From 537057ee9af37e5915c1acc1cdb12d4e56e4a0f7 Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Wed, 22 Oct 2025 16:30:04 -0500
Subject: [PATCH] more redis cleanup

---
 lib/aprsme/redis_rate_limiter.ex     | 165 ---------------------------
 lib/aprsme_web/plugs/health_check.ex |  18 +--
 2 files changed, 1 insertion(+), 182 deletions(-)
 delete mode 100644 lib/aprsme/redis_rate_limiter.ex

diff --git a/lib/aprsme/redis_rate_limiter.ex b/lib/aprsme/redis_rate_limiter.ex
deleted file mode 100644
index cd836b0..0000000
--- a/lib/aprsme/redis_rate_limiter.ex
+++ /dev/null
@@ -1,165 +0,0 @@
-defmodule Aprsme.RedisRateLimiter do
-  @moduledoc """
-  Redis-backed distributed rate limiter using sliding window algorithm.
-  """
-
-  require Logger
-
-  # 5 seconds timeout for Redis operations
-  @redis_timeout 5000
-
-  def child_spec(_opts) do
-    children = [
-      {Redix, name: __MODULE__, host: redis_host(), port: redis_port(), password: redis_password()}
-    ]
-
-    %{
-      id: __MODULE__,
-      type: :supervisor,
-      start: {Supervisor, :start_link, [children, [strategy: :one_for_one, name: :"#{__MODULE__}_supervisor"]]}
-    }
-  end
-
-  @doc """
-  Check rate limit using sliding window algorithm.
-
-  ## Parameters
-    - bucket: The rate limit bucket (e.g., "user:123" or "ip:192.168.1.1")
-    - limit: Maximum number of requests allowed
-    - window_ms: Time window in milliseconds
-    
-  ## Returns
-    - {:allow, count} if under limit
-    - {:deny, limit} if over limit
-  """
-  def check_rate(bucket, limit, window_ms) do
-    now = System.system_time(:millisecond)
-    window_start = now - window_ms
-    key = make_key(bucket)
-
-    # Lua script for atomic sliding window rate limiting
-    lua_script = """
-    local key = KEYS[1]
-    local now = tonumber(ARGV[1])
-    local window_start = tonumber(ARGV[2])
-    local limit = tonumber(ARGV[3])
-
-    -- Remove old entries
-    redis.call('ZREMRANGEBYSCORE', key, 0, window_start)
-
-    -- Count current entries
-    local current = redis.call('ZCARD', key)
-
-    if current < limit then
-      -- Add new entry
-      redis.call('ZADD', key, now, now)
-      -- Set expiry
-      redis.call('EXPIRE', key, math.ceil(ARGV[4] / 1000))
-      return {1, current + 1}
-    else
-      return {0, limit}
-    end
-    """
-
-    case Redix.command(__MODULE__, ["EVAL", lua_script, 1, key, now, window_start, limit, window_ms],
-           timeout: @redis_timeout
-         ) do
-      {:ok, [1, count]} ->
-        {:allow, count}
-
-      {:ok, [0, limit]} ->
-        {:deny, limit}
-
-      {:error, reason} ->
-        Logger.error("Redis rate limit error for #{bucket}: #{inspect(reason)}")
-        # Fail open - allow request if Redis is down
-        {:allow, 1}
-    end
-  end
-
-  @doc """
-  Reset rate limit for a bucket
-  """
-  def reset(bucket) do
-    key = make_key(bucket)
-
-    case Redix.command(__MODULE__, ["DEL", key], timeout: @redis_timeout) do
-      {:ok, _} ->
-        :ok
-
-      {:error, reason} ->
-        Logger.error("Redis rate limit reset error for #{bucket}: #{inspect(reason)}")
-        {:error, reason}
-    end
-  end
-
-  @doc """
-  Get current count for a bucket
-  """
-  def count(bucket, window_ms) do
-    now = System.system_time(:millisecond)
-    window_start = now - window_ms
-    key = make_key(bucket)
-
-    # Clean up old entries and count
-    case Redix.pipeline(
-           __MODULE__,
-           [
-             ["ZREMRANGEBYSCORE", key, 0, window_start],
-             ["ZCARD", key]
-           ],
-           timeout: @redis_timeout
-         ) do
-      {:ok, [_, count]} ->
-        {:ok, count}
-
-      {:error, reason} ->
-        Logger.error("Redis rate limit count error for #{bucket}: #{inspect(reason)}")
-        {:error, reason}
-    end
-  end
-
-  @doc """
-  Get remaining requests for a bucket
-  """
-  def remaining(bucket, limit, window_ms) do
-    case count(bucket, window_ms) do
-      {:ok, current} -> {:ok, max(0, limit - current)}
-      error -> error
-    end
-  end
-
-  # Private functions
-
-  defp make_key(bucket) do
-    "aprsme:rate_limit:#{bucket}"
-  end
-
-  defp redis_host do
-    redis_url = System.get_env("REDIS_URL", "redis://localhost:6379")
-    uri = URI.parse(redis_url)
-    uri.host || "localhost"
-  end
-
-  defp redis_port do
-    redis_url = System.get_env("REDIS_URL", "redis://localhost:6379")
-    uri = URI.parse(redis_url)
-    uri.port || 6379
-  end
-
-  defp redis_password do
-    redis_url = System.get_env("REDIS_URL", "redis://localhost:6379")
-    uri = URI.parse(redis_url)
-
-    case uri.userinfo do
-      nil ->
-        nil
-
-      userinfo ->
-        case String.split(userinfo, ":") do
-          [_, password] -> password
-          _ -> nil
-        end
-    end
-  end
-end
diff --git a/lib/aprsme_web/plugs/health_check.ex b/lib/aprsme_web/plugs/health_check.ex
index bf3e8c6..8d588f8 100644
--- a/lib/aprsme_web/plugs/health_check.ex
+++ b/lib/aprsme_web/plugs/health_check.ex
@@ -69,8 +69,7 @@ defmodule AprsmeWeb.Plugs.HealthCheck do
 
   defp full_health_checks do
     # Comprehensive checks for readiness
-    with :ok <- check_database_connection(),
-         :ok <- check_redis_connection() do
+    with :ok <- check_database_connection() do
       check_pubsub()
     end
   end
@@ -84,21 +83,6 @@ defmodule AprsmeWeb.Plugs.HealthCheck do
     _ -> {:error, "Database check failed"}
   end
 
-  defp check_redis_connection do
-    if System.get_env("REDIS_URL") do
-      try do
-        case Redix.command(:query_cache_redis, ["PING"]) do
-          {:ok, "PONG"} -> :ok
-          _ -> {:error, "Redis connection failed"}
-        end
-      rescue
-        _ -> {:error, "Redis check failed"}
-      end
-    else
-      :ok
-    end
-  end
-
   defp check_pubsub do
     Phoenix.PubSub.broadcast(Aprsme.PubSub, "health_check", :ping)
     :ok