WEBVTT 00:01.440 --> 00:02.700 -: In this section we're gonna take care 00:02.700 --> 00:04.770 of our very last container definition, 00:04.770 --> 00:06.960 the definition for NGINX container. 00:06.960 --> 00:08.370 And remember, this is the container 00:08.370 --> 00:11.130 that's going to do some routing of incoming requests 00:11.130 --> 00:15.120 to either the client or the backend API server. 00:15.120 --> 00:18.240 So, inside my Dockerrun.aws.json file, 00:18.240 --> 00:22.560 I'll add a comma, put in our last configuration object. 00:22.560 --> 00:25.720 So, we're gonna give this a name of NGINX 00:26.910 --> 00:28.110 or image will make use 00:28.110 --> 00:32.493 of your Docker ID/multi-NGINX, like so. 00:34.410 --> 00:37.140 Now this time around, we're not going to add in a host name 00:37.140 --> 00:39.990 because no other service in everything that we have here 00:39.990 --> 00:42.510 needs to directly access NGINX. 00:42.510 --> 00:44.760 The host name is actually an optional field. 00:44.760 --> 00:46.650 And because nothing needs to kind of reach out 00:46.650 --> 00:48.420 to NGINX and get a handle on it, 00:48.420 --> 00:50.850 we are not required to add in a hostname. 00:50.850 --> 00:52.110 Now, you definitely can if you want to. 00:52.110 --> 00:54.060 So, if you want to be 100% complete, 00:54.060 --> 00:56.760 we could add in a hostname of NGINX 00:56.760 --> 00:58.620 or whatever you might wanna do 00:58.620 --> 01:00.900 but it's not strictly required in this case. 01:00.900 --> 01:01.860 You know, now that I think about it, 01:01.860 --> 01:05.040 the worker hostname here is actually not required as well 01:05.040 --> 01:06.630 because nothing is actually reaching out 01:06.630 --> 01:07.560 to the worker as well. 01:07.560 --> 01:09.060 So, you could probably get away with deleting that 01:09.060 --> 01:11.220 if you wanna be a little bit adventurous, 01:11.220 --> 01:12.520 but I'm gonna leave it in. 01:13.560 --> 01:16.590 Okay, so now we're gonna add in our essential flag 01:16.590 --> 01:18.510 to the NGINX definition, 01:18.510 --> 01:20.340 and we're gonna add in two additional flags 01:20.340 --> 01:21.900 on top of that as well. 01:21.900 --> 01:25.050 So, we'll say essential is true. 01:25.050 --> 01:26.190 So, like, I said previously, 01:26.190 --> 01:29.550 at least one container must be marked as essential. 01:29.550 --> 01:32.460 If this container crashes for any reason, 01:32.460 --> 01:34.440 everything else, all these other containers 01:34.440 --> 01:36.900 will be automatically shutdown at the same time. 01:36.900 --> 01:38.310 And that definitely makes a lot of sense 01:38.310 --> 01:39.570 with our current architecture, 01:39.570 --> 01:41.040 'cause like we said just a moment ago 01:41.040 --> 01:44.010 if the NGINX server crashes, well that's pretty much it. 01:44.010 --> 01:47.550 Users cannot access the API, they can't access the client, 01:47.550 --> 01:49.260 and the worker can technically still run 01:49.260 --> 01:52.050 but essentially this group of containers is now kinda dead, 01:52.050 --> 01:53.580 and we should shut everything down 01:53.580 --> 01:55.830 and try to fix it up at some point in the future. 01:55.830 --> 01:59.133 So, that's why we are going to mark NGINX as essential true. 02:00.090 --> 02:02.040 Okay, now we're gonna put in two other flags, 02:02.040 --> 02:04.680 so we did not add into any of the previous ones. 02:04.680 --> 02:08.670 Very quickly I wanna open up the docker-compose.eml file. 02:08.670 --> 02:10.590 You'll recall that to expose traffic 02:10.590 --> 02:11.790 to our group of containers, 02:11.790 --> 02:15.390 we had opened up a port for the NGINX service right here. 02:15.390 --> 02:17.280 And so, we had said that if you ever try to visit 02:17.280 --> 02:20.670 our group of containers at localhost 3050, 02:20.670 --> 02:23.580 that would map up to port 80 inside the container, 02:23.580 --> 02:27.240 because NGINX by default is going to listen on port 80. 02:27.240 --> 02:30.570 And so we need to do that exact same port mapping process 02:30.570 --> 02:35.400 inside of our NGINX server configuration right here as well. 02:35.400 --> 02:37.200 So, we're going to do a port mapping 02:37.200 --> 02:39.243 by saying, port mappings. 02:40.860 --> 02:42.180 This is going to be an array 02:42.180 --> 02:43.470 because we could technically have 02:43.470 --> 02:45.780 several different port mappings. 02:45.780 --> 02:48.550 I'm gonna put in a single record inside of here 02:49.710 --> 02:53.140 that will have a host port of 80 02:54.420 --> 02:58.743 and a container port of 80 as well. 02:59.970 --> 03:04.710 So, this means open up a port on the host or on the machine 03:04.710 --> 03:07.590 that is hosting all of our containers, 03:07.590 --> 03:10.350 and map that to port 80 inside of the container 03:10.350 --> 03:11.820 which again is the default port 03:11.820 --> 03:14.910 that NGINX listens to inside the container. 03:14.910 --> 03:16.980 So, as you can see, setting up a port mapping 03:16.980 --> 03:19.050 is a little bit more typing than it was 03:19.050 --> 03:21.960 back inside of the Docker Compose file. 03:21.960 --> 03:24.023 Back inside a Docker Compose, we got away with just saying, 03:24.023 --> 03:27.120 "Ports is, oh, yeah, 30, 50, colon 80." 03:27.120 --> 03:30.060 And the docker run file, a lot more syntax goes into it 03:30.060 --> 03:32.790 but at the end of the day, it does the exact same thing. 03:32.790 --> 03:34.890 It maps the port inside the container 03:34.890 --> 03:36.150 to a port on the host 03:36.150 --> 03:38.900 where the machine that is running all these containers. 03:40.200 --> 03:42.270 Now, one last flag that we're going to add on 03:42.270 --> 03:44.100 to the NGINX configuration. 03:44.100 --> 03:47.520 So, after the closing square bracket for the port mappings, 03:47.520 --> 03:49.500 I'll make sure I get a comma in there, 03:49.500 --> 03:51.960 and then I'm going to add on links. 03:51.960 --> 03:53.790 We'll talk about what links is in just a second 03:53.790 --> 03:56.310 but first let's fill out the definition for it. 03:56.310 --> 03:58.080 This is going to be an array 03:58.080 --> 03:59.520 and it's going to have a string 03:59.520 --> 04:04.080 that refers to our server and our client. 04:04.080 --> 04:06.213 So, here's the links array. 04:07.200 --> 04:10.290 We'll say client and server like so 04:10.290 --> 04:13.770 in two separate strings separated by a comma. 04:13.770 --> 04:15.750 So, let's talk about what this is doing. 04:15.750 --> 04:18.960 As a quick reminder back inside of our Docker Compose file, 04:18.960 --> 04:21.870 we were very easily able to kind of communicate 04:21.870 --> 04:23.100 between different containers 04:23.100 --> 04:25.620 by making use of the different hostnames. 04:25.620 --> 04:28.620 So, for example, when the API had to connect to Redis, 04:28.620 --> 04:29.453 we simply said, 04:29.453 --> 04:32.670 "Oh, yeah, connect to the hostname of simply Redis." 04:32.670 --> 04:34.440 Anytime that the API made a request 04:34.440 --> 04:37.200 out to a hostname of Redis, it automatically got routed 04:37.200 --> 04:39.210 over to this other running service 04:39.210 --> 04:41.610 or this other running container. 04:41.610 --> 04:42.870 When you start deploying containers 04:42.870 --> 04:45.270 over to Amazon Elastic Beanstalk, however, 04:45.270 --> 04:49.020 or as we've said behind the scenes, technically ECS, 04:49.020 --> 04:51.930 we have to do a little bit more explicit mapping 04:51.930 --> 04:55.260 or kind of more explicitly form up links or connections 04:55.260 --> 04:57.420 between these different containers. 04:57.420 --> 04:59.250 So, in the world of Docker Compose, 04:59.250 --> 05:00.660 everything was easy as pie. 05:00.660 --> 05:02.287 We just said, "Oh, yeah, try to access 05:02.287 --> 05:04.080 "this other running service over here," 05:04.080 --> 05:07.260 or "Try to access this other running service over here," 05:07.260 --> 05:10.410 and Docker Compose kind of took care of everything for us 05:10.410 --> 05:12.540 or all that networking for us. 05:12.540 --> 05:15.270 So, in the world of ECS, 05:15.270 --> 05:18.750 you and I have to form a little bit more distinct links 05:18.750 --> 05:21.090 between each of these running containers. 05:21.090 --> 05:22.620 So, in our case, we know that 05:22.620 --> 05:25.440 NGINX needs to eventually send some traffic 05:25.440 --> 05:28.200 or redirect a request from the NGINX server 05:28.200 --> 05:30.633 to either the client or the API. 05:31.650 --> 05:35.190 So, in our case, we want to make sure that NGINX knows 05:35.190 --> 05:37.350 that these other two containers exist, 05:37.350 --> 05:40.800 and we're going to do so by forming up a link between them. 05:40.800 --> 05:43.710 Now, notice that links are kind of unidirectional. 05:43.710 --> 05:45.510 In other words, NGINX right here 05:45.510 --> 05:48.090 only has to kind of point over to client, 05:48.090 --> 05:49.290 but we don't have to form 05:49.290 --> 05:52.050 a opposite direction connection, like so, 05:52.050 --> 05:53.280 it's just unidirectional. 05:53.280 --> 05:54.877 We just say, "Oh, yeah, form a connection 05:54.877 --> 05:57.387 "from NGINX over to the client." 05:58.350 --> 06:00.097 And so, in our case right here, we're saying, 06:00.097 --> 06:05.047 "Yep, form a link from NGINX over to the client container 06:05.047 --> 06:06.990 "and the server container." 06:06.990 --> 06:08.490 And one thing I wanna mention here is that 06:08.490 --> 06:11.310 the name to links that we're providing 06:11.310 --> 06:12.840 maps up to the name property 06:12.840 --> 06:14.880 of the other container definition. 06:14.880 --> 06:17.010 So, for example, this gets really important 06:17.010 --> 06:18.810 with the server definition right here 06:18.810 --> 06:20.700 because we used a name of server, 06:20.700 --> 06:23.040 but we used a hostname of API. 06:23.040 --> 06:24.720 So, for hostname we did not... 06:24.720 --> 06:25.553 Oh, excuse me. 06:25.553 --> 06:28.680 For the link definition, we did not say API right here 06:28.680 --> 06:31.470 instead we just provided the name to that other container, 06:31.470 --> 06:33.870 that's how we form out the link. 06:33.870 --> 06:34.980 All right, so that's pretty much it 06:34.980 --> 06:37.740 for our container definition file. 06:37.740 --> 06:40.590 Now the last thing that I kind of recommend you do 06:40.590 --> 06:42.480 just because this is a JSON file, 06:42.480 --> 06:44.820 and it's really easy to make typos in here 06:44.820 --> 06:46.110 without realizing it. 06:46.110 --> 06:48.780 One thing that you might do is open up a new tab 06:48.780 --> 06:51.270 and do a search for like JSON Validator 06:51.270 --> 06:52.500 or something like that, 06:52.500 --> 06:55.470 and then find any random service in here. 06:55.470 --> 06:58.860 And then take all the JSON that we just put together, 06:58.860 --> 07:01.983 copy it and throw it into the validator. 07:03.030 --> 07:04.320 And then somewhere on here... 07:04.320 --> 07:06.330 Oh, there we go, Validate JSON. 07:06.330 --> 07:08.550 And that's gonna say, "Okay, you have valid JSON." 07:08.550 --> 07:11.010 So, if you made any typo, this will very quickly tell you 07:11.010 --> 07:12.540 and give you a little bit of feedback 07:12.540 --> 07:14.610 before you try deploying the application 07:14.610 --> 07:18.390 because Elastic Beanstalk is gonna be a little bit brutal 07:18.390 --> 07:20.190 when it comes to validating the JSON here. 07:20.190 --> 07:22.560 It's gonna be a lot more challenging to figure out exactly 07:22.560 --> 07:23.820 where the typo was. 07:23.820 --> 07:25.200 So, again, I do recommend that you do 07:25.200 --> 07:26.970 just a quick validation to make sure 07:26.970 --> 07:29.310 that you don't have any missed commas, 07:29.310 --> 07:30.720 or missed curly braces, 07:30.720 --> 07:33.990 or didn't use single quotes instead of double quotes 07:33.990 --> 07:35.970 or whatever it might be. 07:35.970 --> 07:37.410 All right, so that's pretty much it 07:37.410 --> 07:39.870 for our Dockerrun.aws.json file. 07:39.870 --> 07:41.550 So let's take a quick pause right here. 07:41.550 --> 07:42.780 We're gonna come back to the next section 07:42.780 --> 07:44.700 and start setting up our environment 07:44.700 --> 07:46.983 on Elastic Beanstalk in the next section.