Simplify devcontainer setup (#1687)

* Simplify devcontainer setup

* Add stable shellcheck

* Fix observer port

.devcontainer/Dockerfile

@@ -1,47 +1,34 @@
-FROM mcr.microsoft.com/vscode/devcontainers/base:debian-10
+FROM mcr.microsoft.com/vscode/devcontainers/base:debian
 
 WORKDIR /workspaces
 
-# Default ENV
-ENV LANG C.UTF-8
-ENV DEBIAN_FRONTEND noninteractive
-
-# Set shell
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
-# Install docker
-# https://docs.docker.com/engine/installation/linux/docker-ce/ubuntu/
-RUN apt-get update && apt-get install -y --no-install-recommends \
-        apt-transport-https \
-        ca-certificates \
-        curl \
-        software-properties-common \
-        gnupg \
-    && curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add - \
-    && add-apt-repository "deb https://download.docker.com/linux/debian $(lsb_release -cs) stable" \
-    && apt-get update && apt-get install -y --no-install-recommends \
-        docker-ce \
-        docker-ce-cli \
-        containerd.io \
-    && rm -rf /var/lib/apt/lists/*
+# Set Docker daemon config
+RUN \
+    mkdir -p /etc/docker \
+    && echo '{"storage-driver": "vfs"}' > /etc/docker/daemon.json
 
-# Install tools
-ARG SHELLCHECK_VERSION=0.7.0
-RUN apt-get update && apt-get install -y --no-install-recommends \
-        jq \
+# Installa aditional tools
+RUN \
+    apt-get update \
+    && apt-get install -y --no-install-recommends \
         dbus \
         network-manager \
         libpulse0 \
-        git \
-        tar \
-        xz-utils \
-    && rm -rf /var/lib/apt/lists/* \
+        xz-utils
+
+# Install docker
+RUN curl -fsSL https://get.docker.com | sh -
+
+# Install shellcheck
+RUN \
+    curl -fLs \
+        "https://github.com/koalaman/shellcheck/releases/download/stable/shellcheck-stable.linux.x86_64.tar.xz" \
+        | tar -xJ \
     \
-    && curl -SL "https://storage.googleapis.com/shellcheck/shellcheck-v${SHELLCHECK_VERSION}.linux.x86_64.tar.xz" | tar xJf - \
-    && cp "shellcheck-v${SHELLCHECK_VERSION}/shellcheck" /usr/bin/ \
-    && rm -rf shellcheck-v${SHELLCHECK_VERSION}
+    && mv -f "./shellcheck-stable/shellcheck" "/usr/bin/shellcheck" \
+    && rm -rf "./shellcheck-stable"
 
 # Generate a machine-id for this container
-RUN rm /etc/machine-id && dbus-uuidgen --ensure=/etc/machine-id
-
-ENV DEBIAN_FRONTEND=dialog
+RUN rm /etc/machine-id && dbus-uuidgen --ensure=/etc/machine-id