improve README, add tests, reinstate cache hits

cmd/ko/README.md

@@ -4,16 +4,20 @@
 binary fetched using `go get` and built into a container image using
 [ko](https://github.com/google/ko).
 
-For example, `docker pull ko.kontain.me/ko/github.com/google/ko/cmd/ko` will
-fetch, build and (eventually) serve a Docker image containing `ko` itself.
-_Koception!_
-
 ## Examples
 
 Build and pull `ko` itself:
 
 ```
-docker pull ko.kontain.me/github.com/google/ko/cmd/ko
+docker pull ko.kontain.me/github.com/google/ko
 ```
 
 _Koception!_
+
+Source is pulled from the Go module proxy, and as such, packages must use Go modules.
+
+The `:latest` tag corresponds to the `@latest` version of the Go module, usually the highest semver tagged release.
+You can use tags like `:v1.2.3` to pull and build a specific release, or a branch name (e.g., `:main`) to build a branch.
+
+Images are built for all available platforms, depending on their base image.
+Manifests are cached for faster rebuilds.

cmd/ko/deploy.sh

@@ -8,7 +8,7 @@ gcloud run deploy ko \
   --allow-unauthenticated \
   --set-env-vars=BUCKET=kontaindotme \
   --image=$(KO_DOCKER_REPO=gcr.io/kontaindotme ko publish -P ./cmd/ko) \
-  --memory=4Gi \
-  --cpu=2 \
+  --memory=8Gi \
+  --cpu=4 \
   --concurrency=1 \
   --timeout=900 # 15m

cmd/ko/main.go

@@ -118,10 +118,8 @@ func (s *server) serveKoManifest(w http.ResponseWriter, r *http.Request) {
 	ck := cacheKey(ip, version)
 	if _, err := s.storage.BlobExists(ctx, ck); err == nil {
 		s.info.Println("serving cached manifest:", ck)
-		/*
-			serve.Blob(w, r, ck)
-			return
-		*/
+		serve.Blob(w, r, ck)
+		return
 	}
 	filepath := strings.TrimPrefix(ip, module)
 

cmd/ko/test.sh

@@ -2,6 +2,8 @@
 
 set -euxo pipefail
 
-#time crane validate --remote=ko.kontain.me/github.com/google/ko
-#time crane validate --remote=ko.kontain.me/github.com/google/ko
+time crane validate --remote=ko.kontain.me/knative.dev/serving/cmd/controller:latest
+time crane validate --remote=ko.kontain.me/knative.dev/serving/cmd/controller:latest
 
+time crane validate --remote=ko.kontain.me/knative.dev/serving/cmd/controller:v0.26.0
+time crane validate --remote=ko.kontain.me/knative.dev/serving/cmd/controller:main