simpler client dockerfile (#116)

client/Dockerfile

@@ -1,21 +1,10 @@
 # ---- build stage ----
-FROM debian:bullseye-slim as builder
-RUN apt-get update -y && apt-get install -y curl \
-    && apt-get clean && rm -f /var/lib/apt/lists/*_*
+FROM node:18-alpine as builder
 workdir client
 COPY . .
-RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash - \
-    && apt-get install nodejs
-RUN npm install -g yarn
 RUN yarn && yarn run build
-
 # ---- app stage ----
-FROM debian:bullseye-slim
-RUN apt-get update -y && apt-get install -y curl \
-    && apt-get clean && rm -f /var/lib/apt/lists/*_*
-RUN curl -fsSL https://deb.nodesource.com/setup_16.x | bash - \
-    && apt-get install nodejs
-RUN npm install -g yarn
+FROM node:18-alpine
 WORKDIR "/app"
 RUN chown nobody /app
 COPY --from=builder --chown=nobody:root /client ./