ERROR: unsatisfiable constraints using apk in dockerfile

Question

I\'m trying to install postgis into a postgres container. Dockerfile:

FROM postgres:9.6.4-alpine

RUN apk update \\
    && apk add -u postgresql-9.6-         


        

Answer 1

Postgis package is only available in edge alpine repo, not in a stable one. That's why you are getting "unsatisfiable constraints" error.

But anyway you can install postgis from edge repo:

# echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories

# apk update
fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/community/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/edge/testing/x86_64/APKINDEX.tar.gz
WARNING: This apk-tools is OLD! Some packages might not function properly.
v3.5.2-254-g9d4623dc57 [http://dl-cdn.alpinelinux.org/alpine/v3.5/main]
v3.5.2-247-gc85efb30e1 [http://dl-cdn.alpinelinux.org/alpine/v3.5/community]
v3.7.0-2163-ge03552fc58 [http://dl-cdn.alpinelinux.org/alpine/edge/testing]
OK: 10930 distinct packages available

# apk search --no-cache postgis
fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.5/community/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/edge/testing/x86_64/APKINDEX.tar.gz
WARNING: This apk-tools is OLD! Some packages might not function properly.
postgis-dev-2.4.1-r1
postgis-2.4.1-r1
postgis-doc-2.4.1-r1

So, the final Dockerfile is:

FROM postgres:9.6.4-alpine

RUN echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories

RUN apk update \
    && apk add -u postgis \
    && rm -rf /var/lib/apt/lists/*

COPY ./scripts/postgis.sh  /docker-entrypoint-initdb.d/postgis.sh

UPDATED on January 23th 2020:

Postgis is available in main and community repositories starting from Alpine version 3.11:

/ # cat /etc/os-release
NAME="Alpine Linux"
ID=alpine
VERSION_ID=3.11.3
PRETTY_NAME="Alpine Linux v3.11"
HOME_URL="https://alpinelinux.org/"
BUG_REPORT_URL="https://bugs.alpinelinux.org/"
/ #
/ # apk search --no-cache postgis
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.11/community/x86_64/APKINDEX.tar.gz
postgis-3.0.0-r1
postgis-doc-3.0.0-r1

You don't need to use edge repo testing branch for Alpine version 3.11 and later.