tools/refenginediscovery: Refactor Ref-Engine Discovery library API

.gitignore

@@ -1 +1,2 @@
+/oci-discovery
 __pycache__

Makefile

@@ -12,6 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+all: oci-discovery
+
+.PHONY: oci-discovery
+oci-discovery:
+	go build -o oci-discovery ./tools/cmd
+
 test: test-go test-python
 
 test-debug: test-go-debug test-python-debug
@@ -27,3 +33,6 @@ test-python:
 
 test-python-debug:
 	DEBUG=1 python3 -m unittest discover -v
+
+clean:
+	rm -f oci-discovery

tools/README.md

@@ -1,24 +1,30 @@
 # Discovery Tools
 
-## Eaxmple:
+## Example:
 
 ```
-$ go run cmd/main.go --debug discovery example.com/app#1.0 2>/tmp/log
-[
-	{
-		"mediaType": "application/vnd.oci.image.manifest.v1+json",
-		"digest": "sha256:e9770a03fbdccdd4632895151a93f9af58bbe2c91fdfaaf73160648d250e6ec3",
-		"size": 799,
-		"annotations": {
-			"org.opencontainers.image.ref.name": "1.0"
-		},
-		"platform": {
-			"architecture": "ppc64le",
-			"os": "linux"
-		}
-	}
-]
+$ oci-discovery --debug resolve example.com/app#1.0 2>/tmp/log
+{
+  "example.com/app#1.0": [
+    {
+      "mediaType": "application/vnd.oci.descriptor.v1+json",
+      "root": {
+        "mediaType": "application/vnd.oci.image.manifest.v1+json",
+        "digest": "sha256:e9770a03fbdccdd4632895151a93f9af58bbe2c91fdfaaf73160648d250e6ec3"
+        "size": 799,
+        "annotations": {
+          "org.opencontainers.image.ref.name": "1.0"
+        },
+        "platform": {
+          "architecture": "ppc64le",
+          "os": "linux"
+        }
+      },
+      "uri": "https://example.com/oci-index/app"
+    }
+  ]
+}
 $ cat /tmp/log
-time="2017-09-19T12:43:41-07:00" level=debug msg="requesting application/vnd.oci.ref-engines.v1+json from http://example.com/.well-known/oci-host-ref-engines"
+time="2017-09-19T12:43:41-07:00" level=debug msg="requesting application/vnd.oci.ref-engines.v1+json from https://example.com/.well-known/oci-host-ref-engines"
 time="2017-09-19T12:43:41-07:00" level=debug msg="requesting application/vnd.oci.image.index.v1+json from https://example.com/oci-index/app"
 ```

tools/cmd/main.go

@@ -1,35 +1,32 @@
+// Copyright 2017 oci-discovery contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package main
 
 import (
 	"os"
 
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
-	"github.com/xiekeyang/oci-discovery/tools/discovery"
 
 	_ "github.com/xiekeyang/oci-discovery/tools/indextemplate"
 )
 
-var discoveryCommand = cli.Command{
-	Name:   "discovery",
-	Usage:  "Resolve image names via OCI Ref-engine Discovery.",
-	Action: discovery.DiscoveryHandler,
-	Flags: []cli.Flag{
-		cli.StringFlag{
-			Name:  "protocol",
-			Usage: "Protocol to use for ref-engine discovery",
-		},
-		cli.UintFlag{
-			Name:  "port",
-			Usage: "Port to use for ref-engine discovery",
-		},
-	},
-}
-
 func main() {
 	app := cli.NewApp()
 	app.Name = "oci-discovery-tool"
-	app.Usage = "OCI (Open Container Initiative) image discovery tools"
+	app.Usage = "OCI (Open Container Initiative) image discovery tools."
 	app.Flags = []cli.Flag{
 		cli.BoolFlag{
 			Name:  "debug",
@@ -43,7 +40,7 @@ func main() {
 		return nil
 	}
 	app.Commands = []cli.Command{
-		discoveryCommand,
+		resolveCommand,
 	}
 
 	if err := app.Run(os.Args); err != nil {

tools/cmd/resolve.go

@@ -0,0 +1,88 @@
+// Copyright 2017 oci-discovery contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli"
+	"github.com/xiekeyang/oci-discovery/tools/hostbasedimagenames"
+	"github.com/xiekeyang/oci-discovery/tools/refengine"
+	"github.com/xiekeyang/oci-discovery/tools/refenginediscovery"
+	"golang.org/x/net/context"
+)
+
+// resolved is a flag for breaking discovery iteration.
+var resolved = fmt.Errorf("satisfactory resolution")
+
+var resolveCommand = cli.Command{
+	Name:  "resolve",
+	Usage: "Resolve image names via OCI Ref-Engine Discovery.",
+	Flags: []cli.Flag{
+		cli.StringFlag{
+			Name:  "protocol",
+			Usage: "Protocol to use for ref-engine discovery",
+		},
+		cli.UintFlag{
+			Name:  "port",
+			Usage: "Port to use for ref-engine discovery",
+		},
+	},
+	Action: func(c *cli.Context) error {
+		ctx := context.Background()
+		allRoots := map[string][]refengine.MerkleRoot{}
+
+		protocols := []string{}
+		if c.IsSet("protocol") {
+			protocols = append(protocols, c.String("protocol"))
+		}
+
+		for _, name := range c.Args() {
+			parsedName, err := hostbasedimagenames.Parse(name)
+			if err != nil {
+				logrus.Warn(err)
+				continue
+			}
+
+			err = refenginediscovery.Discover(
+				ctx, protocols, parsedName["host"],
+				func(ctx context.Context, refEngine refengine.Engine, casEngines []refenginediscovery.ResolvedCASEngines) error {
+					return resolveCallback(ctx, allRoots, refEngine, casEngines, name)
+				})
+			if err == resolved {
+				continue
+			} else if err != nil {
+				logrus.Warn(err)
+			}
+		}
+
+		encoder := json.NewEncoder(os.Stdout)
+		encoder.SetIndent("", "\t")
+		return encoder.Encode(allRoots)
+	},
+}
+
+func resolveCallback(ctx context.Context, allRoots map[string][]refengine.MerkleRoot, refEngine refengine.Engine, casEngines []refenginediscovery.ResolvedCASEngines, name string) (err error) {
+	roots, err := refEngine.Get(ctx, name)
+	if err != nil {
+		logrus.Warn(err)
+		return nil
+	}
+	allRoots[name] = roots
+	return resolved
+}