feat: Add support for remote config file

pkg/commands/run.go

@@ -51,7 +51,10 @@ func wh(text string) string {
 	return color.GreenString(text)
 }
 
-const defaultTimeout = time.Minute
+const (
+	defaultTimeout                     = time.Minute
+	defaultRemoteConfigDownloadTimeout = 10 * time.Second
+)
 
 //nolint:funlen
 func initFlagSet(fs *pflag.FlagSet, cfg *config.Config, m *lintersdb.Manager, isFinalInit bool) {
@@ -104,7 +107,9 @@ func initFlagSet(fs *pflag.FlagSet, cfg *config.Config, m *lintersdb.Manager, is
 	fs.BoolVar(&rc.AnalyzeTests, "tests", true, wh("Analyze tests (*_test.go)"))
 	fs.BoolVar(&rc.PrintResourcesUsage, "print-resources-usage", false,
 		wh("Print avg and max memory usage of golangci-lint and total time"))
-	fs.StringVarP(&rc.Config, "config", "c", "", wh("Read config from file path `PATH`"))
+	fs.StringVarP(&rc.Config, "config", "c", "", wh("Read config from file path `PATH` or remote using (should start with http or https)"))
+	fs.DurationVar(&rc.RemoteConfigDownloadTimeout, "config-download-timeout", defaultRemoteConfigDownloadTimeout,
+		wh("Timeout for the remote config file download"))
 	fs.BoolVar(&rc.NoConfig, "no-config", false, wh("Don't read config"))
 	fs.StringSliceVar(&rc.SkipDirs, "skip-dirs", nil, wh("Regexps of directories to skip"))
 	fs.BoolVar(&rc.UseDefaultSkipDirs, "skip-dirs-use-default", true, getDefaultDirectoryExcludeHelp())

pkg/config/reader.go

@@ -1,8 +1,13 @@
 package config
 
 import (
+	"context"
 	"errors"
 	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
 	"os"
 	"path/filepath"
 	"strings"
@@ -19,6 +24,7 @@ type FileReader struct {
 	log            logutils.Log
 	cfg            *Config
 	commandLineCfg *Config
+	remoteConfig   bool
 }
 
 func NewFileReader(toCfg, commandLineCfg *Config, log logutils.Log) *FileReader {
@@ -43,6 +49,8 @@ func (r *FileReader) Read() error {
 		return fmt.Errorf("can't parse --config option: %s", err)
 	}
 
+	defer r.cleanConfigFile(configFile)
+
 	if configFile != "" {
 		viper.SetConfigFile(configFile)
 	} else {
@@ -212,10 +220,69 @@ func (r *FileReader) parseConfigOption() (string, error) {
 		return "", errConfigDisabled
 	}
 
+	r.remoteConfig = r.isRemoteFile(configFile)
+
+	if r.remoteConfig {
+		r.log.Infof("Provided config file is remote %s", configFile)
+
+		ctx, cancel := context.WithTimeout(context.Background(), r.commandLineCfg.Run.RemoteConfigDownloadTimeout)
+		defer cancel()
+
+		tmpConfigFile, err := r.downloadFile(ctx, configFile)
+		if err != nil {
+			return "", fmt.Errorf("failed to download config file")
+		}
+		return tmpConfigFile, nil
+	}
+
 	configFile, err := homedir.Expand(configFile)
 	if err != nil {
 		return "", fmt.Errorf("failed to expand configuration path")
 	}
 
 	return configFile, nil
 }
+
+func (r *FileReader) isRemoteFile(configFile string) bool {
+	u, err := url.Parse(configFile)
+	return err == nil && u.Scheme != "" && u.Host != "" && (u.Scheme == "http" || u.Scheme == "https")
+}
+
+func (r *FileReader) downloadFile(ctx context.Context, configFile string) (string, error) {
+	tmpfile, err := ioutil.TempFile("", "*.golangci.yml")
+	if err != nil {
+		return "", err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, configFile, nil)
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	_, err = io.Copy(tmpfile, resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	err = tmpfile.Close()
+	if err != nil {
+		return "", err
+	}
+
+	return tmpfile.Name(), nil
+}
+
+func (r *FileReader) cleanConfigFile(configFile string) {
+	if r.remoteConfig {
+		err := os.Remove(configFile)
+		if err != nil {
+			r.log.Warnf("Can't clean config file: %s", err)
+		}
+	}
+}

pkg/config/reader_test.go

@@ -0,0 +1,49 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsRemoteFile(t *testing.T) {
+	r := NewFileReader(nil, nil, nil)
+	tests := []struct {
+		ConfigFile string
+		IsRemote   bool
+	}{
+		{
+			ConfigFile: "~/config/.golangcilint.yaml",
+			IsRemote:   false,
+		},
+		{
+			ConfigFile: "~/http/config/.golangcilint.yaml",
+			IsRemote:   false,
+		},
+		{
+			ConfigFile: ".golangcilint.yaml",
+			IsRemote:   false,
+		},
+		{
+			ConfigFile: ".golangcilint.yaml",
+			IsRemote:   false,
+		},
+		{
+			ConfigFile: "localhost:8080/.golangci.example.yml",
+			IsRemote:   false, // Scheme is mandatory to determine if this is a remote file
+		},
+		{
+			ConfigFile: "https://raw.githubusercontent.com/golangci/golangci-lint/master/.golangci.example.yml",
+			IsRemote:   true,
+		},
+		{
+			ConfigFile: "http://localhost:8080/.golangci.example.yml",
+			IsRemote:   true,
+		},
+	}
+
+	for _, test := range tests {
+		result := r.isRemoteFile(test.ConfigFile)
+		assert.Equal(t, test.IsRemote, result)
+	}
+}

pkg/config/run.go

@@ -11,8 +11,9 @@ type Run struct {
 	Concurrency         int
 	PrintResourcesUsage bool `mapstructure:"print-resources-usage"`
 
-	Config   string
-	NoConfig bool
+	Config                      string
+	RemoteConfigDownloadTimeout time.Duration `mapstructure:"config-download-timeout"`
+	NoConfig                    bool
 
 	Args []string