1 1 00:00:00,552 --> 00:00:02,560 Hi guys and welcome back. 2 2 00:00:02,560 --> 00:00:04,773 In this video we're going to setup Nginx. 3 3 00:00:05,680 --> 00:00:08,480 Nginx is going to be the most forward facing 4 4 00:00:08,480 --> 00:00:10,640 application in our server which is what users 5 5 00:00:10,640 --> 00:00:12,760 are going to interact with. 6 6 00:00:12,760 --> 00:00:14,843 Let's begin by installing it. 7 7 00:00:17,980 --> 00:00:19,150 Now that we've got it installed 8 8 00:00:19,150 --> 00:00:21,110 we have to do some configuration, 9 9 00:00:21,110 --> 00:00:24,193 but first of all let's check our server's firewall, 10 10 00:00:26,860 --> 00:00:29,560 and you can see that the firewall is inactive. 11 11 00:00:29,560 --> 00:00:32,100 We're going to enable the firewall later on 12 12 00:00:32,100 --> 00:00:34,330 to help us keep things safe. 13 13 00:00:34,330 --> 00:00:35,940 But before we enable the firewall 14 14 00:00:35,940 --> 00:00:38,100 we have to do a couple of things. 15 15 00:00:38,100 --> 00:00:41,030 We have to allow Nginx HTTP 16 16 00:00:42,380 --> 00:00:47,120 so that we will be able to access Nginx 17 17 00:00:47,120 --> 00:00:48,710 from the outside world essentially 18 18 00:00:48,710 --> 00:00:51,300 make requests to our application 19 19 00:00:51,300 --> 00:00:53,850 and we also have to allow SSH 20 20 00:00:53,850 --> 00:00:57,320 so that we can stay logged in when we enable the firewall. 21 21 00:00:57,320 --> 00:01:00,310 Next, we're gonna do ufw enable. 22 22 00:01:00,310 --> 00:01:01,430 And it tells you that this 23 23 00:01:01,430 --> 00:01:03,350 may disrupt existing ssh connections 24 24 00:01:03,350 --> 00:01:06,200 but we have just allowed SSH earlier 25 25 00:01:06,200 --> 00:01:08,670 so we're gonna say yes. 26 26 00:01:08,670 --> 00:01:11,660 Next thing to do is we're gonna do sudo systemctl 27 27 00:01:11,660 --> 00:01:15,420 status nginx and you can see hopefully 28 28 00:01:15,420 --> 00:01:18,800 that Nginx is already active and running. 29 29 00:01:18,800 --> 00:01:21,000 You can always stop, restart, 30 30 00:01:21,000 --> 00:01:24,880 or reload Nginx by using the appropriate commands. 31 31 00:01:24,880 --> 00:01:28,970 So instead of status you can do start, stop, or reload. 32 32 00:01:28,970 --> 00:01:32,296 Reload is useful when you change any configuration of Nginx 33 33 00:01:32,296 --> 00:01:34,720 so that it will reload the configuration 34 34 00:01:34,720 --> 00:01:36,480 without having to restart. 35 35 00:01:36,480 --> 00:01:39,410 Now let's configure Nginx for our application. 36 36 00:01:39,410 --> 00:01:42,030 We're gonna do sudo vi etc nginx 37 37 00:01:42,030 --> 00:01:46,330 sites-available pricing service.conf. 38 38 00:01:46,330 --> 00:01:48,680 This will be an empty file where we're gonna define 39 39 00:01:48,680 --> 00:01:52,840 how Nginx is going to behave in this context. 40 40 00:01:52,840 --> 00:01:56,470 Nginx works by defining different server blocks 41 41 00:01:56,470 --> 00:01:59,020 and each server block is completely independent 42 42 00:01:59,020 --> 00:02:01,600 and runs 100% of the time. 43 43 00:02:01,600 --> 00:02:06,580 So, we will say server and then these curly braces. 44 44 00:02:06,580 --> 00:02:10,640 Next, we need to say where the server will be listening. 45 45 00:02:10,640 --> 00:02:13,500 So, if we say listen 80 for example, 46 46 00:02:13,500 --> 00:02:15,910 this server or all of the code 47 47 00:02:15,910 --> 00:02:18,040 that we include inside this server block 48 48 00:02:18,040 --> 00:02:22,320 will happen when a user makes a request on port 80. 49 49 00:02:22,320 --> 00:02:25,650 Port 80 is the default port for HTTP requests 50 50 00:02:25,650 --> 00:02:27,670 so whenever somebody accesses 51 51 00:02:27,670 --> 00:02:31,763 our server's address this block will run. 52 52 00:02:32,870 --> 00:02:37,870 So, we will say real ip header is X Forwarded For. 53 53 00:02:40,640 --> 00:02:43,040 And what this does is it instead 54 54 00:02:43,040 --> 00:02:46,410 of hiding the IP header from our Flask app 55 55 00:02:46,410 --> 00:02:50,110 it will forward the IP header to our Flask app. 56 56 00:02:50,110 --> 00:02:52,553 So, our Flask app knows who made which request. 57 57 00:02:53,710 --> 00:02:57,163 And we will set real ip from 127.0.0.1, 58 58 00:02:58,720 --> 00:03:03,120 the server name is going to be localhost for now. 59 59 00:03:03,120 --> 00:03:04,870 That's just a couple of configuration variables 60 60 00:03:04,870 --> 00:03:07,270 and now we get into the meat of things. 61 61 00:03:07,270 --> 00:03:10,460 What happens when we get a request 62 62 00:03:10,460 --> 00:03:14,660 made to the root of our application 63 63 00:03:14,660 --> 00:03:16,890 or anything that comes after it? 64 64 00:03:16,890 --> 00:03:19,060 When you define a location block 65 65 00:03:19,060 --> 00:03:20,900 the configuration inside this block 66 66 00:03:20,900 --> 00:03:25,540 will happen when a request is made to the slash endpoint. 67 67 00:03:25,540 --> 00:03:27,030 So, basically the root endpoint 68 68 00:03:27,030 --> 00:03:29,773 of our application or indeed anything else. 69 69 00:03:30,830 --> 00:03:33,640 If you wanted to define an application 70 70 00:03:33,640 --> 00:03:35,890 that starts with slash app for example 71 71 00:03:35,890 --> 00:03:37,930 you would do something like that and this block 72 72 00:03:37,930 --> 00:03:41,673 would only happen on requests that start with slash app, 73 73 00:03:42,820 --> 00:03:45,170 but because we are defining our app 74 74 00:03:45,170 --> 00:03:47,590 as the top level app we're gonna keep it as that. 75 75 00:03:47,590 --> 00:03:50,990 So, basically whenever a request accesses our application, 76 76 00:03:50,990 --> 00:03:55,000 we're gonna say include uwsg params 77 77 00:03:55,000 --> 00:03:57,450 and then we're gonna pass the request 78 78 00:03:57,450 --> 00:04:01,623 to the socket file that we defined earlier, 79 79 00:04:05,712 --> 00:04:07,380 and that's pretty much everything we need to do 80 80 00:04:07,380 --> 00:04:12,290 because Nginx is already geared talk to uWSGI. 81 81 00:04:12,290 --> 00:04:14,330 When we give the socket file Nginx 82 82 00:04:14,330 --> 00:04:16,880 will now how to pass the information there. 83 83 00:04:16,880 --> 00:04:20,390 As long as uWSGI is running it will be able to take that 84 84 00:04:20,390 --> 00:04:23,080 and respond with whatever our Flask application 85 85 00:04:23,080 --> 00:04:25,770 would respond with and send it back to Nginx 86 86 00:04:25,770 --> 00:04:26,770 to send to the user. 87 87 00:04:28,020 --> 00:04:30,600 In some cases, we may get some error pages 88 88 00:04:31,660 --> 00:04:34,400 so we're gonna define 404.html 89 89 00:04:35,280 --> 00:04:39,500 and what this does is when we get an 404 code 90 90 00:04:39,500 --> 00:04:41,810 from our Flask app we're gonna send 91 91 00:04:41,810 --> 00:04:45,460 the user to slash 404.html in their browser 92 92 00:04:45,460 --> 00:04:47,370 and this also defines that when the user 93 93 00:04:47,370 --> 00:04:50,400 accesses 404.html we're gonna serve them 94 94 00:04:50,400 --> 00:04:52,290 with this page here. 95 95 00:04:52,290 --> 00:04:55,113 Again, same thing if the error code is 500, 96 96 00:04:55,113 --> 00:04:57,410 502, 503, or 504, we're gonna send 97 97 00:04:57,410 --> 00:05:00,550 the user to slash 50x.html 98 98 00:05:00,550 --> 00:05:03,870 and I forgot the forward slash here. 99 99 00:05:03,870 --> 00:05:06,800 When they access slash 50x.html 100 100 00:05:06,800 --> 00:05:09,290 we're gonna serve them from this folder here. 101 101 00:05:09,290 --> 00:05:11,760 And I realise I said file earlier 102 102 00:05:11,760 --> 00:05:12,750 but really what's happening here 103 103 00:05:12,750 --> 00:05:14,080 is we're gonna serve the file 104 104 00:05:14,080 --> 00:05:19,080 slash usr slash share slash nginx slash html slash 404.html. 105 105 00:05:19,680 --> 00:05:23,010 So, that's what we're gonna give the user when this happens. 106 106 00:05:23,010 --> 00:05:25,680 And that's a default 404 page 107 107 00:05:25,680 --> 00:05:27,740 and a default 50x page. 108 108 00:05:27,740 --> 00:05:30,140 That's everything we need to do for Nginx config, 109 109 00:05:30,140 --> 00:05:34,195 so let's press escape colon wq to write and quit 110 110 00:05:34,195 --> 00:05:39,195 and now we have to do sudo rm etc nginx sites-enabled 111 111 00:05:42,530 --> 00:05:47,290 and remove the default server that's already there 112 112 00:05:47,290 --> 00:05:48,340 and then we're gonna do sudo 113 113 00:05:48,340 --> 00:05:53,340 ln-s etc nginx sites-available pricing service.conf 114 114 00:05:54,690 --> 00:05:57,490 to etc nginx sites-enabled. 115 115 00:05:57,490 --> 00:06:01,320 What this does is actually makes the site enabled. 116 116 00:06:01,320 --> 00:06:03,480 By default Nginx recommends 117 117 00:06:03,480 --> 00:06:06,090 that you store all your configurations 118 118 00:06:06,090 --> 00:06:09,480 inside a folder called sites-available. 119 119 00:06:09,480 --> 00:06:12,880 Those sites are not actually in Nginx 120 120 00:06:12,880 --> 00:06:17,120 until you put them inside sites-enabled. 121 121 00:06:17,120 --> 00:06:20,980 That way if you want to temporarily disable a site 122 122 00:06:20,980 --> 00:06:22,840 you can delete it from sites-enabled 123 123 00:06:22,840 --> 00:06:25,010 but you still have it in sites-available 124 124 00:06:25,010 --> 00:06:27,540 in case you wanna bring it back later. 125 125 00:06:27,540 --> 00:06:32,540 So, by doing ln-s that essentially makes like a shortcut 126 126 00:06:32,670 --> 00:06:37,630 from this in sites-available to sites-enabled. 127 127 00:06:37,630 --> 00:06:39,490 Now that we've gotten that we are going 128 128 00:06:39,490 --> 00:06:43,910 to do sudo systemctl reload nginx 129 129 00:06:43,910 --> 00:06:46,860 and make sure that your uWSGI service 130 130 00:06:46,860 --> 00:06:51,860 is also running and now we're ready to try out our app. 131 131 00:06:52,560 --> 00:06:55,870 I have gone over to the IP address of the server 132 132 00:06:55,870 --> 00:06:59,820 and you can see that we have our app here running. 133 133 00:06:59,820 --> 00:07:00,933 Let's try to sign up. 134 134 00:07:03,060 --> 00:07:04,090 There you have it. 135 135 00:07:04,090 --> 00:07:05,260 You can see that MongoDB 136 136 00:07:05,260 --> 00:07:08,850 is also running in the background because this succeeded. 137 137 00:07:08,850 --> 00:07:11,343 So, we've got everything working now. 138 138 00:07:12,290 --> 00:07:13,270 The next thing we'd like to do 139 139 00:07:13,270 --> 00:07:16,770 is of course to set up something that runs periodically 140 140 00:07:16,770 --> 00:07:19,130 to check our alerts and send an email 141 141 00:07:19,130 --> 00:07:21,870 when an alert does reach the desired price. 142 142 00:07:21,870 --> 00:07:23,640 Let's do that in the next video. 143 143 00:07:23,640 --> 00:07:24,590 I'll see you there.