Set and unset aws environment variables

in order to provide the CodeOcean context for some scripts and hide AWS credentials from the users.

internal/runner/aws_runner.go

@@ -84,6 +84,7 @@ func (w *AWSFunctionWorkload) ExecuteInteractively(id string, _ io.ReadWriter, s
 	if !ok {
 		return nil, nil, ErrorUnknownExecution
 	}
+	w.prepareEnvironmentVariables(request)
 	command, ctx, cancel := prepareExecution(request)
 	exitInternal := make(chan ExitInfo)
 	exit := make(chan ExitInfo, 1)
@@ -208,3 +209,12 @@ func (w *AWSFunctionWorkload) handleRunnerTimeout(ctx context.Context,
 		exit <- ExitInfo{255, ErrorRunnerInactivityTimeout}
 	}
 }
+
+// prepareEnvironmentVariables sets the CODEOCEAN variable and unsets some AWS variables.
+func (w *AWSFunctionWorkload) prepareEnvironmentVariables(request *dto.ExecutionRequest) {
+	if request.Environment == nil {
+		request.Environment = make(map[string]string)
+	}
+	request.Environment["CODEOCEAN"] = "true"
+	request.Command = "unset \"${!AWS@}\" && " + request.Command
+}