#69 Add Xdebug to existing PHP container projects
Introduction
I found out there are many outdated setup articles which may not work for the Xdebug 3.1.X version. Therefore I jot down the setup of PHP with Xdebug and docker.
Setup
edit dockerfile to install xdebug
RUN pecl install xdebug && docker-php-ext-enable xdebug
copy xdebug config to php config folder
[xdebug]
xdebug.mode=off
xdebug.start_with_request = yes
xdebug.client_host = "host.docker.internal"
xdebug.idekey="VSCODE"
In docker-compose.yml
, add host.docker.internal
to extra_hosts
as follow
services:
app:
extra_hosts:
- host.docker.internal:host-gateway
open vscode and create a launch.json file
make sure the attribute pathMappings
is set correctly.
If you have installed the Remote Development extension from Microsoft, you may face an issue that the breakpoint does not work because of the wrong pathMappings
.
"the path of project in container":"${workspaceFolder}"
After you Attach to Running Container
, your vscode is "working" inside the container and your pathMappings
should be like this.
"${workspaceFolder}":"${workspaceFolder}"
Things should be working right now and you can try adding breakpoints to check whether the process is broken correctly.
Explaination
extra_hosts:
- it adds hostname mappings to the container network interface configuration. Entries will be added to the container
/etc/hosts
file
host.docker.internal:
- Docker has defined a special magic DNS,
host.docker.internal
, that every service on the host can be accessed from the container athost.docker.internal
host-gateway:
- A special string which points to the host gateway.
Now we know host.docker.internal:host-gateway
in extra_hosts
is going to map host.docker.internal
to the host's gateway which the container can connect the services running from outside.
To sum up
It seems that there are not many articles and blogs discussing the Xdebug with docker, so it is a memo to remind myself if I need to have the same setup in the future.
Discussion