connect ECONNREFUSED - Mongo Compass cannot connect to remote DB - database

I am having problems establishing a connection to a remotely hosted MongoDB instance.
I think I have tried almost everything I could find to resolve it but nothing has worked, including:
Multiple different edits of bindIp mongod.conf,to allow separate IPs, for example:
bindIp: 127.0.0.1,<my-public-web-app-ip>
bindIp: 127.0.0.1;<my-public-web-app-ip>
bindIp: [127.0.0.1,<my-public-web-app-ip>]
bindIp: ["127.0.0.1,<my-public-web-app-ip>"]
None of these worked. I couldn't even get Mongo to either restart successfully after any of the changes above.
Mongo restart and access to the Mongo shell is only possible using, bindIp: 127.0.0.1
I have a ufw firewall configured to allow access from the IP of the machine which I want to access the DB to port 27017, where Mongo is available on my VPS.
I have used sudo systemctl restart mongod and checked that Mongo is running with sudo systemctl status mongod with every change to try to identify the specific problem, but Mongo simply won't start with any of the bindIp configurations I try.
I have created and recreated Mongo admin users and tried again with new credentials in the connect sting in Compass without any luck.
My Mongo version is v4.4.9. I have seen mostly suggestions for versions below this.
If anyone has any ideas how this can be resolved I'd be very grateful.

Related

Docker Containers cannot communicate with Host Database

I know this question has been asked before, but I haven't managed to solve it from those answers.
System spec: I am running the server on Ubuntu 22.10 docker version is 20.10.16 and docker-compose version is 1.29.2
What I want to achieve: I have nextcloud running as a docker container and have MariaDB installed on the host machine uncontainerized. I want to use a database I created in MariaDB by nextcloud in docker container. But Hostname is always incorrect, and I get the following error.
Failed to connect to the database: An exception occurred in the driver: SQLSTATE[HY000] [2002] Connection refused
Troubleshooting I've tried so far
Option 1: I added an extra host to my docker compose file so it can listen to the host system. Here's how my docker compose file like
version: '2'
services:
app:
image: nextcloud
restart: always
ports:
- 8080:80
volumes:
- /home/ritzz/nextcloud:/var/www/html
extra_hosts:
- host.docker.internal:host-gateway
However, when adding database if I use host.docker.internal as hostname I still get the error mentioned above.
Option2: Using docker host IP as database hostname. I used the following command to find out my host ip which was 172.17.0.1
ip addr show docker0
However, again adding 172.17.0.1 or 172.17.0.1:3306 returns with the same error.
Option 3: I saw an option on the Internet to use network_mode: host to make the container use the same network as host. However, since docker container uses port 80 and on my host I can't use port 80. This method won't work for me I assume.
Additional Troubleshooting
I made sure Mariadb is with command sudo systemctl status mariadb as well as checked that it's listening to port 3306 using command sudo netstat -tlnp I also logged in to the database with the user and pass using command sudo mysql -u<username> -p<password> <database> and I can login successfully.
I am at the edge with this. Hopefully someone else can help me out

How to connect superset to postgresql - The port is closed

My operating system is Linux.
I am going to connect Superset to PostgreSQL.
PostgreSQL port is open and its value is 5432.
PostgreSQL is also running and not closed.
Unfortunately, after a day of research on the Internet, I could not solve the problem and it gives the following error:
The port is closed.
Database port:
command: lsof -i TCP:5432
python3 13127 user 13u IPv4 279806 0t0 TCP localhost:40166->localhost:postgresql (ESTABLISHED)
python3 13127 user 14u IPv4 274261 0t0 TCP localhost:38814->localhost:postgresql (ESTABLISHED)
Please help me, I am a beginner, but I searched a lot and did not get any results.
Since you're running Superset in a docker container, you can't use 127.0.0.1 nor localhost, since they resolve to the container, not the host. For the host, use host.docker.internal
I had a similar problem using docker compose. Port is closed can be due to networking problem. Host.docker.internal doesn’t worked for me on Ubuntu 22. I would like to recommend to not follow official doc and use better approach with single docker image to start. Instead of running 5 containers by compose, run everything in one. Use official docker image, here image. Than modify docker file as follows to install custom db driver:
FROM apache/superset
USER root
RUN pip install mysqlclient
RUN pip install sqlalchemy-redshift
USER superset
Second step is to build new image based on docker file description. To avoid networking problems start both containers on same network (superset, your db) easier is to use host network. I used this on Google cloud example as follow:
docker run -d --network host --name superset supers
The same command to start container with your database. —network host. This solved my problems. More about in whole step to step tutorial: medium or here blog
From the configuration file, you set port 5432, but it does not mean that your pg service is available

Can't Connect to External SQL Server From Docker Container

I've developed a SpringBoot(Java) application that calls out to an external SQL Server on port 1433. The SQL Server instance is located on-premises (not local SQL Server instances). However, it's reachable from my desktop using either IntelliJ or SQL Clients.
I am using the Microsoft SQL Server JDBC connector to communicate with the instances.
If I run the app from IntelliJ all is well, the app can call the SQL Server, execute the command and returns a resultsset.
However, now I'm trying to Dockerize the api app. The container does the usual SpringBoot initialization but when it tries to call the SQL Server I get the following error:
com.microsoft.sqlserver.jdbc.SQLServerException: The TCP/IP connection to the host myexternalsqlserver.domain, port 1433 has failed. Error: "myexternalsqlserver.domain. Verify the connection properties. Make sure that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. Make sure that TCP connections to the port are not blocked by a firewall.".
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:234)
at com.microsoft.sqlserver.jdbc.SQLServerException.ConvertConnectExceptionToSQLServerException(SQLServerException.java:285)
at com.microsoft.sqlserver.jdbc.SocketFinder.findSocket(IOBuffer.java:2434)
at com.microsoft.sqlserver.jdbc.TDSChannel.open(IOBuffer.java:659)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:2546)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:2216)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectInternal(SQLServerConnection.java:2067)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:1204)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:825)
at java.sql/java.sql.DriverManager.getConnection(Unknown Source)
at java.sql/java.sql.DriverManager.getConnection(Unknown Source)
at com.symetra.SdsApi.SqlConnector.getResultSet(SqlConnector.java:26)
This is my Docker file
FROM openjdk:11.0.4-jre-slim-buster
VOLUME /tmp
COPY target/myapi-1.0-SNAPSHOT.jar app.jar
EXPOSE 8080
EXPOSE 1433
ENTRYPOINT [ "sh", "-c", "java $JAVA_OPTS -Djava.security.egd=file:/dev/./urandom -Dspring.profiles.active=docker -jar /app.jar" ]
And these are the Docker commands I use to build and run the container:
docker build -t myapi . && docker run -p 8080:8080 -p 1433:1433 --name myapi myapi "java","-jar","myapi-1.0-SNAPSHOT.jar"
I don't think the mapping of port 1433 is necessary, it's just an experiment. I should be able to communicate outside of my container through to port 1433 on the host. Port 1433 isn't being blocked on the host because I have no problems running this outside the container.
Finally, this is the connection string I'm using:
//Create Connection Url.
String connectionUrl="jdbc:sqlserver://myexternalsqlserver.domain:1433;database=mydb;user=MyUser;password=MyPassword";
I'm not sure what I'm doing wrong here. I'm wondering if I need to set up Docker networking.
Thanks for your help!
It should work.
NB I'm assuming myexternalsqlserver.domain is not what you're using.
One way to test your container is to shell into it (or create a variant) and try resolving the SQL Server's host name:
docker run --interactive --tty openjdk:11.0.4-jre-slim-buster /bin/bash
# then from within the container's shell
apt update && apt install -y dnsutils
nslookup ${SQL_SERVER}
If that succeeds, it's your code.
If not, it's the network.
NB Your container need not publish 1443 (--publish=1433:1433) since it's consuming that port (on the SQL Server) not exposing the port itself.
The same issue bugged me for days and finally was able to solve it by following the steps below.
In my case the SQL server was hosted on Azure managed instance and exposed a private endpoint. The docker was able to resolve the DNS name of the Azure managed instance to a private IP address (as expected ). But this resolved IP was considered by the docker network/bridge as a locally running application because upon inspecting docker's bridge (docker network inspect bridge)The subnet of the bridge was found to be a range of IP addresses where the resolved IP of the SQL server also falls. Hence, the docker assumed the SQL server to be hosted in the same local network and not outside (here enterprise network). In my case the Windows VM I was working was already on the private network of the enterprise.
Solution:
In the docker desktop -> settings -> Docker Engine json file, add a new key value pair
"bip": "<local IP address range which is outside of the resolved sql server IP>".
Restart the docker desktop and the issue should be solved.

Connect to docker sqlserver via ssh

I've created a docker container that contains a mssql Database. On the command line ip a gives an ip address for the container, however trying to ssh into it username#docker_ip_address yields ssh: connect to host ip_address port 22: Connection refused. So I'm wondering if I am even able to ssh into the container so I don't have to always be using the docker tool docker exec .... and if so how would I go about doing that?
To ssh into container you should full-fill followings
SSH server(Openssh) should be installed within the container and ssh service should be running
Port 22 should be published from container (when you run the container).more info here > Publish ports on Docker
docker ps command should display mapped ports 22
Hope above information helps for you to understand the situation...
If your container contains a database server, the normal way to interact with will be through an SQL client that connects to it; Google suggests SQL Server Management Studio and that connector libraries exist for popular languages. I'm not clear what you would do given a shell in the container, and my main recommendation here would be to focus on working with the server in the normal way.
Docker containers normally run a single process, and that's normally the main server process. In this case, the container runs only SQL Server. As some other answers here suggest, you'd need to significantly rearchitect the container to even have it be possible to run an ssh daemon, at which point you need to worry about a bunch of other things like ssh host keys and user accounts and passwords that a typical Docker image doesn't think about at all.
Also note that the Docker-internal IP address (what you got from ip addr; what docker inspect might tell you) is essentially useless. There are always better ways to reach a container (using inter-container DNS to communicate between containers; using the host's IP address or DNS name to reach published ports from the same or other hosts).
Basically, alter your Dockerfile to something like the following - that will install openssh-server, alter a prohibitive default configs and start the service:
# FROM a-image-with-mssql
RUN echo "root:toor" | chpasswd
RUN apt-get update
RUN apt-get install -y openssh-server
COPY entrypoint.sh .
RUN cd /;wget https://gist.githubusercontent.com/spekulant/e04521d6c6e1ccffbd3455c673518c5b/raw/1e4f6f2cb32caf3a4a9f73b02efdcbd5dde4ba7a/sshd_config
RUN rm /etc/ssh/sshd_config; cp sshd_config /etc/ssh/
ENTRYPOINT ["./entrypoint.sh"]
# further commands
Now you've got yourself an image with ssh server inside, all you have to do is start the service, you cant do RUN service ssh start because it won't work - docker specifics, refer to the documentation. You have to use a Entrypoint like the following:
#!/bin/bash
set -e
sh -c 'service ssh start'
exec "$#"
Put it in a file entrypoint.sh next to your Dockerfile - remember to chmod 755 entrypoint.sh it. There's one thing to mention here, you still wouldn't be able to ssh into the container - the default SSH server configuration doesn't allow login into root account using a password. So you either change the configs yourself and provide it to the image, or you can trust me and use the file I created - inspect it with the link from Dockerfile - nothing malicious there, only a change from prohibit-password to yes.
Fortunately for us - MSSQL official images start from Ubuntu so all the commands above fit perfectly into the environment.
Edit
Be sure to ask if something is unclear or I'm jumping too fast.

Apache2 Ubuntu Server Failed to connect to localhost port 5984: Connection refused with CouchDB

I have an Apache2 Ubuntu Server that is running and want to replicate my couchDB database locally to remote on the server. With terminal curl from this documentation on how to replicate. I performed this:
curl -X POST -d '{"source":"http://127.0.0.1:5984/demo","http://server_IP_here/":"demo"}' \http://127.0.0.1:5984/_replicate
The error comes up everytime. Is there something wrong with the above statement?
The server IP has doesn't require ports as a side not.
curl: (7) Failed to connect to 127.0.0.1 port 5984: Connection refused
Try to use port 8092
I couldn't found documentation on this, though random trying different ports found that my couchbase instance answer there :)

Resources