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General

Find out if I am inside a Docker container​

PHP example

public function __construct()
{
  // if I am inside a Docker container, use other path than if I am on a real system
  if (file_exists('/.dockerenv'))
  {
    $this->env = Yaml::parseFile($_SERVER["DOCUMENT_ROOT"] . '/.env.yml');
  }
  else
  {
      $this->env = Yaml::parseFile(__DIR__ . '/../../.env.yml');
  }
}

Bash example

#!/bin/bash
if [ -f /.dockerenv ]; then
    echo "I'm inside a container ;(";
else
    echo "I'm living in real world!";
fi

Update container restart policy​

CONTAINER_NAME="my_container"
sudo docker update --restart=always $CONTAINER_NAME

Access host services​

Use host.docker.internal or default gateway of the Docker interface

Clear local Docker data and shrink virtual storage​

On Windows, run Powershell as adminstrator

# Can also be done from Docker Desktop
docker system prune -a -f

# Shrinks the Docker virtual disk, path to the vhdx file may vary between systems
Optimize-VHD -Path "$env:localappdata\Docker\wsl\data\ext4.vhdx" -Mode Full