step-3-running-the-app-locally.md

Step 3: Running the application locally

Go applications are usually started with go run while in development mode.

In order to simplify the experience of running the application locally, there is a Makefile in the root of the project with the dev target. This target starts the application in local dev mode, and it will basically be the entrypoint to start the application.

Start the application

In a terminal, run the following command:

make dev

A similar output log will appear:

go run ./...

 ┌───────────────────────────────────────────────────┐ 
 │                   Fiber v2.52.6                   │ 
 │               http://127.0.0.1:8080               │ 
 │       (bound on host 0.0.0.0 and port 8080)       │ 
 │                                                   │ 
 │ Handlers ............. 5  Processes ........... 1 │ 
 │ Prefork ....... Disabled  PID ............. 17433 │ 
 └───────────────────────────────────────────────────┘ 

If we open the browser in the URL http://localhost:8080, we will see the metadata of the application, but all the values are empty:

{"metadata":{"ratings_lambda":"","ratings":"","streams":"","talks":""}}

On the contrary, if we open the ratings endpoint from the API (http://localhost:8080/ratings?talkId=testcontainers-integration-testing), we will get a 500 error and a similar message:

{"message":"failed to connect to `host=/private/tmp user=mdelapenya database=`: dial error (dial unix /private/tmp/.s.PGSQL.5432: connect: no such file or directory)"}

The logs will show the following:

Unable to connect to database: failed to connect to `host=/private/tmp user=mdelapenya database=`: dial error (dial unix /private/tmp/.s.PGSQL.5432: connect: no such file or directory)
13:03:27 | 500 |     4.20625ms | 127.0.0.1 | GET | /ratings | -

It seems the application is not able to connect to the database. Let's fix it.

Next: Dev Mode with Testcontainers