chore: add error handling to entrypoint.sh

entrypoint.sh

@@ -3,7 +3,21 @@
 # Decode the base64 environment variables and write them to files
 mkdir -p /lndconf
 echo "$LND_MACAROON_BASE64" | base64 -d > /lndconf/admin.macaroon
+if [ $? -ne 0 ]; then
+    echo "LND_MACAROON_BASE64 is not valid base64"
+    exit 1
+fi
+
 echo "$LND_TLS_CERT_BASE64" | base64 -d > /lndconf/tls.cert
+if [ $? -ne 0 ]; then
+    echo "LND_TLS_CERT_BASE64 is not valid base64"
+    exit 1
+fi
+
+# Restrict permissions of the files
+chmod 700 /lndconf
+chmod 400 /lndconf/admin.macaroon
+chmod 400 /lndconf/tls.cert
 
 # Start your application
 exec "$@"