config: Use global user config if required (#1378)

If a config file is not found in a parent of the workspace, then we
attempt to load the user's global default file instead.

Signed-off-by: Charlie Egan <charlie@styra.com>

README.md

@@ -403,13 +403,26 @@ project:
 Regal will automatically search for a configuration file (`.regal/config.yaml`
 or `.regal.yaml`) in the current directory, and if not found, traverse the
 parent directories either until either one is found, or the top of the directory
-hierarchy is reached. If no configuration file is found, Regal will use the
-default configuration.
+hierarchy is reached. If no configuration file is found, and no file is found at
+`~/.config/regal/config.yaml` either, Regal will use the default configuration.
 
 A custom configuration may be also be provided using the `--config-file`/`-c`
 option for `regal lint`, which when provided will be used to override the
 default configuration.
 
+### User-level Configuration
+
+Generally, users will want to commit their Regal configuration file to the repo
+containing their Rego source code. This allows configurations to be shared
+among team members and makes the configuration options available to Regal when
+running as a [CI linter](https://docs.styra.com/regal/cicd) too.
+
+Sometimes however it can be handy to have some user defaults when a project
+configuration file is not found, hasn't been created yet or is not applicable.
+
+In such cases Regal will check for a configuration file at
+`~/.config/regal/config.yaml` instead.
+
 ## Ignoring Rules
 
 If one of Regal's rules doesn't align with your team's preferences, don't worry! Regal is not meant to be the law,

cmd/lint.go

@@ -362,7 +362,7 @@ func updateCheckAndWarn(params *lintCommandParams, regalRules *bundle.Bundle, us
 			CurrentVersion: version.Version,
 			CurrentTime:    time.Now().UTC(),
 			Debug:          params.debug,
-			StateDir:       config.GlobalDir(),
+			StateDir:       config.GlobalConfigDir(true),
 		}, os.Stderr)
 	}
 }

cmd/utils.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"path/filepath"
 	"time"
 
 	"github.com/styrainc/regal/pkg/config"
@@ -29,6 +30,20 @@ func readUserConfig(params configFileParams, searchPath string) (userConfig *os.
 		userConfig, err = config.FindConfig(searchPath)
 	}
 
+	// if there is no config found, attempt to load the user's global config if
+	// it exists
+	if err != nil {
+		globalConfigDir := config.GlobalConfigDir(false)
+		if globalConfigDir != "" {
+			globalConfigFile := filepath.Join(globalConfigDir, "config.yaml")
+
+			userConfig, err = os.Open(globalConfigFile)
+			if err != nil {
+				return nil, fmt.Errorf("failed to open global config file %w", err)
+			}
+		}
+	}
+
 	return userConfig, err //nolint:wrapcheck
 }
 

internal/lsp/server.go

@@ -660,7 +660,7 @@ func (l *LanguageServer) StartConfigWorker(ctx context.Context) {
 						CurrentVersion: version.Version,
 						CurrentTime:    time.Now().UTC(),
 						Debug:          false,
-						StateDir:       config.GlobalDir(),
+						StateDir:       config.GlobalConfigDir(true),
 					}, os.Stderr)
 				}
 			}()
@@ -2359,11 +2359,19 @@ func (l *LanguageServer) handleInitialize(ctx context.Context, params types.Init
 		})
 
 		configFile, err := config.FindConfig(workspaceRootPath)
-		if err == nil {
+
+		globalConfigDir := config.GlobalConfigDir(false)
+
+		switch {
+		case err == nil:
 			l.logf(log.LevelMessage, "using config file: %s", configFile.Name())
 			l.configWatcher.Watch(configFile.Name())
-		} else {
-			l.logf(log.LevelMessage, "no config file found in workspace: %s", err)
+		case globalConfigDir != "":
+			globalConfigFile := filepath.Join(globalConfigDir, "config.yaml")
+			l.logf(log.LevelMessage, "using global config file: %s", globalConfigFile)
+			l.configWatcher.Watch(globalConfigFile)
+		default:
+			l.logf(log.LevelMessage, "no config file found for workspace: %s", err)
 		}
 
 		if _, err = l.loadWorkspaceContents(ctx, false); err != nil {

pkg/config/global.go

@@ -5,17 +5,22 @@ import (
 	"path/filepath"
 )
 
-// GlobalDir is the config directory that will be used for user-wide configuration.
-// This is different from the .regal directories that are searched for when
-// linting.
-func GlobalDir() string {
+// GlobalConfigDir is the config directory that will be used for user-wide
+// configuration. This is different from the .regal directories that are
+// searched for when linting. If create is false, the function will return an
+// empty string if the directory does not exist.
+func GlobalConfigDir(create bool) string {
 	cfgDir, err := os.UserHomeDir()
 	if err != nil {
 		return ""
 	}
 
 	regalDir := filepath.Join(cfgDir, ".config", "regal")
 	if _, err := os.Stat(regalDir); os.IsNotExist(err) {
+		if !create {
+			return ""
+		}
+
 		if err := os.Mkdir(regalDir, os.ModePerm); err != nil {
 			return ""
 		}