WEBVTT 00:00.990 --> 00:03.390 -: In the last section, we set up some configuration inside 00:03.390 --> 00:06.120 of our Docker Compose file for Postgres, Redis 00:06.120 --> 00:08.040 and our server. 00:08.040 --> 00:09.360 We have one last thing to do, 00:09.360 --> 00:10.680 we need to make sure that we provide 00:10.680 --> 00:14.880 some environment variables off to the server service. 00:14.880 --> 00:16.770 So inside of our Docker Compose file, 00:16.770 --> 00:17.940 here's the server right here. 00:17.940 --> 00:19.500 We're gonna add on another section 00:19.500 --> 00:21.930 of configuration to specify some number 00:21.930 --> 00:24.060 of configuration variables. 00:24.060 --> 00:26.070 The configuration that we're going to pass in here, 00:26.070 --> 00:29.070 is gonna customize the way in which our server behaves 00:29.070 --> 00:31.740 when it is started up as a container. 00:31.740 --> 00:33.900 Just in case you didn't go through all the configuration 00:33.900 --> 00:35.520 with me a couple videos ago, 00:35.520 --> 00:37.020 if you look in the server directory 00:37.020 --> 00:39.679 and find the keys.js file, you'll find a bunch 00:39.679 --> 00:43.620 of references to something called processs.env. 00:43.620 --> 00:45.840 These are all environment variables. 00:45.840 --> 00:48.900 And so essentially, when the server starts up 00:48.900 --> 00:50.550 it's gonna look at its environment 00:50.550 --> 00:52.500 and it's gonna try to pull some information 00:52.500 --> 00:54.060 from the environment 00:54.060 --> 00:55.860 and it's then gonna use that information 00:55.860 --> 00:57.646 to customize the way in which it behaves. 00:57.646 --> 01:01.980 In our case, the server relies upon these environment 01:01.980 --> 01:04.590 variables for deciding how it's gonna connect 01:04.590 --> 01:07.350 to its instance of Redis, and how it's gonna connect 01:07.350 --> 01:09.333 to the Postgres server as well. 01:10.920 --> 01:12.930 Now, we've not yet gone through the process of setting 01:12.930 --> 01:15.360 up any environment variables through Docker Compose, 01:15.360 --> 01:17.400 so let's look at a diagram really quickly just 01:17.400 --> 01:19.353 to get a better idea of how to do this. 01:21.600 --> 01:24.270 Okay, so here's how we specify environment variables 01:24.270 --> 01:25.830 in a Docker Compose file. 01:25.830 --> 01:28.470 And I'm showing you some very fine grained details 01:28.470 --> 01:30.870 about the different syntax that we're gonna use. 01:32.370 --> 01:35.100 So on the left hand side, you'll see the syntax 01:35.100 --> 01:38.250 that you and I are going to use most frequently. 01:38.250 --> 01:40.590 We specify the name of the variable, 01:40.590 --> 01:44.640 then an equal right here, and then the value that we want 01:44.640 --> 01:45.960 to set it to. 01:45.960 --> 01:47.430 This is gonna set up a variable 01:47.430 --> 01:51.360 inside the container at runtime of the container. 01:51.360 --> 01:54.150 So what I mean by runtime right here, is you'll recall 01:54.150 --> 01:56.880 that when we build an image, it's a two step process, 01:56.880 --> 01:58.650 or I should say when we build and run an image 01:58.650 --> 02:00.420 it's really a two step process. 02:00.420 --> 02:02.850 The first step is when we build the image, 02:02.850 --> 02:04.680 that's the kind of preparation part. 02:04.680 --> 02:06.870 That's where we create a new image. 02:06.870 --> 02:08.700 And then at some point in the future when we actually 02:08.700 --> 02:11.130 run the container, that's the second part, 02:11.130 --> 02:12.510 that's when we actually take the image 02:12.510 --> 02:15.510 and create an instance of the container out of it. 02:15.510 --> 02:17.430 When we set up an environment variable inside 02:17.430 --> 02:20.280 of a Docker Compose file, we are setting up an environment 02:20.280 --> 02:22.710 variable that is applied at run time. 02:22.710 --> 02:26.280 So only when the container is started up. 02:26.280 --> 02:28.440 So when you specify an environment variable inside 02:28.440 --> 02:31.007 of a Docker Compose file, that information is not 02:31.007 --> 02:33.420 being encoded inside the image. 02:33.420 --> 02:36.270 The image doesn't get created and have some memory 02:36.270 --> 02:37.830 of this environment variable, 02:37.830 --> 02:40.650 it's only when a container is created, a environment 02:40.650 --> 02:43.053 variable is set up inside of the container. 02:43.980 --> 02:46.080 You'll see another syntax over here for setting 02:46.080 --> 02:48.580 up an environment variable on the right hand side. 02:49.830 --> 02:52.820 You can specify just the variable name by itself without 02:52.820 --> 02:55.740 any equal sign or any value for it. 02:55.740 --> 02:58.770 If you specify just the variable name, then the value for 02:58.770 --> 03:01.980 this variable is going to be taken from your computer. 03:01.980 --> 03:04.080 So if you have some environment variables set up 03:04.080 --> 03:07.590 on your machine, like let's say some secret API key 03:07.590 --> 03:08.970 or something like that, 03:08.970 --> 03:12.390 that might be when you want to use this variable name syntax 03:12.390 --> 03:15.570 by just itself without specifying any value, 03:15.570 --> 03:17.130 because then you don't have to specify 03:17.130 --> 03:20.353 or hard code in any specific value for the API key, 03:20.353 --> 03:22.410 excuse me, for the environment variable, 03:22.410 --> 03:24.960 it'll be taken from your machine at runtime 03:24.960 --> 03:27.188 and it's not gonna be saved along with the source code 03:27.188 --> 03:29.850 of your project or the Docker Compose file 03:29.850 --> 03:31.770 or anything like that. 03:31.770 --> 03:34.327 So in our case, we want to always use the same set 03:34.327 --> 03:36.510 of variable names and values inside of our 03:36.510 --> 03:37.590 Docker Compose file, 03:37.590 --> 03:40.830 and we are not adding any environment variables directly 03:40.830 --> 03:42.150 to our machine. 03:42.150 --> 03:43.500 That's why we're gonna use this syntax 03:43.500 --> 03:44.790 on the left hand side. 03:44.790 --> 03:46.290 So let's try it out right now. 03:48.120 --> 03:50.910 I'm gonna find my server configuration section 03:50.910 --> 03:52.770 and then on the same tab level 03:52.770 --> 03:57.770 as build and volumes, I'll specify environment like so. 03:58.080 --> 04:01.320 Now really quickly, in case English is a second language 04:01.320 --> 04:03.240 for you, or even if it's your first, 04:03.240 --> 04:05.040 environment is a tricky word. 04:05.040 --> 04:07.110 So I gotta ask you, please pay very close 04:07.110 --> 04:09.240 attention to the spelling on this word right here. 04:09.240 --> 04:12.030 It has an N right in the middle right there. 04:12.030 --> 04:15.363 So environment, M-E-N-T. 04:16.680 --> 04:19.830 So inside of here, we're going to add an array 04:19.830 --> 04:21.360 of environment variables. 04:21.360 --> 04:23.550 And remember we specify an array with a single 04:23.550 --> 04:24.930 dash like so. 04:24.930 --> 04:29.160 Every record in this array will get its own individual dash. 04:29.160 --> 04:30.720 The first environment variable that we're gonna 04:30.720 --> 04:33.750 specify, is the Redis host, which is kind of like 04:33.750 --> 04:38.490 the URL that our server should reach out to to access Redis. 04:38.490 --> 04:41.883 So for this, I'll specify the key Redis_host, 04:43.014 --> 04:47.340 then the equals, and then the value on the right hand side. 04:47.340 --> 04:48.543 Now in our case, I'm gonna... 04:48.543 --> 04:50.970 This is kind of a gimme for the value of Redis host 04:50.970 --> 04:51.840 right here. 04:51.840 --> 04:54.360 Remember that anytime that we access a service 04:54.360 --> 04:57.060 that has been defined inside of a Docker Compose file, 04:57.060 --> 04:59.730 we just specify the name of the service. 04:59.730 --> 05:02.010 We don't have to do any additional like, "Oh yeah, 05:02.010 --> 05:05.400 go over to this particular IP or anything like that 05:05.400 --> 05:06.720 that is hosting the service." 05:06.720 --> 05:09.480 We just put the name of the service in. 05:09.480 --> 05:12.000 So in our case, the name of the Redis host 05:12.000 --> 05:13.577 is going to be simply Redis, 05:13.577 --> 05:17.145 'cause that's the name of the service that was created 05:17.145 --> 05:21.390 for hosting our Redis service. 05:21.390 --> 05:24.723 We'll say Redis host is simply Redis like so. 05:26.730 --> 05:29.310 The next environment variable that we need to specify, 05:29.310 --> 05:30.930 is the Redis port. 05:30.930 --> 05:32.910 Now this one is a little bit more challenging. 05:32.910 --> 05:35.640 For this, you might look at the documentation 05:35.640 --> 05:37.140 for Redis on Docker Hub. 05:37.140 --> 05:39.330 Let's do that right now very quickly. 05:39.330 --> 05:41.280 If you go back over to Docker Hub 05:41.280 --> 05:44.430 and go to the explorer tab, you can scroll on down to 05:44.430 --> 05:45.960 Redis right here. 05:45.960 --> 05:47.370 And then in the full description, 05:47.370 --> 05:49.300 you can scroll down a little bit 05:50.850 --> 05:53.130 and you'll notice that to start a Redis image, 05:53.130 --> 05:56.970 you want to connect to the default port of 6379. 05:56.970 --> 06:00.000 Now this can be configured on the Redis image, but for us 06:00.000 --> 06:02.220 there's no reason in configuring it, 06:02.220 --> 06:04.683 we're just gonna leave it as 6379. 06:07.260 --> 06:09.540 So back inside of my Docker Compose file, 06:09.540 --> 06:11.940 I'm gonna specify another environment variable 06:11.940 --> 06:16.230 of Redis_port equals 6379. 06:18.780 --> 06:23.100 So in both these cases right here, we used the first syntax 06:23.100 --> 06:24.900 of defining an environment variable. 06:24.900 --> 06:27.270 We put the variable name in, an equal sign, 06:27.270 --> 06:29.550 and then the value that we want to set it to. 06:29.550 --> 06:31.140 And we used this syntax over here 06:31.140 --> 06:33.690 because we did not want to attempt to pull the value 06:33.690 --> 06:36.960 from my shell or my computer essentially, 06:36.960 --> 06:39.150 'cause I do not have any environment variables to find 06:39.150 --> 06:41.973 on my computer of Redis host or Redis port. 06:43.230 --> 06:46.350 Okay, so that's our two first environment variables. 06:46.350 --> 06:48.210 Now we've got a handful of others that we're gonna 06:48.210 --> 06:49.830 go through rather quickly. 06:49.830 --> 06:53.340 So the other ones we have to define are PG user, host, 06:53.340 --> 06:55.233 database, password and port. 06:56.070 --> 06:58.590 Now as a quick tip here, if you are making use 06:58.590 --> 07:02.100 of Adam or VS code, I think this hotkey works 07:02.100 --> 07:04.590 with other editors as well, but this is... 07:04.590 --> 07:06.150 Those are the only two editors where I know 07:06.150 --> 07:07.650 for sure this hotkey works. 07:07.650 --> 07:09.900 In order to get these key names 07:09.900 --> 07:12.480 over to the Docker Compose file very quickly, 07:12.480 --> 07:15.940 you can highlight env. right there 07:17.160 --> 07:19.560 and then press command D several times 07:19.560 --> 07:22.860 and that will do a multi select on that text selection. 07:22.860 --> 07:24.360 You can then press right 07:24.360 --> 07:28.890 on your arrow key and then option shift right arrow 07:28.890 --> 07:31.890 and that will select just the keyword like so. 07:31.890 --> 07:34.053 You can then do a command C, 07:35.340 --> 07:38.220 go back over to the Docker Compose file 07:38.220 --> 07:41.223 and then do a command V to paste all that stuff in. 07:42.210 --> 07:43.830 And so that's just saving us from having to do 07:43.830 --> 07:45.063 a little bit of typing. 07:46.500 --> 07:49.350 So now I'll add in all of my little dashes here. 07:49.350 --> 07:53.550 And actually, technically you can use these same command D 07:53.550 --> 07:56.000 multi slack talk key here as well if you want to. 07:57.060 --> 07:58.860 And then we'll add in equal signs 07:58.860 --> 08:00.933 on the right hand side of each of these. 08:05.460 --> 08:06.990 All right, so for each of these we're gonna do 08:06.990 --> 08:11.160 a little bit more research on the Postgres documentation 08:11.160 --> 08:12.990 back on Docker Hub. 08:12.990 --> 08:15.483 So I'm gonna go back over to Docker Hub, 08:16.380 --> 08:18.390 I'll find the explore tab. 08:18.390 --> 08:21.210 And again, I'll search for Postgres on this list. 08:21.210 --> 08:22.800 Here it is right here. 08:22.800 --> 08:24.540 And like I said, just a moment ago, if you scroll 08:24.540 --> 08:28.290 down a pretty good amount, you'll see some documentation 08:28.290 --> 08:30.963 on the default values for each of those variables. 08:32.160 --> 08:34.620 So for Postgres password, somewhere in here 08:34.620 --> 08:36.090 it will tell you the default password. 08:36.090 --> 08:37.650 Actually, I'm not sure that actually tells you 08:37.650 --> 08:39.063 what the default is. 08:40.140 --> 08:42.360 It might be a little bit higher up here. 08:42.360 --> 08:44.820 Oh, come on, I don't wanna look forever. 08:44.820 --> 08:46.110 Where is it? 08:46.110 --> 08:48.150 Okay, it doesn't actually tell us the default password 08:48.150 --> 08:49.050 but I'll just tell you right now 08:49.050 --> 08:53.133 the default password for Postgres is Postgres password. 08:54.720 --> 08:57.963 We're gonna connect to a default database of Postgres. 08:58.890 --> 09:02.280 The default user that we'll connect to is Postgres, 09:02.280 --> 09:04.440 the host which is very similar to the Redis host that 09:04.440 --> 09:07.050 we defined up here, is also Postgres because that's 09:07.050 --> 09:09.990 the name of our Postgres service that we defined right here. 09:09.990 --> 09:11.700 And then finally the port, and that's something 09:11.700 --> 09:14.100 you can reference the documentation for back over here, 09:14.100 --> 09:16.890 you'll notice expose 5432. 09:16.890 --> 09:19.230 That's the default port for Postgres. 09:19.230 --> 09:22.323 And so we'll do 5432 for that one as well. 09:23.490 --> 09:24.570 Okay, so that's it. 09:24.570 --> 09:26.460 So hopefully you're starting to learn here that 09:26.460 --> 09:28.980 getting some information from these very common images 09:28.980 --> 09:30.886 that you'll probably use, such as Postgres, 09:30.886 --> 09:34.530 or MySQL or Redis, you have to look at the documentation 09:34.530 --> 09:36.810 for the repository to get some information about 09:36.810 --> 09:40.050 the default values here to make use of with that image. 09:40.050 --> 09:42.360 So, let's save this Docker Compose file 09:42.360 --> 09:45.030 and we're gonna very quickly test this out at our terminal. 09:45.030 --> 09:46.440 I know this is a really long section 09:46.440 --> 09:48.510 but we're almost done with this. 09:48.510 --> 09:50.130 So, I'll go back over to my tunnel, 09:50.130 --> 09:53.640 I'm gonna stop everything with Control+C, 09:53.640 --> 09:56.133 and I'll do a Docker Compose up. 09:57.780 --> 10:01.050 Now that's going to rebuild the server image from scratch, 10:01.050 --> 10:02.340 The (indistinct) you recall 10:02.340 --> 10:04.080 for the server does not take very long 10:04.080 --> 10:06.280 so we'll just wait a couple of seconds here. 10:07.620 --> 10:08.453 There it goes. 10:08.453 --> 10:10.020 And then it's gonna start to create all those 10:10.020 --> 10:13.530 different services and eventually we see listening up here. 10:13.530 --> 10:14.970 Perfect. 10:14.970 --> 10:16.230 So that's looking pretty good. 10:16.230 --> 10:17.640 Let's take a quick pause right here 10:17.640 --> 10:19.590 and we'll continue in the next section.