Update base images and introduce health endpoint (ankitects#3273)

* Update base images and introduce health endpoint

sync-server: introduce `/health` endpoint to check if the service is reachable.

bump(alpine): bump alpine base image from `3.19` to `3.20`

bump(rust): bump rust-alpine build image from `1.76` to `1.79`

* fix cargo fmt

* add allow clippy::extra_unused_type_parameters

* Remove unused type param (dae)

* Route /health directly (dae)

* Fix for latest axum (dae)

docs/syncserver/Dockerfile

@@ -1,14 +1,14 @@
-FROM rust:1.76-alpine3.19 AS builder
+FROM rust:1.79-alpine3.20 AS builder
 
 ARG ANKI_VERSION="23.12.1"
 
 RUN apk update && apk add --no-cache build-base protobuf && rm -rf /var/cache/apk/*
 RUN cargo install --git https://github.com/ankitects/anki.git \
-    --tag ${ANKI_VERSION} \
-    --root /anki-server  \
-    anki-sync-server
+--tag ${ANKI_VERSION} \
+--root /anki-server  \
+anki-sync-server
 
-FROM alpine:3.19.1
+FROM alpine:3.20
 
 RUN adduser -D -h /home/anki anki
 
@@ -25,8 +25,9 @@ EXPOSE ${SYNC_PORT}
 
 CMD ["anki-sync-server"]
 
-# TODO - consider exposing endpoint /health to check on health cause currently it will return 404 error
-# HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
-#     CMD wget -qO- http://localhost:${SYNC_PORT} || exit 1
+# This health check will work for Anki versions 24.06.3 and newer.
+# For older versions, it may incorrectly report an unhealthy status, which should not be the case.
+HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
+    CMD wget -qO- http://localhost:${SYNC_PORT}/health || exit 1
 
 LABEL maintainer="Jean Khawand <jk@jeankhawand.com>"