conn closed when trying to make an insert into postgresql

Solution 1:

A single DB Connection is not concurrency safe and has no mechanism for reestablishing connections. Your issue is likely that concurrent access borked the connection, or it was closed for some other reason.

You want a DB Connection Pool so that it can create new connections for concurrent operations (requests for net/http servers handle connections concurrently). From https://pkg.go.dev/github.com/jackc/pgx/v4#hdr-Connection_Pool:

*pgx.Conn represents a single connection to the database and is not concurrency safe. Use sub-package pgxpool for a concurrency safe connection pool.

You should have better results with pgxpool - see https://pkg.go.dev/github.com/jackc/pgx/[email protected]/pgxpool#hdr-Establishing_a_Connection