Can't connect PostGis to database and server - postgresql

Question

I followed these steps to set up QWC services https://github.com/qwc-services/qwc-services-core#quick-start and I can run the demo. But if load my own QGIS project, I receive the following error message:
qwc-qgis-server_1 | 07:50:07 WARNING Server[99]: <ServerException>Layer(s) not valid</ServerException>
qwc-qgis-server_1 |
qwc-qgis-server_1 | 07:50:07 WARNING ClearCapabilities[99]: Cached cleared : /data/MeasurementDemo.qgs
qwc-qgis-server_1 | 07:50:07 WARNING PostGIS[99]: Connection to database failed
qwc-qgis-server_1 | could not connect to server: No such file or directory
qwc-qgis-server_1 | Is the server running locally and accepting
qwc-qgis-server_1 | connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
qwc-qgis-server_1 |
qwc-qgis-server_1 | 07:50:07 CRITICAL Server[99]: Error, Layer(s) measurement_b46e976f_2d0f_4bf0_942a_9d9462b40c3e not valid in project /data/MeasurementDemo.qgs
qwc-qgis-server_1 | 07:50:07 WARNING Server[99]: <ServerException>Layer(s) not valid</ServerException>
qwc-qgis-server_1 |
qwc-config-service_1 | [2022-01-04 07:50:09,360] WARNING in config_generator: Skipping theme item '': Could not get capabilities for /ows/MeasurementDemo
qwc-config-service_1 | [2022-01-04 07:50:19,468] CRITICAL in config_generator: The generation of the configuration files resulted in a failure
qwc-config-service_1 | [2022-01-04 07:50:19,468] CRITICAL in config_generator: The configuration files were not updated!
qwc-config-service_1 | [2022-01-04 07:50:20,856] CRITICAL in config_generator: The generation of the permission files resulted in a failure.
qwc-config-service_1 | [2022-01-04 07:50:20,857] CRITICAL in config_generator: The permission files were not updated!
qwc-config-service_1 | [pid: 15|app: 0|req: 18/18] 172.18.0.11 () {30 vars in 408 bytes} [Tue Jan 4 07:50:05 2022] POST /generate_configs?tenant=default => generated 2881 bytes in 15083 msecs (HTTP/1.1 200) 2 headers in 81 bytes (1 switches on core 0)
As the error is quite similar to this question: PostgreSQL: Why psql can't connect to server?, I followed the answers but with no result.
ps -ef | grep postgres gives me the following result:
postgres 203911 1 0 07:35 ? 00:00:00 /usr/lib/postgresql/13/bin/postgres -D /var/lib/postgresql/13/main -c config_file=/etc/postgresql/13/main/postgresql.conf
Also I found the socket in
/var/run/postgresql/.s.PGSQL.5432
And I run the command
psql -h /var/run/postgresql/ GeoDB
But without result. After that I checked the ph_hba.conf File:
# "local" is for Unix domain socket connections only
local all all peer
Running the command pg_lsclusters gives me:
Ver Cluster Port Status Owner Data directory Log file
13 main 5432 online postgres /var/lib/postgresql/13/main /var/log/postgresql/postgresql-13-main.log
Also after restarting the pg_ctlcluster and PostgreSQL the error remained the same.
Edit 1
After the answer from cnaimi I checked the postgresql.confFile:
# - Connection Settings -
#listen_addresses = '*' # what IP address(es) to listen on;
# comma-separated list of addresses;
# defaults to 'localhost'; use '*' for all
# (change requires restart)
port = 5432 # (change requires restart)
max_connections = 100 # (change requires restart)
#superuser_reserved_connections = 3 # (change requires restart)
unix_socket_directories = '/var/run/postgresql' # comma-separated list of directories
# (change requires restart)
#unix_socket_group = '*' # (change requires restart)
#unix_socket_permissions = 0777 # begin with 0 to use octal notation
# (change requires restart)
#bonjour = off # advertise server via Bonjour
# (change requires restart)
#bonjour_name = '' # defaults to the computer name
# (change requires restart)
But I can't find an error there as the port is 5432 and it listen to all adresses.
Edit 2
During my search I found several pg_service.conf Files:
./qwc-services/qwc-docker/wsgi-service/pg_service.conf
./qwc-services/qwc-docker/qgis-server/pg_service.conf
./qwc-services/qwc-docker/postgis/pg_service.conf
./qwc-services/qwc-docker/pg_service.conf
Each if them contain one or more credentials for databases like the one below:
[qwc_geodb]
host=qwc-postgis
port=5432
dbname=qwc_demo
user=qwc_service
password=qwc_service
sslmode=disable
The port is in all files correct, as far as I saw. But of course the db name and user/password are wrong. Does this could cause the error? Or does QWS get the credentials through the .qgs file?
Edit 3
Thanks to the hints from Devdatta Tengshe I set the host for PostgreSQL to 127.0.0.1. By using sudo docker-compose ps one can see the used container and their ports:
Name Command State Ports
-------------------------------------------------------------------------------------------------------------------------------
qwc-docker_qwc-admin-gui_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5031->9090/tcp
qwc-docker_qwc-api-gateway_1 /docker-entrypoint.sh ngin ... Up 0.0.0.0:8088->80/tcp,:::8088->80/tcp
qwc-docker_qwc-auth-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5017->9090/tcp
qwc-docker_qwc-config-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5010->9090/tcp
qwc-docker_qwc-data-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5012->9090/tcp
qwc-docker_qwc-elevation-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5002->9090/tcp
qwc-docker_qwc-fulltext-search-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5011->9090/tcp
qwc-docker_qwc-map-viewer_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5030->9090/tcp
qwc-docker_qwc-mapinfo-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5016->9090/tcp
qwc-docker_qwc-ogc-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5013->9090/tcp
qwc-docker_qwc-permalink-service_1 /bin/sh -c uwsgi --http-so ... Up 127.0.0.1:5001->9090/tcp
qwc-docker_qwc-postgis_1 docker-entrypoint.sh postgres Up (healthy) 127.0.0.1:5439->5432/tcp
qwc-docker_qwc-qgis-server_1 /sbin/my_init Up 127.0.0.1:8001->80/tcp
qwc-docker_qwc-solr_1 docker-entrypoint.sh solr- ... Up 127.0.0.1:8983->8983/tcp

Answer 1

Can you check the postgres.conf file located in
/etc/postgresql/13/main/postgresql.conf
specially the parameter listen_address
Maybe you have to specify from which host you are listening.
But if the demo example is working the database configuration should be ok.
You can also check the port for postgres on postgres.conf and validate it's 5432.

Answer 2

There are a couple of things that need to be fixed to get this working.
I'm assuming that you have the Postgres Server running on the host machine, and not within any Docker container.
When you configured your QGIS Map file, you probably connected to localhost, and this information got saved in the .qgs file.
This is why your first error message says that it trying to connect to localhost, and no server was found. This error was thrown within the qwc docker container.
This error is occuring, because QGIS server (within the docker container) is not able to connect to the postgres server which is running on the host, using 'localhost' as the hostname
To solve this, you need to do the following:
In QGIS, connect to the Postgres Server using 127.0.0.1 and not localhost.
Save your qgs file using this new connection.
When you run the docker container for qwc, use --network="host" as the commandline parameter.
See: From inside of a Docker container, how do I connect to the localhost of the machine?
After this, the qgis server (within docker container) should be able to connect to the Postgres Server running on your host, using 127.0.0.1 as IP address.