Shulou(Shulou.com)05/31 Report--

This article mainly introduces the relevant knowledge of "how CentOS deploys flask project". The editor shows you the operation process through an actual case. The operation method is simple, fast and practical. I hope this article "how CentOS deploys flask project" can help you solve the problem.

Premise

There is a server (otherwise what will happen). You can refer to the high-quality foreign vps recommendation for purchase.

There is a personal domain name (of course, you can access it directly using ip, but it's a little strange, isn't it? To purchase a domain name, you can go to godaddy.

1. Install git

You can choose github or bitbucket, of course, you can also build your own git server, but I don't think it's necessary. I chose bitbucket mainly because its private library is free.

Sudo yum install git

After that, it is no different from our local development. If you configure the ssh key,clone code, you will not expand it. It is recommended to put the project directory under / home/www/.

two。 Install mysql

Add mysql yum Feed

$wget 'https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm'$sudo rpm-uvh mysql57-community-release-el7-11.noarch.rpm$yum repolist all | grep mysqlmysql-connectors-community/x86_64 mysql connectors community 36mysql-tools-community/x86_64 mysql tools community 47mysql57-community/x86_64 mysql 5.7 community server 187

Install the latest version

$sudo yum install mysql-community-server

Start the mysql service

$sudo service mysqld start $sudo systemctl start mysqld # centos 7$ sudo systemctl status mysqld ● mysqld.service-mysql community server loaded: loaded (/ usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled) active: active (running) since sat 2017-05-27 12:56:26 cst 15s ago process: 2482 execstartpost=/usr/bin/mysql-systemd-start post (code=exited, status=0/success) process: 2421 execstartpre=/usr/bin/mysql-systemd-start pre (code=exited, status=0/success) main pid: 2481 (mysqld_safe) cgroup: / system.slice/mysqld.service ├─ 2481 / bin/sh / usr/bin/mysqld_safe-- basedir=/usr └─ 2647 / usr/sbin/mysqld-- basedir=/usr-- datadir=/var/lib/mysql-- plugin-dir=/usr/...

It means it's already running.

Modify the password

$mysql-uroot-p

You are required to enter a password here. When mysql is installed, a default password will be generated. Use the grep "temporary password" / var/log/mysqld.log command to return the result. The string after the last quotation marks is the default password of root.

Mysql > alter user 'root'@'localhost' identified by' newpassword'

Modify the code

Set the default encoding in / etc/my.cnf

[client] default-character-set = UTF8 [mysqld] default-storage-engine = innodbcharacter-set-server = utf8collation-server = utf8_general_ci # case-insensitive collation-server = utf8_bin # case-sensitive collation-server = utf8_unicode_ci # is more accurate than utf8_general_ci

Create a database

Mysql > create database character set utf8

3. Install python3 pip3

Centos 7 has python 2 installed by default, and when you need to use python 3, you can manually download the python source code and compile and install it.

Install python 3

Sudo mkdir / usr/local/python3 # create installation directory $wget-- no-check-certificate https://www.python.org/ftp/python/3.6.2/python-3.6.2.tgz # download python source file # Note: when wget acquires https, add:-- no-check-certifica$ tar-xzvf python-3.6.2.tgz # extract package $cd python-3.6.2 # enter the decompression directory Record sudo. / configure-- prefix=/usr/local/python3 # specifies the directory created by sudo makesudo make install # to compile and install

There may be an error when executing. / configure, configure: error: no acceptable c compiler found in $path, this is because the appropriate compiler is not installed, just install it

Sudo yum install gcc-c++ (gcc and other dependent packages are automatically installed / upgraded when using sudo yum install gcc-c++.)

Configure two versions to coexist

Create a soft link for python3:

$sudo ln-s / usr/local/python3/bin/python3 / usr/bin/python3

This allows you to use python 2, python3, using the python command to use python3.

Install pip

$sudo yum-y install epel-release # first install the epel extension source $sudo yum-y install python-pip # install python-pip$ sudo yum clean all # clear cache

It seems that you can only install pip2 in this way. If you want to install pip for python 3, you can install it through the following source code.

# download the source code $wget-- no-check-certificate https://github.com/pypa/pip/archive/9.0.1.tar.gz$ tar-zvxf 9.0.1.tar.gz # extract the file $cd pip-9.0.1 $python3 setup.py install # install using python3

Create a link:

$sudo ln-s / usr/local/python3/bin/pip / usr/bin/pip3

Upgrade pip

$pip install-upgrade pip

4. Install gunicorn

Gunicorn (unicorn) is an efficient python wsgi server that is usually used to run wsgi application (written by ourselves to follow the wsgi application writing specification) or wsgi framework (such as django,paster), which is the equivalent of tomcat in java. Wsgi is such a protocol: it is an interface between python programs and user requests. The function of the wsgi server is to accept and analyze the user's request, call the corresponding python object to complete the processing of the request, and then return the corresponding result. To put it simply, gunicorn encapsulates the underlying implementation of http. We start the service through gunicorn, and the user requests and services are transmitted through gunicorn.

Create a virtual environment

Cd / home/www/blogmkdir venvpython3-m venv venv

Activate the virtual environment:

Source venv/bin/activate

Then install the dependency package according to the requirements.txt file:

Pip3 install-r requirements.txt

Install gunicorn

Pip3 install gunicorn

Create a wsgi.py file in the project root directory

From app import create_appapplication = create_app ('production') if _ _ name__ = =' _ main__': application.run ()

No longer start the service through manage.py, that is only used during development

Start the service:

Gunicorn-w 4-b 127.0.0.1 8000 wsgi:application

5. Install nginx

Nginx is a high-performance web server. It is usually used as a reverse proxy server at the front end. The so-called forward and reverse (reverse) is only the translation of English expressions. 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).

Forward proxy: {client-"proxy server} -" server

Reverse proxy: client-"{proxy server -" server}

{} represents a local area network

Nginx can do both forward and reverse.

$yum-y install nginx

Start the nginx service

$service nginx start

Stop the nginx service

$service nginx stop

Restart the nginx service

$service nginx restart

Smooth restart

The nginx configuration has been changed and can be reloaded without having to close and then open it.

$nginx-s reload

After startup, enter the ip address of the server in the browser, and you can see

Here, the yum installation of nginx is complete.

Add configuration

The configuration file for nginx is: / etc/nginx/nginx.conf

Server {listen 80; server_name adisonhyh.com; location / {proxy_pass http://127.0.0.1:8000; proxy_set_header host $host; proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;}}

Listen to the default port number of http 80

Server_name: domain name of personal website

Agent the request to port 8000 of the machine (the port specified by the gunicorn startup service) and copy it with proxy_set_header.

Relationship between gunicorn and nginx:

Gunicorn can provide services separately, but production environments generally do not. First of all, static resources (jscssimg) will take up a lot of request resources, but for gunicorn itself, it should pay more attention to the actual business requests and processing rather than waste resources on static resource requests; in addition, it is impossible to run gunicorn alone with multiple processes and multiple ports to load balance.

The role of nginx is to make up for the above problems. First of all, as a front-end server, it can handle all static file requests. When gunicorn is a back-end server, nginx will forward dynamic requests to the back-end server, so we can start multiple gunicorn processes, and then let nginx balance the load to forward requests to multiple gunicorn processes to improve server processing efficiency and processing capacity. Finally, nginx can also configure a lot of security-related, authentication-related processing, so that your website can pay more attention to the writing of business, and leave some forwarding rules and other business-related things to nginx to do.

After configuration, open the local browser, enter the domain name, and you should be able to access it.

6.supervisor

Supervisor is a good choice if you need the process to be executed all the time, and if the process is interrupted for various reasons and will restart automatically. The supervisor management process starts these managed processes as child processes of supervisor by fork/exec, so we only need to add the path of the executable file of the management process to the configuration file of supervisor. At this time, the managed process is regarded as a child process of supervisor. If the child process has an abnormal terminal, the parent process can accurately obtain the information of the abnormal terminal of the child process. By setting autostart=true in the configuration file, the child process with abnormal interruption can be restarted automatically.

Install supervisor

$pip install supervisor$ echo_supervisord_conf > supervisor.conf # generate supervisor default configuration file $vim supervisor.conf # modify supervisor configuration file and add gunicorn process management

Add at the bottom of the blog supervisor.conf configuration file (note that my work path is www/home/blog/)

[program:blog] command=/home/www/blog/venv/bin/gunicorn-w4-b0.0.0.0 supervisor 8000 wsgi:application; supervisor startup command directory=/home/www/blog; project folder path startsecs=0; startup time stopwaitsecs=0 Stop waiting time autostart=false; whether to automatically start autorestart=false; whether to automatically restart stdout_logfile=/home/www/blog/logs/gunicorn.log; log log stderr _ logfile=/home/www/blog/logs/gunicorn.err; error log

Start gunicorn using supervsior

$sudo supervisord-c supervisor.conf $sudo supervisorctl start blog

Enter the configured address in the browser address bar to access the website.

7. Fabric

As a final step, we use fabric for remote operation and deployment. Fabric is a tool similar to makefiles under python, but can execute commands on a remote server.

Install fabric

Pip install fabric

Create a new fabfile.py file in the blog directory

Import osfrom fabric.api import local, env, run, cd, sudo, prefix, settings, execute, task, putfrom fabric.contrib.files import existsfrom contextlib import contextmanagerenv.hosts = ['204.152.201.69'] env.user =' root'env.password ='*'# password env.group = "root" deploy_dir ='/ home/www/blog'venv_dir = os.path.join (deploy_dir, 'venv') venv_path = os.path.join (venv_dir Bin/activate') @ contextmanagerdef source_virtualenv (): with prefix ("source {}" .format (venv_path)): yielddef update (): with cd ('/ home/www/blog/'): sudo ('git pull') def restart (): with cd (deploy_dir): if not exists (venv_dir): run ("virtualenv {}" .format (venv_dir)) with settings (warn_only=true): With source_virtualenv (): run ("pip install-r {} / requirements.txt" .format (deploy_dir)) with settings (warn_only=true): stop_result = sudo ("supervisorctl-c {} / supervisor.conf stop all" .format (deploy_dir)) if not stop_result.failed: kill_result = sudo ("pkill supervisor") if not kill_result: Sudo ("supervisord-c {} / supervisor.conf" .format (deploy_dir)) sudo ("supervisorctl-c {} / supervisor.conf reload" .format (deploy_dir)) sudo ("supervisorctl-c {} / supervisor.conf status" .format (deploy_dir)) sudo ("supervisorctl-c {} / supervisor.conf start all" .format (deploy_dir)) @ taskdef deploy (): execute (update) execute (restart)

Now if the code is updated, you can perform remote deployment directly locally.

This is the end of fab deploy's introduction to "how CentOS deploys the flask project". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.