Update Dockerfile for building (copy#988)

Update Readme.md (about building using Docker)

Readme.md

@@ -134,8 +134,8 @@ for a full setup on Debian or
 
 - If you have docker installed, you can run the whole system inside a container.
 - See `tools/docker/exec` to find Dockerfile required for this.
-- You can run `docker build -f tools/docker/exec/Dockerfile -t v86:alpine-3.14 .` from the root directory to generate docker image.
-- Then you can simply run `docker run -it -p 8000:8000 v86:alpine-3.14` to start the server.
+- You can run `docker build -f tools/docker/exec/Dockerfile -t v86:alpine-3.19 .` from the root directory to generate docker image.
+- Then you can simply run `docker run -it -p 8000:8000 v86:alpine-3.19` to start the server.
 - Check `localhost:8000` for hosted server.
 
 ### Running via Devcontainer

tools/docker/exec/Dockerfile

@@ -1,15 +1,15 @@
-FROM alpine:3.14 as v86-builder
+FROM alpine:3.19 as v86-builder
 WORKDIR /v86
 
-RUN apk add --update curl clang make openjdk8 npm python3
+RUN apk add --update curl clang make openjdk8-jre-base npm python3
 
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && PATH="${HOME}/.cargo/bin:${PATH}" rustup target add wasm32-unknown-unknown
 
 COPY . .
 
 RUN PATH="${HOME}/.cargo/bin:${PATH}" make all && rm -rf closure-compiler gen lib src tools .cargo cargo.toml Makefile
 
-FROM python:3.9.6-alpine3.14
+FROM python:3.10.13-alpine3.19
 WORKDIR /v86
 
 COPY --from=v86-builder v86 .