ddev: Project start fails after update to 1.18.0 with custom Dockerfile

Diagnostic: https://gist.github.com/pminf/42da8afc08a62ddf8461a112c0e8fe57

Describe the bug After updating to 1.18.0 I’m unable to start any of my existing projects. They all fail with

Failed to start foo: container failed to become healthy: err=container /ddev-foo is unhealthy: phpstatus: FAILED /var/www/html: OK mailhog: FAILED

There seems to be a problem with apache:

[pid 1946] (13)Permission denied: AH00023: Couldn't create the mpm-accept mutex (file /var/lock/apache2/mpm-accept-0.1946)
(13)Permission denied: could not create accept mutex

If I’m switching the webserver-type from apache-fpm to nginx-fpm it’s starting without problems.

To Reproduce I’m able to reproduce it in a clean quickstart project (steps: https://ddev.readthedocs.io/en/stable/users/cli-usage/#php-project-quickstart) plus a custom Dockerfile (attached). The Dockerfile seems to make the difference because without it ddev does start without failure.

Expected behavior Just start within seconds as usual.

Version and configuration information

• Host computer OS and Version: Microsoft Windows 10 Pro (Version 10.0.19043 Build 19043) with WSL2 and Ubuntu 20.04
• Docker Desktop version: 4.0.1
• ddev version information:

DDEV version    v1.18.0
 architecture    amd64
 db              drud/ddev-dbserver-mariadb-10.3:v1.18.0
 dba             phpmyadmin:5
 ddev-ssh-agent  drud/ddev-ssh-agent:v1.18.0
 docker          20.10.8
 docker-compose  1.29.2
 mutagen         0.12.0-beta7
 os              linux
 router          drud/ddev-router:v1.18.0
 web             drud/ddev-webserver:v1.18.0

• config.yaml contents for the misbehaving project (the part before the comments):

name: foo
type: php
docroot: web
php_version: "7.4"
webserver_type: apache-fpm
router_http_port: "80"
router_https_port: "443"
xdebug_enabled: false
additional_hostnames: []
additional_fqdns: []
mariadb_version: "10.2"
mysql_version: ""
provider: default
use_dns_when_possible: true
composer_version: "1"

• Do you have any custom configuration (nginx, php, mysql) in the .ddev folder? If so, have you tried without them? Dockerfile (it’s working fine without it):

# You can copy this Dockerfile.example to Dockerfile to add configuration
# or packages or anything else to your webimage
ARG BASE_IMAGE=drud/ddev-webserver
FROM $BASE_IMAGE
RUN apt-get update

# basics
RUN apt-get install -y openssl curl dirmngr gnupg2

# basics
RUN apt-get install -y \
    openssl \
    curl \
    dirmngr \
    gnupg2 \
    locales \
    python3-pip

# install RVM, Ruby, and Bundler
# https://stackoverflow.com/questions/61787926/how-can-i-get-sass-compass-into-the-ddev-web-container
RUN apt-get update
RUN DEBIAN_FRONTEND=noninteractive apt-get install -y -o Dpkg::Options::="--force-confold" --no-install-recommends --no-install-suggests build-essential ruby-full rubygems
RUN gem install compass

# Install frontend development tools
RUN npm install grunt grunt-cli \
 && npm install -g \
    grunt \
    grunt-cli \
    gulp

# German locales
RUN sed -i -e 's/# de_DE.UTF-8 UTF-8/de_DE.UTF-8 UTF-8/' /etc/locale.gen \
 && echo 'LANG="de_DE.UTF-8"' > /etc/default/locale \
 && dpkg-reconfigure --frontend=noninteractive locales \
 && update-locale LANG=de_DE.UTF-8
ENV LANG de_DE.UTF-8

# Install Python modules
RUN apt-get install -y \
    python3-pip
RUN pip3 install paramiko