ERROR: foreign-data wrapper "multicorn2" has no handler

[cmde-lusional]

Hi! I'm trying to use multicorn to access a docker postgresql database from a virtual machine (ubuntu 20.04) to my local dockerhost on my macbook.

The virtual machine can reach the docker host using psql without any issue:

# psql postgresql://postgres:postgres@10.6.2.64/fb
psql (13.10 (Ubuntu 13.10-1.pgdg20.04+1), server 10.5 (Debian 10.5-2.pgdg90+1))
Type "help" for help.

fb=#

The database in the source system is called fb, the table is called patient.

More information about the table here:

SELECT column_name, data_type FROM information_schema.columns WHERE table_name = 'patient';
column_name  |        data_type
---------------+--------------------------
 id            | text
 txid          | bigint
 ts            | timestamp with time zone
 resource_type | text
 status        | USER-DEFINED
 resource      | jsonb
(6 rows)

I use python3.8.10:

# python3 --version
Python 3.8.10

I installed postgresql13 as follows

sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -

sudo apt-get update
sudo apt-get install postgresql-13

# psql --version
psql (PostgreSQL) 13.10 (Ubuntu 13.10-1.pgdg20.04+1)

I installed multicorn as follows:

sudo apt install -y build-essential libreadline-dev zlib1g-dev flex bison libxml2-dev libxslt-dev libssl-dev libxml2-utils xsltproc postgresql-server-dev-13
git clone git@github.com:pgsql-io/multicorn2.git
cd multicorn2

The makefile has issues with my python version, so i changed

pip${python_version} install .

to

pip3 install .

then I install using

make
sudo make install

I checked the installation:

# pip3 show multicorn
Name: multicorn
Version: 2.4
Summary: UNKNOWN
Home-page: UNKNOWN
Author: Lussier
Author-email: UNKNOWN
License: Postgresql
Location: /usr/local/lib/python3.8/dist-packages
Requires:
Required-by:

# ls /usr/local/lib/python3.8/dist-packages/multicorn
__init__.py  _utils.cpython-38-x86_64-linux-gnu.so  csvfdw.py  gcfdw.py   googlefdw.py  ldapfdw.py     rssfdw.py         statefdw.py  utils.py
__pycache__  compat.py                              fsfdw      gitfdw.py  imapfdw.py    processfdw.py  sqlalchemyfdw.py  testfdw.py   xmlfdw.py

# ls /usr/share/postgresql/13/extension | grep multicorn
multicorn--2.4.sql
multicorn.control

# cat ls /usr/share/postgresql/13/extension/multicorn.control
cat: ls: No such file or directory
comment = 'Multicorn2 Python3.6+ bindings for Postgres 11++ Foreign Data Wrapper'
default_version = '2.4'
module_pathname = '$libdir/multicorn'
relocatable = true

Then I create the extension inside psql, create the server and add the foreign table as follows:

sudo -i -u postgres

psql

# CREATE EXTENSION multicorn;
CREATE EXTENSION

# SELECT name, default_version, installed_version
# FROM pg_available_extensions
# WHERE name LIKE 'multicorn%';
   name    | default_version | installed_version
-----------+-----------------+-------------------
 multicorn | 2.4             | 2.4
(1 row)

# CREATE SERVER alchemy_srv foreign data wrapper multicorn2 OPTIONS ( wrapper 'multicorn.sqlalchemyfdw.SqlAlchemyFdw' );
CREATE SERVER

# CREATE FOREIGN TABLE patient ("id" text, "txid" bigint, "ts" timestamp with time zone, "resource_type" text, "status" text, "resource" jsonb) SERVER alchemy_srv OPTIONS ( tablename 'patient' , db_url 'postgresql://postgres:postgres@10.6.2.64/fb' );
CREATE FOREIGN TABLE

The problem is that the table stays empty and I can't query any data:

# SELECT id FROM patient LIMIT 100;
ERROR:  foreign-data wrapper "multicorn2" has no handler

# \dE[S+]
                                 List of relations
 Schema |  Name   |     Type      |  Owner   | Persistence |  Size   | Description
--------+---------+---------------+----------+-------------+---------+-------------
 public | patient | foreign table | postgres | permanent   | 0 bytes |
(1 row)

Am I doing something wrong? Following the documentation if I only want to access the data in another database by querying inside my own postgresql I don't need to created a 'handler', right?

Thank you