Dockerfile: cachebust

Dockerfile

@@ -1,9 +1,11 @@
 FROM nginx:alpine
 WORKDIR /opt/tar1090
 COPY html .
+COPY install_cachebust.sh /tmp
 COPY nginx.conf /etc/nginx/tar1090.conf
 RUN set -ex && \
-    apk add --virtual=.build-deps git sed && \
+    apk add --virtual=.build-deps git sed bash && \
+    bash /tmp/install_cachebust.sh && \
     mkdir -p /opt/tar1090-db && \
     wget -qO- https://github.com/katlol/tar1090-db/releases/latest/download/db.tar | tar -C /opt/tar1090-db -xvf - && \
     ln -s /opt/tar1090-db/db /opt/tar1090/db2 && \

install_cachebust.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+set -ex
+{
+    spritename="sprites_$(md5sum images/sprites.png | cut -d' ' -f1).png"
+    mv "images/sprites.png" "images/${spritename}"
+    sed -i -e "s#sprites.png#${spritename}#g" script.js
+    sed -i -e "s#sprites.png#${spritename}#g" index.html
+}
+
+# cache busting js / css
+{
+    sedargs=("sed" "-i" "index.html")
+    for file in dbloader.js defaults.js early.js flags.js formatter.js layers.js markers.js planeObject.js registrations.js script.js style.css; do
+        md5sum=$(md5sum $file | cut -d' ' -f1)
+        prefix=$(cut -d '.' -f1 <<< "$file")
+        postfix=$(cut -d '.' -f2 <<< "$file")
+        newname="${prefix}_${md5sum}.${postfix}"
+        mv "$file" "$newname"
+        sedargs+=("-e" "s#${file}#${newname}#")
+    done
+
+    "${sedargs[@]}"
+}