Add devcontainer (#1040)

* Add devcontainer (generic add-on devcontainer also available at https://github.com/issacg/hassio-addon-devcontainer)

* remove example code (https://github.com/home-assistant/hassio-addons/pull/1040#discussion_r374373037)

* Run start_hassio.sh from inside .devcontainer (https://github.com/home-assistant/hassio-addons/pull/1040#discussion_r374373323)

.devcontainer/Dockerfile

@@ -0,0 +1,34 @@
+FROM ubuntu:18.04
+
+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 \
+        dbus \
+        software-properties-common \
+        gpg-agent \
+        git \
+        sudo \
+    && curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - \
+    && add-apt-repository "deb https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" \
+    && apt-get update && apt-get install -y --no-install-recommends \
+        docker-ce \
+        docker-ce-cli \
+        containerd.io
+# This is a development container.  Don't bother to clean up apt cache, this way we have it handy later
+
+# Generate a machine-id for this container
+RUN rm /etc/machine-id && dbus-uuidgen --ensure=/etc/machine-id
+
+ENV DEBIAN_FRONTEND=dialog

.devcontainer/devcontainer.json

@@ -0,0 +1,17 @@
+// Based on https://github.com/issacg/hassio-addon-devcontainer
+{
+	"name": "Hass.io Community Add-Ons",
+	"context": "..",
+	"dockerFile": "Dockerfile",
+	"appPort": 8123,
+	"runArgs": [
+		"-e",
+		"GIT_EDITOR=code --wait",
+		"--privileged"
+	],
+	"settings": { 
+		"terminal.integrated.shell.linux": "/bin/bash"
+	},
+	"workspaceMount": "source=${localWorkspaceFolder},target=/workspaces/test_hassio/addons/local,type=bind,consistency=delegated",
+	"workspaceFolder": "/workspaces/test_hassio/addons/local"
+}

.devcontainer/start_hassio.sh

@@ -0,0 +1,103 @@
+#!/bin/bash
+set -eE
+
+DOCKER_TIMEOUT=30
+DOCKER_PID=0
+
+
+function start_docker() {
+    local starttime
+    local endtime
+
+    echo "Starting docker."
+    dockerd 2> /dev/null &
+    DOCKER_PID=$!
+
+    echo "Waiting for docker to initialize..."
+    starttime="$(date +%s)"
+    endtime="$(date +%s)"
+    until docker info >/dev/null 2>&1; do
+        if [ $((endtime - starttime)) -le $DOCKER_TIMEOUT ]; then
+            sleep 1
+            endtime=$(date +%s)
+        else
+            echo "Timeout while waiting for docker to come up"
+            exit 1
+        fi
+    done
+    echo "Docker was initialized"
+}
+
+
+function stop_docker() {
+    local starttime
+    local endtime
+
+    echo "Stopping in container docker..."
+    if [ "$DOCKER_PID" -gt 0 ] && kill -0 "$DOCKER_PID" 2> /dev/null; then
+        starttime="$(date +%s)"
+        endtime="$(date +%s)"
+
+        # Now wait for it to die
+        kill "$DOCKER_PID"
+        while kill -0 "$DOCKER_PID" 2> /dev/null; do
+            if [ $((endtime - starttime)) -le $DOCKER_TIMEOUT ]; then
+                sleep 1
+                endtime=$(date +%s)
+            else
+                echo "Timeout while waiting for container docker to die"
+                exit 1
+            fi
+        done
+    else
+        echo "Your host might have been left with unreleased resources"
+    fi
+}
+
+
+function install() {
+    docker pull homeassistant/amd64-hassio-supervisor:dev
+    docker pull homeassistant/amd64-hassio-cli:dev
+}
+
+function cleanup_hass_data() {
+    rm -rf /workspaces/test_hassio/{apparmor,backup,config.json,dns,dns.json,homeassistant,homeassistant.json,ingress.json,share,ssl,tmp,updater.json}
+    rm -rf /workspaces/test_hassio/addons/{core,data,git}
+}
+
+function cleanup_docker() {
+    echo "Cleaning up stopped containers..."
+    docker rm $(docker ps -a -q)
+}
+
+function run_supervisor() {
+    docker run --rm --privileged \
+        --name hassio_supervisor \
+        --security-opt seccomp=unconfined \
+        --security-opt apparmor:unconfined \
+        -v /run/docker.sock:/run/docker.sock \
+        -v /run/dbus:/run/dbus \
+        -v "/workspaces/test_hassio":/data \
+        -v /etc/machine-id:/etc/machine-id:ro \
+        -e SUPERVISOR_SHARE="/workspaces/test_hassio" \
+        -e SUPERVISOR_NAME=hassio_supervisor \
+        -e SUPERVISOR_DEV=1 \
+        -e HOMEASSISTANT_REPOSITORY="homeassistant/qemux86-64-homeassistant" \
+        homeassistant/amd64-hassio-supervisor:dev
+}
+
+case "$1" in
+    "--cleanup")
+        echo "Cleaning up old environment"
+        cleanup_docker || true
+        cleanup_hass_data || true
+        exit 0;;
+    *)
+        echo "Creating development Hass.io environment"
+        start_docker
+        trap "stop_docker" ERR
+        cleanup_docker || true
+        install
+        run_supervisor
+        stop_docker;; 
+esac