Support for Postgres in aws rds

[ggrover]

While writing some tests for setting up postgres instance in AWS I noticed that rds.go only currently supports mysql. As a result, I've added support for postgres to my local branch. Just wondering if there are plans to add support for postgres in future? Would it be worthwhile to create PR with the set of changes that I have made.

[brikis98]

Most likely, yes! Could you tell us a bit more about what changes you've added?

[ggrover]

I've added to following functions to modules/aws/rds.go to check whether the specified schema/table name exists in the RDS instance

modified: modules/aws/rds.go
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
@@ -8,6 +8,7 @@ import (
    "github.com/aws/aws-sdk-go/service/rds"
    _ "github.com/go-sql-driver/mysql"
    "github.com/gruntwork-io/terratest/modules/testing"
+   _ "github.com/lib/pq"
 )

 // GetAddressOfRdsInstance gets the address of the given RDS Instance in the given region.
@@ -48,6 +49,36 @@ func GetPortOfRdsInstanceE(t testing.TestingT, dbInstanceID string, awsRegion st
    return *dbInstance.Endpoint.Port, nil
 }

+// GetWhetherSchemaExistsInRdsPostgresInstance checks whether the specified schema/table name exists in the RDS instance
+func GetWhetherSchemaExistsInRdsPostgresInstance(t testing.TestingT, dbUrl string, dbPort int64, dbUsername string, dbPassword string, expectedSchemaName string) bool {
+   output, err := GetWhetherSchemaExistsInRdsPostgresInstanceE(t, dbUrl, dbPort, dbUsername, dbPassword, expectedSchemaName)
+   if err != nil {
+       t.Fatal(err)
+   }
+   return output
+}
+
+// GetWhetherSchemaExistsInRdsPostgresInstanceE checks whether the specified schema/table name exists in the RDS instance
+func GetWhetherSchemaExistsInRdsPostgresInstanceE(t testing.TestingT, dbUrl string, dbPort int64, dbUsername string, dbPassword string, expectedSchemaName string) (bool, error) {
+   connectionString := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s", dbUrl, dbPort, dbUsername, dbPassword, expectedSchemaName)
+
+   db, connErr := sql.Open("postgres", connectionString)
+   if connErr != nil {
+       return false, connErr
+   }
+   defer db.Close()
+   var (
+       schemaName string
+   )
+   sqlStatement := `SELECT "catalog_name" FROM "information_schema"."schemata" where catalog_name=$1`
+   row := db.QueryRow(sqlStatement, expectedSchemaName)
+   scanErr := row.Scan(&schemaName)
+   if scanErr != nil {
+       return false, scanErr
+   }
+   return true, nil
+}
+