Mattermost cannot install & start

Hi.

I am trying to install Mattermost through UmbrelOS and on UI I see only installation end on 1 %.

But using docker logs and docker ps -a I can see up and running:

alexlack/mattermost-db:v10.11.2 = mattermost_db_1

getumbrel/app-proxy:1.0.0 = mattermost_app_proxy_1

But:

alexlack/mattermost-app:v10.11.2 = mattermost_app_1 has status Created.

sudo docker logs 96748db31c50

is absolute empty.

sudo journalctl -u docker.service | grep 96748db31c50

has record:

error … Bind for 0.0.0.0:8443 failed: port is already allocated"

This port is occupied by docker-proxy.

I found docker-compose.yaml that way:

sudo docker inspect 96748db31c50| grep “DATA”
=>
/DATA/AppData/big-bear-umbrel/data/app-data/mattermost

nano docker-compose.yml

change port 8443 to 8444

docker up:

sudo docker run alexlack/mattermost-app:v10.11.2
Fixing permissions on /mattermost/data
Fixing permissions on /mattermost/logs
Fixing permissions on /mattermost/config
Fixing permissions on /mattermost/plugins
Fixing permissions on /mattermost/client/plugins
Dropping root and running mattermost entrypoint
No configuration file /mattermost/config/config.json
Creating a new one
Using existing database connection
Starting mattermost
{“timestamp”:“2025-09-15 16:23:59.202 Z”,“level”:“error”,“msg”:“Failed to ping DB”,“caller”:“sql/sql_utils.go:77”,“database”:“master”,“dataSource”:“postgres://:@localhost/mattermost_test?binary_parameters=yes&connect_timeout=10&sslmode=disable”,“retrying in seconds”:2,“error”:“dial tcp [::1]:5432: connect: connection refused”}
{“timestamp”:“2025-09-15 16:24:01.204 Z”,“level”:“error”,“msg”:“Failed to ping DB”,“caller”:“sql/sql_utils.go:77”,“database”:“master”,“dataSource”:“postgres://:@localhost/mattermost_test?binary_parameters=yes&connect_timeout=10&sslmode=disable”,“retrying in seconds”:2,“error”:“dial tcp [::1]:5432: connect: connection refused”}
{“timestamp”:“2025-09-15 16:24:03.206 Z”,“level”:“error”,“msg”:“Failed to ping DB”,“caller”:“sql/sql_utils.go:77”,“database”:“master”,“dataSource”:“postgres://:@localhost/mattermost_test?binary_parameters=yes&connect_timeout=10&sslmode=disable”,“retrying in seconds”:2,“error”:“dial tcp [::1]:5432: connect: connection refused”}
{“timestamp”:“2025-09-15 16:24:05.209 Z”,“level”:“error”,“msg”:“Failed to ping DB”,“caller”:“sql/sql_utils.go:77”,“database”:“master”,“dataSource”:“postgres://:@localhost/mattermost_test?binary_parameters=yes&connect_timeout=10&sslmode=disable”,“retrying in seconds”:2,“error”:“dial tcp [::1]:5432: connect: connection refused”}
Error: failed to initialize platform: cannot create store: error setting up connections: dial tcp [::1]:5432: connect: connection refused
Usage:
mattermost [flags]
mattermost [command]

Available Commands:
completion Generate the autocompletion script for the specified shell
db Commands related to the database
export Export data from Mattermost
help Help about any command
import Import data.
jobserver Start the Mattermost job server
server Run the Mattermost server
version Display version information

Flags:
-c, --config string Configuration file to use.
-h, --help help for mattermost

Use “mattermost [command] --help” for more information about a command.

My server is Linux Mint 22 x86_64, amd64

edit:

change formatting and found more logs

edit 2:

Maybe this is FW problem. But I cannot turn it off, it is important server. I will explore this problem deeply.