1 00:00:02,050 --> 00:00:03,880 We need the IP address, 2 00:00:03,880 --> 00:00:07,110 which has generated for this auth-service. 3 00:00:07,110 --> 00:00:08,450 Because as I mentioned, 4 00:00:08,450 --> 00:00:11,700 with services, you get stable IP addresses. 5 00:00:11,700 --> 00:00:14,480 And one service has it's own IP address, 6 00:00:14,480 --> 00:00:16,930 and that IP address will not change, 7 00:00:16,930 --> 00:00:19,100 and through that IP address, 8 00:00:19,100 --> 00:00:22,220 the pods that are controlled by that service, 9 00:00:22,220 --> 00:00:23,750 can be reached. 10 00:00:23,750 --> 00:00:26,600 So that means we need to find out which IP address 11 00:00:26,600 --> 00:00:28,233 this service has. 12 00:00:29,110 --> 00:00:32,740 Now one way of doing that, is of course, 13 00:00:32,740 --> 00:00:34,930 to go into our kubernetes folder, 14 00:00:34,930 --> 00:00:39,930 and to apply the -f=auth-dash-service.yaml file. 15 00:00:40,730 --> 00:00:45,423 And also maybe already the -f=auth-deployment.yaml file. 16 00:00:47,240 --> 00:00:50,130 Apply that and with that of course, 17 00:00:50,130 --> 00:00:51,530 we got a brand new deployment 18 00:00:51,530 --> 00:00:53,310 and a brand new service. 19 00:00:53,310 --> 00:00:56,800 And hence, if we run kubectl get services, 20 00:00:56,800 --> 00:00:59,550 we see that new service here. 21 00:00:59,550 --> 00:01:01,840 It's this auth-service. 22 00:01:01,840 --> 00:01:03,920 And it's this IP address, 23 00:01:03,920 --> 00:01:06,890 which is now available inside of the cluster. 24 00:01:06,890 --> 00:01:09,970 So you will not be able to use that IP address 25 00:01:09,970 --> 00:01:11,410 on your local machine. 26 00:01:11,410 --> 00:01:13,623 It's only available inside of the cluster. 27 00:01:13,623 --> 00:01:17,290 And we could use this IP address here, 28 00:01:17,290 --> 00:01:19,343 as a value instead of local host. 29 00:01:20,570 --> 00:01:22,170 So let's do that. 30 00:01:22,170 --> 00:01:25,030 Let's insert this IP address here, 31 00:01:25,030 --> 00:01:28,290 as a value for AUTH-ADDRESS. 32 00:01:28,290 --> 00:01:31,963 And therefore let's now apply that changed. 33 00:01:34,092 --> 00:01:36,530 f=users-deployment.yaml file, 34 00:01:36,530 --> 00:01:38,443 which uses this new IP address. 35 00:01:40,060 --> 00:01:41,600 And if you now get your pods, 36 00:01:41,600 --> 00:01:45,330 you see the old two container pod is terminating, 37 00:01:45,330 --> 00:01:48,180 and we got two different pods with one container 38 00:01:48,180 --> 00:01:49,410 each up and running. 39 00:01:49,410 --> 00:01:52,623 Because we also got these two deployments. 40 00:01:53,750 --> 00:01:54,960 So that's working. 41 00:01:54,960 --> 00:01:56,510 And if we now try to send 42 00:01:56,510 --> 00:01:59,980 this login request it still succeeds, 43 00:01:59,980 --> 00:02:02,700 the same as true for the signup request, 44 00:02:02,700 --> 00:02:05,100 because we're using this IP address, 45 00:02:05,100 --> 00:02:08,152 which we found for the service we created, 46 00:02:09,180 --> 00:02:10,833 this IP address. 47 00:02:11,800 --> 00:02:14,270 But of course manually getting this IP address, 48 00:02:14,270 --> 00:02:15,600 is a bit annoying. 49 00:02:15,600 --> 00:02:17,940 The good news is that it's stable, 50 00:02:17,940 --> 00:02:21,400 it won't change all the time, so we could do that. 51 00:02:21,400 --> 00:02:24,590 But still as I just said it is a bit annoying. 52 00:02:24,590 --> 00:02:27,580 There is a more convenient way. 53 00:02:27,580 --> 00:02:31,040 Kubernetes will give you automatically generated 54 00:02:31,040 --> 00:02:32,760 environment variables. 55 00:02:32,760 --> 00:02:36,700 In your programs, with information about all the services, 56 00:02:36,700 --> 00:02:38,690 which are running in your cluster. 57 00:02:38,690 --> 00:02:41,430 So here we got the auth and users-service 58 00:02:41,430 --> 00:02:42,690 up and running basically, 59 00:02:42,690 --> 00:02:45,950 and we automatically get environment variables. 60 00:02:45,950 --> 00:02:50,520 In our code, by kubernetes, if we got these services. 61 00:02:50,520 --> 00:02:52,780 And through these environment variables, 62 00:02:52,780 --> 00:02:55,730 kubernetes will automatically give us information, 63 00:02:55,730 --> 00:02:59,283 like the IP addresses of the different services. 64 00:03:00,350 --> 00:03:03,490 So here in users-api, we could, for example, 65 00:03:03,490 --> 00:03:06,513 take advantage of the automatically generated, 66 00:03:07,540 --> 00:03:11,260 environment variables by accessing process.env 67 00:03:11,260 --> 00:03:14,550 here in node js to use an environment variable, 68 00:03:14,550 --> 00:03:16,310 but by using a different name, 69 00:03:16,310 --> 00:03:20,170 a name automatically generated by kubernetes. 70 00:03:20,170 --> 00:03:24,310 And that is your service name, 71 00:03:24,310 --> 00:03:28,360 all caps with dashes replaced by underscores. 72 00:03:28,360 --> 00:03:30,968 So in my case, since I wanna reach out to the auth-service 73 00:03:30,968 --> 00:03:31,850 here, 74 00:03:31,850 --> 00:03:36,850 it would be auth-service transformed to AUTH_SERVICE 75 00:03:37,920 --> 00:03:39,720 all caps, 76 00:03:39,720 --> 00:03:41,760 and then _SERVICE_HOST. 77 00:03:45,940 --> 00:03:49,480 And this pattern, environment variables of this pattern, 78 00:03:49,480 --> 00:03:52,090 are created for all your services. 79 00:03:52,090 --> 00:03:56,435 So the AUTH would be a USERS_SERVICE_SERVICE_HOST 80 00:03:56,435 --> 00:03:58,000 variable here, 81 00:03:58,000 --> 00:04:02,420 because we've got this users-service up and running as well. 82 00:04:02,420 --> 00:04:04,140 But of course we don't need that here, 83 00:04:04,140 --> 00:04:07,840 we need the auth-service environment variable. 84 00:04:07,840 --> 00:04:09,980 And this is automatically generated 85 00:04:09,980 --> 00:04:11,830 and configured by kubernetes. 86 00:04:11,830 --> 00:04:13,870 And this will hold the IP address, 87 00:04:13,870 --> 00:04:17,490 which was automatically assigned for this service, 88 00:04:17,490 --> 00:04:19,572 for this AUTH_SERVICE and this case. 89 00:04:20,810 --> 00:04:21,642 Now, of course, 90 00:04:21,642 --> 00:04:25,360 this kind of hurts us when we try to run 91 00:04:25,360 --> 00:04:27,530 this with docker-compose, 92 00:04:27,530 --> 00:04:29,270 we simply would have to make sure 93 00:04:29,270 --> 00:04:31,840 that we use the same environment variable name here, 94 00:04:31,840 --> 00:04:35,340 but ultimately of course, that's a problem we can solve. 95 00:04:35,340 --> 00:04:37,110 but we then have the advantage 96 00:04:37,110 --> 00:04:40,840 of getting the generated IP address automatically. 97 00:04:40,840 --> 00:04:44,150 And here I will only replace it in the login route, 98 00:04:44,150 --> 00:04:48,260 and not in the signup route so that we see both in action. 99 00:04:48,260 --> 00:04:53,133 Our manual environment variable with the manually set value, 100 00:04:54,380 --> 00:04:55,680 this one here. 101 00:04:55,680 --> 00:04:59,240 And the automatically generated environment variable, 102 00:04:59,240 --> 00:05:01,810 generated by kubernetes. 103 00:05:01,810 --> 00:05:04,810 Again, to make sure that this runs with docker, 104 00:05:04,810 --> 00:05:07,330 you would have to add this kubernetes 105 00:05:07,330 --> 00:05:09,330 generated environment variable, 106 00:05:09,330 --> 00:05:11,653 to your environment variables here, 107 00:05:12,840 --> 00:05:15,060 in the docker-compose file. 108 00:05:15,060 --> 00:05:17,250 Because of course in the docker-compose world, 109 00:05:17,250 --> 00:05:20,378 this is not generated automatically. 110 00:05:20,378 --> 00:05:25,378 With that though, if we redeploy our updated users image, 111 00:05:26,040 --> 00:05:29,470 and then restart our deployment in the end, 112 00:05:29,470 --> 00:05:30,870 it should again work 113 00:05:30,870 --> 00:05:34,373 but now with the auto-generated environment variable. 114 00:05:35,650 --> 00:05:39,270 Hence here, I'll switch into the users-api folder, 115 00:05:39,270 --> 00:05:41,050 and rebuild the image 116 00:05:41,050 --> 00:05:45,843 with the name of academind/kub-demo-users in my case. 117 00:05:46,752 --> 00:05:51,660 And of course I should give that name with the -t flag. 118 00:05:51,660 --> 00:05:53,963 And once this was built, we push it, 119 00:05:56,380 --> 00:05:58,760 using the latest tag like this, 120 00:05:58,760 --> 00:06:01,570 and now this updated code will be pushed. 121 00:06:01,570 --> 00:06:06,570 And now if we go out of this into the kubernetes folder, 122 00:06:07,360 --> 00:06:12,360 we can run kubctl apply -f=users-deployment.yaml file, 123 00:06:14,750 --> 00:06:16,680 and to ensure that this happens here, 124 00:06:16,680 --> 00:06:21,330 I will simply delete my currently running deployment, 125 00:06:21,330 --> 00:06:22,793 and then apply it again. 126 00:06:24,150 --> 00:06:27,150 Because otherwise this deployment wouldn't do anything, 127 00:06:27,150 --> 00:06:28,800 because the file didn't change 128 00:06:28,800 --> 00:06:32,700 and then kubernetes will not re-pull the image. 129 00:06:32,700 --> 00:06:34,860 For that you would have to use a different tag, 130 00:06:34,860 --> 00:06:36,810 which we change all the time. 131 00:06:36,810 --> 00:06:39,483 But with that, I'm also recreating this. 132 00:06:41,360 --> 00:06:43,640 The old pod is terminating and the new one is up 133 00:06:43,640 --> 00:06:44,670 and running. 134 00:06:44,670 --> 00:06:48,580 And now we should be able to still send both the login 135 00:06:48,580 --> 00:06:50,270 and the signup request. 136 00:06:50,270 --> 00:06:52,380 Though, of course, you should keep in mind, 137 00:06:52,380 --> 00:06:54,230 that for the login request, 138 00:06:54,230 --> 00:06:58,460 we are using this auto-generated environment variable, 139 00:06:58,460 --> 00:07:01,670 which holds the automatically assigned IP address 140 00:07:01,670 --> 00:07:03,783 for this AUTH_SERVICE. 141 00:07:04,620 --> 00:07:07,080 So a signup, of course, it still works. 142 00:07:07,080 --> 00:07:10,880 But if we now test login, that also still works. 143 00:07:10,880 --> 00:07:14,120 Which proves that this auto-generated IP address 144 00:07:14,120 --> 00:07:15,543 does its job. 145 00:07:16,520 --> 00:07:19,070 And that's of course a very useful feature, 146 00:07:19,070 --> 00:07:23,190 since it makes this whole gets the IP address process. 147 00:07:23,190 --> 00:07:25,063 Very, very dynamic.