Kubectl apply -f curl 172.20.0.2# this can't work as expected on MacOS, docker needs some tweaking.
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If you try to setup Kubernetes cluster on bare metal system, you will notice that Load-Balancer always remain in the “pending” state indefinitely when created. This is expected because Kubernetes, by default does not offer an implementation of network load-balancer for bare metal cluster.
In a cloud-enabled Kubernetes cluster, you request a load-balancer, and your cloud platform assigns an IP address to you. In a bare metal cluster, you need an external Load-Balancer implementation which has capability to perform an IP allocation.
Enter MetalLB…
MetalLB is a load-balancer implementation for bare metal Kubernetes clusters, using standard routing protocols. MetalLB provides a network load-balancer implementation for Kubernetes clusters that do not run on a supported cloud provider, effectively allowing the usage of LoadBalancer Services within any cluster. It aims to redress this imbalance by offering a Network LB implementation that integrates with standard network equipment, so that external services on bare metal clusters also “just work” as much as possible.
Why can’t Ingress help me out here?
Yes, Ingress could be one of the best option if you deployed Kubernetes cluster on bare metal. Ingress lets you configure internal load balancing of HTTP or HTTPS traffic to your deployed services using software load balancers like NGINX or HAProxy deployed as pods in your cluster. Ingress makes use of Layer 7 routing of your applications as well. The problem with this is that it doesn’t easily route TCP or UDP traffic. The best way to do this was using a LoadBalancer type of service. However, if you deployed your Kubernetes cluster to bare metal you didn’t have the option of using a LoadBalancer.
How does MetalLB work?
MetalLB hooks into your Kubernetes cluster, and provides a network load-balancer implementation. In short, it allows you to create Kubernetes services of type “LoadBalancer” in clusters that don’t run on a cloud provider, and thus cannot simply hook into paid products to provide load-balancers.
It is important to note that MetalLB cannot create IP addresses out of thin air, so you do have to give it pools of IP addresses that it can use. It will then take care of assigning and unassigning individual addresses as services come and go, but it will only ever hand out IPs that are part of its configured pools.
Okay wait.. How will I get IP Address pool for MetalLB?
How you get IP address pools for MetalLB depends on your environment. If you’re running a bare metal cluster in a colocation facility, your hosting provider probably offers IP addresses for lease. In that case, you would lease, say, a /26 of IP space (64 addresses), and provide that range to MetalLB for cluster services.
Under this blog post, I will showcase how to setup 3-Node Kubernetes cluster using MetalLB. The below steps have also been tested for ESXi Virtual Machines and works flawlessly.
Preparing the Infrastructure
[rml_read_more]
Assign hostname to each of these systems:Installing curl packageInstalling DockerAdd the Kubernetes signing key on both the nodesAdding Xenial Kubernetes Repository on both the nodesInstalling KubeadmVerifying Kubeadm installation![]() Disable swap memory (if running) on both the nodesSteps to setup K8s Cluster
In case you face any issue, just run the below command to see the logs:
Adding Worker NodeListing the NodesConfiguring Metal LoadBalancer
There are 2 components :
Controller component is deployed as deplyment and speaker as daemonset which is running on all worker nodes
Next, we need to look at config files.
To configure MetalLB, write a config map to metallb-system/config
Link: https://metallb.universe.tf/configuration/
Layer 2 mode is the simplest to configure: in many cases, you don’t need any protocol-specific configuration, only IP addresses.
We need to pay attention to the above Internal IP. We need to use this range only.
By now, you should be able to browser NGINX Page underhttp://10.94.214.210
Hurray !!!
Let’s run another nginx service:
Let’s run hellowhale example
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Hence, you saw that it’s so easy to deploy Kubernetes on bare metal using various popular operating systems like Ubuntu Linux, CentOS, SLES or Red Hat Enterprise Linux. Bare Metal Kubernetes deployments are no longer second-class deployments. Now, you, too, can use LoadBalancer resources with Kubernetes Metallb.
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Docker for Mac with Kubernetes のBeta版が利用できるようになってましたので、動かしてみました。
マニュアルはこのへん
https://docs.docker.com/docker-for-mac/#kubernetes インストール
Docker for MacのEdgeバージョンをインストールする必要があります。
ファイルのパス
https://download.docker.com/mac/edge/Docker.dmg
インストールして
About Docker を見るとこんな感じです。
サインイン
Dockerにサインインする必要があるので、メニューからサインインします。
起動
Preferenceから
Kubernetes を選択し、 Enable Kubernetes にチェックを入れて、Apply します。kubectlコマンド
Kubernetesが起動すると、
kubectl コマンドが使えるようになってます。
Homebrew等でkubectlを既にインストールしていて、
/usr/local/bin/kubectl がある場合、先に削除しておく必要があるようです。
contextの変更
kubectlのcontextsを確認します。
contextを
docker-for-desktop に変更します。
確認
これで使えるようになっています。
システムコンテナ
Kubernetes関連のコンテナはデフォルトでは見えないようになっています。
Preferenceで Show system containers にチェックを入れると、見れるようになります。
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January 2023
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