1 00:00:02,420 --> 00:00:04,400 So what do we need to install 2 00:00:04,400 --> 00:00:07,100 to get started with Kubernetes locally 3 00:00:07,100 --> 00:00:10,533 on our local machine for playing around with it? 4 00:00:11,540 --> 00:00:12,780 Well, we need to install 5 00:00:12,780 --> 00:00:16,160 what we need to install no matter where we wanna use it 6 00:00:16,160 --> 00:00:18,510 no matter if it's our local machine 7 00:00:18,510 --> 00:00:20,260 or some machine in the cloud 8 00:00:20,260 --> 00:00:22,720 or in our own data center. 9 00:00:22,720 --> 00:00:25,350 We definitely will need a cluster. 10 00:00:25,350 --> 00:00:28,430 A cluster with our master node 11 00:00:28,430 --> 00:00:31,170 in reality that master node might 12 00:00:31,170 --> 00:00:35,010 actually also be distributed across multiple machines 13 00:00:35,010 --> 00:00:37,940 to ensure it's always up and running 14 00:00:37,940 --> 00:00:39,480 because if it fails 15 00:00:39,480 --> 00:00:41,640 your entire cluster will have a problem 16 00:00:41,640 --> 00:00:45,060 but to keep it simple we need one virtual instance 17 00:00:45,060 --> 00:00:47,120 one machine running in a cluster 18 00:00:47,120 --> 00:00:49,420 which has that master node set up 19 00:00:49,420 --> 00:00:52,720 and we need one or more worker nodes. 20 00:00:52,720 --> 00:00:55,110 And we don't just need these machines 21 00:00:55,110 --> 00:00:56,470 which then are empty 22 00:00:56,470 --> 00:00:59,190 but we also need to have all these software 23 00:00:59,190 --> 00:01:01,910 and all these services, which they need 24 00:01:01,910 --> 00:01:03,560 to be installed on them. 25 00:01:03,560 --> 00:01:04,959 So on the master node, 26 00:01:04,959 --> 00:01:08,020 the API server and schedulers should be installed 27 00:01:08,020 --> 00:01:09,650 and a couple of other things 28 00:01:09,650 --> 00:01:12,839 and on the worker node Docker should be installed 29 00:01:12,839 --> 00:01:14,790 the kubelets should be installed 30 00:01:14,790 --> 00:01:16,800 so there is communication device 31 00:01:16,800 --> 00:01:19,690 for talking to the master node and so on 32 00:01:19,690 --> 00:01:21,593 all of that needs to be installed. 33 00:01:22,570 --> 00:01:25,390 So that is something which we need to create 34 00:01:25,390 --> 00:01:29,080 and then we need another tool locally on our machine 35 00:01:29,080 --> 00:01:34,080 and that's the kubectl or kube-control tool. 36 00:01:34,810 --> 00:01:38,270 The kubectl tool is actually a tool 37 00:01:38,270 --> 00:01:39,630 which you then use 38 00:01:39,630 --> 00:01:42,740 to send instructions to the cluster 39 00:01:42,740 --> 00:01:45,820 for example, to create a new deployment, 40 00:01:45,820 --> 00:01:50,190 delete a deployment or change our running deployment. 41 00:01:50,190 --> 00:01:52,090 With the kubectl tool 42 00:01:52,090 --> 00:01:54,930 you as the developer and administrator 43 00:01:54,930 --> 00:01:56,780 are able to send instructions 44 00:01:56,780 --> 00:02:00,040 to the master node in the end which then will do 45 00:02:00,040 --> 00:02:03,240 whatever it needs to do with the worker nodes. 46 00:02:03,240 --> 00:02:05,800 For example, if you sent the instruction 47 00:02:05,800 --> 00:02:08,830 to create more Pods of a given container 48 00:02:08,830 --> 00:02:11,520 so more instances of a given container 49 00:02:11,520 --> 00:02:14,900 the master node will then interact with the worker nodes 50 00:02:14,900 --> 00:02:18,690 such that these extra Pods are created. 51 00:02:18,690 --> 00:02:23,360 So this is how you actually set or change the configuration 52 00:02:23,360 --> 00:02:27,550 which then should be maintained by Kubernetes. 53 00:02:27,550 --> 00:02:30,680 So the cluster is the technical infrastructure 54 00:02:30,680 --> 00:02:34,750 the kubectl tool is your communication device 55 00:02:34,750 --> 00:02:37,400 for talking with that infrastructure 56 00:02:37,400 --> 00:02:40,520 and for talking with this Kubernetes set up. 57 00:02:40,520 --> 00:02:44,440 Don't confuse the kubectl tool with the API server 58 00:02:44,440 --> 00:02:46,220 or with the master node. 59 00:02:46,220 --> 00:02:49,730 The master node is really the thing in your cluster 60 00:02:49,730 --> 00:02:53,420 which then basically applies your commands 61 00:02:53,420 --> 00:02:57,690 and ensures that your commands are executed correctly. 62 00:02:57,690 --> 00:03:00,660 The kubectl tool is really just a thing 63 00:03:00,660 --> 00:03:03,420 with which you give the commands. 64 00:03:03,420 --> 00:03:06,210 You could compare this, even though I will admit 65 00:03:06,210 --> 00:03:07,830 that it's kind of a strange example 66 00:03:07,830 --> 00:03:09,990 but you could compare this with 67 00:03:09,990 --> 00:03:12,630 let's say the president of the United States 68 00:03:12,630 --> 00:03:14,310 who is the Commander-in-Chief 69 00:03:14,310 --> 00:03:16,230 and who could give the command 70 00:03:16,230 --> 00:03:19,090 that whatever country you should be attacked 71 00:03:19,090 --> 00:03:21,630 and yes, I know it's a stupid example 72 00:03:21,630 --> 00:03:23,980 but let's say that is what the president does 73 00:03:23,980 --> 00:03:27,200 then you would have generals in the army 74 00:03:27,200 --> 00:03:29,380 with soldiers below them 75 00:03:29,380 --> 00:03:30,580 who execute that command 76 00:03:31,500 --> 00:03:33,390 and it would be the duty of the generals 77 00:03:33,390 --> 00:03:35,730 to ensure that the command of the president 78 00:03:35,730 --> 00:03:37,700 is executed correctly. 79 00:03:37,700 --> 00:03:40,060 So kubectl would be the president 80 00:03:40,060 --> 00:03:42,020 the master node would be the general 81 00:03:42,020 --> 00:03:45,170 and the worker nodes would be the soldiers. 82 00:03:45,170 --> 00:03:47,620 And please excuse the strange analogy 83 00:03:47,620 --> 00:03:50,990 but I hope it's now clear how these things work together 84 00:03:52,190 --> 00:03:54,910 and therefore that is what we need to set up. 85 00:03:54,910 --> 00:03:57,130 And if we would set this up in a cloud 86 00:03:57,130 --> 00:03:59,080 or in our own data center 87 00:03:59,080 --> 00:04:02,070 then the cluster would be what happens in the cloud 88 00:04:02,070 --> 00:04:05,010 or in the data center and kubectl is a tool 89 00:04:05,010 --> 00:04:07,323 which we install locally on our machine. 90 00:04:08,300 --> 00:04:11,330 Now for testing and for playing around with that 91 00:04:11,330 --> 00:04:14,510 we will set up everything on our local machine 92 00:04:14,510 --> 00:04:16,560 so not just kubectl 93 00:04:16,560 --> 00:04:19,773 but also a demo, a dummy cluster. 94 00:04:20,829 --> 00:04:24,340 And for setting up this dummy cluster locally 95 00:04:24,340 --> 00:04:27,110 we can use a tool called minikube 96 00:04:27,110 --> 00:04:30,480 and attached you find a link with setup instructions 97 00:04:30,480 --> 00:04:32,610 though we will set it up together 98 00:04:32,610 --> 00:04:34,513 over this in the next lectures. 99 00:04:35,388 --> 00:04:37,550 Minikube is in the end a tool 100 00:04:37,550 --> 00:04:39,230 which you can install locally 101 00:04:39,230 --> 00:04:42,490 for playing around with Kubernetes and for testing it 102 00:04:42,490 --> 00:04:45,820 and it will use a virtual machine on your laptop 103 00:04:45,820 --> 00:04:48,150 on your machine, on your local machine 104 00:04:48,150 --> 00:04:50,570 to create the cluster in there. 105 00:04:50,570 --> 00:04:54,000 So it simulates another machine on your machine 106 00:04:54,000 --> 00:04:55,950 by using such a virtual machine 107 00:04:56,900 --> 00:05:00,450 and the this virtual machine then holds this cluster. 108 00:05:00,450 --> 00:05:03,600 It will actually create a single node cluster 109 00:05:03,600 --> 00:05:06,570 which means there the worker and master node 110 00:05:06,570 --> 00:05:10,300 is combined into one single virtual machine 111 00:05:10,300 --> 00:05:12,770 not something you would do in production 112 00:05:12,770 --> 00:05:15,500 but something we can absolutely do during development 113 00:05:15,500 --> 00:05:18,830 to keep things easy and resource friendly. 114 00:05:18,830 --> 00:05:21,310 Now, minikube is a great tool 115 00:05:21,310 --> 00:05:23,110 for getting started with Kubernetes 116 00:05:23,110 --> 00:05:25,410 and for testing things locally 117 00:05:26,840 --> 00:05:28,970 and the great thing is that you can install it 118 00:05:28,970 --> 00:05:32,800 on Linux, macOS and Windows. 119 00:05:32,800 --> 00:05:34,820 And again, you attached find a link 120 00:05:34,820 --> 00:05:38,380 with setup instructions for all three systems 121 00:05:38,380 --> 00:05:41,430 though I will walk through macOS and Windows 122 00:05:41,430 --> 00:05:42,363 together with you. 123 00:05:43,630 --> 00:05:45,790 It's also worth mentioning that minikube 124 00:05:46,880 --> 00:05:51,270 will not replace the kubectl command or tool 125 00:05:51,270 --> 00:05:53,000 which you also need to install. 126 00:05:53,000 --> 00:05:56,590 You always need to kubectl command locally 127 00:05:56,590 --> 00:06:00,600 even if you don't use minikube because that is the tool 128 00:06:00,600 --> 00:06:03,430 you use for communicating with your cluster 129 00:06:03,430 --> 00:06:06,490 no matter if it's a minikube cluster locally 130 00:06:06,490 --> 00:06:09,357 or your cloud cluster running on AWS. 131 00:06:10,760 --> 00:06:13,850 And therefore we'll actually install two things 132 00:06:13,850 --> 00:06:15,876 we'll install kubectl, 133 00:06:15,876 --> 00:06:17,880 and then we'll install minikube 134 00:06:17,880 --> 00:06:21,280 and we'll start with that in the next lecture on macOS 135 00:06:21,280 --> 00:06:23,933 and in the lecture thereafter on Windows.