Add upload sanity check

config.dist.exs

@@ -44,7 +44,7 @@ config :pleroma, Pleroma.Upload.Filter.Mogrify,
 # On Linux, you can use the following command to get a random key base:
 # dd if=/dev/urandom bs=1 count=128 2>/dev/null | base64 -w 0 | rev | cut -b 2- | rev
 config :pleroma, Pleroma.Web.Endpoint,
-  url: [host: "ihatedocker.io", scheme: "https", port: 443],
+  url: [host: "example.com", scheme: "https", port: 443],
   secret_key_base: "<key>"
 
 ###

entrypoint.sh

@@ -33,6 +33,17 @@ while ! pg_isready -U pleroma -d postgres://db:5432/pleroma -t 1; do
     sleep 1s
 done
 
+log "Performing sanity checks..."
+if ! touch /uploads/.sanity-check; then
+    log "\
+The uploads datadir is NOT writable by `id -u`:`id -g`!\n\
+This will break all upload functionality.\n\
+Please fix the permissions and try again.\
+    "
+    exit 1
+fi
+rm /uploads/.sanity-check
+
 log "Migrating database..."
 mix ecto.migrate