From a9ea0b4533d3b135fb4f536883687a87610c3cf1 Mon Sep 17 00:00:00 2001
From: Peter Thomassen <peter@desec.io>
Date: Wed, 2 Sep 2026 00:35:32 +0200
Subject: [PATCH] chore(api): use pymemcache instead of pylibmc

pymemcache is a pure-Python memcached client, so the API image no longer
needs to compile a C extension against libmemcached.

Django closes cache connections at the end of each request, so the new
backend reconnects to memcached per request. TCP_NODELAY avoids Nagle
delays when storing the serial list and throttle histories.
---
 README.md            | 2 +-
 api/Dockerfile       | 2 +-
 api/api/settings.py  | 7 +++++--
 api/requirements.txt | 2 +-
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index c55bcbdec..bb58e1fd2 100644
--- a/README.md
+++ b/README.md
@@ -143,7 +143,7 @@ While there are certainly many ways to get started hacking desec-stack, here is
     jq, httpie, libmariadbclient-dev, libpq-dev, python3-dev (>= 3.12) and python3-venv (>= 3.12) are useful if you want to follow this guide.
     The webapp requires Node.js. To install everything you need for this guide except docker and docker compose, use
 
-       sudo apt install certbot curl git httpie jq libmariadbclient-dev libpq-dev nodejs npm python3-dev python3-venv libmemcached-dev
+       sudo apt install certbot curl git httpie jq libmariadbclient-dev libpq-dev nodejs npm python3-dev python3-venv
 
 1. **Get the code.** Clone this repository to your favorite location.
 
diff --git a/api/Dockerfile b/api/Dockerfile
index 980692be7..da3802dd3 100644
--- a/api/Dockerfile
+++ b/api/Dockerfile
@@ -13,7 +13,7 @@ ENV PIP_NO_CACHE_DIR=1
 
 COPY requirements.txt /usr/src/app/
 # freetype-dev is needed for captcha generation
-RUN apk add --no-cache gcc freetype-dev libffi-dev musl-dev libmemcached-dev postgresql-dev jpeg-dev zlib-dev
+RUN apk add --no-cache gcc freetype-dev libffi-dev musl-dev postgresql-dev jpeg-dev zlib-dev
 RUN pip install --upgrade pip \
     && pip install -r requirements.txt \
     && pip freeze
diff --git a/api/api/settings.py b/api/api/settings.py
index ef0988979..123caa875 100644
--- a/api/api/settings.py
+++ b/api/api/settings.py
@@ -68,9 +68,12 @@
 
 CACHES = {
     "default": {
-        # TODO 'BACKEND': 'django_prometheus.cache.backends.memcached.PyLibMCCache' not supported
-        "BACKEND": "django.core.cache.backends.memcached.PyLibMCCache",
+        # Django closes cache connections at the end of each request, so this backend
+        # reconnects to memcached per request.  Subclassing it with a no-op close()
+        # keeps the connection open, should the reconnects ever become noticeable.
+        "BACKEND": "django.core.cache.backends.memcached.PyMemcacheCache",
         "LOCATION": "memcached:11211",
+        "OPTIONS": {"no_delay": True},
     }
 }
 
diff --git a/api/requirements.txt b/api/requirements.txt
index 605aac4f4..5fb150450 100644
--- a/api/requirements.txt
+++ b/api/requirements.txt
@@ -13,7 +13,7 @@ dnspython~=2.8.0
 pyotp~=2.9.0
 psycopg[binary]~=3.3.4
 psl-dns~=1.1.1
-pylibmc~=1.6.3
+pymemcache~=4.0.0
 pyyaml~=6.0.3
 requests~=2.32.5
 responses~=0.26.2