Docker configuration for exercising Datasette behind Apache mod_proxy

[simonw]

Having a live demo running on Cloud Run that proxies through Apache and uses base_url would be incredibly useful for replicating and debugging this kind of thing. I wonder how hard it is to run Apache and mod_proxy in the same Docker container as Datasette?

Originally posted by @simonw in #1519 (comment)

[simonw]

This pattern looks like it can help: https://ahmet.im/blog/cloud-run-multiple-processes-easy-way/ - see example in https://github.com/ahmetb/multi-process-container-lazy-solution

I got that demo working locally like this:

cd /tmp
git clone https://github.com/ahmetb/multi-process-container-lazy-solution
cd multi-process-container-lazy-solution
docker build -t multi-process-container-lazy-solution .
docker run -p 5000:8080 --rm multi-process-container-lazy-solution

I want to use apache2 rather than nginx though. I found a few relevant examples of Apache in Alpine:

• https://github.com/Hacking-Lab/alpine-apache2-reverse-proxy/blob/master/Dockerfile
• https://www.sentiatechblog.com/running-apache-in-a-docker-container
• https://github.com/search?l=Dockerfile&q=alpine+apache2&type=code

[simonw]

I'll get this working on my laptop first, but then I want to get it up and running on Cloud Run - maybe with a GitHub Actions workflow in this repo that re-deploys it on manual execution.

[simonw]

From this example: https://github.com/tigelane/dockerfiles/blob/06cff2ac8cdc920ebd64f50965115eaa3d0afb84/Alpine-Apache2/Dockerfile#L25-L31 it looks like running apk add apache2 installs a config file at /etc/apache2/httpd.conf - so one approach is to then modify that file.

# APACHE - Alpine
#################
RUN apk --update add apache2 php5-apache2 && \
    #apk add openrc --no-cache && \
    rm -rf /var/cache/apk/* && \
    sed -i 's/#ServerName www.example.com:80/ServerName localhost/' /etc/apache2/httpd.conf && \
    mkdir -p /run/apache2/

# Upload our files from folder "dist".
COPY dist /var/www/localhost/htdocs

# Manually set up the apache environment variables
ENV APACHE_RUN_USER www-data
ENV APACHE_RUN_GROUP www-data
ENV APACHE_LOG_DIR /var/log/apache2
ENV APACHE_LOCK_DIR /var/lock/apache2
ENV APACHE_PID_FILE /var/run/apache2.pid

# Execute apache2 on run
########################
EXPOSE 80
ENTRYPOINT ["httpd"]
CMD ["-D", "FOREGROUND"]

I think I'll create my own separate copy and modify that.

[simonw]

Made myself this Dockerfile to let me explore a bit:

FROM python:3-alpine

RUN apk add --no-cache \
	apache2

CMD ["sh"]

Then:

% docker run alpine-apache2-sh
% docker run -it alpine-apache2-sh
/ # ls /etc/apache2/httpd.conf
/etc/apache2/httpd.conf
/ # cat /etc/apache2/httpd.conf
#
# This is the main Apache HTTP server configuration file.  It contains the
# configuration directives that give the server its instructions.
...

Copying that into a GIST like so:

docker run -it --entrypoint sh alpine-apache2-sh -c "cat /etc/apache2/httpd.conf" | pbcopy

Gist here: https://gist.github.com/simonw/5ea0db6049192cb9f761fbd6beb3a84a

[simonw]

Stripping comments using this StackOverflow recipe: https://unix.stackexchange.com/a/157619

docker run -it --entrypoint sh alpine-apache2-sh \
  -c "cat /etc/apache2/httpd.conf" | sed '/^[[:blank:]]*#/d;s/#.*//'

Result is here: https://gist.github.com/simonw/0a05090df5fcff8e8b3334621fa17976

[simonw]

There's a promising looking minimal Apache 2 proxy config here: https://stackoverflow.com/questions/26474476/minimal-configuration-for-apache-reverse-proxy-in-docker-container

[simonw]

https://github.com/krallin/tini says:

NOTE: If you are using Docker 1.13 or greater, Tini is included in Docker itself. This includes all versions of Docker CE. To enable Tini, just pass the --init flag to docker run.

[simonw]

Got it working! Here's a Dockerfile which runs completely stand-alone (thanks to using the echo $' trick to write out the config files it needs) and successfully serves Datasette behind Apache and mod_proxy:

FROM python:3-alpine

RUN apk add --no-cache \
	apache2 \
	apache2-proxy \
	bash

RUN pip install datasette

ENV TINI_VERSION v0.18.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini-static /tini
RUN chmod +x /tini

# Append this to the end of the default httpd.conf file
RUN echo $'ServerName localhost\n\
\n\
<Proxy *>\n\
  Order deny,allow\n\
  Allow from all\n\
</Proxy>\n\
\n\
ProxyPass        / http://localhost:9000/\n\
ProxyPassReverse / http://localhost:9000/\n\
Header add X-Proxied-By "Apache2"' >> /etc/apache2/httpd.conf

WORKDIR /app

RUN echo $'#!/usr/bin/env bash\n\
set -e\n\
\n\
httpd -D FOREGROUND &\n\
datasette -p 9000 &\n\
\n\
wait -n' > /app/start.sh

RUN chmod +x /app/start.sh

EXPOSE 80
ENTRYPOINT ["/tini", "--", "/app/start.sh"]

Run it like this:

docker build -t datasette-apache2-proxy .   
docker run -p 5000:80 --rm datasette-apache2-proxy

Then run this to confirm:

~ % curl -i 'http://localhost:5000/-/versions.json'
HTTP/1.1 200 OK
Date: Fri, 19 Nov 2021 19:54:05 GMT
Server: uvicorn
content-type: application/json; charset=utf-8
X-Proxied-By: Apache2
Transfer-Encoding: chunked

{"python": {"version": "3.10.0", "full": "3.10.0 (default, Nov 13 2021, 03:23:03) [GCC 10.3.1 20210424]"}, "datasette": {"version": "0.59.2"}, "asgi": "3.0", "uvicorn": "0.15.0", "sqlite": {"version": "3.35.5", "fts_versions": ["FTS5", "FTS4", "FTS3"], "extensions": {"json1": null}, "compile_options": ["COMPILER=gcc-10.3.1 20210424", "ENABLE_COLUMN_METADATA", "ENABLE_DBSTAT_VTAB", "ENABLE_FTS3", "ENABLE_FTS3_PARENTHESIS", "ENABLE_FTS4", "ENABLE_FTS5", "ENABLE_GEOPOLY", "ENABLE_JSON1", "ENABLE_MATH_FUNCTIONS", "ENABLE_RTREE", "ENABLE_UNLOCK_NOTIFY", "MAX_VARIABLE_NUMBER=250000", "SECURE_DELETE", "THREADSAFE=1", "USE_URI"]}}

[simonw]

And this is the version that proxies to a base_url of /foo/bar/:

FROM python:3-alpine

RUN apk add --no-cache \
	apache2 \
	apache2-proxy \
	bash

RUN pip install datasette

ENV TINI_VERSION v0.18.0
ADD https://github.com/krallin/tini/releases/download/${TINI_VERSION}/tini-static /tini
RUN chmod +x /tini

# Append this to the end of the default httpd.conf file
RUN echo $'ServerName localhost\n\
\n\
<Proxy *>\n\
  Order deny,allow\n\
  Allow from all\n\
</Proxy>\n\
\n\
ProxyPass        /foo/bar/ http://localhost:9000/\n\
Header add X-Proxied-By "Apache2"' >> /etc/apache2/httpd.conf

RUN echo $'<a href="/foo/bar/">Datasette</a>' > /var/www/localhost/htdocs/index.html

WORKDIR /app

ADD https://latest.datasette.io/fixtures.db /app/fixtures.db

RUN echo $'#!/usr/bin/env bash\n\
set -e\n\
\n\
httpd -D FOREGROUND &\n\
datasette fixtures.db --setting base_url "/foo/bar/" -p 9000 &\n\
\n\
wait -n' > /app/start.sh

RUN chmod +x /app/start.sh

EXPOSE 80
ENTRYPOINT ["/tini", "--", "/app/start.sh"]

[simonw]

This configuration works great.