1 00:00:02,220 --> 00:00:05,770 That's it for this key module. 2 00:00:05,770 --> 00:00:08,710 We learned a lot in this course module. 3 00:00:08,710 --> 00:00:11,710 We learned a lot about the core fundamentals 4 00:00:11,710 --> 00:00:15,200 you have to know when working with Docker. 5 00:00:15,200 --> 00:00:17,370 One of the most important takeaways 6 00:00:17,370 --> 00:00:21,450 and kind of the heart of Docker is that Docker 7 00:00:21,450 --> 00:00:24,740 is all about images and containers. 8 00:00:24,740 --> 00:00:28,450 But in this module you learned what this means. 9 00:00:28,450 --> 00:00:30,860 It means that images are the templates, 10 00:00:30,860 --> 00:00:34,660 the blueprints for containers and you can run 11 00:00:34,660 --> 00:00:37,040 multiple containers which are based 12 00:00:37,040 --> 00:00:40,650 on one and the same image and you can have multiple images 13 00:00:40,650 --> 00:00:42,890 for different containers as well. 14 00:00:42,890 --> 00:00:46,470 And you learned that these containers would then be run 15 00:00:46,470 --> 00:00:51,470 in an efficient way as a tiny layer on top of your image 16 00:00:51,850 --> 00:00:54,040 using the code and the environment 17 00:00:54,040 --> 00:00:57,430 which is stored in the image, not in the container, 18 00:00:57,430 --> 00:01:00,150 but then actually running the application 19 00:01:00,150 --> 00:01:03,700 which is set up and configured with help of the image. 20 00:01:03,700 --> 00:01:07,460 That's how work is split between image and container 21 00:01:07,460 --> 00:01:11,520 and how multiple containers running the same application 22 00:01:11,520 --> 00:01:14,070 can be executed in isolation 23 00:01:14,070 --> 00:01:18,020 with a very low footprint on your system. 24 00:01:18,020 --> 00:01:22,580 Now images are either downloaded with docker pull 25 00:01:22,580 --> 00:01:25,150 or created with help of a Dockerfile 26 00:01:25,150 --> 00:01:26,530 if you build your own image. 27 00:01:26,530 --> 00:01:31,220 A Dockerfile and docker build builds a new image. 28 00:01:31,220 --> 00:01:34,800 And in this module we built a couple of Dockerfiles 29 00:01:34,800 --> 00:01:37,900 and the structure's always very similar. 30 00:01:37,900 --> 00:01:42,010 Often we use a base image, like in this case Node 31 00:01:42,010 --> 00:01:43,650 which then in turn might use 32 00:01:43,650 --> 00:01:46,220 even another base image internally. 33 00:01:46,220 --> 00:01:50,610 And then we have our instructions that configure this image, 34 00:01:50,610 --> 00:01:53,780 that control what is copied into the image 35 00:01:53,780 --> 00:01:56,610 and how the environment should be set up. 36 00:01:56,610 --> 00:01:58,990 And last but not least we have that command 37 00:01:58,990 --> 00:02:02,070 which should be executed whenever we run 38 00:02:02,070 --> 00:02:04,640 a container based on that image. 39 00:02:04,640 --> 00:02:06,220 And all these instructions 40 00:02:06,220 --> 00:02:10,280 which you put into your Dockerfile create layers. 41 00:02:10,280 --> 00:02:14,070 Images as you learned are made up of multiple layers 42 00:02:14,070 --> 00:02:19,070 and this layer concept exists to optimize build speed 43 00:02:19,280 --> 00:02:22,830 since Docker is able to cache layers and doesn't need 44 00:02:22,830 --> 00:02:26,640 to rerun them if nothing changed about that step 45 00:02:26,640 --> 00:02:29,470 and it also helps with reusability. 46 00:02:29,470 --> 00:02:32,170 For example, if you share an image 47 00:02:32,170 --> 00:02:34,020 which is based on Node, 48 00:02:34,020 --> 00:02:36,120 then Docker is able to find out 49 00:02:36,120 --> 00:02:38,900 that this Node image already exists, 50 00:02:38,900 --> 00:02:42,370 maybe didn't change and therefore it's able to efficiently 51 00:02:42,370 --> 00:02:44,270 link this to your image. 52 00:02:44,270 --> 00:02:48,403 For example, if you share your Docker image on Docker Hub. 53 00:02:49,400 --> 00:02:51,200 So that's images. 54 00:02:51,200 --> 00:02:54,520 Containers of course are why we're all here though. 55 00:02:54,520 --> 00:02:57,030 We run containers based on images 56 00:02:57,030 --> 00:02:59,190 with the docker run command 57 00:02:59,190 --> 00:03:01,430 and throughout this module you saw 58 00:03:01,430 --> 00:03:04,060 that there are a lot of options and flags 59 00:03:04,060 --> 00:03:07,510 which can be set on the docker run command. 60 00:03:07,510 --> 00:03:10,760 You can make the container interactive if it needs it 61 00:03:10,760 --> 00:03:13,500 to allow the user or yourself 62 00:03:13,500 --> 00:03:16,340 to enter something into the running application. 63 00:03:16,340 --> 00:03:17,780 You can assign a name. 64 00:03:17,780 --> 00:03:19,360 You can ensure that the container 65 00:03:19,360 --> 00:03:22,530 is automatically removed if it stops. 66 00:03:22,530 --> 00:03:24,800 And there are many other options, 67 00:03:24,800 --> 00:03:27,070 some which you need often 68 00:03:27,070 --> 00:03:30,170 and a lot of options which you rarely need. 69 00:03:30,170 --> 00:03:31,930 We're going to see more options 70 00:03:31,930 --> 00:03:34,080 throughout this course of course. 71 00:03:34,080 --> 00:03:36,260 Now running containers is one thing, 72 00:03:36,260 --> 00:03:40,010 but you got various commands to manage containers as well. 73 00:03:40,010 --> 00:03:42,110 You can list and remove containers 74 00:03:42,110 --> 00:03:43,600 with the respective commands 75 00:03:43,600 --> 00:03:47,130 and you can stop and start them if you want to. 76 00:03:47,130 --> 00:03:49,650 And the same is true for images. 77 00:03:49,650 --> 00:03:52,930 They can also be listed or removed if you need to 78 00:03:52,930 --> 00:03:55,740 and you can share them with docker push and pull. 79 00:03:55,740 --> 00:03:57,620 For example with Docker Hub 80 00:03:57,620 --> 00:04:01,150 as you saw in the last lectures of this module. 81 00:04:01,150 --> 00:04:03,810 Now at this point, all the core concepts 82 00:04:03,810 --> 00:04:06,570 discussed in this module should be clear. 83 00:04:06,570 --> 00:04:10,530 If they're not, definitely revisit the lectures 84 00:04:10,530 --> 00:04:13,420 where I talk about them, where I explain them 85 00:04:13,420 --> 00:04:17,660 so that we all are on the same page after this module. 86 00:04:17,660 --> 00:04:20,519 Also make sure you have a look at that assignment 87 00:04:20,519 --> 00:04:22,250 which you find in this module. 88 00:04:22,250 --> 00:04:23,580 It's a great practice 89 00:04:23,580 --> 00:04:27,020 and I recommend that you take advantage of that. 90 00:04:27,020 --> 00:04:30,250 Attached to the last lecture of this module 91 00:04:30,250 --> 00:04:32,290 so the lecture after this one, 92 00:04:32,290 --> 00:04:36,790 you find a cheat sheet with the key commands and concepts 93 00:04:36,790 --> 00:04:38,840 you should know after this module 94 00:04:38,840 --> 00:04:42,440 so that can be great as well as an additional help 95 00:04:42,440 --> 00:04:45,590 to also keep all these concepts in mind 96 00:04:45,590 --> 00:04:49,250 and have a resource for quickly looking up certain concepts. 97 00:04:49,250 --> 00:04:52,600 So definitely also take advantage of that cheat sheet 98 00:04:52,600 --> 00:04:54,630 attached to the next lecture. 99 00:04:54,630 --> 00:04:56,330 And with that, let's move on 100 00:04:56,330 --> 00:04:58,653 and let's dig deeper into Docker.