[feature] Allow user to show instead of landing page on / (#922)

* configurable user instead of landing page

* rename DefaultUser to LandingPageUser

* code review changes and fix tests

* try to fix pipeline error

* code review changes

* code review changes

* code review changes

* remove unnecessary line

6 files changed, 37 insertions, 1 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
index 79babf8bc..98114dea3 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -47,6 +47,7 @@ type Configuration struct {
 	LogLevel        string   `name:"log-level" usage:"Log level to run at: [trace, debug, info, warn, fatal]"`
 	LogDbQueries    bool     `name:"log-db-queries" usage:"Log database queries verbosely when log-level is trace or debug"`
 	ApplicationName string   `name:"application-name" usage:"Name of the application, used in various places internally"`
+	LandingPageUser string   `name:"landing-page-user" usage:"the user that should be shown on the instance's landing page"`
 	ConfigPath      string   `name:"config-path" usage:"Path to a file containing gotosocial configuration. Values set in this file will be overwritten by values set as env vars or arguments"`
 	Host            string   `name:"host" usage:"Hostname to use for the server (eg., example.org, gotosocial.whatever.com). DO NOT change this on a server that's already run!"`
 	AccountDomain   string   `name:"account-domain" usage:"Domain to use in account names (eg., example.org, whatever.com). If not set, will default to the setting for host. DO NOT change this on a server that's already run!"`
diff --git a/internal/config/defaults.go b/internal/config/defaults.go
index 7a2b806f8..37ca5e31d 100644
--- a/internal/config/defaults.go
+++ b/internal/config/defaults.go
@@ -26,6 +26,7 @@ var Defaults = Configuration{
 	LogLevel:        "info",
 	LogDbQueries:    false,
 	ApplicationName: "gotosocial",
+	LandingPageUser: "",
 	ConfigPath:      "",
 	Host:            "",
 	AccountDomain:   "",
diff --git a/internal/config/flags.go b/internal/config/flags.go
index 7b416815e..38d4cd51a 100644
--- a/internal/config/flags.go
+++ b/internal/config/flags.go
@@ -29,6 +29,7 @@ func AddGlobalFlags(cmd *cobra.Command) {
 	Config(func(cfg *Configuration) {
 		// General
 		cmd.PersistentFlags().String(ApplicationNameFlag(), cfg.ApplicationName, fieldtag("ApplicationName", "usage"))
+		cmd.PersistentFlags().String(LandingPageUserFlag(), cfg.LandingPageUser, fieldtag("LandingPageUser", "usage"))
 		cmd.PersistentFlags().String(HostFlag(), cfg.Host, fieldtag("Host", "usage"))
 		cmd.PersistentFlags().String(AccountDomainFlag(), cfg.AccountDomain, fieldtag("AccountDomain", "usage"))
 		cmd.PersistentFlags().String(ProtocolFlag(), cfg.Protocol, fieldtag("Protocol", "usage"))
diff --git a/internal/config/helpers.gen.go b/internal/config/helpers.gen.go
index 71f96920f..f42593a54 100644
--- a/internal/config/helpers.gen.go
+++ b/internal/config/helpers.gen.go
@@ -1794,3 +1794,29 @@ func GetAdvancedCookiesSamesite() string { return global.GetAdvancedCookiesSames
 
 // SetAdvancedCookiesSamesite safely sets the value for global configuration 'AdvancedCookiesSamesite' field
 func SetAdvancedCookiesSamesite(v string) { global.SetAdvancedCookiesSamesite(v) }
+
+// GetLandingPageUser safely fetches the Configuration value for state's 'LandingPageUser' field
+func (st *ConfigState) GetLandingPageUser() (v string) {
+	st.mutex.Lock()
+	v = st.config.LandingPageUser
+	st.mutex.Unlock()
+	return
+}
+
+// SetLandingPageUser safely sets the Configuration value for state's 'LandingPageUser' field
+func (st *ConfigState) SetLandingPageUser(v string) {
+	st.mutex.Lock()
+	defer st.mutex.Unlock()
+	st.config.LandingPageUser = v
+	st.reloadToViper()
+}
+
+// LandingPageUserFlag returns the flag name for the 'LandingPageUser' field
+func LandingPageUserFlag() string { return "landing-page-user" }
+
+// GetLandingPageUser safely fetches the value for global configuration 'LandingPageUser' field
+func GetLandingPageUser() string { return global.GetLandingPageUser() }
+
+// SetLandingPageUser safely sets the value for global configuration 'LandingPageUser' field
+func SetLandingPageUser(v string) { global.SetLandingPageUser(v) }
+
diff --git a/internal/web/base.go b/internal/web/base.go
index 61b4634ed..0dae30772 100644
--- a/internal/web/base.go
+++ b/internal/web/base.go
@@ -20,6 +20,7 @@ package web
 
 import (
 	"net/http"
+	"strings"
 
 	"github.com/gin-gonic/gin"
 	"github.com/superseriousbusiness/gotosocial/internal/api"
@@ -28,6 +29,13 @@ import (
 )
 
 func (m *Module) baseHandler(c *gin.Context) {
+
+	// if a landingPageUser is set in the config, redirect to that user's profile
+	if landingPageUser := config.GetLandingPageUser(); landingPageUser != "" {
+		c.Redirect(http.StatusFound, "/@"+c.Param(strings.ToLower(landingPageUser)))
+		return
+	}
+
 	host := config.GetHost()
 	instance, err := m.processor.InstanceGet(c.Request.Context(), host)
 	if err != nil {
diff --git a/internal/web/profile.go b/internal/web/profile.go
index 27de99e13..5023fa238 100644
--- a/internal/web/profile.go
+++ b/internal/web/profile.go
@@ -49,7 +49,6 @@ func (m *Module) profileGETHandler(c *gin.Context) {
 		return
 	}
 
-	// usernames on our instance will always be lowercase
 	username := strings.ToLower(c.Param(usernameKey))
 	if username == "" {
 		err := errors.New("no account username specified")