1 00:00:02,300 --> 00:00:05,310 For pod-internal communication 2 00:00:05,310 --> 00:00:08,230 so when two containers run in the same pod, 3 00:00:08,230 --> 00:00:09,930 and that's important, only then, 4 00:00:09,930 --> 00:00:12,900 kubernetes allows you to send a request 5 00:00:12,900 --> 00:00:16,770 to the localhost address and then using the pod 6 00:00:16,770 --> 00:00:19,173 which is exposed by that other container. 7 00:00:20,160 --> 00:00:23,850 So localhost is the magic address 8 00:00:23,850 --> 00:00:26,710 you can use inside of a pod. 9 00:00:26,710 --> 00:00:29,450 So if you have one container running in a pod, 10 00:00:29,450 --> 00:00:31,330 which executes some code 11 00:00:31,330 --> 00:00:34,360 which also runs on the server side so to say, 12 00:00:34,360 --> 00:00:37,530 ends up the pod, and that code needs an address 13 00:00:37,530 --> 00:00:40,030 you can use a localhost as an address 14 00:00:40,030 --> 00:00:41,800 if you wanna send the request 15 00:00:41,800 --> 00:00:45,093 to another container running in the same pod. 16 00:00:46,770 --> 00:00:50,120 Therefore here, in the users-deployment, 17 00:00:50,120 --> 00:00:55,120 for our users container, we wanna add the env field 18 00:00:55,420 --> 00:00:58,342 to provide a value for that 19 00:00:58,342 --> 00:01:02,700 AUTH_ADDRESS environment variable, in that users container 20 00:01:02,700 --> 00:01:05,250 and then as you learned in the last core section 21 00:01:05,250 --> 00:01:08,690 for env, we can have multiple environment variables. 22 00:01:08,690 --> 00:01:10,600 And for every environment variable 23 00:01:11,550 --> 00:01:14,890 created with such a dash here, we provide a name 24 00:01:14,890 --> 00:01:16,770 which is the name of the environment variable. 25 00:01:16,770 --> 00:01:18,733 So in my case AUTH_ADDRESS 26 00:01:19,670 --> 00:01:22,040 and then we also have a value 27 00:01:22,040 --> 00:01:23,940 and we could get that from a file 28 00:01:23,940 --> 00:01:26,000 as shown in the last section 29 00:01:26,000 --> 00:01:27,770 but here, I will just hard-code it 30 00:01:27,770 --> 00:01:30,887 into debt's deployment file and use localhost, 31 00:01:31,750 --> 00:01:33,800 and this should do the trick. 32 00:01:33,800 --> 00:01:36,550 Now we provide auth as an address 33 00:01:36,550 --> 00:01:41,260 in the docker-compose world using that other services name 34 00:01:42,780 --> 00:01:46,340 and we use local hosts in the kubernetes world 35 00:01:46,340 --> 00:01:49,490 which should work since that is the special address 36 00:01:49,490 --> 00:01:52,660 that can be used inside of one and the same pod, 37 00:01:52,660 --> 00:01:55,440 if two containers running in that same pod 38 00:01:55,440 --> 00:01:57,283 wanna communicate with each other. 39 00:01:58,550 --> 00:02:01,750 So, if we now save this, 40 00:02:01,750 --> 00:02:04,320 we can go out of that users API folder 41 00:02:04,320 --> 00:02:08,310 into the kubernetes folder and apply 42 00:02:09,610 --> 00:02:14,383 the updated users-deployment.yaml file. 43 00:02:15,350 --> 00:02:18,610 This updates, the deployment 44 00:02:18,610 --> 00:02:20,590 hence if we now run get pods, 45 00:02:20,590 --> 00:02:22,870 we see that one pod is being created now 46 00:02:22,870 --> 00:02:25,020 and the containers are being created there. 47 00:02:26,880 --> 00:02:28,010 And once that finished 48 00:02:28,010 --> 00:02:30,190 we see the old pod is being terminated 49 00:02:30,190 --> 00:02:31,880 and the new pod is up and running 50 00:02:31,880 --> 00:02:34,320 and there we got two containers in the pod. 51 00:02:34,320 --> 00:02:37,200 That's what this 2/2 means two containers 52 00:02:37,200 --> 00:02:39,460 and both are up and running. 53 00:02:39,460 --> 00:02:42,510 So that's looking good we got two containers up and running. 54 00:02:42,510 --> 00:02:46,550 Now let's see whether that really all works. 55 00:02:46,550 --> 00:02:50,360 Our service IP and the service address exposed by minikube 56 00:02:50,360 --> 00:02:51,990 didn't change in the meantime 57 00:02:51,990 --> 00:02:55,210 changing the deployment does not change the service 58 00:02:55,210 --> 00:02:57,440 and therefore we should be able to send 59 00:02:57,440 --> 00:03:00,900 that same sign up request again, in postman. 60 00:03:00,900 --> 00:03:04,170 So a POST request to that minikube exposed 61 00:03:04,170 --> 00:03:05,720 IP address and port 62 00:03:05,720 --> 00:03:10,040 two slash signup with some raw JSON data attached 63 00:03:10,040 --> 00:03:13,050 an email address and a password 64 00:03:13,050 --> 00:03:16,420 and if I click send, this is looking good. 65 00:03:16,420 --> 00:03:19,690 This is looking good because if something would fail 66 00:03:19,690 --> 00:03:23,520 about sending that request here, when we sign up 67 00:03:23,520 --> 00:03:26,460 sending that request to the off service, 68 00:03:26,460 --> 00:03:28,810 if something would fail about that, 69 00:03:28,810 --> 00:03:32,430 we should not get back 'User created' as a response, 70 00:03:32,430 --> 00:03:35,510 instead, if this would throw some kind of error, 71 00:03:35,510 --> 00:03:38,530 because the address isn't found or anything like that, 72 00:03:38,530 --> 00:03:41,960 we should actually get back an error response 73 00:03:41,960 --> 00:03:44,513 and we are not which proves that it works. 74 00:03:45,740 --> 00:03:48,690 Now let's try sending the same request data 75 00:03:48,690 --> 00:03:51,030 to the slash login service. 76 00:03:51,030 --> 00:03:53,280 and we get back token 'abc', 77 00:03:53,280 --> 00:03:55,660 which again, proves that it works 78 00:03:55,660 --> 00:03:59,570 because that token value, is actually not created 79 00:03:59,570 --> 00:04:02,770 in the users service file here 80 00:04:02,770 --> 00:04:05,370 but in the auth-app.js file. 81 00:04:05,370 --> 00:04:08,580 Is here where this token is being generated 82 00:04:08,580 --> 00:04:11,883 and where this value of 'abc' is being sent back. 83 00:04:12,740 --> 00:04:15,230 So that again proves, that it works 84 00:04:15,230 --> 00:04:18,899 because we're using localhost as an address name here 85 00:04:18,899 --> 00:04:22,740 since we got two containers running in the same pod, 86 00:04:22,740 --> 00:04:25,790 and then for the pod-internal communication, 87 00:04:25,790 --> 00:04:27,497 we can use localhost.