Use zram

Dockerfile

@@ -36,6 +36,7 @@ COPY --from=builder /usr/src/clicklock/clicklock /usr/bin/clicklock
 
 # Etcher configuration script
 COPY update-config-and-start.js /usr/src/app/
+COPY zram.sh /usr/src/app/
 
 COPY --from=builder /usr/src/app/dist/linux-arm64-unpacked/resources/app /usr/src/app
 COPY --from=builder /usr/src/app/node_modules/electron/ /usr/src/app/node_modules/electron
@@ -43,4 +44,11 @@ WORKDIR /usr/src/app/node_modules/.bin
 RUN ln -s ../electron/cli.js electron
 WORKDIR /usr/src/app
 
-CMD node /usr/src/app/update-config-and-start.js
+RUN \
+	apt-get update \
+	&& apt-get install -y kmod \
+	&& rm -rf /var/lib/apt/lists/*
+
+CMD \
+	./zram.sh \
+	&& node /usr/src/app/update-config-and-start.js

docker-compose.yml

@@ -14,6 +14,7 @@ services:
     labels:
       io.balena.features.dbus: 1
       io.balena.features.supervisor-api: 1
+      io.balena.features.kernel-modules: 1
     volumes:
       - 'etcher_pki:/root/.pki'
       - 'etcher_cache:/root/.cache'

zram.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+DEVICE=/dev/zram0
+
+if [ ! -b $DEVICE ]; then
+	modprobe zram
+	zramctl $DEVICE --size 1024M
+	mkswap $DEVICE
+	swapon $DEVICE
+fi