1 00:00:02,160 --> 00:00:04,090 So to put this into a container, 2 00:00:04,090 --> 00:00:06,890 I will first of all quit my running service here, 3 00:00:06,890 --> 00:00:09,570 which ran locally on my host machine. 4 00:00:09,570 --> 00:00:12,570 I can delete package-lock JSON and Node modules, 5 00:00:12,570 --> 00:00:14,900 because I don't need them locally anymore. 6 00:00:14,900 --> 00:00:17,330 Instead, we're going to dockerize this. 7 00:00:17,330 --> 00:00:19,820 And I already have a Docker file here, 8 00:00:19,820 --> 00:00:22,150 it was also part of the attachment. 9 00:00:22,150 --> 00:00:25,400 It's a straightforward Docker file for dockerizing 10 00:00:25,400 --> 00:00:27,400 this as a Node application, 11 00:00:27,400 --> 00:00:31,420 and it does what we did many times before in this course. 12 00:00:31,420 --> 00:00:35,910 Hence, we can go ahead and just run docker build 13 00:00:35,910 --> 00:00:37,250 and build this Docker file. 14 00:00:37,250 --> 00:00:39,500 And maybe also add a name and a tag, 15 00:00:39,500 --> 00:00:43,380 and I'm going to name it favorites-node. 16 00:00:43,380 --> 00:00:44,480 And I could add a tag, 17 00:00:44,480 --> 00:00:46,500 but I will go with the latest tag 18 00:00:46,500 --> 00:00:47,963 which is automatically added. 19 00:00:49,240 --> 00:00:51,790 So with that, that's built, 20 00:00:51,790 --> 00:00:52,910 this image is built. 21 00:00:52,910 --> 00:00:55,520 And now we can run a container based on it. 22 00:00:55,520 --> 00:00:59,990 So we can use docker run to run a container 23 00:00:59,990 --> 00:01:02,250 on this favorites-node image. 24 00:01:02,250 --> 00:01:05,560 And I'll give this container a name of favorites. 25 00:01:05,560 --> 00:01:07,780 I'll run it in detached mode and remove it 26 00:01:07,780 --> 00:01:09,113 when it shuts down. 27 00:01:10,030 --> 00:01:12,810 We definitely need to publish a port, 28 00:01:12,810 --> 00:01:17,810 because I do work with a port in there with localhost 3000, 29 00:01:19,560 --> 00:01:22,120 or I'm using the 3000 port. 30 00:01:22,120 --> 00:01:24,670 And we could use environment variables for that, 31 00:01:24,670 --> 00:01:27,170 but I'm keeping it simple here, it's hard coded. 32 00:01:27,170 --> 00:01:31,300 And therefore I will expose the 3000 port 33 00:01:31,300 --> 00:01:34,053 on 3000 thousand port of our local machine. 34 00:01:35,040 --> 00:01:38,220 Now I won't add any volume or bind mount here. 35 00:01:38,220 --> 00:01:41,640 We could definitely add our code here as a bind mount, 36 00:01:41,640 --> 00:01:44,310 but I wanna keep this instruction simple here 37 00:01:44,310 --> 00:01:45,300 in the terminal. 38 00:01:45,300 --> 00:01:48,670 And we need no volume because this application 39 00:01:48,670 --> 00:01:51,250 does not write anything to any file 40 00:01:51,250 --> 00:01:52,960 which would need to survive 41 00:01:52,960 --> 00:01:55,210 a container shut down and removal. 42 00:01:55,210 --> 00:01:57,840 There is nothing which needs to survive that 43 00:01:57,840 --> 00:02:00,710 except for the data stored in the database, 44 00:02:00,710 --> 00:02:04,050 but that database is not part of this container. 45 00:02:04,050 --> 00:02:05,860 And I really wanna emphasize this, 46 00:02:05,860 --> 00:02:08,639 this MongoDB database which I'm connecting here 47 00:02:08,639 --> 00:02:10,550 is not part of the container. 48 00:02:10,550 --> 00:02:12,990 Sure, my Node code is part of it, 49 00:02:12,990 --> 00:02:17,180 and therefore, also this code where I try to connect, 50 00:02:17,180 --> 00:02:19,680 but the installation of MongoDB 51 00:02:19,680 --> 00:02:22,000 is not part of this container. 52 00:02:22,000 --> 00:02:25,680 We have no code in the Docker file to install MongoDB 53 00:02:25,680 --> 00:02:27,020 or anything like that. 54 00:02:27,020 --> 00:02:29,640 So therefore, I really wanna emphasize this, 55 00:02:29,640 --> 00:02:32,430 this container only contains the Node app 56 00:02:32,430 --> 00:02:34,290 and all the code that belongs to it, 57 00:02:34,290 --> 00:02:37,303 it does not contain the MongoDB database. 58 00:02:38,780 --> 00:02:42,070 So therefore, if we now run this, let's see what we get. 59 00:02:42,070 --> 00:02:45,510 If I hit Enter, this of course works. 60 00:02:45,510 --> 00:02:47,790 But if I now have a look at my running containers 61 00:02:47,790 --> 00:02:51,483 with docker ps, I see no containers there. 62 00:02:53,720 --> 00:02:55,750 And of course for stopped containers, 63 00:02:55,750 --> 00:02:57,070 we also don't see it, 64 00:02:57,070 --> 00:03:01,203 because we started this container with the --rm flag. 65 00:03:02,200 --> 00:03:05,540 So to see what's wrong, let's again start it 66 00:03:05,540 --> 00:03:08,343 but now in non-detached mode. 67 00:03:09,830 --> 00:03:12,980 Let's start it, and we see this crashes. 68 00:03:12,980 --> 00:03:15,540 And it crashes with an error message 69 00:03:15,540 --> 00:03:18,410 where in the end some connection fails, 70 00:03:18,410 --> 00:03:20,580 and it's a Mongo network error. 71 00:03:20,580 --> 00:03:23,960 So in the end, what fails here is this connection 72 00:03:23,960 --> 00:03:27,010 where I try to connect my Node application 73 00:03:27,010 --> 00:03:29,240 to the MongoDB database. 74 00:03:29,240 --> 00:03:31,500 And that of course is a problem. 75 00:03:31,500 --> 00:03:36,410 It means that connecting to our host machine failed here. 76 00:03:36,410 --> 00:03:38,840 Because MongoDB the database itself 77 00:03:38,840 --> 00:03:40,800 is running on my host machine here. 78 00:03:40,800 --> 00:03:43,380 I installed it before this module started, 79 00:03:43,380 --> 00:03:45,463 so I have MongoDB installed. 80 00:03:46,550 --> 00:03:48,700 And if you follow the installation instructions 81 00:03:48,700 --> 00:03:49,950 on MongoDB.com, 82 00:03:49,950 --> 00:03:52,000 you can of course also follow along, 83 00:03:52,000 --> 00:03:55,340 try this on your own and you will get the same result. 84 00:03:55,340 --> 00:03:56,980 So that is good to know, 85 00:03:56,980 --> 00:03:59,900 out of the box connecting to the host machine like this 86 00:03:59,900 --> 00:04:02,210 with localhost fails. 87 00:04:02,210 --> 00:04:04,790 Now, before we look into fixing this, 88 00:04:04,790 --> 00:04:07,730 I wanna see if sending HTTP requests 89 00:04:07,730 --> 00:04:10,030 to some other website would work. 90 00:04:10,030 --> 00:04:12,150 And in order to test this, 91 00:04:12,150 --> 00:04:15,470 we can copy app listen 3000 here 92 00:04:15,470 --> 00:04:18,740 and move that out of this mongoose connect code 93 00:04:18,740 --> 00:04:22,713 and temporarily comment this mongoose connect code out. 94 00:04:23,570 --> 00:04:24,940 So that for the moment, 95 00:04:24,940 --> 00:04:27,830 we can start this Node container 96 00:04:27,830 --> 00:04:30,800 without connecting to the MongoDB database 97 00:04:30,800 --> 00:04:33,550 just by spinning up the web server. 98 00:04:33,550 --> 00:04:36,800 So I'm going to save this and then since I changed the code, 99 00:04:36,800 --> 00:04:41,800 I'm going to rebuild my image with the same name and tag. 100 00:04:42,030 --> 00:04:44,950 And thereafter I'm going to rerun the container. 101 00:04:44,950 --> 00:04:48,370 And I'll again do that in detached mode now. 102 00:04:48,370 --> 00:04:51,083 So running the container on the updated image. 103 00:04:52,090 --> 00:04:54,740 And with that if we now run docker ps, 104 00:04:54,740 --> 00:04:57,460 we see the container stays up and running. 105 00:04:57,460 --> 00:05:00,270 Of course, because now I'm not trying to connect 106 00:05:00,270 --> 00:05:04,003 to the database anymore and this was the part which failed. 107 00:05:04,920 --> 00:05:08,690 So therefore, of course parts of our application won't work. 108 00:05:08,690 --> 00:05:12,600 To be precise, the favorites endpoints won't work. 109 00:05:12,600 --> 00:05:16,350 But the movies endpoint and the people endpoint, 110 00:05:16,350 --> 00:05:18,720 these endpoints should work fine. 111 00:05:18,720 --> 00:05:22,120 Because there I'm not working with my local database, 112 00:05:22,120 --> 00:05:26,250 I'm instead reaching out to the Star Wars dummy API. 113 00:05:26,250 --> 00:05:29,290 Hence, if I now try sending a get request 114 00:05:29,290 --> 00:05:33,750 to localhost 3000 movies again, this works. 115 00:05:33,750 --> 00:05:38,300 And the same if I send it to localhost 3000 people, 116 00:05:38,300 --> 00:05:40,400 it works just fine. 117 00:05:40,400 --> 00:05:44,420 And this is now using the API running in our container, 118 00:05:44,420 --> 00:05:47,230 which is exposed on port 3000. 119 00:05:47,230 --> 00:05:51,770 So this works, and this has one important implication. 120 00:05:51,770 --> 00:05:53,130 Out of the box, 121 00:05:53,130 --> 00:05:58,130 containers can send requests to the World Wide Web. 122 00:05:58,260 --> 00:06:02,360 You can communicate with web API's and web pages 123 00:06:02,360 --> 00:06:06,010 from inside your dockerized applications. 124 00:06:06,010 --> 00:06:08,470 You don't need any special setup 125 00:06:08,470 --> 00:06:12,670 or any changes to your code, this code just works. 126 00:06:12,670 --> 00:06:14,940 Sending this HTTP request 127 00:06:14,940 --> 00:06:18,040 from inside the dockerized application works. 128 00:06:18,040 --> 00:06:20,980 It works just as it worked without containers 129 00:06:20,980 --> 00:06:22,860 and without Docker. 130 00:06:22,860 --> 00:06:27,000 And that's super important to understand and keep in mind. 131 00:06:27,000 --> 00:06:30,210 Sending requests from inside your container 132 00:06:30,210 --> 00:06:33,360 to the World Wide Web just works. 133 00:06:33,360 --> 00:06:37,010 It works out of the box without any special settings. 134 00:06:37,010 --> 00:06:39,720 So now let's have a look at the other two ways 135 00:06:39,720 --> 00:06:43,313 of communication and understand how we can make those work.