Docker + Xdebug + VSCode Could not connect to client - php

Question

PHP version: 7.1.20
XDebug version: 2.7.0
I'm using a Docker container on MacOS Mojave.
On pressing "F5", it shows debug options Pause, Restart, and Stop. But Step Over, Step Into, Step Out are disabled.
I'm kind of learner because I was used to code till 2012-13 on Windows OS. After that year, I am back to coding this month. :) Even after reviewing a lot of posts on Google about how to resolve this issue, I'm not sure how to finally make it work. Please help.
My launch.json file:
{
"version": "0.2.0",
"configurations": [
{
"name": "Listen for XDebug",
"type": "php",
"request": "launch",
"port": 9001,
"log": true,
"pathMappings": {
"/var/www/html": "${workspaceFolder}/learn"
}
},
{
"name": "Launch currently open script",
"type": "php",
"request": "launch",
"program": "${file}",
"cwd": "${fileDirname}",
"port": 9001
}
]
}
XDebug php.ini config:
xdebug.remote_host = 172.20.0.1
xdebug.remote_port = 9001
xdebug.scream = 1
xdebug.remote_enable = 1
xdebug.show_local_vars = 1
xdebug.remote_autostart = 1
xdebug.remote_connect_back = 1
xdebug.remote_log = "/var/www/html/xdebug.log"
xdebug.idekey = "VSCODE"
XDebug logfile (from setting xdebug.remote_log in php.ini):
[12] Log opened at 2019-05-12 10:16:44
[12] I: Checking remote connect back address.
[12] I: Checking header 'HTTP_X_FORWARDED_FOR'.
[12] I: Checking header 'REMOTE_ADDR'.
[12] I: Remote address found, connecting to 172.20.0.1:9001.
[12] W: Creating socket for '172.20.0.1:9001', poll success, but error: Operation now in progress (29).
[12] E: Could not connect to client. :-(
[12] Log closed at 2019-05-12 10:16:44
Debug console:
<- launchResponse
Response {
seq: 0,
type: 'response',
request_seq: 2,
command: 'launch',
success: true }
Here's the dockerfile.
FROM php:7.1.20-apache
RUN apt-get -y update --fix-missing
RUN apt-get upgrade -y
# Install tools & libraries
RUN apt-get -y install apt-utils nano wget dialog \
build-essential git curl libcurl3 libcurl3-dev zip
# Install important libraries
RUN apt-get -y install --fix-missing apt-utils build-essential git curl libcurl3 libcurl3-dev zip \
libmcrypt-dev libsqlite3-dev libsqlite3-0 mysql-client zlib1g-dev \
libicu-dev libfreetype6-dev libjpeg62-turbo-dev libpng-dev
# Composer
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
# PHP Extensions
RUN pecl install xdebug-2.7.0 \
&& docker-php-ext-enable xdebug \
&& docker-php-ext-install mcrypt \
&& docker-php-ext-install pdo_mysql \
&& docker-php-ext-install pdo_sqlite \
&& docker-php-ext-install mysqli \
&& docker-php-ext-install curl \
&& docker-php-ext-install tokenizer \
&& docker-php-ext-install json \
&& docker-php-ext-install zip \
&& docker-php-ext-install -j$(nproc) intl \
&& docker-php-ext-install mbstring \
&& docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
&& docker-php-ext-install -j$(nproc) gd \
&& pecl install redis \
&& docker-php-ext-enable redis
# Enable apache modules
RUN a2enmod rewrite headers
ENTRYPOINT ["/usr/sbin/apache2ctl", "-D", "FOREGROUND"]
Here's the docker-compose.yml file.
version: "3"
services:
webserver:
build:
context: ./bin/webserver
container_name: '7.1.x-webserver'
restart: 'always'
ports:
- "80:80"
- "443:443"
links:
- mysql
volumes:
- ${DOCUMENT_ROOT-./www}:/var/www/html
- ${PHP_INI-./config/php/php.ini}:/usr/local/etc/php/php.ini
- ${VHOSTS_DIR-./config/vhosts}:/etc/apache2/sites-enabled
- ${LOG_DIR-./logs/apache2}:/var/log/apache2
mysql:
build: ./bin/mysql
container_name: '5.7-mysql'
restart: 'always'
ports:
- "3306:3306"
volumes:
- ${MYSQL_DATA_DIR-./data/mysql}:/var/lib/mysql
- ${MYSQL_LOG_DIR-./logs/mysql}:/var/log/mysql
environment:
MYSQL_ROOT_PASSWORD: tiger
phpmyadmin:
image: phpmyadmin/phpmyadmin
container_name: 'sc-phpmyadmin'
links:
- mysql
environment:
PMA_HOST: mysql
PMA_PORT: 3306
ports:
- '8080:80'
volumes:
- /sessions
redis:
container_name: 'sc-redis'
image: redis:latest
ports:
- "6379:6379"
Thank you in advance.

Answer 1

You can have your docker container connect to your host by configuring PHP appropriately.
Note that I've used Docker's host.docker.internal domain, that always points to the host IP.
xdebug.remote_enable=1
xdebug.remote_port=9000
xdebug.idekey=docker
xdebug.profiler_enable=0
xdebug.profiler_enable_trigger=1
xdebug.remote_host=host.docker.internal
There's no need to open ports to the docker container.
Just make sure that your debugging application can listen on the appointed port (9000 in my case) and that this port is not occupied.
Take for example this PhpStorm configuration:
Troubleshooting
Validate that xdebug is installed, run in the php container:
php -i | grep xdebug
Make sure that you're editing the appropriate .ini files, check:
php -i | grep \.ini
If you have idekey enabled, make sure to configure them in your IDE too:
There's a Debugger Config Validator in PhpStorm if you're exposing PHP scripts on a webserver:

Answer 2

Try to open port 9001 in the docker-compose.yml by inserting:
ports:
- "9001:9001"
Example
services:
webserver:
build:
context: ./bin/webserver
container_name: '7.1.x-webserver'
restart: 'always'
ports:
- "80:80"
- "443:443"
- "9001:9001"
links:
- mysql
volumes:
- ${DOCUMENT_ROOT-./www}:/var/www/html
- ${PHP_INI-./config/php/php.ini}:/usr/local/etc/php/php.ini
- ${VHOSTS_DIR-./config/vhosts}:/etc/apache2/sites-enabled
- ${LOG_DIR-./logs/apache2}:/var/log/apache2
See more about configuring docker-compose.yml: https://docs.docker.com/compose/compose-file/
You might be able to use expose. We have that in some of our old Dockerfiles which is intended to allow xDebug connections, but I haven't used it personally.
expose:
- "9001"

Answer 3

You should open port 9001 in your host machine, not in Docker.
Also try to check if Xdebug is configured properly: add phpinfo() to your code and open that page in browser. You shold see xdebug enabled
If Xdebug enabled, maybe your IDE settings are incorrect

Answer 4

For VSCode as the OP has asked and xdebug 3.x.x, the configuration should be -
xdebug.mode=debug
xdebug.start_with_request=yes
xdebug.start_upon_error=yes
xdebug.client_host=[IP address] <<<< NOTE
xdebug.discover_client_host=true
xdebug.client_port=9000
Note: xdebug.client_host should have the host IP address for vscode (192.168...) and not host.docker.internal which does not seem to work for vscode.
Note 2: There is no need to open any port (9000 in the config above) for this purpose. This could be because docker connects back to host at port 9000 and not vice versa!