Shulou(Shulou.com)06/02 Report--

Python web is deployed as follows: nginx + gunicorn + supervisor + flask

First, to prepare the work, first install pip

Detailed tutorials such as:

1. First check whether python-pip package is installed in linux, and then execute yum install python-pip directly.

Display No package python-pip available. If not, continue as follows

2. Execute the command yum-y install epel-release without python-pip package

3. After the execution is successful, execute yum install python-pip again

4. Upgrade the installed pip pip install-upgrade pip

At this point, the pip tool is installed.

Create a project and python virtual environment

Create a virtual environment using python's virtualenv. Used to create different python isolated environments in one system. It doesn't affect each other, and it's quite easy to use.

Mkdir myflaskcd myflaskvirtualenv venv

Once you have created the venv environment, activate it

Source venv/bin/activate

3. Install the python web framework-flask

Flask is a lightweight python web framework that is simple and efficient. Flask relies on two libraries, werkzeug and jinjia2. Can be installed in pip mode:

Pip install flask

Test our flask installation and write a simple web service using flask.

Vim run.py

From flask import Flaskapp = Flask (_ _ name__) @ app.route ('/') def index (): return 'hello Worldwide worldly situations created if _ _ name__ =' _ _ main__': app.run ()

Start flask

Python run.py

At this point, visit http://127.0.0.1:5000 with a browser and you can see the web page showing hello world!

Third, deploy python web using gunicorn

Now we have completed the startup of the web service using the server that comes with flask. In a production environment, the server that comes with flask cannot meet the performance requirements. We use gunicorn as the wsgi container here to deploy python and install it directly with pip.

Pip install gunicorn

Pip is an important tool that python uses to manage packages. Each time you install a new library and write it into a requirement file, you can not only know what libraries you have installed, but also make it convenient for others to install the corresponding libraries when deploying them.

Pip freeze > requirements.txt

Every time pip installs a new library, you need to freeze it. Save the requirement text completely, and reinstall the library by doing the following:

Pip install-r requirements.txt

When we have installed gunicorn, we need to start flask with gunicorn. Notice that the code in name in flask starts app.run (), which means to start app with the server that comes with flask. Here we use gunicorn,run.py, which is equivalent to a library file that is called by gunicorn.

Number of gunicorn-w4-b0.0.0.0 5000 run:app #-w worker-b access address

At this point, we can access it using port 5000.

To end the gunicorn, all you have to do is execute pkill gunicorn, and sometimes you need to use ps to find the pid process number to kill.

4. Use nginx

Nginx, a high-performance web server. It is usually used as a reverse proxy server at the front end. Proxy service, in short, a request is sent from the local area network through the proxy server and then reaches the server on the Internet. The proxy for this process is the forward agent. If a request comes from the Internet, it first enters the proxy server, and then it is forwarded by the proxy server to the target server of the local area network. At this time, the proxy server is a reverse proxy (relatively forward).

1. Gcc installation

To install nginx, you need to compile the source code downloaded from the official website. The compilation depends on the gcc environment. If there is no gcc environment, you need to install:

Yum install gcc-c++

2. PCRE pcre-devel installation

PCRE (Perl Compatible Regular Expressions) is a Perl library, including a perl-compatible library of regular expressions. Nginx's http module uses pcre to parse regular expressions, so you need to install the pcre library on linux. Pcre-devel is a secondary development library developed using pcre. This library is also required for nginx. Command:

Yum install-y pcre pcre-devel

3. Zlib installation

The zlib library provides many ways to compress and decompress. Nginx uses zlib to gzip the contents of the http package, so you need to install the zlib library on Centos.

Yum install-y zlib zlib-devel

4. OpenSSL installation

OpenSSL is a powerful secure socket layer cipher library that includes major cryptographic algorithms, commonly used key and certificate encapsulation management functions, and SSL protocols, and provides rich applications for testing or other purposes.

Nginx supports not only the http protocol, but also https (that is, http over the ssl protocol), so you need to install the OpenSSL library on Centos.

Yum install-y openssl openssl-devel

5. Use wget to download nginx:

Wget https://nginx.org/download/nginx-1.13.12.tar.gztar-zxvf nginx-1.13.12.tar.gzcd nginx-1.13.12make make install # compilation and installation

Then configure Nginx. After installing Nginx just now, we open / etc/nginx/conf.d/default.conf and change the default default.conf to:

Server {listen 80; server_name localhost; location / {proxy_pass http://127.0.0.1:5000; proxy_redirect off; proxy_set_header Host $host:80; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;}}

Server_name is your domain name. Here, use localhost to represent access through ip. After configuring default.conf, try to start Nginx!

[root@server ~] # service nginx startStarting nginx: [OK] [root@server ~] # nginx-s reload

Ok! At this point, the whole deployment process is complete!

6. Use supervisor to facilitate management

1. Install supervisor

Pip install supervisorecho_supervisord_conf > supervisor.conf # generate supervisor default configuration file vim supervisor.conf # modify supervisor configuration file, add gunicorn and nginx

two。 Add gunicorn to supervisor and add to the bottom of the configuration. Because the python virtual environment is used here, you can first find the gunicorn address in the virtual environment. Use whereis such as: / usr/local/bin/gunicorn, and remember to add this location to the command of supervisor, as follows:

[program:myflask] command = / usr/local/bin/gunicorn-w4-b0.0.0.0run:appdirectory 5000 run:appdirectory = / home/myflask # location autostart = true # Auto start startsecs = 5autorestart = true # automatic restart startretries = 3 # maximum number of retries redirect_stderr = true # redirect stderr to stdoutstdout_logfile = / var/log/flask_supervisor.log

3. Add nginx process to supervisor

Create a new log folder first

Mkdir / home/myflask/ log [program: up_nginx] command = / usr/sbin/nginxautostart = true # start with supervisord startup autorestart = true # automatic restart startretries = 10 # maximum number of retries on startup failure exitcodes = 0 # normal exit code stopsignal = KILL # signal used to kill the process stopwaitsecs = 10 # wait time before sending SIGKILL redirect_stderr = true # Redirect stderr to stdoutstdout_logfile = / home/myflask/log/nginx.logstdout_logfile = / home/myflask/log/nginx.err

4. Enable supervisor management tools

Supervisord-c supervisord.conf#sudo unlink / tmp/supervisor.sock # if the startup fails above, use this command first and then use the above command supervisorctl start all

At this point, all the configurations are over. Try to see if the website is working properly, and you can also add supervisor boot self-boot (this is not tested, let's try it):

# Boot task automatically starts vi / etc/rc.d/rc.local # and adds supervisord-c / home/myflask/supervisord.conf# at the end: through the above steps, then you can basically open the startup website! Reboot, try ~ ~

Basic commands for using supervisor

Supervisord-c supervisor.conf # start supervisorsupervisorctl status through the configuration file # View the status of the supervisor supervisorctl reload # reload the configuration file supervisorctl start [all] | [appname] # start the specified / all supervisor managed program processes supervisorctl stop [all] | [appname] # close the specified / all supervisor managed program processes

The above is the whole content of this article, I hope it will be helpful to your study, and I also hope that you will support it.

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