1 00:00:02,120 --> 00:00:04,360 Now let's start by understanding 2 00:00:04,360 --> 00:00:08,690 what I mean when I say network and requests. 3 00:00:08,690 --> 00:00:12,230 And for this, let's assume that we have a container 4 00:00:12,230 --> 00:00:14,460 with our application inside of it, 5 00:00:14,460 --> 00:00:16,630 could be a Node application, 6 00:00:16,630 --> 00:00:18,540 could be a Python application, 7 00:00:18,540 --> 00:00:20,420 or a PHP application, 8 00:00:20,420 --> 00:00:22,080 it does not matter, 9 00:00:22,080 --> 00:00:25,930 and now let's say that this application, 10 00:00:25,930 --> 00:00:28,690 as part of its application logic, 11 00:00:28,690 --> 00:00:32,659 actually wants to talk to an API, 12 00:00:32,659 --> 00:00:36,890 so to some website out there in the World Wide Web. 13 00:00:36,890 --> 00:00:41,410 For example, to send data there or to fetch data from there, 14 00:00:41,410 --> 00:00:46,050 and just to make this clear here with this API website, 15 00:00:46,050 --> 00:00:49,630 I'm talking about a site not owned by us. 16 00:00:49,630 --> 00:00:53,250 So this is not another container or anything like that, 17 00:00:53,250 --> 00:00:56,570 it's just a website, a web API, 18 00:00:56,570 --> 00:00:59,940 to which your application might want to talk. 19 00:00:59,940 --> 00:01:03,560 It might want to send a GET HTTP request 20 00:01:03,560 --> 00:01:05,840 to this API, for example. 21 00:01:05,840 --> 00:01:10,120 So this scenario here would be about sending a request, 22 00:01:10,120 --> 00:01:14,860 in this case, an HTTP request, from your container, 23 00:01:14,860 --> 00:01:17,960 so from the application running in a container 24 00:01:17,960 --> 00:01:19,423 to the World Wide Web. 25 00:01:20,480 --> 00:01:23,330 And I actually do have an example for this. 26 00:01:23,330 --> 00:01:26,770 Attached, you'll find another simple starting project. 27 00:01:26,770 --> 00:01:29,040 It's another Node.js application, 28 00:01:29,040 --> 00:01:31,300 but again, it's just an example. 29 00:01:31,300 --> 00:01:33,610 I tend to use Node.js a lot 30 00:01:33,610 --> 00:01:35,380 because I work with it a lot, 31 00:01:35,380 --> 00:01:38,550 but you could have any kind of application, 32 00:01:38,550 --> 00:01:41,760 but in this application, I'm doing something special. 33 00:01:41,760 --> 00:01:44,170 In there in this app.js file, 34 00:01:44,170 --> 00:01:46,290 which holds my application code, 35 00:01:46,290 --> 00:01:50,430 I am using Axios, which is a third party package, 36 00:01:50,430 --> 00:01:54,940 which has also mentioned in package.json as a dependency. 37 00:01:54,940 --> 00:01:56,890 I'm using Axios to send a GET request 38 00:01:57,805 --> 00:02:00,923 to this Star Wars API here. 39 00:02:01,960 --> 00:02:06,400 And this is not an API created or owned by me. 40 00:02:06,400 --> 00:02:08,160 It's not a Docker container. 41 00:02:08,160 --> 00:02:10,830 It's a website in the end, a web API, 42 00:02:10,830 --> 00:02:12,340 which you can also visit. 43 00:02:12,340 --> 00:02:17,340 For example, swapi.dev/api/films will yield some data, 44 00:02:18,410 --> 00:02:22,260 some information about the Star Wars movies. 45 00:02:22,260 --> 00:02:25,480 So this is simply a dummy API, you could say, 46 00:02:25,480 --> 00:02:27,940 which we can use to play around with it 47 00:02:27,940 --> 00:02:30,230 in dummy demo applications, 48 00:02:30,230 --> 00:02:33,470 and that is the kind of application we have here. 49 00:02:33,470 --> 00:02:37,870 This application here will actually create another API, 50 00:02:37,870 --> 00:02:40,680 which then will live in a container later, 51 00:02:40,680 --> 00:02:43,080 but under the hood, this API, 52 00:02:43,080 --> 00:02:44,350 which I'm building here, 53 00:02:44,350 --> 00:02:46,770 will reach out to another API, 54 00:02:46,770 --> 00:02:49,840 this Star Wars API to fetch movie 55 00:02:49,840 --> 00:02:52,600 and character data from there. 56 00:02:52,600 --> 00:02:56,100 Now, I'll dig deeper into this example application 57 00:02:56,100 --> 00:02:57,370 in just a second, 58 00:02:57,370 --> 00:03:01,050 because we are going to work with it throughout this module, 59 00:03:01,050 --> 00:03:03,180 but I just want to highlight already 60 00:03:03,180 --> 00:03:05,380 that this is a Node application 61 00:03:05,380 --> 00:03:09,310 that sends an HTTP request to some other site, 62 00:03:09,310 --> 00:03:11,500 to some other website in this case, 63 00:03:11,500 --> 00:03:15,460 and therefore will definitely have HTTP communication 64 00:03:15,460 --> 00:03:20,460 between this app and this Star Wars API website. 65 00:03:20,480 --> 00:03:22,320 And that of course implies 66 00:03:22,320 --> 00:03:25,770 that if we put this Node app into a container, 67 00:03:25,770 --> 00:03:27,870 which we're going to do in this module, 68 00:03:27,870 --> 00:03:32,040 we need to ensure that this request can still be sent 69 00:03:32,040 --> 00:03:35,840 and that it can go from inside our container 70 00:03:35,840 --> 00:03:38,180 to outside the container. 71 00:03:38,180 --> 00:03:41,410 So that is one possible way of communicating 72 00:03:41,410 --> 00:03:42,910 in a dockerized app, 73 00:03:42,910 --> 00:03:47,080 sending an HTTP request to some other website or web API, 74 00:03:47,080 --> 00:03:48,073 which is out there.