1 00:00:00,452 --> 00:00:02,273 - [Instructor] Hi, and welcome back to the course. 2 00:00:02,273 --> 00:00:04,897 In this video we're going to be installing Nginx 3 00:00:04,897 --> 00:00:06,564 and running our app. 4 00:00:07,880 --> 00:00:11,864 Nginx is what's called a reverse proxy. 5 00:00:11,864 --> 00:00:14,320 What that means is that Nginx is going to 6 00:00:14,320 --> 00:00:18,487 act as a gateway between our application and external users. 7 00:00:20,440 --> 00:00:23,113 It's going to accept incoming requests, 8 00:00:23,113 --> 00:00:23,984 and then it's going to decide 9 00:00:23,984 --> 00:00:26,224 what to do with those requests. 10 00:00:26,224 --> 00:00:28,288 We are going to configure Nginx 11 00:00:28,288 --> 00:00:32,216 so those requests go straight to our application. 12 00:00:32,216 --> 00:00:34,688 Now, you may wonder, well, why do we need that? 13 00:00:34,688 --> 00:00:37,302 And I've got to say that's a good question. 14 00:00:37,302 --> 00:00:41,469 Nginx will also do things like communicate with uwsgi 15 00:00:42,518 --> 00:00:46,654 to enable multi-threaded operation of our Flask app. 16 00:00:46,654 --> 00:00:48,510 It can also do things like allow you to run 17 00:00:48,510 --> 00:00:52,294 multiple Flask apps simultaneously in your server 18 00:00:52,294 --> 00:00:56,838 while redirecting incoming requests to different apps 19 00:00:56,838 --> 00:00:59,262 depending on some parameters. 20 00:00:59,262 --> 00:01:01,318 So it's overall a nice piece of software 21 00:01:01,318 --> 00:01:04,086 to have in your server, and it's very useful, 22 00:01:04,086 --> 00:01:06,013 and it's also really fast, 23 00:01:06,013 --> 00:01:10,421 so it's not going to slow down your app at all. 24 00:01:10,421 --> 00:01:12,926 The first thing to do is to log in to your server, 25 00:01:12,926 --> 00:01:16,062 and then sudo apt-get update. 26 00:01:16,062 --> 00:01:19,406 Now, apt-get is going to communicate 27 00:01:19,406 --> 00:01:22,557 with the Ubuntu package manager 28 00:01:22,557 --> 00:01:25,174 and it's going to change some stuff. 29 00:01:25,174 --> 00:01:27,934 It's going to essentially change the version number, 30 00:01:27,934 --> 00:01:28,910 some things like that. 31 00:01:28,910 --> 00:01:32,662 So you have to be root to be able to run this command. 32 00:01:32,662 --> 00:01:34,621 And sudo does that. 33 00:01:34,621 --> 00:01:38,534 It says, run the following command as root. 34 00:01:38,534 --> 00:01:40,294 So we're going to press enter, 35 00:01:40,294 --> 00:01:43,750 and then we're going to run the command as sudo, 36 00:01:43,750 --> 00:01:45,342 and you may have to put in your password, 37 00:01:45,342 --> 00:01:48,286 so just do that if that's required. 38 00:01:48,286 --> 00:01:51,286 And then sudo apt-get instal nginx. 39 00:01:52,238 --> 00:01:55,154 And that's going to instal Nginx there. 40 00:01:55,154 --> 00:01:57,030 Once again, I'm going to press enter 41 00:01:57,030 --> 00:02:01,197 when it asks me if I want to continue to continue. 42 00:02:17,734 --> 00:02:20,501 Now that Nginx is installed, 43 00:02:20,501 --> 00:02:24,758 you can see that we've set up a bunch of things, 44 00:02:24,758 --> 00:02:26,716 and there's one thing that we must do, 45 00:02:26,716 --> 00:02:30,484 which is let our firewall have access, 46 00:02:30,484 --> 00:02:33,260 well, let Nginx have access through the firewall, 47 00:02:33,260 --> 00:02:36,021 so the incoming requests don't get blocked. 48 00:02:36,021 --> 00:02:37,180 So what we're going to do is say 49 00:02:37,180 --> 00:02:41,180 sudo ufw status, and ufs is the Ubuntu firewall. 50 00:02:43,316 --> 00:02:45,164 And as you can see, it says status: inactive, 51 00:02:45,164 --> 00:02:48,972 so we're going to enable the firewall 52 00:02:48,972 --> 00:02:51,222 to improve the connections, 53 00:02:52,580 --> 00:02:54,844 and it says that it may disrupt existing ssh connections, 54 00:02:54,844 --> 00:02:56,916 but it doesn't. 55 00:02:56,916 --> 00:02:59,044 And finally we have to give Nginx access, 56 00:02:59,044 --> 00:03:03,628 so we're going to do sudo ufw allow 'Nginx HTTP' 57 00:03:03,628 --> 00:03:07,236 and make sure to put that inside quotation marks. 58 00:03:07,236 --> 00:03:08,260 And what that's going to do 59 00:03:08,260 --> 00:03:11,843 is it's going to put Nginx in the firewall. 60 00:03:12,696 --> 00:03:17,089 And that's the rule added, and now if we do sudo ufw status, 61 00:03:17,089 --> 00:03:20,339 you can see that Nginx HTTP is allowed. 62 00:03:25,031 --> 00:03:28,003 Now, we're going to make sure that Nginx is running, 63 00:03:28,003 --> 00:03:29,051 and it should be running, 64 00:03:29,051 --> 00:03:30,291 and the way we check that in Ubuntu 65 00:03:30,291 --> 00:03:32,043 is with the system controller. 66 00:03:32,043 --> 00:03:34,210 So systemctl status nginx. 67 00:03:37,907 --> 00:03:41,507 And we're going to be using systemctl quite a bit, 68 00:03:41,507 --> 00:03:44,451 so it's good to get to know it. 69 00:03:44,451 --> 00:03:48,347 And as you can see here, it's active, and it's running. 70 00:03:48,347 --> 00:03:50,579 So that's all good. 71 00:03:50,579 --> 00:03:52,938 There are a bunch of other things we can do with systemctl. 72 00:03:52,938 --> 00:03:55,955 We can potentially stop Nginx. 73 00:03:55,955 --> 00:03:59,595 We can also start Nginx if it's not running. 74 00:03:59,595 --> 00:04:01,678 And we can restart Nginx. 75 00:04:03,084 --> 00:04:04,923 So those are a few of the things we can do 76 00:04:04,923 --> 00:04:07,173 with the system controller. 77 00:04:08,452 --> 00:04:09,551 Okay, now what we're going to do, 78 00:04:09,551 --> 00:04:12,666 is we're going to go over to the Nginx config 79 00:04:12,666 --> 00:04:17,611 and we're going to add our rest api to the Nginx config. 80 00:04:17,611 --> 00:04:19,805 We've not yet put the rest api in the server, 81 00:04:19,805 --> 00:04:21,668 but we're going to do that in just a moment, 82 00:04:21,668 --> 00:04:24,192 but we're going to add some configuration parameters 83 00:04:24,192 --> 00:04:28,185 to Nginx to make sure that it can access our api. 84 00:04:28,185 --> 00:04:29,165 So we're going to do 85 00:04:29,165 --> 00:04:33,332 sudo vi /etc/nginx/sites-available/items-rest.conf. 86 00:04:41,338 --> 00:04:44,771 And this is a brand new file which we are creating, 87 00:04:44,771 --> 00:04:45,961 and what we're going to do is we're going to press 88 00:04:45,961 --> 00:04:48,898 the letter I to go into Insert mode, 89 00:04:48,898 --> 00:04:52,153 and then we're going to start writing our Nginx config. 90 00:04:52,153 --> 00:04:53,560 Now this is going to be a bit long, 91 00:04:53,560 --> 00:04:56,818 but please bear with me while I explain exactly what it is. 92 00:04:56,818 --> 00:05:01,273 The first part of any Nginx config is the server. 93 00:05:01,273 --> 00:05:04,269 What that says is this block here 94 00:05:04,269 --> 00:05:07,887 inside these curly braces is a server. 95 00:05:07,887 --> 00:05:11,478 Essentially a Flask app or something like that. 96 00:05:11,478 --> 00:05:13,974 And this server is going to be able to 97 00:05:13,974 --> 00:05:16,585 listen to incoming requests and then 98 00:05:16,585 --> 00:05:19,811 dispatch them where appropriate. 99 00:05:19,811 --> 00:05:20,644 Okay. 100 00:05:21,635 --> 00:05:25,385 So this app, this server, is going to listen, 101 00:05:26,828 --> 00:05:27,826 sorry, apologies for that, 102 00:05:27,826 --> 00:05:30,246 is going to listen on port 80, 103 00:05:30,246 --> 00:05:33,106 which is the default HTTP port. 104 00:05:33,106 --> 00:05:35,402 Whenever we access a website on the internet, 105 00:05:35,402 --> 00:05:37,004 we're accessing on port 80. 106 00:05:37,004 --> 00:05:39,202 That's just the default. 107 00:05:39,202 --> 00:05:41,429 So listening on port 80 is going to be interesting 108 00:05:41,429 --> 00:05:45,078 because it means that users don't have to do something 109 00:05:45,078 --> 00:05:46,828 like get mysite.com:. 110 00:05:51,903 --> 00:05:54,611 The colon will be omitted whenever we access 111 00:05:54,611 --> 00:05:58,517 our rest api because the default is port 80. 112 00:05:58,517 --> 00:06:00,257 So if we're listening on port 80, 113 00:06:00,257 --> 00:06:03,924 we don't have to do specify the port number. 114 00:06:05,362 --> 00:06:08,945 Next, a couple of configuration parameters. 115 00:06:09,884 --> 00:06:13,717 Real_ip_header is going to be X-Forwarded-For, 116 00:06:15,865 --> 00:06:16,978 and all that's going to do is it's going to 117 00:06:16,978 --> 00:06:20,943 forward the ip address of the requester 118 00:06:20,943 --> 00:06:22,969 over to our Flask app. 119 00:06:22,969 --> 00:06:25,091 Now, I understand that that doesn't make a lot of sense, 120 00:06:25,091 --> 00:06:28,546 but it just means that whenever somebody 121 00:06:28,546 --> 00:06:30,812 makes a request to our server, 122 00:06:30,812 --> 00:06:34,979 Nginx is going to tell our Flask app who made that request. 123 00:06:36,977 --> 00:06:41,144 Next, we're going to set the real ip from to be 127.0.0.1. 124 00:06:44,657 --> 00:06:47,689 Although Nginx is going to forward the ip address 125 00:06:47,689 --> 00:06:50,837 of the requester to our Flask app, 126 00:06:50,837 --> 00:06:52,718 it's also going to say that the request 127 00:06:52,718 --> 00:06:55,733 really is coming from 127.0.0.1, 128 00:06:55,733 --> 00:06:57,500 which as you know is local host, 129 00:06:57,500 --> 00:07:00,745 because Nginx is receiving the request, 130 00:07:00,745 --> 00:07:04,585 and then it's going to send that request to the Flask app, 131 00:07:04,585 --> 00:07:07,168 which is running on local host, 132 00:07:08,214 --> 00:07:10,459 or which will be running on local host. 133 00:07:10,459 --> 00:07:14,626 And to do with that, server_name is going to be localhost. 134 00:07:16,142 --> 00:07:17,179 Okay? 135 00:07:17,179 --> 00:07:20,165 So some config properties there. 136 00:07:20,165 --> 00:07:23,814 Next we're going to do location /, 137 00:07:23,814 --> 00:07:25,254 and what this is going to do is 138 00:07:25,254 --> 00:07:29,476 it's going to say whenever somebody accesses 139 00:07:29,476 --> 00:07:32,143 the root location of the server, 140 00:07:33,258 --> 00:07:36,341 it's going to redirect them somewhere, 141 00:07:36,341 --> 00:07:40,689 and where it's going to redirect them is to our Flask app. 142 00:07:40,689 --> 00:07:41,522 Okay? 143 00:07:42,984 --> 00:07:46,817 So what we have to do is include uwsgi_params. 144 00:07:47,995 --> 00:07:49,320 Now, as you know we're running the app 145 00:07:49,320 --> 00:07:52,660 using uwsgi, as you know from the Heroku deployments, 146 00:07:52,660 --> 00:07:54,499 and if you don't, then I'll tell you now. 147 00:07:54,499 --> 00:07:58,032 We're running the app using uwsgi, which is a programme 148 00:07:58,032 --> 00:08:00,941 that allows our Flask app to run multi-threaded 149 00:08:00,941 --> 00:08:03,965 more efficiently and to restart threads as they fail 150 00:08:03,965 --> 00:08:04,882 if they do. 151 00:08:06,201 --> 00:08:09,379 And Nginx deals very well with uwsgi. 152 00:08:09,379 --> 00:08:11,577 Uwsgi is a very complex thing, 153 00:08:11,577 --> 00:08:14,501 but we have to include uwsgi_params 154 00:08:14,501 --> 00:08:18,668 so that it can communicate with the uwsgi programme. 155 00:08:20,151 --> 00:08:20,984 Okay. 156 00:08:20,984 --> 00:08:23,606 Then we're going to do uwsgi_pass, 157 00:08:23,606 --> 00:08:25,747 and then we're going to type the following: 158 00:08:25,747 --> 00:08:29,914 unix:/var/www/html/items-rest/socket.sock. 159 00:08:37,473 --> 00:08:39,710 What this is doing is it's going to pass 160 00:08:39,710 --> 00:08:44,002 to this file all the necessary parameters. 161 00:08:44,002 --> 00:08:45,845 And what this file is going to be 162 00:08:45,845 --> 00:08:47,947 is this is going to be the connection point 163 00:08:47,947 --> 00:08:50,614 between our Flask app and Nginx. 164 00:08:51,816 --> 00:08:54,486 So this is really important. 165 00:08:54,486 --> 00:08:57,191 We don't have a socket.sock file yet, 166 00:08:57,191 --> 00:08:58,852 but we will have it soon. 167 00:08:58,852 --> 00:09:01,519 We're going to be creating that. 168 00:09:02,434 --> 00:09:06,017 Then we're going to say uwsgi_modifier1 30. 169 00:09:07,926 --> 00:09:09,211 And what this is passing in 170 00:09:09,211 --> 00:09:13,378 is a uwsgi parameter that tells the threads when to die 171 00:09:16,391 --> 00:09:18,707 if they become blocked. 172 00:09:18,707 --> 00:09:21,040 So just a bit of info there. 173 00:09:22,028 --> 00:09:23,630 Okay. 174 00:09:23,630 --> 00:09:26,769 And then we can add a bunch more stuff here, 175 00:09:26,769 --> 00:09:28,436 such as error pages. 176 00:09:32,098 --> 00:09:35,726 If we return a 404 code, we can tell Nginx 177 00:09:35,726 --> 00:09:39,508 to redirect the user to the 404 page, 178 00:09:39,508 --> 00:09:43,675 and we can say location = /404.html, 179 00:09:45,922 --> 00:09:48,062 and what this means is when the location 180 00:09:48,062 --> 00:09:51,758 is exactly /404.html do the following, 181 00:09:51,758 --> 00:09:54,609 and what we're going to do is say 182 00:09:54,609 --> 00:09:58,776 root /usr/share/nginx/html, 183 00:10:00,388 --> 00:10:03,154 and what that's going to do is it's going to serve 184 00:10:03,154 --> 00:10:06,487 the 404.html page from this folder here, 185 00:10:08,577 --> 00:10:12,350 which is /usr/share/nginx/html, 186 00:10:12,350 --> 00:10:16,689 and Nginx comes quite handily with a page called 404.html, 187 00:10:16,689 --> 00:10:18,388 so the user is going to see that page 188 00:10:18,388 --> 00:10:21,662 if we return a 404, and also we can say 189 00:10:21,662 --> 00:10:25,829 error_page 500, 502, 503 and 504 go to /50x.html 190 00:10:31,051 --> 00:10:34,634 and we can say if the location is 50x.html, 191 00:10:35,630 --> 00:10:40,469 do root /user/share/nginx/html. 192 00:10:40,469 --> 00:10:42,302 And once again, if we return error codes 193 00:10:42,302 --> 00:10:46,468 500, 502, 503 and 504, we're going to serve the 194 00:10:46,468 --> 00:10:50,117 50x.html page, which is going to tell the user 195 00:10:50,117 --> 00:10:52,784 that an internal error occurred. 196 00:10:54,167 --> 00:10:57,412 I appreciate that this is particularly confusing. 197 00:10:57,412 --> 00:10:59,227 And the first few times that I had to do this, 198 00:10:59,227 --> 00:11:00,917 I had no clue what was going on, 199 00:11:00,917 --> 00:11:03,240 but I just knew it worked. 200 00:11:03,240 --> 00:11:06,619 And if you want to delve into the depths of 201 00:11:06,619 --> 00:11:09,942 what this all means, then you'll have to go 202 00:11:09,942 --> 00:11:13,563 and investigate about the uwsgi protocol, 203 00:11:13,563 --> 00:11:16,749 and how these applications connect 204 00:11:16,749 --> 00:11:20,407 to the receiving server, which can be something like Apache, 205 00:11:20,407 --> 00:11:22,960 or something like Nginx. 206 00:11:22,960 --> 00:11:24,747 You don't have to worry about that, 207 00:11:24,747 --> 00:11:27,569 because when you do this, it will work. 208 00:11:27,569 --> 00:11:30,439 So I've chosen not to delve into 209 00:11:30,439 --> 00:11:32,606 any of the uwsgi concepts. 210 00:11:34,049 --> 00:11:37,054 They get confusing very quickly. 211 00:11:37,054 --> 00:11:38,743 But just know that that is essentially 212 00:11:38,743 --> 00:11:40,058 what's happening here. 213 00:11:40,058 --> 00:11:42,324 Whenever we access any page, 214 00:11:42,324 --> 00:11:44,110 we're going to go through to the Flask app, 215 00:11:44,110 --> 00:11:47,860 except if we go to the 404 and 50x end points 216 00:11:50,554 --> 00:11:52,916 and then we're going to set up those pages. 217 00:11:52,916 --> 00:11:53,883 And then what we're doing here 218 00:11:53,883 --> 00:11:55,554 is we're listening on port 80, 219 00:11:55,554 --> 00:11:59,471 which is the default port for HTTP connections, 220 00:12:00,343 --> 00:12:02,907 and then we're passing in who requested the page. 221 00:12:02,907 --> 00:12:04,664 We're also passing in localhost, 222 00:12:04,664 --> 00:12:07,495 which is actually the Nginx server, 223 00:12:07,495 --> 00:12:08,925 and then we're passing in localhost, 224 00:12:08,925 --> 00:12:11,624 which is the Nginx server again. 225 00:12:11,624 --> 00:12:13,476 When we've written all of this stuff here, 226 00:12:13,476 --> 00:12:14,848 we're going to press Escape, 227 00:12:14,848 --> 00:12:17,431 and then :wq to write and quit, 228 00:12:18,478 --> 00:12:22,561 and that's our Nginx config being made available. 229 00:12:23,414 --> 00:12:25,821 However, it's not been enabled. 230 00:12:25,821 --> 00:12:27,444 We have to enable the config, 231 00:12:27,444 --> 00:12:28,817 and the way we'll do that is by doing 232 00:12:28,817 --> 00:12:32,984 sudo ln -s /etc/nginx/sites-available/items-rest.conf, 233 00:12:39,559 --> 00:12:43,726 and then space, /etc/nginx/sites-enabled. 234 00:12:44,907 --> 00:12:46,308 Okay, so what this is doing is it's going to 235 00:12:46,308 --> 00:12:50,658 create a link, a soft link between the config file 236 00:12:50,658 --> 00:12:54,864 we just created and the sites enabled folder, 237 00:12:54,864 --> 00:12:58,548 where Nginx reads the config properties. 238 00:12:58,548 --> 00:13:00,354 So we're going to do that. 239 00:13:00,354 --> 00:13:01,187 Okay. 240 00:13:02,436 --> 00:13:06,074 Now that we've done that, Nginx will know about 241 00:13:06,074 --> 00:13:10,241 our config file, and it will try to access that socket file. 242 00:13:11,594 --> 00:13:13,353 That socket file doesn't yet exist, 243 00:13:13,353 --> 00:13:16,433 but we're going to make sure that it does in a moment. 244 00:13:16,433 --> 00:13:17,662 The next thing that we're going to do is 245 00:13:17,662 --> 00:13:21,829 sudo mkdir /var/www/html/items-rest. 246 00:13:25,953 --> 00:13:29,497 Remember, we used this folder in the config file. 247 00:13:29,497 --> 00:13:33,661 This is where our application is going to live. 248 00:13:33,661 --> 00:13:35,040 Now something interesting to remember 249 00:13:35,040 --> 00:13:39,836 is we've created this directory as the root user, 250 00:13:39,836 --> 00:13:42,562 which means our user, Jose, 251 00:13:42,562 --> 00:13:45,085 is not going to have access to that directory. 252 00:13:45,085 --> 00:13:48,349 So we have to make sure to give the directory 253 00:13:48,349 --> 00:13:50,250 to the Jose user, and what that is 254 00:13:50,250 --> 00:13:53,754 is make the Jose user the owner of that directory. 255 00:13:53,754 --> 00:13:58,151 So the way we do that is sudo chown, change owner, 256 00:13:58,151 --> 00:14:02,318 Jose:jose /var/www/html/items-rest. 257 00:14:05,350 --> 00:14:08,615 So we're going to change the owner of this directory 258 00:14:08,615 --> 00:14:12,119 to the Jose user and to the Jose group, 259 00:14:12,119 --> 00:14:15,750 as opposed to the root user and the root group. 260 00:14:15,750 --> 00:14:16,949 Okay. 261 00:14:16,949 --> 00:14:20,449 Now we're going to go into that directory. 262 00:14:22,755 --> 00:14:25,184 And now as you can see we are in that directory, 263 00:14:25,184 --> 00:14:26,771 and the next thing we have to do 264 00:14:26,771 --> 00:14:29,021 is to clone our Python app. 265 00:14:30,378 --> 00:14:31,905 So I'm going to use the same app 266 00:14:31,905 --> 00:14:35,831 as we used in the Heroku section, in the last section. 267 00:14:35,831 --> 00:14:36,762 Okay. 268 00:14:36,762 --> 00:14:40,429 So I'm just going to go ahead and copy that. 269 00:14:42,350 --> 00:14:43,194 And I'm going to paste it in here, 270 00:14:43,194 --> 00:14:45,152 and I'm going to explain exactly what I'm doing. 271 00:14:45,152 --> 00:14:48,235 What I'm going to do is git clone the 272 00:14:49,165 --> 00:14:53,332 https://github.com/schoolofcode-me/stores-rest-api.git. 273 00:14:57,251 --> 00:14:59,878 So that's the git hub repository 274 00:14:59,878 --> 00:15:02,588 and with the stores-rest.api 275 00:15:02,588 --> 00:15:06,311 that we deployed in the last section. 276 00:15:06,311 --> 00:15:08,605 And after that, I'm going to put a space, 277 00:15:08,605 --> 00:15:12,859 and a full stop, and that means clone all the items 278 00:15:12,859 --> 00:15:14,692 into this folder here. 279 00:15:17,431 --> 00:15:18,455 Okay. 280 00:15:18,455 --> 00:15:22,333 And there we have, we've now cloned it. 281 00:15:22,333 --> 00:15:23,166 Okay. 282 00:15:24,810 --> 00:15:28,977 Now, in order to be able to produce logs for our app, 283 00:15:30,714 --> 00:15:33,853 we're going to have to create a directory called log. 284 00:15:33,853 --> 00:15:35,603 So just do mkdir log. 285 00:15:36,705 --> 00:15:40,996 Because we own this folder, we own the items-rest folder, 286 00:15:40,996 --> 00:15:44,346 the Jose user owns it, we don't have to use sudo anymore, 287 00:15:44,346 --> 00:15:46,381 and indeed you shouldn't use sudo. 288 00:15:46,381 --> 00:15:47,881 Just do mkdir log. 289 00:15:49,110 --> 00:15:51,049 Okay, now I'm going to press ls, 290 00:15:51,049 --> 00:15:53,303 and you can see that we've got a bunch of things here 291 00:15:53,303 --> 00:15:55,761 which are all our application files, 292 00:15:55,761 --> 00:15:58,630 as well as the log folder. 293 00:15:58,630 --> 00:15:59,463 Okay. 294 00:16:00,695 --> 00:16:02,192 The next thing we have to instal 295 00:16:02,192 --> 00:16:05,561 a bunch of Python related things that we're going to need. 296 00:16:05,561 --> 00:16:09,190 So we're going to sudo apt-get instal, 297 00:16:09,190 --> 00:16:11,389 and the first thing we're going to instal is pip, 298 00:16:11,389 --> 00:16:13,318 the Python package manager. 299 00:16:13,318 --> 00:16:14,485 So python-pip. 300 00:16:15,529 --> 00:16:17,891 Then we're going to instal a set of tools 301 00:16:17,891 --> 00:16:21,565 that Python needs to be able to compile from source. 302 00:16:21,565 --> 00:16:24,315 So we're going to do python3-dev, 303 00:16:25,501 --> 00:16:27,018 and what that's going to allow us is to 304 00:16:27,018 --> 00:16:30,676 instal things like uwsgi and psycoPG, 305 00:16:30,676 --> 00:16:33,270 which is needed for SQLAlchemy. 306 00:16:33,270 --> 00:16:36,618 And finally we're going to instal libpq-dev, 307 00:16:36,618 --> 00:16:40,785 which again, is going to allow us to run psycoPG2. 308 00:16:42,061 --> 00:16:44,978 So we're going to instal all that. 309 00:16:45,843 --> 00:16:48,343 And this may take a wee while. 310 00:16:49,233 --> 00:16:52,564 Now that's finished, we're ready to proceed, 311 00:16:52,564 --> 00:16:55,837 and we have to first instal virtualenv. 312 00:16:55,837 --> 00:16:59,274 So we're going to use pip to instal virtualenv, 313 00:16:59,274 --> 00:17:01,281 and as you know, a virtual environment 314 00:17:01,281 --> 00:17:03,940 is just another Python installation 315 00:17:03,940 --> 00:17:05,486 that doesn't have the libraries that the 316 00:17:05,486 --> 00:17:07,731 main Python installation has. 317 00:17:07,731 --> 00:17:10,343 So we're going to use virtualenv for this project 318 00:17:10,343 --> 00:17:14,413 so we don't pollute the main Ubuntu Python installation 319 00:17:14,413 --> 00:17:16,717 with our libraries. 320 00:17:16,717 --> 00:17:18,820 We're going to create a virtual environment 321 00:17:18,820 --> 00:17:21,651 within the same folder, and the way we do that is with 322 00:17:21,651 --> 00:17:23,956 virtualenv, then the name of the folder 323 00:17:23,956 --> 00:17:25,924 which is going to host our virtual environment. 324 00:17:25,924 --> 00:17:28,046 I'm calling it venv. 325 00:17:28,046 --> 00:17:30,796 And then --python=python3.5. 326 00:17:32,145 --> 00:17:34,880 Ubuntu comes with Python 3.5, which is great. 327 00:17:34,880 --> 00:17:38,174 We don't have to instal it ourselves. 328 00:17:38,174 --> 00:17:39,335 (sneezes) 329 00:17:39,335 --> 00:17:40,737 Apologies for that. 330 00:17:40,737 --> 00:17:44,260 Now that we have created the virtual environment, 331 00:17:44,260 --> 00:17:46,794 we can see that it is there inside 332 00:17:46,794 --> 00:17:49,156 the same folder as everything else. 333 00:17:49,156 --> 00:17:51,450 And now we're going to go into the virtual environment 334 00:17:51,450 --> 00:17:55,712 by doing source venv/bin/activate. 335 00:17:55,712 --> 00:17:58,823 Now, remember we are in Unix right now, 336 00:17:58,823 --> 00:18:02,451 so even if we're running this terminal in Windows, 337 00:18:02,451 --> 00:18:06,095 you're still going to have to run source venv activate. 338 00:18:06,095 --> 00:18:08,524 And then we're going to be in the venv. 339 00:18:08,524 --> 00:18:10,194 Finally, the last thing to do is to 340 00:18:10,194 --> 00:18:12,527 instal -r requirements.txt. 341 00:18:14,668 --> 00:18:18,835 So we're going to do pip instal -r requirements.txt. 342 00:18:19,709 --> 00:18:20,542 And what that's going to do 343 00:18:20,542 --> 00:18:22,030 is it's going to get all of the requirements 344 00:18:22,030 --> 00:18:25,878 from the requirements.txt file, and it's going to 345 00:18:25,878 --> 00:18:29,497 instal them in this virtual environment. 346 00:18:29,497 --> 00:18:30,966 Remember that all of these files were created 347 00:18:30,966 --> 00:18:34,799 in the last section in the Heroku deployments. 348 00:18:41,719 --> 00:18:42,552 Okay. 349 00:18:42,552 --> 00:18:45,050 So what this has done is it has installed 350 00:18:45,050 --> 00:18:48,800 Flask-JWT, Flask-SQLAlchemy, uwsgi, psycopg2, 351 00:18:50,964 --> 00:18:53,230 itsdangerous, which is part of Flask, 352 00:18:53,230 --> 00:18:57,397 aniso8601, which is for dates and the iso standard, 353 00:18:59,378 --> 00:19:01,874 SQLAlchemy and MarkupSafe, which is also part of Flask. 354 00:19:01,874 --> 00:19:05,484 So it's installed everything that we need to run our app. 355 00:19:05,484 --> 00:19:07,058 Okay. 356 00:19:07,058 --> 00:19:08,651 Now, the next thing we have to do 357 00:19:08,651 --> 00:19:12,136 is set up uwsgi so that our application 358 00:19:12,136 --> 00:19:15,909 can communicate with uwsgi and Nginx can communicate 359 00:19:15,909 --> 00:19:19,125 with uwsgi to create a complete chain. 360 00:19:19,125 --> 00:19:20,575 And we're going to do that in the next video, 361 00:19:20,575 --> 00:19:22,552 because this one is getting pretty long, 362 00:19:22,552 --> 00:19:23,552 and so yeah. 363 00:19:24,492 --> 00:19:27,554 So if you have any problems up until now, let me know. 364 00:19:27,554 --> 00:19:31,576 It's very important that we don't get stuck in here. 365 00:19:31,576 --> 00:19:34,670 Without further adieu, I'll see you in the very next video.