Add .devcontainer for remote containers

.devcontainer/Dockerfile

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+# Update the VARIANT arg in docker-compose.yml to pick an Elixir version: 1.9, 1.10, 1.10.4
+ARG VARIANT=latest
+FROM elixir:${VARIANT}
+
+# This Dockerfile adds a non-root user with sudo access. Update the “remoteUser” property in
+# devcontainer.json to use it. More info: https://aka.ms/vscode-remote/containers/non-root-user.
+ARG USERNAME=vscode
+ARG USER_UID=1000
+ARG USER_GID=$USER_UID
+
+# Options for common package install script
+ARG INSTALL_ZSH="true"
+ARG UPGRADE_PACKAGES="true"
+ARG COMMON_SCRIPT_SOURCE="https://raw.githubusercontent.com/microsoft/vscode-dev-containers/main/script-library/common-debian.sh"
+ARG COMMON_SCRIPT_SHA="dev-mode"
+
+# Install needed packages and setup non-root user. Use a separate RUN statement to add your own dependencies.
+RUN apt-get update \
+  && export DEBIAN_FRONTEND=noninteractive \
+  && apt-get -y install --no-install-recommends curl ca-certificates 2>&1 \
+  && curl -sSL ${COMMON_SCRIPT_SOURCE} -o /tmp/common-setup.sh \
+  && ([ "${COMMON_SCRIPT_SHA}" = "dev-mode" ] || (echo "${COMMON_SCRIPT_SHA} */tmp/common-setup.sh" | sha256sum -c -)) \
+  && /bin/bash /tmp/common-setup.sh "${INSTALL_ZSH}" "${USERNAME}" "${USER_UID}" "${USER_GID}" "${UPGRADE_PACKAGES}" \
+  #
+  # Install dependencies
+  && apt-get install -y build-essential redis-server \
+  #
+  # Clean up
+  && apt-get autoremove -y \
+  && apt-get clean -y \
+  && rm -rf /var/lib/apt/lists/* /tmp/common-setup.sh /tmp/node-setup.sh
+
+RUN su ${USERNAME} -c "mix local.hex --force \
+  && mix local.rebar --force"
+
+# [Optional] Uncomment this section to install additional OS packages.
+# RUN apt-get update \
+#     && export DEBIAN_FRONTEND=noninteractive \
+#     && apt-get -y install --no-install-recommends <your-package-list-here>
+
+# [Optional] Uncomment this line to install additional package.
+# RUN  mix ...

.devcontainer/devcontainer.json

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+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.245.0/containers/elixir
+{
+	"name": "Elixir (Community)",
+	"dockerComposeFile": "docker-compose.yml",
+	"service": "app",
+	"workspaceFolder": "/home/app/exq",
+
+	// Configure tool-specific properties.
+	"customizations": {
+		// Configure properties specific to VS Code.
+		"vscode": {			
+			// Add the IDs of extensions you want installed when the container is created.
+			"extensions": [
+				"jakebecker.elixir-ls"
+			]
+		}
+	},
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	"forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "mix deps.get"
+
+	// Uncomment to connect as a non-root user. See https://aka.ms/vscode-remote/containers/non-root.
+	"remoteUser": "vscode"
+}

.devcontainer/docker-compose.yml

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+version: "3.3"
+services:
+  app:
+    build:
+      context: ..
+      dockerfile: ./.devcontainer/Dockerfile
+    environment:
+      VARIANT: "latest"
+      REDIS_HOST: redis_db
+      REDIS_PORT: 6379
+      REDIS_URL: "redis://redis_db:6379"
+      CACHE_TEST_REDIS_URL: "redis://redis_db:6379/2"
+      CACHE_DEV_REDIS_URL: "redis://redis_db:6379/3"
+      # just DEV, because jobs don't use redis in tests
+      JOBS_DEV_REDIS_URL: "redis://redis_db:6379/4"
+    command: sleep infinity
+    volumes:
+      - ..:/home/app/exq:cached
+    links:
+      - redis_db
+    depends_on:
+      - redis_db
+
+  redis_db:
+    image: redis:4
+    restart: always
+    expose:
+      - "6379"