If no configuration file is passed to platydock generate a minimal Dockerfile.

platypush/install/docker/alpine.Dockerfile

@@ -1,8 +1,12 @@
 FROM alpine
+
 ADD . /install
 WORKDIR /var/lib/platypush
 
-RUN DOCKER_CTX=1 /install/platypush/install/scripts/alpine/install.sh
+ARG DOCKER_CTX=1
+ENV DOCKER_CTX=1
+
+RUN /install/platypush/install/scripts/alpine/install.sh
 RUN cd /install && pip install -U --no-input --no-cache-dir .
 RUN rm -rf /install
 
@@ -11,4 +15,7 @@ EXPOSE 8008
 VOLUME /etc/platypush
 VOLUME /var/lib/platypush
 
-CMD /run.sh
+CMD platypush \
+  --start-redis \
+  --config /etc/platypush/config.yaml \
+  --workdir /var/lib/platypush

platypush/install/docker/debian.Dockerfile

@@ -1,10 +1,16 @@
 FROM debian
+
 ADD . /install
 WORKDIR /var/lib/platypush
 
+ARG DEBIAN_FRONTEND=noninteractive
+ENV DEBIAN_FRONTEND=noninteractive
+ARG DOCKER_CTX=1
+ENV DOCKER_CTX=1
+
 RUN apt update
-RUN DOCKER_CTX=1 /install/platypush/install/scripts/debian/install.sh
-RUN cd /install && pip install -U --no-input --no-cache-dir .
+RUN /install/platypush/install/scripts/debian/install.sh
+RUN cd /install && pip install -U --no-input --no-cache-dir . --break-system-packages
 RUN rm -rf /install
 RUN apt autoclean -y
 RUN apt autoremove -y
@@ -15,4 +21,7 @@ EXPOSE 8008
 VOLUME /etc/platypush
 VOLUME /var/lib/platypush
 
-CMD /run.sh
+CMD platypush \
+  --start-redis \
+  --config /etc/platypush/config.yaml \
+  --workdir /var/lib/platypush

platypush/install/docker/ubuntu.Dockerfile

@@ -1,9 +1,15 @@
 FROM ubuntu
+
 ADD . /install
 WORKDIR /var/lib/platypush
 
+ARG DEBIAN_FRONTEND=noninteractive
+ENV DEBIAN_FRONTEND=noninteractive
+ARG DOCKER_CTX=1
+ENV DOCKER_CTX=1
+
 RUN apt update
-RUN DOCKER_CTX=1 /install/platypush/install/scripts/debian/install.sh
+RUN /install/platypush/install/scripts/debian/install.sh
 RUN cd /install && pip install -U --no-input --no-cache-dir .
 RUN rm -rf /install
 RUN apt autoclean -y
@@ -15,4 +21,7 @@ EXPOSE 8008
 VOLUME /etc/platypush
 VOLUME /var/lib/platypush
 
-CMD /run.sh
+CMD platypush \
+  --start-redis \
+  --config /etc/platypush/config.yaml \
+  --workdir /var/lib/platypush

platypush/install/scripts/debian/PKGCMD

@@ -1 +1 @@
-DEBIAN_FRONTEND=noninteractive apt install -y
+apt install -y

platypush/install/scripts/docker-run.sh

@@ -1,8 +0,0 @@
-#!/bin/sh
-
-# This script is used as a default entry point for Docker containers
-
-DOCKER_CTX=1 platypush \
-  --start-redis \
-  --config /etc/platypush/config.yaml \
-  --workdir /var/lib/platypush

platypush/install/scripts/install.sh

@@ -14,15 +14,9 @@ CMD="$(cat "${SCRIPT_PATH}/PKGCMD")"
 REQUIREMENTS="$(cat "${SCRIPT_PATH}/../../requirements/${OS}.txt" | tr '\n' ' ')"
 SUDO=
 
-# If we are running in a Docker context then we want to copy the docker-run.sh
-# script where we can easily find it.
-if [ -n "$DOCKER_CTX" ]; then
-  cp -v /install/platypush/install/scripts/docker-run.sh /run.sh
-fi
-
 # If we aren't running in a Docker context, or the user is not root, we should
 # use sudo to install system packages.
-if [[ "$(id -u)" != "0" ]] || [ -z "$DOCKER_CTX" ]; then
+if [ $(id -u) -ne 0 ] || [ -z "$DOCKER_CTX" ]; then
   if ! type sudo >/dev/null; then
     echo "sudo executable not found, I can't install system packages" >&2
     exit 1

platypush/platydock/__init__.py

@@ -4,7 +4,6 @@ Dockerfile for Platypush starting from a configuration file.
 """
 
 import argparse
-from enum import Enum
 import inspect
 import os
 import pathlib
@@ -12,23 +11,12 @@ import sys
 from typing import Iterable
 
 from platypush.config import Config
-from platypush.utils.manifest import Dependencies, InstallContext, PackageManagers
-
-
-class BaseImage(Enum):
-    """
-    Supported base images for Dockerfiles.
-    """
-
-    ALPINE = 'alpine'
-    DEBIAN = 'debian'
-    UBUNTU = 'ubuntu'
-
-    def __str__(self) -> str:
-        """
-        Explicit __str__ override for argparse purposes.
-        """
-        return self.value
+from platypush.utils.manifest import (
+    BaseImage,
+    Dependencies,
+    InstallContext,
+    PackageManagers,
+)
 
 
 # pylint: disable=too-few-public-methods
@@ -67,6 +55,7 @@ class DockerfileGenerator:
             self.cfgfile,
             pkg_manager=pkg_manager,
             install_context=InstallContext.DOCKER,
+            base_image=self.image,
         )
 
         is_after_expose_cmd = False
@@ -135,7 +124,11 @@ def main():
         '-h', '--help', dest='show_usage', action='store_true', help='Show usage'
     )
     parser.add_argument(
-        'cfgfile', type=str, nargs='?', help='The path to the configuration file.'
+        'cfgfile',
+        type=str,
+        nargs='?',
+        help='The path to the configuration file. If not specified a minimal '
+        'Dockerfile with no extra dependencies will be generated.',
     )
     parser.add_argument(
         '--image',
@@ -154,11 +147,15 @@ def main():
         return 0
 
     if not opts.cfgfile:
+        opts.cfgfile = os.path.join(
+            str(pathlib.Path(inspect.getfile(Config)).parent),
+            'config.auto.yaml',
+        )
+
         print(
-            f'Please specify a configuration file.\nRun {sys.argv[0]} --help to get the available options.',
+            f'No configuration file specified. Using {opts.cfgfile}.',
             file=sys.stderr,
         )
-        return 1
 
     dockerfile = DockerfileGenerator(opts.cfgfile, image=opts.image).generate()
     print(dockerfile)

platypush/utils/manifest.py

@@ -31,6 +31,22 @@ _available_package_manager = None
 logger = logging.getLogger(__name__)
 
 
+class BaseImage(Enum):
+    """
+    Supported base images for Dockerfiles.
+    """
+
+    ALPINE = 'alpine'
+    DEBIAN = 'debian'
+    UBUNTU = 'ubuntu'
+
+    def __str__(self) -> str:
+        """
+        Explicit __str__ override for argparse purposes.
+        """
+        return self.value
+
+
 @dataclass
 class PackageManager:
     """
@@ -55,7 +71,7 @@ class PackageManagers(Enum):
 
     APT = PackageManager(
         executable='apt',
-        command=('DEBIAN_FRONTEND=noninteractive', 'apt', 'install', '-y'),
+        command=('apt', 'install', '-y'),
     )
 
     PACMAN = PackageManager(
@@ -142,6 +158,9 @@ class Dependencies:
     pkg_manager: Optional[PackageManagers] = None
     """ Override the default package manager detected on the system. """
     install_context: InstallContext = InstallContext.NONE
+    """ The installation context - Docker, virtual environment or bare metal. """
+    base_image: Optional[BaseImage] = None
+    """ Base image used in case of Docker installations. """
 
     @property
     def _is_venv(self) -> bool:
@@ -154,17 +173,34 @@ class Dependencies:
             self.install_context == InstallContext.VENV or sys.prefix != sys.base_prefix
         )
 
+    @property
+    def _is_docker(self) -> bool:
+        """
+        :return: True if the dependencies scanning logic is running either in a
+            Docker environment.
+        """
+        return (
+            self.install_context == InstallContext.DOCKER
+            or 'DOCKER_CTX' in os.environ
+            or os.path.isfile('/.dockerenv')
+        )
+
     @classmethod
     def from_config(
         cls,
         conf_file: Optional[str] = None,
         pkg_manager: Optional[PackageManagers] = None,
         install_context: InstallContext = InstallContext.NONE,
+        base_image: Optional[BaseImage] = None,
     ) -> "Dependencies":
         """
         Parse the required dependencies from a configuration file.
         """
-        deps = cls(pkg_manager=pkg_manager, install_context=install_context)
+        deps = cls(
+            pkg_manager=pkg_manager,
+            install_context=install_context,
+            base_image=base_image,
+        )
 
         for manifest in Manifests.by_config(conf_file, pkg_manager=pkg_manager):
             deps.before += manifest.install.before
@@ -179,7 +215,7 @@ class Dependencies:
         Generates the package manager commands required to install the given
         dependencies on the system.
         """
-        wants_sudo = self.install_context != InstallContext.DOCKER and os.getuid() != 0
+        wants_sudo = not (self._is_docker or os.getuid() == 0)
         pkg_manager = self.pkg_manager or PackageManagers.scan()
         if self.packages and pkg_manager:
             yield ' '.join(
@@ -196,8 +232,9 @@ class Dependencies:
         the system.
         """
         wants_break_system_packages = not (
-            # Docker installations shouldn't require --break-system-packages in pip
-            self.install_context == InstallContext.DOCKER
+            # Docker installations shouldn't require --break-system-packages in
+            # pip, except for Debian
+            (self._is_docker and self.base_image != BaseImage.DEBIAN)
             # --break-system-packages has been introduced in Python 3.10
             or sys.version_info < (3, 11)
             # If we're in a virtual environment then we don't need