Can't use apt-get in Dockerfile when using datasetteproj/datasette as base #1320
Description
The datasette base Docker image is super convenient, but there's one problem: if any of the plugins you install require additional system dependencies (e.g., xz, git, curl) then any attempt to use apt in said Dockerfile results in an explosion:
$ docker-compose build
Building server
[+] Building 9.9s (7/9)
=> [internal] load build definition from Dockerfile 0.0s
=> => transferring dockerfile: 666B 0.0s
=> [internal] load .dockerignore 0.0s
=> => transferring context: 34B 0.0s
=> [internal] load metadata for docker.io/datasetteproject/datasette:latest 0.6s
=> [base 1/4] FROM docker.io/datasetteproject/datasette@sha256:2250d0fbe57b1d615a8d6df0c9d43deb9533532e00bac68854773d8ff8dcf00a 0.0s
=> [internal] load build context 1.8s
=> => transferring context: 2.44MB 1.8s
=> CACHED [base 2/4] WORKDIR /datasette 0.0s
=> ERROR [base 3/4] RUN apt-get update && apt-get install --no-install-recommends -y git ssh curl xz-utils 9.2s
------
> [base 3/4] RUN apt-get update && apt-get install --no-install-recommends -y git ssh curl xz-utils:
#6 0.446 Get:1 http://security.debian.org/debian-security buster/updates InRelease [65.4 kB]
#6 0.449 Get:2 http://deb.debian.org/debian buster InRelease [121 kB]
#6 0.459 Get:3 http://httpredir.debian.org/debian sid InRelease [157 kB]
#6 0.784 Get:4 http://deb.debian.org/debian buster-updates InRelease [51.9 kB]
#6 0.790 Get:5 http://httpredir.debian.org/debian sid/main amd64 Packages [8626 kB]
#6 1.003 Get:6 http://deb.debian.org/debian buster/main amd64 Packages [7907 kB]
#6 1.180 Get:7 http://security.debian.org/debian-security buster/updates/main amd64 Packages [286 kB]
#6 7.095 Get:8 http://deb.debian.org/debian buster-updates/main amd64 Packages [10.9 kB]
#6 8.058 Fetched 17.2 MB in 8s (2243 kB/s)
#6 8.058 Reading package lists...
#6 9.166 E: flAbsPath on /var/lib/dpkg/status failed - realpath (2: No such file or directory)
#6 9.166 E: Could not open file - open (2: No such file or directory)
#6 9.166 E: Problem opening
#6 9.166 E: The package lists or status file could not be parsed or opened.
The problem seems to be from completely wiping out /var/lib/dpkg in the upstream Dockerfile:
Line 18 in 1b69753
I've tested without removing the directory and apt works as expected.