Tag: .NET

.Net 5.0 – This package is required for the Entity Framework Core Tools to work

I was trying to create a migration in a new project within a solution and received the following error:

Build started…
Build succeeded.
Your startup project ‘SubscriptionManagementGrpcService’ doesn’t reference Microsoft.EntityFrameworkCore.Design. This package is required for the Entity Framework Core Tools to work. Ensure your startup project is correct, install the package, and try again.

The error was a bit confusing because all of my migrations for the rest of the solution were still working and none of my other startup projects had Microsoft.EntityFrameworkCore.Design as a reference.

After a bit of comparing I realised that the other projects all referenced data projects that in turn referenced Microsoft.EntityFramework.Design. Adding the package reference to the subscription data library referenced by my GrpcService fixed the issue.

Unable to Migrate after Adding Config to Startup

Hi everyone,

Just a quick post on fixing up a migration error after I added new config to startup.cs via DI. The error after running add-migration was pretty unintuitive:

Unable to create an object of type 'ApplicationDbContext'. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

To find out a bit more I ran the following:

add-migration -verbose

This revealed the fact that there was an issue with adding my config line. The error stated that I had to have an empty constructor which led me on a bit of a wild goose chase.

The solution was simply a missed entry in application.json. In my case it was an omitted “assembly” section. Having said that, I did come across a few instances where people had the same problem when omitting commas etc.

Hopefully that’s able to get you on the right track!

Thanks,
Chris

Unable to Access RDS Database from Elastic Beanstalk Application

Hey everyone,

I ran into a bit of an issue today where I was unable to access my RDS SQL Express instance from my .NET Elastic Beanstalk instance. I was receiving the following error:

The server was not found or was not accessible.

The solution turned out to be fairly simply thanks to this StackOverflow post: http://stackoverflow.com/a/33207022/522859

Get your server instance security group:
– Log into AWS
– Navigate to elastic beanstalk
– Open your application instance
– Open configuration
– Open instances
– Find “server” on the page and copy the value in the “EC2 security groups” field

Add your server instance security group to your rds rules:
– Navigate to the RDS Dashboard
– Open your RDS instance
– Click on view details (left hand side or top)
– Find Security and Network
– Click on the rds-launch-wizard under security groups
– Click on inbound rules (very bottom currently)
– Add a new inbound rule with the copied security group as the source