WEBVTT 00:00.750 --> 00:01.583 Narrator: In the last section 00:01.583 --> 00:05.130 we put together the core of the node.js web application. 00:05.130 --> 00:06.050 If you didn't follow along 00:06.050 --> 00:08.700 in the last section and you just copy pasted the code 00:08.700 --> 00:11.400 just make sure that you've got your index.js file 00:11.400 --> 00:13.590 and a package.json file. 00:13.590 --> 00:14.760 You'll also want to make sure 00:14.760 --> 00:17.040 that you've got your terminal open inside 00:17.040 --> 00:18.420 of your project directory. 00:18.420 --> 00:20.520 And so if I list out my current files and folders 00:20.520 --> 00:24.600 I should see the index.js and package.json files. 00:24.600 --> 00:26.580 Okay, so we've got some source code here 00:26.580 --> 00:28.590 and now we need to figure out how we can wrap this all 00:28.590 --> 00:30.900 up inside of a Docker container. 00:30.900 --> 00:32.520 I wanna first begin by telling you 00:32.520 --> 00:34.200 a little bit about node.js 00:34.200 --> 00:36.900 and how we're going to start up this application. 00:36.900 --> 00:40.080 So just in case you've never made use of node before 00:40.080 --> 00:41.880 two commands that you need to be aware of 00:41.880 --> 00:45.630 to install dependencies and start up this application. 00:45.630 --> 00:47.730 Anytime that we want to start up a node app 00:47.730 --> 00:49.690 we have to first install a set 00:50.549 --> 00:51.382 of dependencies 00:51.382 --> 00:53.070 and we can install all of our dependencies 00:53.070 --> 00:55.770 by running a command npm install inside 00:55.770 --> 00:57.540 of our project directory. 00:57.540 --> 01:00.270 This starts up a little program called npm 01:00.270 --> 01:01.920 which is somewhat colloquially 01:01.920 --> 01:04.350 known as the node package manager. 01:04.350 --> 01:06.270 This is going to run that program 01:06.270 --> 01:08.160 and install a couple dependencies for us. 01:08.160 --> 01:09.420 And of course it assumes 01:09.420 --> 01:12.120 that npm is installed on our local machine. 01:12.120 --> 01:14.420 We're inside the container as the case may be. 01:15.570 --> 01:16.650 The other thing to be aware of 01:16.650 --> 01:18.180 is that we're going to have to eventually 01:18.180 --> 01:20.370 start our server up and to do so 01:20.370 --> 01:21.660 we're going to run the command 01:21.660 --> 01:24.120 npm start at the terminal as well. 01:24.120 --> 01:25.890 And again, this also kind of assumes 01:25.890 --> 01:28.560 that npm is already installed. 01:28.560 --> 01:29.790 All right, so with all this in mind, 01:29.790 --> 01:30.780 let's now start thinking 01:30.780 --> 01:33.480 about the Docker file that we have to put together. 01:33.480 --> 01:35.970 Now, this series of operations that we are gonna put 01:35.970 --> 01:38.910 into the Docker file is going to end up looking very similar 01:38.910 --> 01:41.670 to what we did in the last application. 01:41.670 --> 01:44.460 So in this somewhat complicated diagram 01:44.460 --> 01:46.380 our template that we're kind of following here 01:46.380 --> 01:49.890 for our Docker file is to specify a base image 01:49.890 --> 01:52.500 run some command to install some dependencies 01:52.500 --> 01:55.470 which definitely sounds like something we have to do. 01:55.470 --> 01:57.840 And then specify the command to run on startup 01:57.840 --> 02:00.603 which as we just discussed is that npm start thing. 02:01.680 --> 02:04.350 Now over when we were working on the Redis image 02:04.350 --> 02:07.320 we said from Alpine to specify the base image. 02:07.320 --> 02:10.270 We ran apk add Redis to install the dependency 02:11.160 --> 02:13.530 and then we set up the default command as Redis server. 02:13.530 --> 02:15.210 And so it really seems like we have 02:15.210 --> 02:18.030 some very direct parallels this time around. 02:18.030 --> 02:19.710 I think that for the node application 02:19.710 --> 02:23.040 we could probably do a Docker file that specifies Alpine 02:23.040 --> 02:24.480 as our base image. 02:24.480 --> 02:26.790 We can then run npm install 02:26.790 --> 02:28.470 to install all of our dependencies, 02:28.470 --> 02:31.860 and then we can set up the default command of npm start to 02:31.860 --> 02:35.280 run the server when the container first comes online. 02:35.280 --> 02:37.620 So we're gonna take this type of approach right here 02:37.620 --> 02:39.540 by creating a Docker file and then essentially 02:39.540 --> 02:43.170 putting almost exactly these instructions inside of it. 02:43.170 --> 02:46.230 Now, quick disclaimer, just quick disclaimer here. 02:46.230 --> 02:48.960 Remember I had said we're gonna do a few things here 02:48.960 --> 02:51.570 slightly wrong, just so you can see some very 02:51.570 --> 02:54.780 common error messages that you are just about 02:54.780 --> 02:57.630 guaranteed to see on your own personal projects. 02:57.630 --> 02:59.550 So maybe in this discussion 02:59.550 --> 03:01.154 or the series of steps that I just described 03:01.154 --> 03:04.230 there might be something in here that doesn't quite 03:04.230 --> 03:07.470 line up with what's reality or what we really have to do. 03:07.470 --> 03:08.940 Okay? 03:08.940 --> 03:10.140 All right, so let's get started. 03:10.140 --> 03:12.000 I'm going to begin by making sure 03:12.000 --> 03:14.130 I've got my code editor open 03:14.130 --> 03:16.530 based on that simple web directory 03:16.530 --> 03:20.610 and inside of here I'm gonna make a new Docker file. 03:20.610 --> 03:22.860 Remember, it's Docker with a capital D 03:22.860 --> 03:25.830 and there is no file extension on there. 03:25.830 --> 03:26.670 Then inside of here 03:26.670 --> 03:29.820 we're going to first specify our base image. 03:29.820 --> 03:31.320 And just to be really complete 03:31.320 --> 03:33.073 I'm gonna add in some comments for these steps 03:33.073 --> 03:35.130 just to remind you what we're doing 03:35.130 --> 03:36.450 every step along the way. 03:36.450 --> 03:40.290 So I'll say specify a base image. 03:40.290 --> 03:41.123 And you know what? 03:41.123 --> 03:42.720 Let's use that Alpine image again. 03:42.720 --> 03:45.370 It really seemed like it worked out last time for us. 03:46.380 --> 03:50.583 Next up, we're going to install some dependencies. 03:52.650 --> 03:55.860 To do so, we will run the command npm install 03:55.860 --> 03:58.500 like I just said, the npm install command is how 03:58.500 --> 04:01.710 we install dependencies on a node.js project. 04:01.710 --> 04:05.400 And then finally, we will set up a default command 04:05.400 --> 04:07.410 which we can do by running out CMD. 04:07.410 --> 04:10.320 And then we put down a set of square brackets. 04:10.320 --> 04:12.210 And then in a set of double quotes, 04:12.210 --> 04:15.000 we separately list out all the parts of the command 04:15.000 --> 04:18.030 that we want to run when the container is first created. 04:18.030 --> 04:19.710 And so to start up our server 04:19.710 --> 04:23.310 we are probably going to want npm start like so. 04:23.310 --> 04:26.223 Notice that I've got a comma between those two strings. 04:27.930 --> 04:29.550 All right, I think this looks pretty good. 04:29.550 --> 04:32.370 It definitely looks very similar to what we did for Redis. 04:32.370 --> 04:34.440 So let's now flip back over to our terminal 04:34.440 --> 04:38.901 and see what happens when we try to build this image. 04:38.901 --> 04:41.400 So I'm gonna list out my files and folders 04:41.400 --> 04:44.820 and verify that I now see the Docker file inside of here. 04:44.820 --> 04:47.010 And then remember to build an image 04:47.010 --> 04:49.380 we can run Docker build 04:49.380 --> 04:51.060 and then we put the dot in there 04:51.060 --> 04:55.119 to specify the build context of the current directory. 04:55.119 --> 05:00.119 So I'll run that and then we very quickly see npm not found. 05:00.810 --> 05:02.280 All right, so first problem 05:02.280 --> 05:04.020 of a couple that we're going to see. 05:04.020 --> 05:05.700 So let's take a quick pause right here. 05:05.700 --> 05:07.530 We're going to start to investigate 05:07.530 --> 05:10.140 why we are seeing this error and fix it up. 05:10.140 --> 05:12.563 So quick break and I'll see you in just a minute.