add devcontainer

.devcontainer/Dockerfile

@@ -0,0 +1,26 @@
+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.154.0/containers/ruby/.devcontainer/base.Dockerfile
+
+# [Choice] Ruby version: 2, 2.7, 2.6, 2.5
+ARG VARIANT="2"
+FROM mcr.microsoft.com/vscode/devcontainers/ruby:0-${VARIANT}
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+COPY Gemfile /tmp/Gemfile
+
+RUN \
+  apt-get update \
+  && \
+  apt-get -y install --no-install-recommends \
+    jq \
+    libjq-dev \
+    libonig-dev \
+    gnupg2 \
+  && \
+  sh -c "$(curl --location https://taskfile.dev/install.sh)" -- -d -b /usr/local/bin \
+  && \
+  curl -fsSL https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | /bin/bash - \
+  && \
+  bundle config set system 'true' \
+  && bundle install --gemfile /tmp/Gemfile \
+  && rm /tmp/Gemfile

.devcontainer/devcontainer.json

@@ -0,0 +1,33 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.154.0/containers/ruby
+{
+	"name": "Ruby",
+	"build": {
+		"context": "..",
+		"dockerfile": "Dockerfile",
+		"args": {
+			// Update 'VARIANT' to pick a Ruby version: 2, 2.7, 2.6, 2.5
+			"VARIANT": "2.7",
+		}
+	},
+
+	// Set *default* container specific settings.json values on container create.
+	"settings": {
+		"terminal.integrated.shell.linux": "/bin/bash"
+	},
+
+	// Add the IDs of extensions you want installed when the container is created.
+	"extensions": [
+		"ms-kubernetes-tools.vscode-kubernetes-tools",
+		"rebornix.Ruby"
+	],
+
+	// 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": "export RUBYJQ_USE_SYSTEM_LIBRARIES=1 && bundle install",
+
+	// Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+	"remoteUser": "vscode"
+}