🎉 initial commit

devices-worker/worker.lua

@@ -0,0 +1,111 @@
+local redis = require("redis")
+local cjson = require("cjson")
+local socket = require("socket")
+local log = require("log")
+
+local REDIS_HOST = os.getenv("REDIS_HOST") or "127.0.0.1"
+local REDIS_PORT = tonumber(os.getenv("REDIS_PORT")) or 6379
+local MAX_RETRIES = tonumber(os.getenv("WORKER_MAX_RETRIES")) or 3
+local DLQ_KEY = "devices:events:dlq"
+
+local device_handler = require("handlers.device_handler")
+local rating_handler = require("handlers.rating_handler")
+local review_handler = require("handlers.review_handler")
+
+local handlers = {
+    DevicePublished = device_handler.handle,
+    DeviceDeleted = device_handler.handle,
+    DeviceUpdated = device_handler.handle,
+    RatingPublished = rating_handler.handle,
+    ReviewPublished = review_handler.handle,
+    UserCreated = function(event)
+        log.info("User created", { component = "worker", user_id = event.user_id })
+    end,
+}
+
+local function move_to_dlq(red, event_json, reason)
+    red:lpush(DLQ_KEY, cjson.encode({
+        event = event_json,
+        reason = reason,
+        failed_at = os.time(),
+    }))
+    log.warn("Event moved to DLQ", { reason = reason, dlq_key = DLQ_KEY })
+end
+
+local function process_event(red, event_json)
+    local ok_decode, event = pcall(cjson.decode, event_json)
+    if not ok_decode or not event then
+        return false, "decode_failed"
+    end
+
+    local handler = handlers[event.event_type]
+    if not handler then
+        return true, nil -- Acknowledge unknown event types
+    end
+
+    local attempt = 0
+    local last_err
+
+    while attempt < MAX_RETRIES do
+        attempt = attempt + 1
+        local success, handler_err = pcall(handler, event)
+        if success then
+            return true, nil
+        end
+        last_err = tostring(handler_err)
+        if attempt < MAX_RETRIES then
+            local delay = math.min(2 ^ attempt * 0.5, 10)
+            log.warn("Handler failed, retrying", {
+                component = "worker",
+                attempt = attempt,
+                max_retries = MAX_RETRIES,
+                delay = delay,
+                err = last_err,
+            })
+            socket.sleep(delay)
+        end
+    end
+
+    return false, last_err
+end
+
+local function run_worker()
+    while true do
+        local ok, err = pcall(function()
+            log.info("Connecting to Redis", { component = "worker" })
+
+            local red = redis.connect(REDIS_HOST, REDIS_PORT)
+            log.info("Connected to Redis, waiting for events", { component = "worker" })
+
+            while true do
+                local event_json = red:brpoplpush("devices:events:queue", "devices:events:processing", 0)
+
+                if event_json then
+                    local success, reason = process_event(red, event_json)
+
+                    if success then
+                        red:lrem("devices:events:processing", 1, event_json)
+                        log.info("Event processed", { component = "worker" })
+                    else
+                        -- Move to DLQ and remove from processing
+                        move_to_dlq(red, event_json, reason)
+                        red:lrem("devices:events:processing", 1, event_json)
+                    end
+                end
+            end
+        end)
+
+        if not ok then
+            log.error("Worker error", { component = "worker", err = tostring(err) })
+            log.info("Reconnecting in 5 seconds", { component = "worker" })
+            socket.sleep(5)
+        end
+    end
+end
+
+log.info("Handheld Devices Worker starting", {
+    component = "worker",
+    redis = REDIS_HOST .. ":" .. REDIS_PORT,
+})
+
+run_worker()