Cannot connect remotely after changing the port -Mongodb

Question

I have Ubuntu 18.04 VM running on GCP and I have a problem when connecting remote after changing the default port on Mongodb

After the installation on Mongodb I followed a few steps to enable remote access on default port in the file /etc/mongodb.conf changed the bindIP to 0.0.0.0 and open the default port on GCP firewall and I was able to connect to Mongodb.

But I want to change default Mongodb port switch from 27017 to for example: 38018 I changed the port in /etc/mongodb.conf from 27017 to 38018, I've restarted mongo service and open the new port on GCP firewall.

After changing the port I'm able to connect from terminal with the following command

mongo --port 38018 -u "user" -p "pass" --authenticationDatabase "admin"

But when I try to connect from outside on the new port with mongo compass the connection is refused, what I'm missing here?

Also I've checked is it mongo running on the new port with

sudo netstat -tulpn | grep 38018

I get the following message

tcp        0      0 0.0.0.0:38018           0.0.0.0:*               LISTEN      6644/mongod

Ubuntu 18.04.4 LTS
mongod --version db version v4.2.7
UFW inactive

Here is my mongo config file

    # for documentation of all options, see:
#   http://docs.mongodb.org/manual/reference/configuration-options/

# Where and how to store data.
storage:
  dbPath: /var/lib/mongodb
  journal:
    enabled: true
#  engine:
#  mmapv1:
#  wiredTiger:

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/mongod.log

# network interfaces
net:
  port: 38018
  bindIp: 0.0.0.0


# how the process runs
processManagement:
  timeZoneInfo: /usr/share/zoneinfo

security:
    authorization: enabled

#operationProfiling:

#replication:

#sharding:

## Enterprise-Only Options:

#auditLog:

#snmp:

I execute the following command as @YasBES said

mongod -f your_config_file.conf

and restarted the mongo process, the process was unable to start

After checking the log i found this error Failed to start up WiredTiger under any compatibility version.

And I found the following command to fix the error

sudo chown -R mongodb:mongodb /var/lib/mongodb/

Next I removed 27017 .sock file

sudo rm /tmp/mongodb-27017.sock

and give proper ownership on the newly created file

sudo chown mongodb:mongodb mongodb-38018.sock

after executing those commands the process started successfully when I look at the mongod.log I got those messages

2020-05-28T17:13:06.807+0000 I  SHARDING [initandlisten] Marking collection local.startup_log as collection version: <unsharded>
2020-05-28T17:13:06.807+0000 I  FTDC     [initandlisten] Initializing full-time diagnostic data capture with directory '/var/lib/mongodb/diagnostic.data'
2020-05-28T17:13:06.811+0000 I  SHARDING [LogicalSessionCacheRefresh] Marking collection config.system.sessions as collection version: <unsharded>
2020-05-28T17:13:06.812+0000 I  SHARDING [LogicalSessionCacheReap] Marking collection config.transactions as collection version: <unsharded>
2020-05-28T17:13:06.812+0000 I  NETWORK  [listener] Listening on /tmp/mongodb-38018.sock
2020-05-28T17:13:06.812+0000 I  NETWORK  [listener] Listening on 0.0.0.0
2020-05-28T17:13:06.812+0000 I  NETWORK  [listener] waiting for connections on port 38018
2020-05-28T17:13:07.003+0000 I  SHARDING [ftdc] Marking collection local.oplog.rs as collection version: <unsharded>

Now the process start and it says it's listening on 38018 but still can't connect remotely

2020-05-28T17:13:06.812+0000 I  NETWORK  [listener] Listening on 0.0.0.0
2020-05-28T17:13:06.812+0000 I  NETWORK  [listener] waiting for connections on port 38018

i think it's ok for your config can you excute this command please : mongod -f your_config_file.conf — YasBES
I executed the command and you can check the edited post for more info, thanks — jok

jok jok · Accepted Answer · 2020-06-17T09:04:11

After some time of research I came to decision to test the same setup on Azure cloud with the same Mongo version, configuration like on GCP.

After changing the default mongo port from 27017 to 38018 I opened the firewall on Azure with the new 38018 port and the remote connection was established.

This is the moment where I discovered that there is something wrong with the port forwarding on GCP.

I was using GCP and I did a lot of forwardings for other machines and other services but this one was strange.

I tried couple of different types of forwarding with different priorities IP ranges etc.

The one that worked is with logs on, priority 100, ip ranges 0.0.0.0/0 and protocol and ports 38018 tcp/udp.

Cannot connect remotely after changing the port -Mongodb

1 Answers