Files
photog/android
puttaalu 210ce69e18 Add an Android uploader app
Native single-photo uploader for POST /upload. Lives in android/ with its
own flake, so the root flake stays Go-only and NixOS consumers of
nixosModules.default do not pull the Android SDK into their lock.

The server is untouched, so the app closes every gap client side:

- The slug is the enqueue-time timestamp, persisted in the work input.
  server.go derives the stored slug from the uploaded filename, so reusing
  that filename across WorkManager retries overwrites the same post rather
  than creating a duplicate. That stands in for an idempotency key.
- EXIF is stripped before upload. The gallery publishes the uploaded file
  verbatim as its full-size download, and phone photos carry GPS. JPEG and
  PNG drop metadata at marker and chunk level with the compressed pixels
  untouched; HEIC is decoded to JPEG because the extension check rejects it.
- Photos flagged for rotation are rotated into the pixels instead of relying
  on the orientation tag, which cannot survive the strip and which the
  thumbnailer ignores regardless.
- Anything over 18 MiB steps quality, then resolution, to stay inside
  nginx's client_max_body_size 20M.
- Credentials are sealed with an AES-GCM key in the Android Keystore. The
  key deliberately does not require user authentication, or background
  retries could not read it. Basic auth is attached by an interceptor
  rather than an Authenticator, which reacts to a 401 by replaying a
  multipart body that is not reliably replayable.
- The connection test uses GET /upload. /health is unreachable from outside
  because the nginx vhost only proxies location /upload.

WorkManager's SystemForegroundService needs foregroundServiceType declared
on the service entry, not just as a permission, or setForeground throws on
Android 14+. Only lintVitalRelease catches that, never a debug build.

Also anchors the .gitignore patterns. Unanchored, "photogallery" matched the
Kotlin package directory ws/inflo/photogallery/ and silently swallowed every
source file on git add.
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Gallery Upload — Android client

Native uploader for the photogallery POST /upload endpoint. Pick or share a photo, add a caption and date, post. Credentials are entered once and sealed with a key held in the Android Keystore.

The server is not modified by this app. Everything it needs, it does client side.

Build

cd android
nix develop          # Android SDK 36, build-tools 36.0.0, JDK 17, gradle
gradle wrapper       # first time only, generates ./gradlew
./gradlew assembleDebug
adb install -r app/build/outputs/apk/debug/app-debug.apk

The dev shell exports ANDROID_HOME, JAVA_HOME and a GRADLE_OPTS that points AGP at the nix-provided aapt2. Without that last one AGP downloads a generic-linux aapt2 from Maven which will not run on NixOS.

Release signing

app/build.gradle.kts wires up a release signing config only when android/keystore.properties exists. Both that file and *.jks are gitignored — keep the keystore outside the repo and back it up somewhere you will still have in five years, because losing it means you can never upgrade an installed build in place.

mkdir -p ~/keys
keytool -genkeypair -v \
  -keystore ~/keys/photogallery-release.jks \
  -alias photogallery \
  -keyalg RSA -keysize 4096 -validity 10000

Then write android/keystore.properties:

storeFile=/home/you/keys/photogallery-release.jks
storePassword=
keyAlias=photogallery
keyPassword=
./gradlew assembleRelease

Without keystore.properties the release build still runs, it just comes out unsigned.

How it maps onto the server

Server behaviour What the app does about it
Slug derived from the uploaded filename Sends yyyy-MM-dd-HHmmss.jpg, generated once at enqueue
Same filename overwrites the same post Reused across retries, which makes retries idempotent
Uploaded file published verbatim as "full size" Strips EXIF, including GPS, before upload
Extension check rejects HEIC Converts HEIC to JPEG; JPEG and PNG pass through losslessly
nginx client_max_body_size 20M Steps quality, then resolution, if the result exceeds 18 MiB
Thumbnailer ignores EXIF orientation Bakes rotation into the pixels rather than relying on the tag
nginx only proxies /upload, so /health 404s Tests credentials with GET /upload instead
Replies uploaded <slug>.jpg in plain text Parses that into <base>/photo/<slug>/ for the "Open" link