add sqlx Dockerfile

sqlx/Dockerfile

@@ -0,0 +1,12 @@
+FROM rust:alpine as build
+RUN apk add musl-dev
+RUN cargo install sqlx-cli \
+    --version 0.7.3 \
+    --no-default-features \
+    -F postgres,rustls
+
+FROM alpine
+COPY --from=build /usr/local/cargo/bin/sqlx /usr/local/bin/sqlx
+
+CMD sqlx migrate run --source /migrations
+VOLUME /migrations