Cloud Native Computing Foundation Kubernetes Community Days Bangalore 2022, 11 May 2022

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From YouTube: Kubectl Plugins

Description

Kubectl commands are one of the essential building blocks which help in interaction with the Kubernetes cluster and using Plugins as sub-commands with it helps in extending the features of kubectl. In this talk, I will be explaining what Kubectl plugins are and how it is managed and installed by Krew, an open-source plugin manager for kubectl. Along with this, different kubectl plugins will be explained by showing a practical demo of them which will give attendees a better understanding of plugins and how to adapt it and use it in daily practice.
Some of the widely used plugins are kubectx,kubens, popeye, and so on. I am a final year Computer Science Engineering student who is learning about Kubernetes and the cloud-native world. I am working as a technical writer where I write blogs related to different cloud-native projects and kubectl plugins attracted me the most in the Kubernetes project and I decided to give a talk on kubectl plugins. As kubectl plugins are managed through Krew and these plugins give new and custom features to kubectl and give a way to consolidate common Kubernetes management actions in a way that are easily distributed across the team and it correctly fits in KCD and in an open-source ecosystem as these plugins help users and developers to manage and enhance kubectl, as well as giving a motivation to contribute in it.

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Hello, everyone welcome to cassidy bengaluru. My name is oshi, and today I will be talking about cube, ctl plugins, a brief introduction about myself. I am a final year, computer science, engineering student and currently working as a devops engineer and technical writer at claudia technologies, and for this spring cohort I am lfx mendy at kyono project.

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uh So first I will be talking about what are capsule plugins, why we need it and what different challenges we face, while working with the skip city plugins and how our crew helps in solving those challenges and then we'll be doing some hands-on lab where we'll be exploring about uh different cube city plugins with crew.

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So uh what are capabil plugins? uh If I talk about cubesating first, so cube ctl is a command line tool which helps in interacting with kubernetes control plane by kubernetes api, so uh like in this diagram. If I want to get parts from the default namespace, I can execute skip ctl that puts command, and this skip ctrl will send an http request to kubernetes api to the kubernetes control plane to get the parts from the default name space. On the other side.

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Plugins are the standalone, executable binaries, which means they are the add-ons to the softwares which helps in enhancing their capabilities. So keepsake plugins are nothing but they are used to extend the functionalities of cubesat command link tool and these plugins work as sub commands of skip city itself.

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uh But the question is why we need cuba, city plugins. We already have uh four commands of cube. Ctl like gibson, create cube ctl run, but we need these plugins to get our tasks from more easily and efficiently.

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Like consider a situation where we are working with multiple contacts and name spaces in the cluster, and we are frequently switching between those contexts and name spaces. So, instead of using uh keepsaker config set context command, we can use uh plugins like cube, ctx and qbns, which will help us in doing our work more easily more about this, we'll be seeing in a while. When we'll uh do the hands-on for the script. Plugins.

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So, while working with the skip ctrl plugins, we often face with some challenges like to manage these uh plugins binaries, uh taking care of its installation, updating them regularly and managing it with cube ctl. So to solve these challenges. uh Crew got introduced. Preview is a plugin manager for cube ctl, and it is a kubernetes seek project. It takes proper care of plugin installation, its management.

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It also helps in packaging and distributing the plugins on cross platforms and the and all the plugins can be accessible through a centralized repository uh till now there are about 190 plugins have been supported by true, and the most interesting fact is that true itself is a plugin, so crew can be worked as a sub command, with cube ctl like cuba, city, true install command, which will help us in installing plugins more about the more about such commands, we'll be seeing in a while, while working with a hands-on.

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So for the hands-on, you can go to this link and try the hands-on there. So at your end, you will get a lapse at a button and on clicking the that laptop button, you will get a terminal and id in a few seconds, so I have already done at my side. So, first of all, I am going to check the kubernetes cluster status, uh which will come as soon as you trigger the left.

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So I am going to check now the status of a kubernetes cluster with the cube ctrl get nodes command, and here the my master node is in the red status. The next step is to install trip, so crew can be installed in various ways. According to the system, requirements like uh linux, mac, os and windows, and for this lab uh creates already installed according to the linux system requirements. Now I am going to execute pubescent true command, which will open a help guide.

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For me like what different sub commands, I can execute with quipsitil crew, and I can execute install uh search, uninstall type of commands with cubesat l3 right now. I am going to check the version of uh crew with the help of pubesity version command, and it will give me some details of it.

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uh uh Like particular, it's gita git commit now I'm going to execute publicity, crew search command, which will give me all the lists of the plugins which are supported by true right now and and the list will come in alphabetical order like you can see. uh Who am I who can uh type plugin tail score and so on like this now? uh The next is we are going to explore different cube, ctrl plugins and the first plugins we are going to understand about is cube. Ctx, so cube.

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Ctx is a plugin which helps in switching between multiple context easily and for this first I am going to install this plugin with the help of cryptical crew install command and uh specifying the name of that uh ctx plugin.

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Now, after installing, I have to set up my environment path so that uh this plugin can work. So I'm setting this environment path and executing tip ctl ctx for now, which will list all the contexts we have in the cluster right now and so for now. uh I have only one context that is kubernetes admin.

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Next, I can execute quicksitl ctx hyphen f1 help command to see what different uh sub commands. I can use along with this ctx plugin right now. I can use hyphen c flag to see the current context name.

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The next plugin is cube ns. It is a plugin which helps in switching between kubernetes name spaces, so this can be installed.

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Similarly, with the help of cubesatelpro install command and and then I have to set an environment variable for this and then execute quick, ctl ns, which will insert all the name spaces of the cluster and right now we have this many name: special default cube system queue, public and so on, like similarly with cube ctx, I can also execute the help guide of this uh cube city, lns plugin, and if I want to know the current name spaces in which I am working, I can use a hyphen save flag along with keep ctl ns, and it will give me a default name space, as I mean default.

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Namespace next plugin is example plugin. This is also one of the useful plugins. This plugins basically gives a predefined template of kubernetes resources like for config map uh for pod and so on. So similarly, this can be installed with uh cuba. Ctel pro install command and then uh I want a template for ingress, let's say so. I can get this with the help of publicity example and specifying the ingress kubernetes resource, and as I got the template, I can like make the necessary changes, according to my requirement in this particular template.

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Similarly, I can get a template for config map, also by executing cube ctl example config command and make the necessary changes here. Also, the next plugin is images. It is also one of the useful plugins and it helps out listing all the container images used in the cluster. So uh it basically calls the cube ctl get parts command false, which helps in retrieving all the port details, and then it filters out the container images from it and present it in a tabular format.

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uh So again, this can be installed with a cubesat pro install command, and then I can execute help command on it or to know how this plugin works. So I can specify all them specials, flag context, flag, coupon, flip flag on this cube, ctrl images, and for now let's say I want to get the images from the cube system.

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Name space, so I can do this by specifying the cube system name space with the hyphen n flag and execute it with the help of cryptical images, comma and, as you can see, I am getting all the images which are present in the cube system, namespaces in a tabular format.

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So next plugin is tree, so this plugin helps in exploring and browsing kubernetes object hierarchies as a tree. So uh again I can install this with the help of cryptical, true, comma, install command.

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Now, to get a better understanding of this three plugin, I'm going to first create a nginx deployment with nginx alpine image and, along with this free replicas, and this I can check with cubesatel get deployments command and as soon as the deployment is in registered, I can apply a cubesatl tree on this nginx deployment and here, as you can see, the hierarchical structure of this deployment, where I can see about replica set and all the three replicas of this nginx.

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Next, I'm going to update this nginx deployment.

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uh Here I am going to update this nginx alpine image to nginx latest image and if I again apply kubectl triplugin on this uh deployment, and then I can see that all the replicas in the older replica set have been updated and the new replica set has been created with a new tree replicas and if I check the replica sets of this deployment- and I can see that that all the three replicas of the new replica set are in registered and the replicas of all the replica sets are deleted.

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Now I am going to delete this nginx deploy for further demo. So next is popeye plugin. It helps in making our kubernetes cluster more secure by scanning it alive, and it also reports some potential issues if it got a lot on the deployed, resources and configurations.

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So uh this can be installed again with the help of flipsicle install command, and then I can uh see the what different uh sub commands I can use along with this uh copy plugin that I can use different flags like all name spaces uh contacts and so on, so to understand the working of popeye. I am going to create a nginx pod first and then going to apply copy plugin on the default namespace as this uh engine export has been created in the default namespace.

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So uh for this I am going to uh execute cuba, city popeye on default name space, and then I am going to see some results uh from this popeye plugin on the default namespace, and here I can see some results here. It's showing the the cluster.

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It is scanned along with some other details, and here it says that uh in the default name, spaces uh everything is correct and it also has generated the report for engine export like uh uh it's using default service account or no port disrupt budget or define an import et and so on, and it in the last it also generates a summary in the form of uh your cluster is full and right now I'm getting 90, which means like a cluster, is secure for now.

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And the next is via locations plugins, which helps in listing all the allocations for resources like for cpu memory, uh which we defined in our nodes and in the ports. So again I can install this with the help of a quick city crew install command, and then I can execute help command on it. So you see what different commands I can use, so I can specify context uh group by flag name space and so on. Now I'm going to see the locations on parts and nodes by grouping it through namespace.

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So first I am going to get all the namespaces which are present in the cluster and then going to use group group by flag and grouping it through name spaces.

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So here I can see all the details like uh what uh particular cpu resources, this uh cube system and ingress nginx namespace is using uh can see more details about memory and parts in it. So next is called plugin which helps in doing analysis of kubernetes objects, and it also lists out the some recommendations if it forms to make our applications more secure and resilient.

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So I can install it again with a cryptital pro install command and execute a help guide on it and see what different flags and all sub commands you can use. So it uses a score sub command, which will uh which says that it will check all the inputs and give us a score and recommendations uh on how to improve our kubernetes objects.

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So again, I am going to create a nginx deployment with three replicas and labels app equal to nginx. On creating this. Now I am going to check the score of this deployment, manifest uh with the help of score sub command on this script. Ctl score plugin, and here I will get some recommendations like image. Full policies not set to always uh the pod also does not have a matching network policy.

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Cpu limit is not said. Memory request is also not set and sort such type of recommendations. Next plugin is access matrix. This plugin shows our back roles for servers resources in a form of matrix, so that one can understand about a different arbitrals in the cluster more easily.

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So uh this can be installed with gibson tilt through install command, and then I can execute a cubesat access matrix uh by specifying a name namespace flick of default to see uh what are different arbitrals. uh It has on the resources present in the default name space here I can see for different works lists, create update, delete and the different uh resources like what can be done on this. Four type of works like con on config maps uh list, create update, delete books will work.

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Similarly, on uh demon sets deployments events uh hp, auto scaling, so next is albect tool, plugin, which is also one of the important plugins which helps in simplifying the complexity of albec, with the help of analyzing and visualizing it. So again, I can install this with the help of capacity to install command, and then I can execute help command on it to see what different subcommands and I can use. I can use analysis of command which helps in analyzing different outback permission. I can also use lookup command to see different subjects.

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I can also use visualize command, which will help me in getting a proper visualization through some sort of visualizer of all the are back roles and cluster roles present in the cluster.

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So to get a proper visualization of uh our back roles and cluster roles, I am going to use visualize sub command along with quick city are back to and the output I will get will be in a form of html file uh with name arbit.html, and this I can get by opening this ide.

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And here, as you can see, that I have got a rba.html file and on downloading it and opening it, I will get a proper visualization of all the cluster roles and arbitrals present in the cluster, and I can compare it with the help of this legend here like uh for ingress nginx, I am having subject of ingress nginx service account, ingress, nginx admission service account with different role bindings and along with their particular roles, cluster roles and cluster role binding.

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I can also say uh about uh different other name spaces like for cube public local path, storage.

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So, coming uh back to the albect tool again, I can also use analysis sub command on this rvec tool, uh which will uh give me a proper analysis report of all the are back roles and cluster roles present in the cluster. uh So the next plugin is hook and plugin, which will show me the what uh subjects present in the cluster have what different type of arbitrations uh like who can perform?

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What actions on different resources present in the cluster and uh again, I can install it with qtl to install command and then I can uh execute help command on it like to see what different uh commands I can use like here, uh along with cube ctl, who can again use a particular work along with specifying the resource name or namespaces like here. I can use getwork to list out all the parts from all the namespaces. I can also use creatework.

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Now, I'm going to see which different subjects can list out. The parts are present in the cluster.

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With the help of this quick ctl who can get bots command, and here uh you will see a message that no subjects found with permissions to get parts or central goal bindings, which means basically uh cluster role, bindings and subjects can list out the parts from all the name spaces, and I can also see which subjects have full access to the parts with the help of ctl who can uh and specifying this uh star operator uh before parts and again I am getting the same message for role bindings and here only cluster rule bindings, along with their respective subjects, has full access to all the parts present in the cluster.

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So next plugin is where my plugin, which is also one of the most important plugin related to our web. This plugin shows the subject that is currently authenticated, as means what particular role that particular subject has been assigned, and this uh for this plugin, I can again install it with quick, ctl crew install command.

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Now I want to know the subject which is currently authenticated in the cluster we are working with, so this can be done with the help of cubacetel, who are my command and right now uh the subject is kubernetes admin uh which can be verified with the help of quick, ctl config view command, and here the user is kubernetes admin, and so we are getting that a particular subject as kubernetes admin user.

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So, uh after exploring some of the cubesat plugins uh next, uh what we can do is uh we can also write our own uh custom, qtl plugin, which about which you can find out from the official kubernetes documents like uh how to extend uh keepsake with plugins uh writing on or on custom capacity plugins.

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So after getting hands-on experience with cube city plugins, uh these are some references and resources which are uh used uh for uh keepsake plugins, and you can use the same to study about more capacity plugins. Thank you.