aws golang docker elastic beanstalk connect to rds - postgresql

So I am trying to connect a golang container running on elastic beanstalk to a rds postgres database and am having a lot of trouble doing it. Amazon documents how to connect every other language to rds insances (ruby, php, .net etc) but apparently they have yet to add documentation for go. I've been experimenting with stuff along the lines of
db, err := sql.Open("postgres", "postgres:postgres#tcp(UNIQUEtoINSTANCE.us-east-1.rds.amazonaws.com:5432)/ebdb")
to no avail. (and yes my test password is postgres). I have literally spent most of this afternoon working on this, googleing it, tweeking the local instance and reuploading. The security groups are correct. Any advice in troubleshooting this would be greatly appreciated or better yet actual go code for connecting the two (I know I am not the first person to use aws and an sql database).

Related

"error: too many connections for database 'postgres'" when trying to connect to any Postgres 13 instance

My team and I are currently experiencing an issue where we can't connect to Cloud SQL's Postgres instance(s) from anything other than the psql cli tool. We get a too many connections for database "postgres" error (in PGAdmin, DBeaver, and our node typeorm/pg backend). It initially happened on our (only) Postgres database instance. After restarting, stopping and starting again, increasing machine CPU/memory proved to do nothing, I deleted the database instance entirely and created a new one from scratch.
However, after a few hours the problem came back. I know that we're not actually having too many connections as I am able to query pg_stat_activity from psql command line and see the following:
Only one of those (postgres username) connections is ours.
My coworker also can't connect at all - not even from psql cli.
If it matters, we are using PostgreSQL 13, europe-west2 (London), single zone availability, db-g1-small instance with 1.7GB memory, 10GB HDD, and we have public IP enabled and the correct IP addresses whitelisted.
I'd really appreciate if anyone has any insights into what's causing this.
EDIT: I further increased the instance size (to no longer be a shared core), and I managed to successfully connect my backend to it. However my psql cli no longer works - it appears that only the first client to connect is allowed to connect after a restart (even if it disconnects, other clients can't connect...).
From the error message, it is clear that the database "postgres" has a custom connection limit (set, for example, by ALTER DATABASE postgres CONNECTION LIMIT 1). And apparently, it is quite small. Why is everyone try to connect to that database anyway? Usually 'postgres' database is reserved for maintenance operations, and you should create other databases for daily use.
You can see the setting with:
select datconnlimit from pg_database where datname='postgres';
I don't know if the low setting is something you did, or maybe Google does it on its own for their cloud offering.
#jjanes had the right idea/mention.
I created another database within the Cloud SQL instance that wasn't named postgres and then it was fine.
It wasn't anything to do with maximum connection settings (as this was within Google Cloud SQL) or not closing connections (as TypeORM/pg does this already).

AWS RDS vs local database in EC2 instance

I want to understand AWS Relational Database Service (RDS) and discover benefits from using it.
Why RDS is better than manually installed PostgreSQL database in EC2 instance?
Is it possible to connent existing database in EC2 instance with Amazon RDS?
How it really works?
How I should automation RDS?
When I want create new database in existing EC2 instance I can use Ansible in simply way. How I should connect my application with database which uses RDS ?
Thanks in advance!
I want to understand AWS Relational Database Service (RDS) and discover benefits from using it.
As already commented, read the docs and whitepapers.
Why RDS is better than manually installed PostgreSQL database in EC2 instance?
you can be sure it is well setup, you will get point in time recovery, backups and high availability. As well you can set it up yourself, however using RDS you have it all already configured.
Ifs it possible to connent existing database in EC2 instance with Amazon RDS? How it really works?
you don't have access to any underlying configuration, so nope, you cannot really connect ec2 database w/ rds (e. g. wal for wal streaming).
you still can use database migration tools to migrate all databases and updates to or from rds
How I should automation RDS? When I want create new database in existing EC2 instance I can use Ansible in simply way.
you can use a cloudformation template or cli commands
How I should connect my application with database which uses RDS ?
when you create a rds instance, you will define an admin user and receive a connection url
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_VPC.Scenarios.html#USER_VPC.Scenario1

How to connect a running container(tomcat) on amazon ec2 to RDS postgres

In aws, I have an amazon linux instance running with docker installed and my app running as a container. It's running in tomcat. However I need to connect it to my database.
I have made this work with a postgres container earlier doing this:
docker run --link <dbcontainername>:db -P -d tomcat-image
But to have the database more reliable it is wanted to use amazon RDS instead.
I have created a VPC with two subnets which both the instance and the RDS uses
And they are also both in the same Security Group.
I am able to access the tomcat fine through the public ip, but it throws errors because it isn't connected to the db.
Networking is not my strong suit, so there might be something there I am missing, but I find it hard to find any text describing this process without mentioning Elastic bean stalk.(It is my impression that it should be possible to do everything EBS does, manually)
There's a similar question asked here about 8 months ago, but he didn't get any responses so I'm trying again.

Connection to CloudBees database using MySQL Workbench

I've just uploaded my locally developed app to CloudBees. It works fine: I can load the web pages and it can access the database.
However, I cannot connect to its database (also provided by CloudBees) using MySQL Workbench or the command line tool. It always says
Can't connect to MySQL server on 'ec2-50-19-213-178.compute-1.amazonaws.com' (10060)
Any CloudBees configuration that I might be missing?
double check your database connection parameters using SDK : bees db:info -p <databasename>
you should be able to connect to DB using mysql workbench and other mysql tools.
In the MySQL forum exists a collection of links for various types of connections using MySQL Workbench. One is probably especially interesting for you as it deals with Amazon RDS databases. Among others it shows what connection parameters are needed.
Seems that there were some firewall problems in the corporate router that prevented me from connecting before. I tried at home and it worked.

Logging into Mongo on Amazon's EC2 (AWS) with MongoVUE

This question is specific to MongoVUE, but really I am looking to be able to log in to Mongo on EC2 in any way besides through the SSH tunnel. I can do that and get a server and client up and running, create documents, find things etc. I am new to mongo and ec2 so I will admit there are a lot of variables.
Here is what I've done so far:
I have created a unique database and then added a user to that with the db.addUser('name','password') command.
I am using the public dns that AWS provided which looks like, xxxx.us-west-1.compute.amazonaws.com
I have tried to log in with the plain text password as well as the one mongo displays (hashed).
My ultimate goal is to be able to connect through C#, but MongoVue gives me an easier platform to fiddle around with (I hope).
Any help would be great! Thank you.
I was trying to do the same thing and it actually ended up being pretty easy after following the instructions on Mongovue's Blog
http://www.mongovue.com/2011/08/04/mongovue-connection-to-remote-server-over-ssh/
This allows you to not have to open up the MongoDB port externally also.
Make sure you also convert your EC2 .pem key to a Putty Key via PuttyGen first.
Okay, I solved it for those of you that will find this question and be in the same boat. For some reason I could not change my security group on ec2 to the one I had given access to port 27017. So I added that port exception to the security group that was currently assigned to my instance.
I then had to log in through SSH to get the Mongo server up and running (simply run the mongod command in the bin directory) and then it logged right in. I used the username and password that I had set up earlier through the mongo command line.
I hope this helps someone.