✨ Add support for custom cache sizes

README.md

@@ -20,6 +20,7 @@ for this to work it requires inserting a root CA certificate into system trusted
 - Expose port 3128 to the network
 - Map volume `/docker_mirror_cache` for up to 32gb of cached images from all registries
 - Map volume `/ca`, the proxy will store the CA certificate here across restarts
+- Env `CACHE_MAX_SIZE` (default `32g`): set the max size to be used for caching local Docker image layers. Use [Nginx sizes](http://nginx.org/en/docs/syntax.html).
 - Env `REGISTRIES`: space separated list of registries to cache; no need to include Docker Hub, its already there.
 - Env `AUTH_REGISTRIES`: space separated list of `hostname:username:password` authentication info.
   - `hostname`s listed here should be listed in the REGISTRIES environment as well, so they can be intercepted.
@@ -126,7 +127,6 @@ Yeah. Docker Inc should do it. So should NPM, Inc. Wonder why they don't. 😼
 
 - Allow using multiple credentials for DockerHub; this is possible since the `/token` request includes the wanted repo as a query string parameter.
 - Test and make auth work with quay.io, unfortunately I don't have access to it (_hint, hint, quay_)
-- Make the cache size configurable, today it's fixed at 32gb.
 - Hide the mitmproxy building code under a Docker build ARG.
 - I hope that in the future this can also be used as a "Developer Office" proxy, where many developers on a fast local network
   share a proxy for bandwidth and speed savings; work is ongoing in this direction.

entrypoint.sh

@@ -81,6 +81,13 @@ fi
 echo "        listen 443 ssl default_server;" > /etc/nginx/caching.layer.listen
 echo "error_log  /var/log/nginx/error.log warn;" > /etc/nginx/error.log.debug.warn
 
+# Set Docker Registry cache size, by default, 32 GB ('32g')
+CACHE_MAX_SIZE=${CACHE_MAX_SIZE:-32g}
+
+# The cache directory. This can get huge. Better to use a Docker volume pointing here!
+# Set to 32gb which should be enough
+echo "proxy_cache_path /docker_mirror_cache levels=1:2 max_size=$CACHE_MAX_SIZE inactive=60d keys_zone=cache:10m use_temp_path=off;" > /etc/nginx/conf.d/cache_max_size.conf
+
 # normally use non-debug version of nginx
 NGINX_BIN="nginx"
 

nginx.conf

@@ -42,10 +42,6 @@ http {
     keepalive_timeout  300;
     gzip  off;
 
-    # The cache directory. This can get huge. Better to use a Docker volume pointing here!
-    # Set to 32gb which should be enough
-    proxy_cache_path /docker_mirror_cache levels=1:2 max_size=32g inactive=60d keys_zone=cache:10m use_temp_path=off;
-
     # Just in case you want to rewrite some hosts. Default maps directly.
     map $host $targetHost {
         hostnames;
@@ -93,6 +89,8 @@ http {
         default "DID_NOT_MATCH_PATH";
     }
 
+    include /etc/nginx/conf.d/*.conf;
+
 
     # The proxy director layer, listens on 3128
     server {