes
Recent Posts.You may need more resources to fit your needs. K3s is officially supported and tested on the following operating systems and their subsequent non-major releases:. If you are using Alpine Linuxfollow these steps for additional setup. Hardware requirements scale based on the size of your deployments. Minimum recommendations are outlined here. K3s performance depends on the performance of the database.
To ensure optimal speed, we recommend using an SSD when possible. The node should not listen on any other port. K3s uses reverse tunneling such that the nodes make outbound connections to the server and all kubelet traffic runs through that tunnel.
However, if you do not use Flannel and provide your own custom CNI, then port is not needed by K3s. Important: The VXLAN port on nodes should not be exposed to the world as it opens up your cluster network to be accessed by anyone.
Hardware requirements are based on the size of your K3s cluster. For production and large clusters, we recommend using a high-availability setup with an external database. The following options are recommended for the external database in production:. The following are the minimum CPU and memory requirements for nodes in a high-availability K3s server:. The cluster performance depends on database performance.
To ensure optimal speed, we recommend always using SSD disks to back your K3s cluster. On cloud providers, you will also want to use the minimum size that allows the maximum IOPS.
You can do that by passing the --cluster-cidr option to K3s server upon starting. Installation Requirements. Need Help? K3s is very lightweight, but has some minimum requirements as outlined below.
Prerequisites Two nodes cannot have the same hostname. Operating Systems K3s should run on just about any flavor of Linux. K3s is officially supported and tested on the following operating systems and their subsequent non-major releases: Ubuntu Hardware Hardware requirements scale based on the size of your deployments. Networking The K3s server needs port to be accessible by the nodes. If you wish to utilize the metrics server, you will need to open port on each node.
Large Clusters Hardware requirements are based on the size of your K3s cluster. Edit this page.GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together. If nothing happens, download GitHub Desktop and try again.
If nothing happens, download Xcode and try again. If nothing happens, download the GitHub extension for Visual Studio and try again.
We wanted an installation of Kubernetes that was half the size in terms of memory footprint. Kubernetes is a 10 letter word stylized as k8s. So something half as big as Kubernetes would be a 5 letter word stylized as k3s.
There is no long form of k3s and no official pronunciation. Please see the official docs site for complete documentation on k3s.
The k3s install. The install script will install k3s and additional utilities, such as kubectlcrictlk3s-killall. Please check out our contributing guide if you're interesting in contributing to k3s. Skip to content. Lightweight Kubernetes k3s. Dismiss Join GitHub today GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together. Sign up. Branch: master. Go back. Launching Xcode If nothing happens, download Xcode and try again.
Latest commit.We wanted an installation of Kubernetes that was half the size in terms of memory footprint. Kubernetes is a letter word stylized as K8s. So something half as big as Kubernetes would be a 5-letter word stylized as K3s.
There is no long form of K3s and no official pronunciation. K3s - Lightweight Kubernetes.
Need Help? Lightweight Kubernetes. Easy to install, half the memory, all in a binary of less than MB. K3s is a fully compliant Kubernetes distribution with the following enhancements: Packaged as a single binary.
Lightweight storage backend based on sqlite3 as the default storage mechanism. Wrapped in simple launcher that handles a lot of the complexity of TLS and options. Secure by default with reasonable defaults for lightweight environments. Operation of all Kubernetes control plane components is encapsulated in a single binary and process.
This allows K3s to automate and manage complex cluster operations like distributing certificates. External dependencies have been minimized just a modern kernel and cgroup mounts needed. Edit this page.