Вывод ошибок php docker

But first, you need to redirect your log streams to the output of the Docker container to be able to use them.

Linux streams

Docker containers are running the Linux processes. In linux every running process has 3 streams, STDIN, STDOUT, STDERR. STDIN it’s command input stream, that you can provide for ex. by your keyboard. STDOUT is the stream where the running command may print the output. STDERR is the standard error stream, but the name I think is a bit confusing, because it is basically intended for diagnostic output.

When you run the docker logs [container] command in your terminal, you will see the output of STDOUT and STDERR streams. So our goal is to redirect our logs to one of those streams.

Official docker documentation page

PHP-FPM

In PHP we are often running our application using the PHP-FPM (Process Manager). If you run your docker with FPM inside a docker container, and you run the docker logs command, you should see the output with processed requests, or errors.

[global]
error_log = /proc/self/fd/2

[www]
access.log = /proc/self/fd/2

catch_workers_output = yes
decorate_workers_output = no

[21-Mar-2016 14:10:02] WARNING: [pool www] child 12 said into stdout: "[your log line]"

Remember that decorate_workers_output option is available only for PHP 7.3.0 and higher.

If you are using official docker php-fpm image, this configuration is already set in the /usr/local/etc/php-fpm.d/docker.conf file, so you no need to do anything more 😎

PHP application configuration

Right now everything that will be put to the stdout from PHP workers will be shown in our docker logs. But when logs are forwarded to that stream in PHP?

To write something to STDIN on PHP level, we need to just write to the php://stdout stream.

In the simplest way you can do this like that:

<?php

file_put_contents('php://stdout', 'Hello world');

When you execute this code in php cli, you will get the Hello world text on the output.

But it’s not the optimal way to push your logs to the STDOUT. Every modern framework should have a PSR-3 Logger. I think that the most popular now is the monolog, so I will show you how to configure it in Symfony, Laravel, and in pure usage.

Monolog

Monolog is great library to handle logs in your application. It’s easy and elastic in configuration.

Basic monolog configuration

If you are using monolog in your project with manual configuration, you need to configure handler in this way:

(Modified documentation example)

<?php

use MonologLogger;
use MonologHandlerStreamHandler;

$log = new Logger('stdout');
$log->pushHandler(new StreamHandler('php://stdout', Logger::DEBUG));

$log->debug('Foo');

You just need to configure StreamHandler, to write to the php://stdout file.

Symfony

Symfony Kernel since the Flex was provided, is using minimalist PSR-3 logger, that logs everything to php://stderr by default.

In Symfony, monolog as other components is configured in YAML files. So the same configuration will look like this:

# config/packages/monolog.yaml
monolog:
    handlers:
        stdout:
            type: stream
            path: "php://stdout"
            level: debug

Laravel

Laravel use the arrays for configuration so the same thing will look like this:

# config/logging.php
<?php

use MonologHandlerStreamHandler;

return [
    'channels' =>
        'stdout' => [
            'driver' => 'monolog',
            'handler' => StreamHandler::class,
            'level' => env('LOG_LEVEL', 'debug'),
            'with' => [
                'stream' => 'php://stdout',
            ],
        ],
];

STDERR or STDOUT

Personally, I always used the stdout, so that’s the reason why I use it in this post’s examples. If I will find a great reason for using one of them over another I will update this post.

Originally posted on https://mateuszcholewka.com

Before we start…

The previous post about dockerising a PHP application (which you should read if you haven’t) got a lot more attention than I ever imagined, which is AWESOME. However, while introducing some of  the suggested improvements a number discrepencies between the contents of the blog post and the GitHub repository emerged. Buuut…

The death of php-docker.local

The initial setup included a step that required you to update your hosts file and add an entry for php-docker.local. I received feedback from several people that this step is not completely clear and they ended up skipping it. It turns out this step can be removed easily, so why don’t we just go ahead and do it 🙂

Two things are needed to achieve this. First, we have to update the site.conf in order to handle the connections to localhost. Second, the default configuration in the Nginx image should be replaced with our new config.
For the first part we have to replace the server_name setting with:

    server_name localhost;

and add the following setting:

    listen 80;

Now our site.conf will look like this:

server {
    listen 80;
    index index.php index.html;
    server_name localhost;
    error_log  /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;
    root /code;

    location ~ .php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(.+.php)(/.+)$;
        fastcgi_pass php:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
}

In order to replace the default Nginx config we have to mount our site.conf in its place. To achieve that we have to tweak our docker-compose.yml a bit. The end result will look like this:

web:
    image: nginx:latest
    ports:
        - "8080:80"
    volumes:
        - ./code:/code
        - ./site.conf:/etc/nginx/conf.d/default.conf
    links:
        - php
php:
    image: php:7-fpm
    volumes:
        - ./code:/code

For those who missed it, we changed one of the volumes for the web container with the following:

        - ./site.conf:/etc/nginx/conf.d/default.conf

Now your PHP application will be accessible on any domain pointing to your Docker host.

Docker-compose v2

For a while now docker-compose supports version 2 for the docker-compose files, which adds some improvements to the setup. Let’s see how the docker-compose.yml will look like using the new format:

version: 2

services:
    web:
        image: nginx:latest
        ports:
            - "8080:80"
        volumes:
            - ./code:/code
            - ./site.conf:/etc/nginx/conf.d/site.conf
    php:
        image: php:7-fpm
        volumes:
            - ./code:/code

This doesn’t look much different, except that we don’t have to specify the links between the containers. Docker-compose adds all the containers to the same network and they are “linked” by default. This is especially useful when you add more containers to the setup (e.g. database, cache, queue, etc.) since you don’t have to worry about specifing the links between containers.

Another thing the we can do using version 2 of the docker-compose files is to specify networks for the containers. For example:

version: 2

services:
    web:
        image: nginx:latest
        ports:
            - "8080:80"
        volumes:
            - ./code:/code
            - ./site.conf:/etc/nginx/conf.d/default.conf
        networks:
            - code-network
    php:
        image: php:fpm
        volumes:
            - ./code:/code
        networks:
            - code-network

networks:
    code-network:
        driver: bridge

This option allows grouping different containers in different networks based on the services they need to connect to. In our setup this is not needed, but I believe it’s an important feature to be aware of, especially when expanding the setup with more services.

Special thanks to cipriantepes, who contributed to the repository with this improvement.

PHP logging to stdout

This is something trivial but I never really thought it’s needed until I got several requests and even a PR for it. The issue is that the default php-fpm Docker image is not configured to log the errors. The fix is to enable logging.

First, let’s add a log.conf file with the following content:

php_admin_flag[log_errors] = on
php_flag[display_errors] = off

Next, add this to the configuration of the PHP container:

 version: '2'

services:
    web:
        image: nginx:latest
        ports:
            - "8080:80"
        volumes:
            - ./code:/code
            - ./site.conf:/etc/nginx/conf.d/default.conf
        networks:
            - code-network
    php:
        image: php:fpm
        volumes:
            - ./code:/code
            - ./log.conf:/usr/local/etc/php-fpm.d/zz-log.conf
        networks:
            - code-network

networks:
    code-network:
        driver: bridge

So… what happened? Well, we mounted our new log file in the PHP container, but we added a zz- prefix to it. Why? Because we want to have this configuration loaded last, so that it’s not overriden by the rest of the configs.
Here’s the line for the curious:

            - ./log.conf:/usr/local/etc/php-fpm.d/zz-log.conf

Since this wasn’t part of the initial blog post, it resides in a separate branch – feature/log-to-stdout.

Final summation

I guess no matter how good you make something, there’s always room for improvement. In that sense, any remarks and PRs are more than welcome 🙂

You can find the updated code here – https://github.com/mikechernev/dockerised-php

this is my docker-compose.yml:

services:
 nginx:
 image: nginx:stable-alpine
 container_name: nginx
 ports:
            - "8088:8088"
            - "80:80" 
 volumes:            
            - ./php-fpm:/var/www/html 
            - ./nginx/default.conf:/etc/nginx/conf.d/default.conf
php:        
 build:
 context: ./php-fpm
 dockerfile: Dockerfile
 container_name: php
 user: "1000:1000"
 volumes:
            - ./php-fpm:/var/www/html
 ports:
            - "9000:9000""

This is my nginx default.conf:

server {
    listen 8088;
    index index.php index.html;    
    error_log /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;
    root /var/www/html/public;
    
    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }
    
    location ~ .php$ {        
        try_files $uri = 404;
        fastcgi_split_path_info ^(.+.php)(/.+)$;
        fastcgi_pass php:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }
    
}

}

Can’t find the error log inside the containers…