Use a /nginx directory for pid because /run doesn't exist when running in kubernetes.

docker/server/Dockerfile

@@ -28,6 +28,9 @@ RUN ln -s $(readlink -f /tmp/build/result/bin/sh) /tmp/sh
 # Create a folder which will be copied to /tmp in the final image
 RUN install -d -o root -g root -m 0777 will_be_tmp
 
+# Create a folder which will be copied to /nginx in the final image
+RUN install -d -o 1000 -g 1000 -m 0755 will_be_slash_nginx
+
 #
 # Runner
 #
@@ -56,6 +59,7 @@ COPY --from=builder /tmp/nix-store-closure /nix/store
 COPY --from=builder /tmp/build/result /app
 COPY --from=builder /tmp/sh /bin/sh
 COPY --from=builder /tmp/build/will_be_tmp /tmp
+COPY --from=builder /tmp/build/will_be_slash_nginx /nginx
 
 EXPOSE 8080
 CMD ["/app/bin/launch_nginx"]

docker/server/nginx.conf

@@ -5,7 +5,7 @@ worker_processes 4;
 pcre_jit on;
 
 error_log stderr debug;
-pid /run/nginx.pid;
+pid /nginx/nginx.pid;
 
 events {
     # Connections per worker process.