WEBVTT 00:00.170 --> 00:00.530 All right. 00:00.560 --> 00:03.140 Now we're going to move on to starter code number eight. 00:03.170 --> 00:09.110 Before we do, I want to make note of the fact that our container commands are getting really, really 00:09.110 --> 00:09.680 messy. 00:09.710 --> 00:12.230 We have two different terminals. 00:12.230 --> 00:15.710 Each one of them is running a different process. 00:15.710 --> 00:20.600 And we had to orchestrate each container to run inside of the same network. 00:20.600 --> 00:27.770 And if you think about it, what if we had an application with six different microservices interacting 00:27.770 --> 00:28.340 with each other? 00:28.370 --> 00:34.370 Are we going to start up six different terminals, run them all in the same network, and uh, give 00:34.370 --> 00:38.120 each one environment variables within the command itself? 00:38.120 --> 00:43.220 What if one of the containers had like six different environment environment variables that it needed 00:43.220 --> 00:44.810 to function properly? 00:44.900 --> 00:49.550 You can already see how things are going to get really messy when we do that. 00:49.550 --> 00:58.670 So what we're going to do is set up a Docker compose file that has all of the container definitions 00:58.670 --> 01:00.600 written inside of it. 01:00.600 --> 01:03.840 That way when we call docker compose up. 01:03.870 --> 01:07.650 Docker compose is going to start up all the containers for us. 01:07.650 --> 01:08.790 And when we call. 01:08.820 --> 01:14.700 Docker compose down, docker compose is going to destroy the containers for us and do the cleanup. 01:14.700 --> 01:21.120 And the great thing about Docker compose is that all the containers are going to be running inside of 01:21.120 --> 01:24.990 the same environment, which means they're going to be part of the same network. 01:24.990 --> 01:35.130 So Docker Compose also orchestrates that for us, which means from here I can simply refer to the node 01:35.130 --> 01:41.610 server container name as the host, uh, followed by the port, and therefore be able to connect to 01:41.640 --> 01:43.830 the application that's running inside of it. 01:44.670 --> 01:45.840 All right. 01:46.350 --> 01:47.940 Uh, pretty cool stuff. 01:47.940 --> 01:48.960 Very promising stuff. 01:48.960 --> 01:53.850 Before we do anything, I'm going to remove this terminal. 01:53.880 --> 02:02.530 Remove this terminal, and I'm going to say Docker system Prune dash a I want to delete everything. 02:02.860 --> 02:05.440 Make sure there are no more images. 02:05.440 --> 02:08.350 We still have the great submission API for whatever reason. 02:08.350 --> 02:10.120 Let's just remove it forcefully. 02:10.150 --> 02:13.150 Docker image m. 02:16.780 --> 02:23.380 Say dash f to force it couldn't be forced it because image is being used by a running container. 02:23.380 --> 02:32.890 So we'll say docker PS dash a remove this container first docker rm container id dash f. 02:34.270 --> 02:36.010 Then we'll remove the image. 02:36.010 --> 02:43.600 All right let's start from a clean slate docker images docker PS dash a. 02:44.140 --> 02:45.310 All right let's get started. 02:45.310 --> 02:46.240 Enough talking. 02:46.240 --> 02:53.200 So what I want to do is start by setting a version of three for docker compose. 02:53.230 --> 03:00.030 And the docker compose environment is going to start up a bunch of services. 03:00.210 --> 03:07.320 Every service in Docker compose is going to be a container that's running some sort of application, 03:07.320 --> 03:08.820 some sort of service. 03:09.030 --> 03:13.470 Indenting in a YAML file is really important. 03:13.470 --> 03:22.020 So if I want to specify a service within this field of services I'm going to press enter and then press 03:22.020 --> 03:22.920 tab. 03:22.920 --> 03:27.960 So everything I do here belongs to services. 03:28.080 --> 03:31.680 One of the services is going to be a flask app. 03:32.700 --> 03:33.240 Okay. 03:33.240 --> 03:40.110 So right here I'm specifying that I want to run a container called flask app. 03:41.040 --> 03:44.310 The image from which we're going to create this container. 03:44.310 --> 03:46.620 Again the indentation is really important. 03:46.620 --> 03:48.060 Press enter. 03:48.060 --> 03:55.690 And now the image from which we're going to create this container is going to be the one that we pushed 03:55.690 --> 03:57.520 onto Docker Hub. 03:57.730 --> 04:01.570 I'm going to pull this image 1.0.0. 04:01.600 --> 04:07.660 I'm not going to do latest because what if in the future I pushed an image that was incompatible with 04:07.660 --> 04:10.120 this great submission API? 04:10.150 --> 04:13.570 I want to be specific about the version itself. 04:13.750 --> 04:14.800 All right. 04:15.820 --> 04:22.150 And now the container that we create from this container definition, it's automatically going to be 04:22.150 --> 04:23.770 called flask app. 04:23.770 --> 04:26.770 But I want to specify a container name regardless. 04:26.770 --> 04:30.250 And notice how I've got this autocomplete set up. 04:30.580 --> 04:34.570 That's mainly because I've got the Docker extension installed on VSCode. 04:34.570 --> 04:36.130 Make sure that you do the same. 04:36.130 --> 04:40.810 I'm pretty sure there was a section about that in the very beginning of this course. 04:40.900 --> 04:41.470 All right. 04:41.470 --> 04:44.770 So now I'm going to specify ports. 04:45.670 --> 04:51.280 Now ports unlike these fields accepts an array of fields. 04:51.280 --> 04:54.890 An array in YAML is represented like this. 04:55.910 --> 05:00.320 Um, you press enter, followed by a tab. 05:01.610 --> 05:07.190 Tab, meaning any port we specify here belongs to this field. 05:07.370 --> 05:09.290 One of the ports. 05:11.390 --> 05:15.830 Here we can map the container port to a host machine port. 05:16.250 --> 05:20.840 This is equivalent to the port mapping that we were using in our command. 05:20.840 --> 05:28.310 But the nice thing is, instead of writing command flags, we can specify everything in one file. 05:28.310 --> 05:33.320 We're basically just converting the commands from before into container definitions. 05:33.590 --> 05:34.610 All right. 05:34.610 --> 05:45.410 And you'll remember that the flask application relied on an environment variable that is equal to node 05:45.410 --> 05:51.860 server, which is going to be the name of the container where we run our great submission API. 05:52.100 --> 05:59.250 Okay, That is all the environment variables that the Great Submission Portal relies on. 05:59.310 --> 06:03.600 The next thing we need to do is say depends on. 06:03.600 --> 06:08.130 So what service does this flask app rely on? 06:08.130 --> 06:12.030 It relies on a great submission API service. 06:12.060 --> 06:16.650 We're going to call the container that is hosting that service node server. 06:17.070 --> 06:22.920 So this dictates the order in which Docker compose creates the container. 06:22.920 --> 06:25.200 In this case we're telling Docker compose. 06:25.200 --> 06:30.060 Create the node server container first because the flask app depends on it. 06:30.060 --> 06:32.400 Then create the flask app container. 06:32.640 --> 06:34.590 You'll see that all in action. 06:34.740 --> 06:35.520 All right. 06:35.550 --> 06:43.830 Now we're going to make sure that we're at the same level as the flask app service so that we can create 06:44.190 --> 06:47.970 the node server container service. 06:48.060 --> 06:48.720 All right. 06:48.750 --> 07:00.100 Press tab the image that we're going to use to create this node server container is going to be the 07:00.100 --> 07:02.860 one that we pushed onto Docker Hub. 07:03.430 --> 07:04.540 All right. 07:06.310 --> 07:14.980 And we're going to use image version 1.0.0 because it is the one that's compatible with this portal. 07:16.510 --> 07:17.770 All right. 07:18.430 --> 07:23.440 The container name is going to be Node server. 07:23.470 --> 07:26.890 It's really important that you call the container node server. 07:26.890 --> 07:34.030 Because our flask app container is providing the application inside of it with an environment variable. 07:34.030 --> 07:37.030 Great service host equal to node server. 07:37.030 --> 07:39.430 And now we specify the ports. 07:39.430 --> 07:47.440 The great submission API, if we look at the documentation runs on port 3000 of the container, we can 07:47.440 --> 07:52.730 just map that to port 3000 of our host machine. 07:53.180 --> 07:57.950 So we got the port mapping set up and that's pretty much it. 07:58.580 --> 07:59.870 Pretty easy, don't you think? 07:59.870 --> 08:02.900 If I go ahead, let me go. 08:02.900 --> 08:05.420 Uh, just one second, guys. 08:09.740 --> 08:11.540 Where is that pesky command? 08:12.890 --> 08:20.480 If I go ahead and copy this over here, we basically just recreated this command, but inside of Docker 08:20.480 --> 08:21.080 compose. 08:21.080 --> 08:23.480 So here we've got the port mapping. 08:24.110 --> 08:28.040 Here we've got the image from which we're creating the container. 08:28.910 --> 08:31.730 Here it's just a random output. 08:31.820 --> 08:35.960 We don't need to specify a network anymore okay. 08:36.620 --> 08:44.150 So now what I'm going to do is once again Docker system prune dash a make sure everything is really 08:44.150 --> 08:44.870 gone. 08:48.440 --> 08:49.000 All right. 08:49.000 --> 08:50.470 It did delete the network. 08:50.470 --> 08:51.280 My network. 08:51.280 --> 08:52.180 Anyways. 08:52.210 --> 08:55.690 Now I need to CD out of grade submission API. 08:56.440 --> 08:59.980 I'm at oh seven starter code. 08:59.980 --> 09:10.840 I need to be inside of oh eight starter code, CD, CD out of that CD into oh eight starter code. 09:10.870 --> 09:14.560 Anyways docker compose up. 09:15.070 --> 09:17.830 So notice how it starts by creating the node server. 09:17.830 --> 09:20.530 And then it's going to create the flask application. 09:20.530 --> 09:21.820 So great service. 09:21.820 --> 09:24.640 So the node server starts running on port 3000. 09:24.670 --> 09:26.200 The flask app depends on it. 09:26.200 --> 09:35.650 So it runs second which means now if I go to localhost 5001 09:36.760 --> 09:39.280 everything should work smoothly. 09:39.310 --> 09:45.130 Harry, give him a score of 94 in potions. 09:45.610 --> 09:47.540 Everything works beautifully. 09:47.570 --> 09:49.880 The flask. 09:49.880 --> 09:55.880 The application running inside the flask app container was able to seamlessly interact with the application 09:55.880 --> 09:58.760 running inside the node server container. 09:58.910 --> 10:05.870 Because they're both running inside the same Docker compose environment, we pass an environment variable 10:05.870 --> 10:16.160 of grade service host or whatever equal to node server into the application running inside of the flask 10:16.190 --> 10:17.060 app container. 10:17.090 --> 10:23.690 It was able to make an HTTP request with the host name, node, server and port of 3000. 10:23.720 --> 10:30.200 The node server host name allows it to find the container node server running inside of the same network, 10:30.200 --> 10:36.800 giving it access to the application that's running on port 3000 of the container, and therefore be 10:36.830 --> 10:39.350 able to make requests to it. 10:39.650 --> 10:42.320 And then that was pretty much it. 10:43.640 --> 10:51.900 Now we're going to move on Or before we do anything, we need to remove all of these containers. 10:52.320 --> 10:58.380 And the way we're going to do it is we're not going to stop this process ourselves on a separate terminal. 10:58.410 --> 11:02.250 We're going to say docker compose down. 11:03.960 --> 11:08.910 I'm at the wrong directory, so I need to go inside of oh eight starter code. 11:14.520 --> 11:16.770 Docker compose down. 11:17.220 --> 11:18.900 It removed the containers. 11:18.900 --> 11:21.000 It's stopping the node server currently. 11:21.240 --> 11:25.110 It's taking quite a bit of time to do it, but it is what it is. 11:25.140 --> 11:27.900 As long as it's doing the cleanup for us, I don't care. 11:27.930 --> 11:30.450 It removed both containers. 11:30.450 --> 11:33.150 It removed the network that they were both running on. 11:33.150 --> 11:35.880 So Docker Compose created the network for us. 11:35.880 --> 11:37.080 Isn't that pretty cool? 11:37.110 --> 11:41.460 Ran them both inside the same network and that's all she wrote. 11:41.640 --> 11:45.360 Now let's move on to starter code number nine.