I usually use the default network for docker containers, and I had a mongo database running in one just fine and the port was exposed to the network successfully. Then, I tried to attach a new python container to that container using the --link option (yes, I now realize that that is deprecated). An error was thrown, and in my hubris, I didn't capture it, I just went on. Now, when I try to start my mongo database, it fails saying that it can't bind the network. "Failed to set up listener: SocketException: Permission denied"
I removed the container and tried to re-create it, but no luck. I've put this into a permanent state of bad. Any suggestions on how to fix this so I can get my database back?
Thanks.
Edit: Should have mentioned, Ubuntu 20.04, Docker 19.03.11
Also, this only seems to be a problem with any new mongo containers. I can start postgres, and web servers, etc without issues.
Turns out, whatever that error was when I tried to use --link, it had corrupted the mongo image on my machine, so all new instances of that image failed to connect to the network. That's why removing the container and recreating it didn't fix the problem. I needed to delete the local mongo image, and re-pull from the docker hub.
Related
I'm trying to get RabbitMQ to monitor a postgresql database to create a message queue when database rows are updated. The eventual plan is to feed this message queue into an AWS EKS (Elastic Kubernetes Service) cluster as a job.
I've read many many approaches to this but they are still confusing as a newcomer to RabbitMQ and many seemed to be written more than 5 years ago so I'm not sure if they'll still work with current versions of postgres and rabbitmq.
I've followed this guide about installing the area51/notify-rabbit docker container which can connect the two via a node app, but when I ran the docker container it immediately stopped and didn't seem to do anything.
There is also this guide, which uses a go app to connect the two, but I'd rather not use Go ouside of a docker container.
Additionally, there is also this method, to install the pg_amqp extension from a repository which hasn't been updated in years, which allows for a direct connection from PostgreSQL to RabbitMQ. However, when I followed this and attempted to install pg_amqp on my Postgres db (postgresql 12), I was unable to connect using psql to the database, getting the classic error:
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
My current set-up, is I have a rabbitMQ server installed in a docker container in an AWS EC2 instance which I can access via the internet. I ran the following to install and run it:
docker pull rabbitmq:3-management
docker run --rm -p 15672:15672 -p 5672:5672 rabbitmq:3-management
The postgresql database is running on a separate EC2 instance and both instances have the required ports open for accessing data from each server.
I have also looked into using Amazon SQS as well for this, but it didn't seem to have any info on linking Postgresql up to it. I haven't really seen any guides or Stack Overflow questions on this since 2017/18 so I'm wondering if this is still the best way to create a message broker for a kubernetes system? Any help/pointers on this much appreciated.
In the end, I decided the best thing to do was create some simple Python scripts to do the LISTEN/NOTIFY steps and route traffic from PostgreSQL to RabbitMQ based off the following code https://gist.github.com/kissgyorgy/beccba1291de962702ea9c237a900c79
I set it up inside Docker containers and set them to run in my Kubernetes cluster so they are within the automatic restarts if they fail.
I am learning docker and during my project, i can't enter the mongo db with this command:
mongo -u "username" -p "mypassword"
It throws me this error:
bash: mongo: command not found
I am not sure what the issue is. I have installed the community edition of mongo db and i also tried different terminals but i can't enter the db.
Any suggestions?
Thanks in advance!
I assume, you did the following: Create docker-compose.yml as you wrote before. Start docker compose up. This will start a container on your system, having mongodb installed in it. It will not affect your "normal" system outside this container. (You can imagine it as kind of a virtual machine, though it is not really the same.) So, if you did not install mongodb on your local host system as well, the error you encounter is quite explicable.
If you want to access the mongodb running within the container, you have two possibilities:
1. From outside the container (which is the more common use case)
You will have to install mongo on your regular PC (or anywhere you want to access your db from) as well. Then you would issue mongo 127.0.0.1:3000. The 3000 is important as your docker-compose.yml says, mongo is listening on port 3000. Note that you might have to get your network configuration adapted before this works, especially from other PCs, where 127.0.0.1 won't be correct.
2. From within the container
Once your container is started, you can also execute a command inside it, like this: docker exec -it ${container_id} /bin/bash. You'll have to find out the container's ID beforehand, using something like docker-compose ps -q. This will start a bash shell inside the container and "connect" you to it. (If there's no /bin/bash installed in the container, this will not work. Try e. g. /bin/sh instead.) Now your terminal will be inside the container and just be able to use the commands present there. So, to get back to your local PC, don't forget to issue exit.
Conclusion
IMHO, the crucial point is, that the physical PC you are working in front of and the container running inside it are almost completely different systems, connected only by the docker daemon and some virtual network access. You'll have to keep that in mind and decide what you want to do/run inside the container and what to do outside, on the host.
Here is a little further reference that might help you. And this answer is about how to find out your container ID in an automated way. (Assuming that you are running just that one container!)
I have been using this MUP config for the deployment until recently. When I encountered an issue and I had to stop, reboot the Instance multiple times.
Then, This causes the meteor app container to shut down and the MongoDB container is running just fine but wasn't accessible through an SSH tunnel on a MongoDB GUI (but running systemctl status mongo shows active status: activating.
I troubleshoot and run docker ps -a. It shows the MongoDB container only as a running container and the meteor app container completely shutdown.
I tried running the MUP deployment in an attempt to get the meteor app container up and running.
However, I got an error Removing docker containers. Errors about nonexistent endpoints and containers are normal.
I run the mup setup command successfully and then I tried running mup reconfig and I got the same above error, I have attached the screenshot of the error below.
To Reproduce this error
Create a meteor app with Iron-meteor.
Setup an Instance (Ec2).
Setup Deployment with Meteor-up
Deploy your app with Meteor-up.
SSH into the instance and run cmd docker ps. Should see at least two running containers, app and mongo respectively.
Run a cmd to stop the app container while the mongo container is running.
Finally, Goto your project and redeployed with mup
Should see a similar error as above. for step 6 restarting the instance in my case shut down the two containers and I was able to get the mongo container back up and running.
However, I couldn't get the app container running, so I tried redeploying with the expectation that a new app container would be created if it doesn't exist on the instance.
UPDATED!
I don't know if this will help, but in my experience, mup likes a fresh instance better than an existing one.
My first step would be a mup stop command. This will shut down the docker instances. Then you can remove them with docker rm, and you can remove the images with docker rmi. Then do a mup setup again, followed by a mup deploy.
If the first one doesn't work, you can basically start with a fresh vm, as in the droplet or ec2 instance. This is generally quite successful.
We are running MongoDB as docker container and all of sudden it become unresponsive. We had tried to restart container but it didnt. The docker restart command was success but if we check the service it didnt restarted. We are not able to connect to DB from our Mongo client too.
After full VM restart the problem got solved. I would like to know if anyone has faced this issue and got any solution for it.
Here is the details my docker:
Docker version 19.03.12
Mongo 4.0
Running pgAdmin 4.2.0 in a Docker container using the image dpage/pgadmin4, I notice that server connections are not being saved.
The container is created with the volume mapping:
./data/pgadmin:/root/.pgadmin
When the docker container is restarted, or when a user re-login to the dashboard, all the previously entered server connection details are gone.
How can we ensure that the connection details are properly saved?
For anyone still with this issue, I got it working using container folder /var/lib/pgadmin, so in your yml volume:
./data/pgadmin:/var/lib/pgadmin
Do you start it with docker run dpage/pgadmin4 or docker start {containerID}?
When I was doing it with docker run I had similar issues as you, but when I changed to docker start all connection details were normally there (even after computer reboot).