improve Dockerfile

.dockerignore

@@ -1,2 +1,4 @@
 /target
-site.db
+site.db
+docs/
+README.md

Dockerfile

@@ -1,4 +1,4 @@
-FROM rust:1.63 as builder
+FROM rust:1.63-slim-buster as builder
 RUN rustup component add clippy rustfmt
 WORKDIR /usr/src/sqlpage
 RUN cargo init .
@@ -11,7 +11,11 @@ RUN cargo check --release && \
     cargo install --path .
 
 FROM debian:buster-slim
+RUN apt-get update && apt-get upgrade --yes && apt-get install --yes openssl
 RUN rm -rf /var/lib/apt/lists/*
 COPY --from=builder /usr/local/cargo/bin/sqlpage /usr/local/bin/sqlpage
+RUN groupadd -r sqlpage && useradd --no-log-init -r -g sqlpage sqlpage
+WORKDIR /var/www
 USER sqlpage
+EXPOSE 8080
 CMD ["sqlpage"]