Automatically reload the server after configuration changes (#22)

* Move app logic to separate structure

* Moved mapping normalisation in config loading

* Optimised memory allocation at starting time

* Auto restert draft

* Refactor server stoppting

* Updated roadmap

* Fixed config watching

* Added graceful shutdown

* Cleanup code

* Move server package functionality to uncors app

* Fixed linting

* Added tests for restarting

* WIP: tests

* WIP

* Removed unused deps

* Enables skipped tests

* Fixed tests for GracefulShutdown

* Added helpers.PanicInterceptor for config reloading

.github/workflows/go.yml

@@ -31,7 +31,7 @@ jobs:
         run: go build -tags release -v .
 
       - name: Test
-        run: go test -tags release -v -coverprofile=coverage.out ./...
+        run: go test -tags release -timeout 1m -v -coverprofile=coverage.out ./...
 
       - name: SonarCloud Scan
         uses: SonarSource/sonarcloud-github-action@master

.gitignore

@@ -2,7 +2,6 @@ __debug_bin
 server.key
 server.crt
 dist/
-uncors
 .idea
 node_modules
 .uncors.yaml

ROADMAP.md

@@ -52,14 +52,15 @@
 
 ## [0.1.0 Release](https://github.com/evg4b/uncors/releases/tag/v0.1.0)
 
-- [X] Static file serving [PR](https://github.com/evg4b/uncors/pull/15)
+- [X] Static file serving - [PR](https://github.com/evg4b/uncors/pull/15)
 - [X] Own error page for uncors internal errors
-- [X] Separated mock for each url mapping [PR](https://github.com/evg4b/uncors/pull/16)
+- [X] Separated mock for each url mapping - [PR](https://github.com/evg4b/uncors/pull/16)
 
 ## Next Release
 
-- [X] Response caching [PR](https://github.com/evg4b/uncors/pull/17)
-- [X] JSON Schema for config file [PR](https://github.com/evg4b/uncors/pull/19)
+- [X] Response caching - [PR](https://github.com/evg4b/uncors/pull/17)
+- [X] JSON Schema for config file - [PR](https://github.com/evg4b/uncors/pull/19)
+- [ ] Automatically reload the server after configuration changes - [PR](https://github.com/evg4b/uncors/pull/22)
 
 ## Future features
 

go.mod

@@ -8,13 +8,12 @@ require (
 	github.com/PuerkitoBio/purell v1.2.0
 	github.com/bmatcuk/doublestar/v4 v4.6.0
 	github.com/go-http-utils/headers v0.0.0-20181008091004-fed159eddc2a
-	github.com/go-playground/assert/v2 v2.2.0
 	github.com/go-playground/validator/v10 v10.15.4
 	github.com/gojuno/minimock/v3 v3.1.3
 	github.com/gorilla/mux v1.8.0
 	github.com/hashicorp/go-version v1.6.0
 	github.com/mitchellh/mapstructure v1.5.0
-	github.com/pseidemann/finish v1.2.0
+	github.com/phayes/freeport v0.0.0-20220201140144-74d24b5ae9f5
 	github.com/pterm/pterm v0.12.69
 	github.com/samber/lo v1.38.1
 	github.com/spf13/afero v1.9.5
@@ -30,7 +29,7 @@ require (
 	atomicgo.dev/schedule v0.1.0 // indirect
 	github.com/containerd/console v1.0.3 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/fsnotify/fsnotify v1.6.0 // indirect
+	github.com/fsnotify/fsnotify v1.6.0
 	github.com/gabriel-vasile/mimetype v1.4.2 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect

go.sum

@@ -203,13 +203,13 @@ github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaR
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/pelletier/go-toml/v2 v2.1.0 h1:FnwAJ4oYMvbT/34k9zzHuZNrhlz48GB3/s6at6/MHO4=
 github.com/pelletier/go-toml/v2 v2.1.0/go.mod h1:tJU2Z3ZkXwnxa4DPO899bsyIoywizdUvyaeZurnPPDc=
+github.com/phayes/freeport v0.0.0-20220201140144-74d24b5ae9f5 h1:Ii+DKncOVM8Cu1Hc+ETb5K+23HdAMvESYE3ZJ5b5cMI=
+github.com/phayes/freeport v0.0.0-20220201140144-74d24b5ae9f5/go.mod h1:iIss55rKnNBTvrwdmkUpLnDpZoAHvWaiq5+iMmen4AE=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/sftp v1.13.1/go.mod h1:3HaPG6Dq1ILlpPZRO0HVMrsydcdLt6HRDccSgb87qRg=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
-github.com/pseidemann/finish v1.2.0 h1:XrEc9FCnBPulyM9NvAptAtcOCZZYHwV0MRCcnCfQlnw=
-github.com/pseidemann/finish v1.2.0/go.mod h1:Wl17vXLhlT9a/K7jryhExgJPfbs4+dUpRaauEWt7oQ4=
 github.com/pterm/pterm v0.12.27/go.mod h1:PhQ89w4i95rhgE+xedAoqous6K9X+r6aSOI2eFF7DZI=
 github.com/pterm/pterm v0.12.29/go.mod h1:WI3qxgvoQFFGKGjGnJR849gU0TsEOvKn5Q8LlY1U7lg=
 github.com/pterm/pterm v0.12.30/go.mod h1:MOqLIyMOgmTDz9yorcYbcw+HsgoZo3BQfg2wtl3HEFE=

internal/config/config.go

@@ -3,6 +3,8 @@ package config
 import (
 	"fmt"
 
+	"github.com/evg4b/uncors/internal/helpers"
+
 	"github.com/mitchellh/mapstructure"
 	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
@@ -13,6 +15,8 @@ const (
 	defaultHTTPSPort = 443
 )
 
+var flags *pflag.FlagSet
+
 type UncorsConfig struct {
 	HTTPPort    int         `mapstructure:"http-port"    validate:"required"`
 	Mappings    Mappings    `mapstructure:"mappings"     validate:"required"`
@@ -29,7 +33,8 @@ func (c *UncorsConfig) IsHTTPSEnabled() bool {
 }
 
 func LoadConfiguration(viperInstance *viper.Viper, args []string) *UncorsConfig {
-	flags := defineFlags()
+	defineFlags()
+	helpers.AssertIsDefined(flags)
 	if err := flags.Parse(args); err != nil {
 		panic(fmt.Errorf("filed parsing flags: %w", err))
 	}
@@ -61,14 +66,25 @@ func LoadConfiguration(viperInstance *viper.Viper, args []string) *UncorsConfig
 	}
 
 	if err := readURLMapping(viperInstance, configuration); err != nil {
-		panic(fmt.Errorf("recognize url mapping: %w", err))
+		panic(err)
+	}
+
+	configuration.Mappings = NormaliseMappings(
+		configuration.Mappings,
+		configuration.HTTPPort,
+		configuration.HTTPSPort,
+		configuration.IsHTTPSEnabled(),
+	)
+
+	if err := Validate(configuration); err != nil {
+		panic(err)
 	}
 
 	return configuration
 }
 
-func defineFlags() *pflag.FlagSet {
-	flags := pflag.NewFlagSet("uncors", pflag.ContinueOnError)
+func defineFlags() {
+	flags = pflag.NewFlagSet("uncors", pflag.ContinueOnError)
 	flags.Usage = pflag.Usage
 	flags.StringSliceP("to", "t", []string{}, "Target host with protocol for to the resource to be proxy")
 	flags.StringSliceP("from", "f", []string{}, "Local host with protocol for to the resource from which proxying will take place") //nolint: lll
@@ -79,6 +95,4 @@ func defineFlags() *pflag.FlagSet {
 	flags.String("proxy", "", "HTTP/HTTPS proxy to provide requests to real server (used system by default)")
 	flags.Bool("debug", false, "Show debug output")
 	flags.StringP("config", "c", "", "Path to the configuration file")
-
-	return flags
 }

internal/config/config_test.go

@@ -1,6 +1,8 @@
+// nolint: nosprintfhostport
 package config_test
 
 import (
+	"fmt"
 	"net/http"
 	"testing"
 	"time"
@@ -76,15 +78,22 @@ mappings:
 )
 
 func TestLoadConfiguration(t *testing.T) {
-	viperInstance := viper.New()
-	viperInstance.SetFs(testutils.FsFromMap(t, map[string]string{
+	fs := testutils.FsFromMap(t, map[string]string{
 		corruptedConfigPath: corruptedConfig,
 		fullConfigPath:      fullConfig,
 		incorrectConfigPath: incorrectConfig,
 		minimalConfigPath:   minimalConfig,
-	}))
+	})
 
 	t.Run("correctly parse config", func(t *testing.T) {
+		HTTPf := func(host string, port int) string {
+			return fmt.Sprintf("http://%s:%d", host, port)
+		}
+
+		HTTPSf := func(host string, port int) string {
+			return fmt.Sprintf("https://%s:%d", host, port)
+		}
+
 		tests := []struct {
 			name     string
 			args     []string
@@ -111,7 +120,7 @@ func TestLoadConfiguration(t *testing.T) {
 					HTTPPort:  8080,
 					HTTPSPort: 443,
 					Mappings: config.Mappings{
-						{From: testconstants.HTTPLocalhost, To: testconstants.HTTPSGithub},
+						{From: testconstants.HTTPLocalhostWithPort(8080), To: testconstants.HTTPSGithub},
 					},
 					CacheConfig: config.CacheConfig{
 						ExpirationTime: config.DefaultExpirationTime,
@@ -126,9 +135,9 @@ func TestLoadConfiguration(t *testing.T) {
 				expected: &config.UncorsConfig{
 					HTTPPort: 8080,
 					Mappings: config.Mappings{
-						{From: testconstants.HTTPLocalhost, To: testconstants.HTTPSGithub},
+						{From: testconstants.HTTPLocalhostWithPort(8080), To: testconstants.HTTPSGithub},
 						{
-							From: testconstants.HTTPLocalhost2,
+							From: testconstants.HTTPLocalhost2WithPort(8080),
 							To:   testconstants.HTTPSStackoverflow,
 							Mocks: config.Mocks{
 								{
@@ -178,9 +187,9 @@ func TestLoadConfiguration(t *testing.T) {
 				expected: &config.UncorsConfig{
 					HTTPPort: 8080,
 					Mappings: config.Mappings{
-						{From: testconstants.HTTPLocalhost, To: testconstants.HTTPSGithub},
+						{From: testconstants.HTTPLocalhostWithPort(8080), To: testconstants.HTTPSGithub},
 						{
-							From: testconstants.HTTPLocalhost2,
+							From: testconstants.HTTPLocalhost2WithPort(8080),
 							To:   testconstants.HTTPSStackoverflow,
 							Mocks: config.Mocks{
 								{
@@ -203,9 +212,12 @@ func TestLoadConfiguration(t *testing.T) {
 								},
 							},
 						},
-						{From: testconstants.SourceHost1, To: testconstants.TargetHost1},
-						{From: testconstants.SourceHost2, To: testconstants.TargetHost2},
-						{From: testconstants.SourceHost3, To: testconstants.TargetHost3},
+						{From: HTTPf(testconstants.SourceHost1, 8080), To: testconstants.TargetHost1},
+						{From: HTTPSf(testconstants.SourceHost1, 8081), To: testconstants.TargetHost1},
+						{From: HTTPf(testconstants.SourceHost2, 8080), To: testconstants.TargetHost2},
+						{From: HTTPSf(testconstants.SourceHost2, 8081), To: testconstants.TargetHost2},
+						{From: HTTPf(testconstants.SourceHost3, 8080), To: testconstants.TargetHost3},
+						{From: HTTPSf(testconstants.SourceHost3, 8081), To: testconstants.TargetHost3},
 					},
 					Proxy:     "localhost:8080",
 					Debug:     true,
@@ -223,8 +235,13 @@ func TestLoadConfiguration(t *testing.T) {
 				},
 			},
 		}
+
 		for _, testCase := range tests {
 			t.Run(testCase.name, func(t *testing.T) {
+				viper.Reset()
+				viperInstance := viper.New()
+				viperInstance.SetFs(fs)
+
 				uncorsConfig := config.LoadConfiguration(viperInstance, testCase.args)
 
 				assert.Equal(t, testCase.expected, uncorsConfig)
@@ -253,7 +270,7 @@ func TestLoadConfiguration(t *testing.T) {
 					params.To, testconstants.TargetHost1,
 				},
 				expected: []string{
-					"recognize url mapping: `from` values are not set for every `to`",
+					"`from` values are not set for every `to`",
 				},
 			},
 			{
@@ -263,7 +280,7 @@ func TestLoadConfiguration(t *testing.T) {
 					params.From, testconstants.SourceHost2,
 				},
 				expected: []string{
-					"recognize url mapping: `to` values are not set for every `from`",
+					"`to` values are not set for every `from`",
 				},
 			},
 			{
@@ -273,19 +290,18 @@ func TestLoadConfiguration(t *testing.T) {
 					params.To, testconstants.TargetHost2,
 				},
 				expected: []string{
-					"recognize url mapping: `from` values are not set for every `to`",
+					"`from` values are not set for every `to`",
+				},
+			},
+			{
+				name: "config file doesn't exist",
+				args: []string{
+					params.Config, "/not-exist-config.yaml",
+				},
+				expected: []string{
+					"filed to read config file '/not-exist-config.yaml': open /not-exist-config.yaml: file does not exist",
 				},
 			},
-			//{
-			//	name: "config file doesn't exist",
-			//	args: []string{
-			//		params.Config, "/not-exist-config.yaml",
-			//	},
-			//	expected: []string{
-			//		"filed to read config file '/not-exist-config.yaml': open ",
-			//		"open /not-exist-config.yaml: file does not exist",
-			//	},
-			// },
 			{
 				name: "config file is corrupted",
 				args: []string{
@@ -318,8 +334,13 @@ func TestLoadConfiguration(t *testing.T) {
 			},
 		}
 		for _, testCase := range tests {
+			testCase := testCase
 			t.Run(testCase.name, func(t *testing.T) {
 				for _, expected := range testCase.expected {
+					viper.Reset()
+					viperInstance := viper.New()
+					viperInstance.SetFs(fs)
+
 					assert.PanicsWithError(t, expected, func() {
 						config.LoadConfiguration(viperInstance, testCase.args)
 					})

internal/config/helpers.go

@@ -75,7 +75,7 @@ const (
 )
 
 func NormaliseMappings(mappings Mappings, httpPort int, httpsPort int, useHTTPS bool) Mappings {
-	var processedMappings Mappings
+	processedMappings := Mappings{}
 	for _, mapping := range mappings {
 		sourceURL, err := urlx.Parse(mapping.From)
 		if err != nil {

internal/helpers/graceful_shutdown.go

@@ -0,0 +1,43 @@
+package helpers
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+var (
+	notifyFn  = signal.Notify
+	sigintFix = func() {
+		// fix prints after "^C"
+		println("") // nolint:forbidigo
+	}
+)
+
+func GracefulShutdown(ctx context.Context, shutdownFunc func(ctx context.Context) error) error {
+	if done := waiteSignal(ctx); done {
+		return nil
+	}
+
+	return shutdownFunc(ctx)
+}
+
+func waiteSignal(ctx context.Context) bool {
+	stop := make(chan os.Signal, 1)
+
+	notifyFn(stop, syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
+
+	defer close(stop)
+
+	select {
+	case sig := <-stop:
+		if sig == syscall.SIGINT {
+			sigintFix()
+		}
+	case <-ctx.Done():
+		return true
+	}
+
+	return false
+}