From 5679a675f345b151fd6b079c799f6849800822fa Mon Sep 17 00:00:00 2001
From: Mohammed Sohail <sohailsameja@gmail.com>
Date: Thu, 16 Mar 2023 08:01:58 +0000
Subject: [PATCH] fix: system global lock

* add middleware to entire API group
* setNX system lock key
---
 cmd/service/api.go | 10 +++-------
 pkg/redis/pool.go  | 23 ++++++++++++++---------
 2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/cmd/service/api.go b/cmd/service/api.go
index 99d7e9d..a628507 100644
--- a/cmd/service/api.go
+++ b/cmd/service/api.go
@@ -1,7 +1,6 @@
 package main
 
 import (
-	"errors"
 	"net/http"
 	"time"
 
@@ -11,7 +10,6 @@ import (
 	"github.com/grassrootseconomics/cic-custodial/internal/custodial"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
-	"github.com/redis/go-redis/v9"
 )
 
 const (
@@ -49,9 +47,7 @@ func initApiServer(custodialContainer *custodial.Custodial) *echo.Echo {
 		})
 	}
 
-	apiRoute := server.Group("/api")
-
-	apiRoute.Use(systemGlobalLock)
+	apiRoute := server.Group("/api", systemGlobalLock)
 
 	apiRoute.POST("/account/create", api.HandleAccountCreate)
 	apiRoute.POST("/sign/transfer", api.HandleSignTransfer)
@@ -95,12 +91,12 @@ func systemGlobalLock(next echo.HandlerFunc) echo.HandlerFunc {
 		)
 
 		locked, err := cu.RedisClient.Get(c.Request().Context(), systemGlobalLockKey).Bool()
-		if !errors.Is(err, redis.Nil) {
+		if err != nil {
 			return err
 		}
 
 		if locked {
-			return c.JSON(http.StatusOK, api.ErrResp{
+			return c.JSON(http.StatusServiceUnavailable, api.ErrResp{
 				Ok:      false,
 				Message: "System manually locked.",
 			})
diff --git a/pkg/redis/pool.go b/pkg/redis/pool.go
index 4513ae8..4965404 100644
--- a/pkg/redis/pool.go
+++ b/pkg/redis/pool.go
@@ -7,14 +7,20 @@ import (
 	"github.com/redis/go-redis/v9"
 )
 
-type RedisPoolOpts struct {
-	DSN          string
-	MinIdleConns int
-}
+const (
+	systemGlobalLockKey = "system:global_lock"
+)
 
-type RedisPool struct {
-	Client *redis.Client
-}
+type (
+	RedisPoolOpts struct {
+		DSN          string
+		MinIdleConns int
+	}
+
+	RedisPool struct {
+		Client *redis.Client
+	}
+)
 
 // NewRedisPool creates a reusable connection across the cic-custodial componenent.
 // Note: Each db namespace requires its own connection pool.
@@ -31,8 +37,7 @@ func NewRedisPool(ctx context.Context, o RedisPoolOpts) (*RedisPool, error) {
 	ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
 	defer cancel()
 
-	_, err = redisClient.Ping(ctx).Result()
-	if err != nil {
+	if err := redisClient.SetNX(ctx, systemGlobalLockKey, false, 0).Err(); err != nil {
 		return nil, err
 	}