add vscode-server binary

Author: hephaex

python/Dockerfile.3.6-ubuntu18.04

@@ -59,8 +59,15 @@ COPY ./service-defs /etc/backend.ai/service-defs
 COPY policy.yml /etc/backend.ai/jail/policy.yml
 COPY ./vscode-exts.tar.gz /etc/backend.ai/vscode-exts.tar.gz
 
+WORKDIR /tmp
+RUN curl -fL https://github.com/cdr/code-server/releases/download/v3.4.1/code-server-3.4.1-linux-amd64.tar.gz \
+  | tar -C /usr/local/lib -xz && \
+    mv /usr/local/lib/code-server-3.4.1-linux-amd64 /usr/local/lib/code-server-3.4.1 && \
+    ln -s /usr/local/lib/code-server-3.4.1/bin/code-server /usr/local/bin/code-server
+
 RUN mkdir -p /etc/backend.ai/vscode-exts && \
     tar xvzf /etc/backend.ai/vscode-exts.tar.gz -C /etc/backend.ai/vscode-exts && \
     rm -rf /etc/backend.ai/vscode-exts.tar.gz
 
+WORKDIR /home/work
 # vim: ft=dockerfile