While I'm typing
CREATE EXTENSION postgis;
or
CREATE EXTENSION IF NOT EXISTS postgis;
I'm getting an error saying:
could not open extension control file "/usr/local/share/postgresql/extension/postgis.control": No such file or directory
Who can help?
You're probably using the Alpine version, meaning PostGIS can't be added that way.
See https://github.com/docker-library/docs/tree/master/postgres#additional-extensions
When using the Alpine variants, any postgres extension not listed in postgres-contrib will need to be compiled in your own image
Rather use an image that has PostGIS baked into it, e.g. postgis/postgis
or
Create your own Alpine based dockerfile that mimics the example they provide:
https://github.com/postgis/docker-postgis/blob/master/12-3.0/alpine/Dockerfile