Establish conn to curret-context if no args given

cmd/modern/main.go

@@ -45,10 +45,32 @@ func main() {
 		cmdparser.Initialize(initializeCallback)
 		rootCmd.Execute()
 	} else {
+		initializeEnvVars()
 		legacyCmd.Execute(version)
 	}
 }
 
+// initializeEnvVars intializes SQLCMDSERVER, SQLCMDUSER and SQLCMDPASSWORD
+// if the currentContext is set and if these env vars are not already set.
+// In terms of precedence, command line switches/flags take higher precedence
+// than env variables and env variables take higher precedence over config
+// file info.
+func initializeEnvVars() {
+	initializeCallback()
+	if config.CurrentContextName() != "" {
+		server, username, password := config.GetCurrentContextInfo()
+		if os.Getenv("SQLCMDSERVER") == "" {
+			os.Setenv("SQLCMDSERVER", server)
+		}
+		if os.Getenv("SQLCMDUSER") == "" {
+			os.Setenv("SQLCMDUSER", username)
+		}
+		if os.Getenv("SQLCMDPASSWORD") == "" {
+			os.Setenv("SQLCMDPASSWORD", password)
+		}
+	}
+}
+
 // isFirstArgModernCliSubCommand is TEMPORARY code, to be removed when
 // we remove the Kong based CLI
 func isFirstArgModernCliSubCommand() (isNewCliCommand bool) {

internal/config/context.go

@@ -75,10 +75,12 @@ func CurrentContext() (endpoint Endpoint, user *User) {
 				}
 			}
 
-			for _, u := range config.Users {
-				if u.Name == *c.User {
-					user = &u
-					break
+			if UserExists(c) {
+				for _, u := range config.Users {
+					if u.Name == *c.User {
+						user = &u
+						break
+					}
 				}
 			}
 		}
@@ -94,6 +96,23 @@ func CurrentContext() (endpoint Endpoint, user *User) {
 	return
 }
 
+// GetCurrentContextInfo returns endpoint and basic auth info
+// associated with current context
+func GetCurrentContextInfo() (server string, username string, password string) {
+	endpoint, user := CurrentContext()
+	server = fmt.Sprintf("%s,%d", endpoint.Address, endpoint.Port)
+	if user != nil {
+		username = user.BasicAuth.Username
+		if user.AuthenticationType == "basic" {
+			password = decryptCallback(
+				user.BasicAuth.Password,
+				user.BasicAuth.PasswordEncrypted,
+			)
+		}
+	}
+	return
+}
+
 // DeleteContext removes the context with the given name from the application's
 // configuration. If the context does not exist, the function does nothing. The
 // function also updates the CurrentContext field in the configuration to the

internal/config/user.go

@@ -5,8 +5,9 @@ package config
 
 import (
 	"fmt"
-	. "github.com/microsoft/go-sqlcmd/cmd/modern/sqlconfig"
 	"strconv"
+
+	. "github.com/microsoft/go-sqlcmd/cmd/modern/sqlconfig"
 )
 
 // AddUser adds a new user to the configuration.
@@ -123,3 +124,9 @@ func userOrdinal(name string) (ordinal int) {
 	}
 	return
 }
+
+// UserExists checks if the current context has a 'user', e.g. a context used
+// for trusted authentication will not have a user.
+func UserExists(context Context) bool {
+	return context.ContextDetails.User != nil && *context.ContextDetails.User != ""
+}