WEBVTT 00:00.020 --> 00:00.290 Okay. 00:00.290 --> 00:05.480 So ready to generate our final microservice, which will be our notification service which we'll use 00:05.480 --> 00:11.000 to notify the users after we have successfully charged their card and created their reservation. 00:11.000 --> 00:18.290 So let's go ahead and in the terminal we'll go ahead and use the CLI to generate a new app and we'll 00:18.290 --> 00:22.460 go ahead and call this application notifications. 00:22.610 --> 00:25.550 So I've gone ahead and created our new app here. 00:25.550 --> 00:32.480 So we'll start off by creating a new Docker file as we've done before in the root of the Notification 00:32.480 --> 00:33.230 Service. 00:33.230 --> 00:39.200 And I'll go ahead and copy over the Docker file from the payment service and paste this in here, just 00:39.200 --> 00:45.920 swapping out the last line where we go into the notifications folder to start this service up. 00:46.250 --> 00:53.270 So after we've added our Docker file, we can go into our Docker compose and we will go ahead and copy 00:53.270 --> 00:57.200 the payments setup here and paste it once again. 00:57.200 --> 01:02.010 And we're going to swap this out for the notifications service. 01:02.010 --> 01:07.110 So we'll keep everything the same, except we'll change the path to the Docker file here. 01:07.290 --> 01:11.940 And of course we'll make sure we start the notification service with the command here. 01:11.940 --> 01:15.960 And for our M file we will also look for the notifications. 01:15.990 --> 01:23.160 M Now we don't need to expose any ports here and we also don't need to expose ports on the payment service 01:23.160 --> 01:26.310 either because this is only exposed over TCP. 01:26.310 --> 01:32.610 So I'll get rid of this section here, but I will go ahead and create a dot env in the notifications 01:32.850 --> 01:38.970 root directory as well here so that we can actually provide environment variables to this service. 01:38.970 --> 01:42.840 But this should be everything we need to actually start up our notification service. 01:42.840 --> 01:47.370 So let's go back in our terminal and run a docker, compose up here. 01:47.370 --> 01:51.840 So you can see here that our notification service has started up successfully here. 01:51.900 --> 01:57.080 So we can go back to the notifications main.ts and start fleshing this out. 01:57.090 --> 02:04.110 I'll go ahead and copy over the main.ts from our payments bootstrap here because it'll largely be very 02:04.110 --> 02:05.010 similar. 02:05.100 --> 02:09.810 We'll paste this in here and we'll go ahead and swap out the payments module here. 02:09.810 --> 02:15.870 Now for the notifications module to pass into the nest factory, we'll go ahead and import the config 02:15.870 --> 02:21.510 service from nest config as well as the transport from Nestjs microservices. 02:21.510 --> 02:26.690 So we're still going to listen on all IP addresses for this microservice and get the port from the dot 02:26.730 --> 02:27.870 m file here. 02:27.870 --> 02:33.480 So if we look at the dot m for the payment service, we know we're listening on Port 3003. 02:33.480 --> 02:37.470 So let's go ahead and listen on Port 3004 here. 02:37.470 --> 02:43.590 And lastly, make sure we import the logger here from Nestjs Pino so we can hook into the logger module. 02:43.590 --> 02:50.340 Next, let's go to our notifications module and we'll go to the payments module here and just copy over 02:50.340 --> 02:52.380 the existing imports as well. 02:52.590 --> 02:57.630 So if we go to the notifications module, we'll go ahead and add these imports. 02:57.630 --> 03:06.270 So import the config module from nestjs config and we'll import star as joy from joy and then go ahead 03:06.270 --> 03:09.000 and import the logger module as well. 03:09.000 --> 03:15.570 So in the terminal we'll have to go ahead and restart our containers to read in the new dot m file for 03:15.570 --> 03:17.130 our notification service. 03:17.130 --> 03:20.910 So you can see here we're complaining about the stripe and the notification service. 03:20.910 --> 03:25.620 So let's go ahead and make sure we remove the stripe secret key as of course we don't need this in the 03:25.620 --> 03:27.300 notification service. 03:27.300 --> 03:31.620 So after we remove this, we should see the notification service starting up. 03:31.620 --> 03:34.920 And you can see we now have an error about the logger module. 03:34.920 --> 03:39.000 And the problem is we're importing logger module from Pino. 03:39.030 --> 03:45.540 Make sure we import the logger module from app slash common here instead. 03:45.540 --> 03:51.300 So finally we can see the notification service saying the nest microservice has successfully started. 03:51.300 --> 03:57.660 Okay, so next I'll go ahead and in our notifications controller I'll delete our default route here 03:57.660 --> 04:01.440 and I'll delete this default function in the notification service. 04:01.440 --> 04:05.010 We want to expose a new event pattern for this microservice. 04:05.010 --> 04:12.030 So an event pattern is the event based microservice communication approach where we actually won't be 04:12.030 --> 04:15.630 sending a response back from this notification service. 04:15.630 --> 04:21.120 Instead, we will simply receive an event from a different service and do something with that without 04:21.120 --> 04:22.530 having to reply back. 04:22.530 --> 04:28.200 So this is ideal because we don't have to maintain overhead by requiring a request response channel. 04:28.200 --> 04:33.390 It takes less time and it's more of a simpler approach because we're just notifying users. 04:33.390 --> 04:37.560 We don't really need to respond back to the calling application in this approach. 04:37.560 --> 04:43.620 So we'll go ahead and define a new event pattern decorator here from Nestjs Microservices. 04:43.620 --> 04:49.440 So I'm going to go ahead and call this notify email because we are going to be emailing the user. 04:49.440 --> 04:55.920 So I'll have an async function here with the same name, notify email, and we are of course going to 04:55.920 --> 04:58.680 extract the payload so we can still send a payload. 04:58.680 --> 04:59.970 So we'll go ahead and define the type. 04:59.990 --> 05:00.500 Here. 05:00.500 --> 05:10.280 I'll create a new folder as we've done before, and I'll create a notify email updates and I'll export 05:10.280 --> 05:17.150 this notify email, DTO, which is just going to have an email of type string here and we can actually 05:17.150 --> 05:23.840 apply the same validation as we've done before and specify that this should be an email from class validator 05:23.950 --> 05:25.760 in the notifications controller. 05:25.760 --> 05:33.440 We'll now say that this is a type notify email, DTO and then we'll call this DOT notification service 05:33.440 --> 05:37.730 dot, notify email and pass the data down into it. 05:37.730 --> 05:46.400 So to apply validation, of course we'll go ahead and apply the use pipes operator and call new validation 05:46.400 --> 05:47.270 pipe here. 05:47.270 --> 05:54.620 So in the Notification Service, let's go ahead and create a new async notify email method here that 05:54.620 --> 06:04.140 takes in the email which will be of type notify email, DTO And for now, let's just go ahead and console.log 06:04.140 --> 06:06.840 the email here so we can see that we are receiving it. 06:06.840 --> 06:12.420 So what we're actually going to do, the notification is in the payments service directly. 06:12.420 --> 06:20.010 So in the payment service, after we create a charge of any type, we are going to email the respective 06:20.010 --> 06:22.080 user that we're creating the charge for. 06:22.080 --> 06:27.780 So you could imagine that there could be multiple services utilizing this payment service, not just 06:27.780 --> 06:30.120 the reservation service, no matter what. 06:30.120 --> 06:31.830 We always want to notify the user. 06:31.830 --> 06:34.860 So we'll keep this event emitting in this service. 06:34.860 --> 06:40.740 Likewise, there could be multiple notification channels we want to use eventually beyond just email. 06:40.740 --> 06:45.150 So this is good because we now have a service dedicated just for notifying. 06:45.150 --> 06:48.870 And of course we can scale these services independently of one another. 06:48.870 --> 06:55.740 So back in the payments module now we're going to go ahead and call clients module dot register async 06:55.740 --> 06:59.070 here where we can provide all of our different clients. 06:59.070 --> 07:01.920 In this case, we're only going to have the payment service set up. 07:01.920 --> 07:07.590 So I'll go ahead and have a new object here where we specify the name and I want to add the notification 07:07.590 --> 07:08.430 service, of course. 07:08.430 --> 07:19.650 So I'll follow our similar pattern of adding our service to our Libs slash common services file here 07:19.650 --> 07:22.500 so that way we can use this in other services as well. 07:22.500 --> 07:29.640 If we need to communicate to this service, I'll export a const called notifications service and I'll 07:29.640 --> 07:31.470 call this notifications here. 07:31.470 --> 07:40.020 So I'll go ahead and now import the notification service from app slash Common and we can have a use 07:40.020 --> 07:45.330 factory here to actually inject the config service as we've done before. 07:45.330 --> 07:49.920 So this will be of type config service from nestjs config. 07:49.920 --> 07:53.850 And now we can go ahead and return an object that has. 07:53.880 --> 07:58.830 And so now inside of this use factory we'll go ahead and specify the transport here. 07:58.860 --> 08:04.430 Of course we know this is transport dot TCP and then we'll have the options object where we'll specify 08:04.430 --> 08:05.270 the host. 08:05.270 --> 08:10.670 In this case, we'll pull it off the config service and provide the environment variable, which I'll 08:10.670 --> 08:13.070 go ahead and call notifications. 08:13.100 --> 08:17.570 Host And then for the port we'll do the same thing here. 08:17.660 --> 08:25.180 I'll pull it off the config service dot, get port now and I'll go ahead and also add this to our joy 08:25.190 --> 08:26.480 validation here. 08:26.480 --> 08:34.820 So I'll have a new notifications host environment variable that will be a string and that's required. 08:34.820 --> 08:43.820 And I'll also copy this for the notifications port and this will be a number that is also required. 08:43.820 --> 08:51.650 So we need to go ahead and update our dot env now to actually have the notifications information here. 08:51.650 --> 08:59.330 So I'll add the notifications host first, which as of course we know from the Docker compose will be 08:59.330 --> 09:03.240 the name we've specified, which in here is just notifications. 09:03.240 --> 09:07.590 So we can go ahead and copy this directly and just paste this in. 09:07.590 --> 09:12.930 And then also the notifications port we know is on 3004. 09:12.960 --> 09:20.730 This is what we specified in our EMF here and where we are listening on our microservice here in our 09:20.730 --> 09:21.900 bootstrap function. 09:21.900 --> 09:27.780 So of course we'll have to restart our containers to pick up these latest environment variables. 09:27.780 --> 09:34.320 And finally in the payments module, don't forget we also need to add an inject property here where 09:34.320 --> 09:37.440 we go ahead and actually inject the config service. 09:37.440 --> 09:42.630 So the payment service has started back off successfully, which means we have all of the environment 09:42.630 --> 09:43.770 variables we need. 09:43.770 --> 09:50.040 And this also means now we can go into payment service and actually use the inject decorator here, 09:50.070 --> 09:51.900 notification service. 09:51.900 --> 09:56.370 And remember, we're importing this from app slash common. 09:56.370 --> 09:59.610 So let's go ahead and update our imports here and we'll also add the. 09:59.650 --> 10:02.260 Rate charge data from apps common. 10:02.260 --> 10:10.540 So we'll go ahead and call this the notification service which will be of type client proxy from nestjs 10:10.540 --> 10:18.220 microservices and of course make sure that this is also private read only so we can use it in the class 10:18.220 --> 10:18.610 here. 10:18.610 --> 10:23.710 So like I said, right after we create this payment intent and we actually successfully charge the user, 10:23.710 --> 10:27.550 that's when we want to actually emit the event to the notification service. 10:27.550 --> 10:31.630 And like I said, we don't need to wait for a response from the Notification Service. 10:31.630 --> 10:34.300 We'll just send this off and let it handle it. 10:34.300 --> 10:41.710 So to do this we can call this DOT notification service dot Emit, and we know we need to specify the 10:41.710 --> 10:42.640 pattern here. 10:42.640 --> 10:45.880 If you remember, the pattern here was notify email. 10:45.880 --> 10:52.480 So let's go ahead and add, notify email, and then we have the data where we can specify the email 10:52.480 --> 10:52.990 here. 10:52.990 --> 10:58.380 Now, right now we actually aren't even providing an email to the payment service. 10:58.390 --> 11:00.310 Let's go ahead and change this. 11:00.310 --> 11:00.700 Okay. 11:00.700 --> 11:08.230 So in order to receive the email in the payment service, we know we're sending the Create charge request 11:08.230 --> 11:14.230 from the reservation service when we actually create a new reservation and we already have access to 11:14.230 --> 11:22.420 the user in our reservations controller thanks to our JWT auth guard and our current user decorator. 11:22.420 --> 11:29.680 So let's refactor this a bit by instead of taking in the user ID here, let's go ahead and get the entire 11:29.680 --> 11:36.040 user directly and we can destructure the properties we know we want off of it, which will be the email 11:36.040 --> 11:43.420 and the ID and this will come off of the user DTO from app slash common and make sure we have an underscore 11:43.420 --> 11:44.680 ID here as well. 11:44.680 --> 11:48.820 And I'll also go ahead and rename this variable to user ID. 11:49.030 --> 11:52.840 So we're still providing the user ID in the reservations repository. 11:52.870 --> 12:00.160 However, now instead of just passing in the Create Reservation, DTO dot charge, which we know is 12:00.260 --> 12:03.500 the card in the amount, we will also include the user's email. 12:03.500 --> 12:05.750 So let's go ahead and create a new object here. 12:05.750 --> 12:12.320 We'll spread the Create Reservation DTO charge and then add the email property here. 12:12.320 --> 12:17.510 Now go back to the reservations controller and instead of passing in the underscore ID, we'll pass 12:17.510 --> 12:18.800 in the whole user object. 12:18.800 --> 12:25.340 So now in the payments controller, we want to update the DTO for Create charge method to include the 12:25.340 --> 12:25.970 email. 12:25.970 --> 12:32.720 However, right now we're using the shared Create charge DTO from our app slash common folder and we 12:32.720 --> 12:35.330 don't want to add the email to this base. 12:35.330 --> 12:41.840 Create charge DTO Instead we can create a new DTO that's specific to the payment service and extend 12:41.840 --> 12:48.740 this create charge DTO to get the card and amount properties with the validation and add our own email 12:48.740 --> 12:49.820 property on top of it. 12:49.820 --> 12:52.310 So let's go ahead and do this in the payment service. 12:52.310 --> 13:00.710 I'll go ahead and create a new DTO in the DTO folder called Payments Create Charge dot DTO, and this 13:00.710 --> 13:08.990 will be a class called payments Create Charge DTO and importantly, this is going to extend the create 13:08.990 --> 13:13.040 charge DTO from app slash common. 13:13.400 --> 13:17.960 So again, we're going to inherit the existing properties, the card and the amount, and now we can 13:17.960 --> 13:25.520 add the email field of type string and specify that this should be an email here from class validator. 13:25.520 --> 13:31.250 Now in the payments controller here, instead of using the Create charge DTO, we will use the payments, 13:31.250 --> 13:34.940 create charge, DTO we can delete the unused import. 13:34.940 --> 13:41.210 And now when we pass our data to the create charge method and make sure we import the payments, create 13:41.210 --> 13:47.630 charge DTO instead where we know we have the card amount as well as the email, and now we can properly 13:47.660 --> 13:51.530 emit the notify email event here to the specified email. 13:51.530 --> 13:54.320 We'll make sure all of our containers are started up. 13:54.320 --> 14:02.870 And now if we firstly log in to get a JWT cookie and create a new reservation, we wait for the reservation 14:02.870 --> 14:08.750 to get created and in the logs we should now see the notification service correctly console logging 14:08.750 --> 14:15.500 out our email so we can see that we're sending off the email correctly from the reservation service.