Could not open extension control file “/usr/share/postgresql/10/extension/pg_similarity.control”: No such file or directory

Hi,
I’m trying to create the extension pg_similarity
<https://github.com/eulerto/pg_similarity> (
https://github.com/eulerto/pg_similarity) in a docker container.
Dockerfile:

FROM postgres:10

ENV POSTGRES_USER user
ENV POSTGRES_PASSWORD user
ENV POSTGRES_DB user_db

RUN apt-get update \
&& apt-get upgrade -y \
&& apt-get -y install \
postgresql-server-dev-all \
wget \
make \
gcc \
&& rm -rf /var/lib/apt/lists/*
RUN wget -c 'pgfoundry.org/frs/download.php/2237/pg_similarity-0.0.19.tgz'
RUN tar -zxf pg_similarity-0.0.19.tgz
RUN cd pg_similarity \
&& USE_PGXS=1 make \
&& USE_PGXS=1 make install

Then I build the image and I run the container. I exec into the container:

psql -U user -d user_db
psql (10.3 (Debian 10.3-1.pgdg90+1))
Type "help" for help.
user_db=# create extension pg_similarity;

I got this error:

ERROR: could not open extension control file
"/usr/share/postgresql/10/extension/pg_similarity.control": No such
file or directory

Under /usr/share/postgres/10/contrib I find the file pg_similarity.sql.How
can I fix this problem?