Adds dev container and updates docs with Codespaces information

.devcontainer/devcontainer.json

@@ -0,0 +1,32 @@
+// For format details, see https://aka.ms/devcontainer.json.
+{
+    "name": "Knative Serving",
+    "image": "gcr.io/knative-tests/test-infra/prow-tests:latest",
+
+    // Features to add to the dev container. More info: https://containers.dev/features.
+    "features": {
+        "ghcr.io/devcontainers/features/go:1": {}
+    },
+
+    "privileged": true,
+
+    // Creates a local container registry, a Kind cluster, and deploys Knative Serving and Knative Ingress
+    // To explore the setup logs, use the "Codespaces: View Creation Log" command in the Command Palette (Cmd/Ctrl + Shift + P or F1)
+    "postCreateCommand": "bash .devcontainer/setup.sh",
+    "postStartCommand": "bash .devcontainer/docker-start.sh",
+
+    "forwardPorts": [
+        5001
+    ],
+    "containerEnv": {
+        "KO_DOCKER_REPO": "kind.local"
+    },
+
+    "mounts": [
+        {
+            "source": "dind-var-lib-docker",
+            "target": "/docker-graph",
+            "type": "volume"
+        }
+    ]
+}

.devcontainer/docker-start.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+set -eux
+
+if ! docker info > /dev/null 2>&1; then
+    echo "Starting docker..."
+    service docker start
+fi

.devcontainer/setup.sh

@@ -0,0 +1,66 @@
+#!/bin/sh
+set -eux
+
+.devcontainer/docker-start.sh
+
+until docker info > /dev/null 2>&1 ; do
+  echo "Waiting for docker to start..."
+  sleep 0.1
+done
+
+echo "Setting up local container registry..."
+REGISTRY_NAME='registry.local'
+REGISTRY_PORT='5001'
+
+if [ "$(docker inspect -f '{{.State.Running}}' "${REGISTRY_NAME}" 2>/dev/null || true)" != 'true' ]; then
+  docker run \
+    -d --restart=always -p "127.0.0.1:${REGISTRY_PORT}:5000" --name "${REGISTRY_NAME}" \
+    registry:2
+fi
+
+echo "Creating KinD cluster..."
+cat <<EOF | kind create cluster --config=-
+
+kind: Cluster
+apiVersion: kind.x-k8s.io/v1alpha4
+containerdConfigPatches:
+- |-
+  [plugins."io.containerd.grpc.v1.cri".registry.mirrors."localhost:${REGISTRY_PORT}"]
+    endpoint = ["http://${REGISTRY_NAME}:5000"]
+EOF
+
+echo "Connecting registry to KinD cluster..."
+if [ "$(docker inspect -f='{{json .NetworkSettings.Networks.kind}}' "${REGISTRY_NAME}")" = 'null' ]; then
+  docker network connect "kind" "${REGISTRY_NAME}"
+fi
+
+# Document the local registry
+# https://github.com/kubernetes/enhancements/tree/master/keps/sig-cluster-lifecycle/generic/1755-communicating-a-local-registry
+cat <<EOF | kubectl apply -f -
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: local-registry-hosting
+  namespace: kube-public
+data:
+  localRegistryHosting.v1: |
+    host: "localhost:${REGISTRY_PORT}"
+    help: "https://kind.sigs.k8s.io/docs/user/local-registry/"
+EOF
+
+echo "Deploying cert-manager..."
+kubectl apply -f ./third_party/cert-manager-latest/cert-manager.yaml
+kubectl wait --for=condition=Established --all crd
+kubectl wait --for=condition=Available -n cert-manager --all deployments
+
+echo "Deploying Knative Serving..."
+ko apply --selector knative.dev/crd-install=true -Rf config/core/
+kubectl wait --for=condition=Established --all crd
+ko apply -Rf config/core/
+
+echo "Deploying Knative ingress with Kourier..."
+kubectl apply -f ./third_party/kourier-latest/kourier.yaml
+kubectl patch configmap/config-network \
+  -n knative-serving \
+  --type merge \
+  -p '{"data":{"ingress.class":"kourier.ingress.networking.knative.dev"}}'

DEVELOPMENT.md

@@ -23,6 +23,18 @@ Start by creating [a GitHub account](https://github.com/join), then set up
 
 ### Install requirements
 
+#### Getting started with GitHub Codespaces
+
+To get started, create a codespace for this repository by clicking this 👇
+
+[![Open in GitHub Codespaces](https://github.com/codespaces/badge.svg)](https://github.com/codespaces/new?hide_repo_select=true&ref=main&repo=118828329)
+
+A codespace will open in a web-based version of Visual Studio Code. The [dev container](.devcontainer/devcontainer.json) is fully configured with software needed for this project. It creates a local container registry, a Kind cluster and deploys Knative Serving and Knative Ingress. If you use a codespace, then you can directly skip to the [Iterating](#Iterating) section of this document.
+
+**Note**: Dev containers is an open spec which is supported by [GitHub Codespaces](https://github.com/codespaces) and [other tools](https://containers.dev/supporting).
+
+#### Local Setup
+
 You must install these tools:
 
 1. [`go`](https://golang.org/doc/install): The language `Knative Serving` is