Structured logging (#8673)

* Implementing structured logging

* Changes to en.json to allow refactor to run.

* Fixing global logger

* Structured logger initalization.

* Add caller.

* Do some log redirection.

* Auto refactor

* Cleaning up l4g reference and removing dependancy.

* Removing junk.

* Copyright headers.

* Fixing tests

* Revert "Changes to en.json to allow refactor to run."

This reverts commit fd8249e99bcad0231e6ea65cd77c32aae9a54026.

* Fixing some auto refactor strangeness and typo.

* Making keys more human readable.

app/app.go

@@ -5,6 +5,7 @@ package app
 
 import (
 	"crypto/ecdsa"
+	"fmt"
 	"html/template"
 	"net"
 	"net/http"
@@ -13,13 +14,13 @@ import (
 	"sync"
 	"sync/atomic"
 
-	l4g "github.com/alecthomas/log4go"
 	"github.com/gorilla/mux"
 	"github.com/pkg/errors"
 
 	"github.com/mattermost/mattermost-server/einterfaces"
 	ejobs "github.com/mattermost/mattermost-server/einterfaces/jobs"
 	"github.com/mattermost/mattermost-server/jobs"
+	"github.com/mattermost/mattermost-server/mlog"
 	"github.com/mattermost/mattermost-server/model"
 	"github.com/mattermost/mattermost-server/plugin/pluginenv"
 	"github.com/mattermost/mattermost-server/store"
@@ -35,6 +36,8 @@ type App struct {
 
 	Srv *Server
 
+	Log *mlog.Logger
+
 	PluginEnv              *pluginenv.Environment
 	PluginConfigListenerId string
 
@@ -77,6 +80,7 @@ type App struct {
 	sessionCache         *utils.Cache
 	configListenerId     string
 	licenseListenerId    string
+	logListenerId        string
 	disableConfigWatch   bool
 	configWatcher        *utils.ConfigWatcher
 	asymmetricSigningKey *ecdsa.PrivateKey
@@ -127,15 +131,23 @@ func New(options ...Option) (outApp *App, outErr error) {
 	}
 	model.AppErrorInit(utils.T)
 
-	// The first time we load config, clear any existing filters to allow the configuration
-	// changes to take effect. This is safe only because no one else is logging at this point.
-	l4g.Close()
-
 	if err := app.LoadConfig(app.configFile); err != nil {
-		// Re-initialize the default logger as we bail out.
-		l4g.Global = l4g.NewDefaultLogger(l4g.DEBUG)
 		return nil, err
 	}
+
+	// Initalize logging
+	app.Log = mlog.NewLogger(utils.MloggerConfigFromLoggerConfig(&app.Config().LogSettings))
+
+	// Redirect default golang logger to this logger
+	mlog.RedirectStdLog(app.Log)
+
+	// Use this app logger as the global logger (eventually remove all instances of global logging)
+	mlog.InitGlobalLogger(app.Log)
+
+	app.logListenerId = app.AddConfigListener(func(_, after *model.Config) {
+		app.Log.ChangeLevels(utils.MloggerConfigFromLoggerConfig(&after.LogSettings))
+	})
+
 	app.EnableConfigWatch()
 
 	app.LoadTimezones()
@@ -166,7 +178,7 @@ func New(options ...Option) (outApp *App, outErr error) {
 	})
 	app.regenerateClientConfig()
 
-	l4g.Info(utils.T("api.server.new_server.init.info"))
+	mlog.Info("Server is initializing...")
 
 	app.initEnterprise()
 
@@ -177,7 +189,7 @@ func New(options ...Option) (outApp *App, outErr error) {
 	}
 
 	if htmlTemplateWatcher, err := utils.NewHTMLTemplateWatcher("templates"); err != nil {
-		l4g.Error(utils.T("api.api.init.parsing_templates.error"), err)
+		mlog.Error(fmt.Sprintf("Failed to parse server templates %v", err))
 	} else {
 		app.htmlTemplateWatcher = htmlTemplateWatcher
 	}
@@ -210,7 +222,7 @@ func (a *App) configOrLicenseListener() {
 func (a *App) Shutdown() {
 	appCount--
 
-	l4g.Info(utils.T("api.server.stop_server.stopping.info"))
+	mlog.Info("Stopping Server...")
 
 	a.StopServer()
 	a.HubStop()
@@ -229,7 +241,8 @@ func (a *App) Shutdown() {
 
 	a.RemoveConfigListener(a.configListenerId)
 	a.RemoveLicenseListener(a.licenseListenerId)
-	l4g.Info(utils.T("api.server.stop_server.stopped.info"))
+	a.RemoveConfigListener(a.logListenerId)
+	mlog.Info("Server stopped")
 
 	a.DisableConfigWatch()
 }
@@ -499,7 +512,7 @@ func (a *App) HTTPClient(trustURLs bool) *http.Client {
 func (a *App) Handle404(w http.ResponseWriter, r *http.Request) {
 	err := model.NewAppError("Handle404", "api.context.404.app_error", nil, "", http.StatusNotFound)
 
-	l4g.Debug("%v: code=404 ip=%v", r.URL.Path, utils.GetIpAddress(r))
+	mlog.Debug(fmt.Sprintf("%v: code=404 ip=%v", r.URL.Path, utils.GetIpAddress(r)))
 
 	utils.RenderWebAppError(w, r, err, a.AsymmetricSigningKey())
 }
@@ -511,7 +524,7 @@ func (a *App) DoAdvancedPermissionsMigration() {
 		return
 	}
 
-	l4g.Info("Migrating roles to database.")
+	mlog.Info("Migrating roles to database.")
 	roles := model.MakeDefaultRoles()
 	roles = utils.SetRolePermissionsFromConfig(roles, a.Config(), a.License() != nil)
 
@@ -521,8 +534,8 @@ func (a *App) DoAdvancedPermissionsMigration() {
 		if result := <-a.Srv.Store.Role().Save(role); result.Err != nil {
 			// If this failed for reasons other than the role already existing, don't mark the migration as done.
 			if result2 := <-a.Srv.Store.Role().GetByName(role.Name); result2.Err != nil {
-				l4g.Critical("Failed to migrate role to database.")
-				l4g.Critical(result.Err)
+				mlog.Critical("Failed to migrate role to database.")
+				mlog.Critical(fmt.Sprint(result.Err))
 				allSucceeded = false
 			} else {
 				// If the role already existed, check it is the same and update if not.
@@ -534,8 +547,8 @@ func (a *App) DoAdvancedPermissionsMigration() {
 					role.Id = fetchedRole.Id
 					if result := <-a.Srv.Store.Role().Save(role); result.Err != nil {
 						// Role is not the same, but failed to update.
-						l4g.Critical("Failed to migrate role to database.")
-						l4g.Critical(result.Err)
+						mlog.Critical("Failed to migrate role to database.")
+						mlog.Critical(fmt.Sprint(result.Err))
 						allSucceeded = false
 					}
 				}
@@ -553,7 +566,7 @@ func (a *App) DoAdvancedPermissionsMigration() {
 	}
 
 	if result := <-a.Srv.Store.System().Save(&system); result.Err != nil {
-		l4g.Critical("Failed to mark advanced permissions migration as completed.")
-		l4g.Critical(result.Err)
+		mlog.Critical("Failed to mark advanced permissions migration as completed.")
+		mlog.Critical(fmt.Sprint(result.Err))
 	}
 }