Legacy apt package `postgresql-9.6-postgis-scripts` causes docker image build failure

[nam20485]

See below output.

Removing postgresql-9.6-postgis-scripts package from docker image dependency install in DOCKERFILE.db.development resolves problem and allows docker image build to successfully complete.

$ bin/build.sh -d
Building db_development
Step 1/6 : FROM postgres:9.6
 ---> 564cc4c97fef
Step 2/6 : LABEL maintainer "M. Edward (Ed) Borasky <znmeb@znmeb.net>"
 ---> Using cache
 ---> f4c01d1afc7c
Step 3/6 : RUN apt-get update   && apt-get install -qqy --no-install-recommends     postgis     postgresql-9.6-postgis-2.4     postgresql-9.6-postgis-2.4-scripts     postgresql-9.6-postgis-scripts     postgresql-9.6-pgrouting   && apt-get clean
 ---> Running in b58c58e643d8
Ign:1 http://deb.debian.org/debian stretch InRelease
Get:2 http://security.debian.org/debian-security stretch/updates InRelease [94.3 kB]
Get:3 http://deb.debian.org/debian stretch-updates InRelease [91.0 kB]
Get:4 http://deb.debian.org/debian stretch Release [118 kB]
Get:5 http://deb.debian.org/debian stretch Release.gpg [2,434 B]
Get:6 http://security.debian.org/debian-security stretch/updates/main amd64 Packages [484 kB]
Get:7 http://apt.postgresql.org/pub/repos/apt stretch-pgdg InRelease [46.3 kB]
Get:8 http://deb.debian.org/debian stretch-updates/main amd64 Packages [11.1 kB]
Get:9 http://deb.debian.org/debian stretch/main amd64 Packages [7,084 kB]
Get:10 http://apt.postgresql.org/pub/repos/apt stretch-pgdg/main amd64 Packages [168 kB]
Get:11 http://apt.postgresql.org/pub/repos/apt stretch-pgdg/9.6 amd64 Packages [1,829 B]
Fetched 8,100 kB in 1s (4,139 kB/s)
Reading package lists...
E: Unable to correct problems, you have held broken packages.
ERROR: Service 'db_development' failed to build: The command '/bin/sh -c apt-get update   && apt-get install -qqy --no-install-recommends     postgis     postgresql-9.6-postgis-2.4     postgresql-9.6-postgis-2.4-scripts     postgresql-9.6-postgis-scripts     postgresql-9.6-pgrouting   && apt-get clean' returned a non-zero code: 100

[znmeb]

When did this manifest as a problem?

[nam20485]

I am unsure specifically at what point it began to manifest. I first noticed it in the disaster-resilience-backend repo last year and applied this same fix. During the course of testing some unrelated changes for your repo I noticed that you had the same problem and had to make this fix to be able to build the development images.

Note that this only affects the development images, as the production/deployment images do not actually contain or build a development DB image, so this issue and fix would only be encountered when running bin/build.sh -d on a local development machine.

I don't know what changed, but it wasn't anything in our image definition file or anywhere in this repo that I can tell. My guess is that some of the package dependencies changed, were removed, or were upgraded in the Debian PostgreSQL 9.6 image as you mentioned in the PR #123 comment.