WIP: Feature/healthcheck signal (#177)

* added basic healthcheck implementation

* updated go-containerregistry version

* added build args parameter to healthcheck execute

* added go-containerregistry HealthCheck passing

* dereferenced health for conversion

vendor/github.com/google/go-containerregistry/name/ref.go

@@ -45,5 +45,6 @@ func ParseReference(s string, strict Strictness) (Reference, error) {
 	if d, err := NewDigest(s, strict); err == nil {
 		return d, nil
 	}
+	// TODO: Combine above errors into something more useful?
 	return nil, errors.New("could not parse reference")
 }

vendor/github.com/google/go-containerregistry/v1/config.go

@@ -64,6 +64,27 @@ type RootFS struct {
 	DiffIDs []Hash `json:"diff_ids"`
 }
 
+// HealthConfig holds configuration settings for the HEALTHCHECK feature.
+type HealthConfig struct {
+	// Test is the test to perform to check that the container is healthy.
+	// An empty slice means to inherit the default.
+	// The options are:
+	// {} : inherit healthcheck
+	// {"NONE"} : disable healthcheck
+	// {"CMD", args...} : exec arguments directly
+	// {"CMD-SHELL", command} : run command with system's default shell
+	Test []string `json:",omitempty"`
+
+	// Zero means to inherit. Durations are expressed as integer nanoseconds.
+	Interval    time.Duration `json:",omitempty"` // Interval is the time to wait between checks.
+	Timeout     time.Duration `json:",omitempty"` // Timeout is the time to wait before considering the check to have hung.
+	StartPeriod time.Duration `json:",omitempty"` // The start period for the container to initialize before the retries starts to count down.
+
+	// Retries is the number of consecutive failures needed to consider a container as unhealthy.
+	// Zero means inherit.
+	Retries int `json:",omitempty"`
+}
+
 // Config is a submessage of the config file described as:
 //   The execution parameters which SHOULD be used as a base when running
 //   a container using the image.
@@ -77,6 +98,7 @@ type Config struct {
 	AttachStdin     bool
 	AttachStdout    bool
 	Cmd             []string
+	Healthcheck     *HealthConfig
 	Domainname      string
 	Entrypoint      []string
 	Env             []string

vendor/github.com/google/go-containerregistry/v1/mutate/mutate.go

@@ -300,7 +300,14 @@ func extract(img v1.Image, w io.Writer) error {
 			}
 
 			// check if we have seen value before
-			name := filepath.Join(dirname, basename)
+			// if we're checking a directory, don't filepath.Join names
+			var name string
+			if header.Typeflag == tar.TypeDir {
+				name = header.Name
+			} else {
+				name = filepath.Join(dirname, basename)
+			}
+
 			if _, ok := fileMap[name]; ok {
 				continue
 			}

vendor/github.com/google/go-containerregistry/v1/random/image.go

@@ -15,6 +15,7 @@
 package random
 
 import (
+	"archive/tar"
 	"bytes"
 	"crypto/rand"
 	"fmt"
@@ -50,8 +51,15 @@ var _ partial.UncompressedLayer = (*uncompressedLayer)(nil)
 func Image(byteSize, layers int64) (v1.Image, error) {
 	layerz := make(map[v1.Hash]partial.UncompressedLayer)
 	for i := int64(0); i < layers; i++ {
-		b := bytes.NewBuffer(nil)
-		if _, err := io.CopyN(b, rand.Reader, byteSize); err != nil {
+		var b bytes.Buffer
+		tw := tar.NewWriter(&b)
+		if err := tw.WriteHeader(&tar.Header{
+			Name: fmt.Sprintf("random_file_%d.txt", i),
+			Size: byteSize,
+		}); err != nil {
+			return nil, err
+		}
+		if _, err := io.CopyN(tw, rand.Reader, byteSize); err != nil {
 			return nil, err
 		}
 		bts := b.Bytes()

vendor/github.com/google/go-containerregistry/v1/remote/image.go

@@ -19,7 +19,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"log"
 	"net/http"
 	"net/url"
 	"sync"
@@ -115,7 +114,6 @@ func (r *remoteImage) RawManifest() ([]byte, error) {
 		err := fmt.Errorf("manifest digest: %q does not match Docker-Content-Digest: %q for %q", digest, checksum, r.ref)
 		if r.ref.Context().RegistryStr() == name.DefaultRegistry {
 			// TODO(docker/distribution#2395): Remove this check.
-			log.Println(err)
 		} else {
 			// When pulling by tag, we can only validate that the digest matches what the registry told us it should be.
 			return nil, err

vendor/github.com/google/go-containerregistry/v1/remote/list.go

@@ -0,0 +1,64 @@
+// Copyright 2018 Google LLC All Rights Reserved.
+//
+// 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 remote
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"github.com/google/go-containerregistry/authn"
+	"github.com/google/go-containerregistry/name"
+	"github.com/google/go-containerregistry/v1/remote/transport"
+)
+
+type Tags struct {
+	Name string   `json:"name"`
+	Tags []string `json:"tags"`
+}
+
+// TODO(jonjohnsonjr): return []name.Tag?
+func List(repo name.Repository, auth authn.Authenticator, t http.RoundTripper) ([]string, error) {
+	scopes := []string{repo.Scope(transport.PullScope)}
+	tr, err := transport.New(repo.Registry, auth, t, scopes)
+	if err != nil {
+		return nil, err
+	}
+
+	uri := url.URL{
+		Scheme: transport.Scheme(repo.Registry),
+		Host:   repo.Registry.RegistryStr(),
+		Path:   fmt.Sprintf("/v2/%s/tags/list", repo.RepositoryStr()),
+	}
+
+	client := http.Client{Transport: tr}
+	resp, err := client.Get(uri.String())
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if err := checkError(resp, http.StatusOK); err != nil {
+		return nil, err
+	}
+
+	tags := Tags{}
+	if err := json.NewDecoder(resp.Body).Decode(&tags); err != nil {
+		return nil, err
+	}
+
+	return tags.Tags, nil
+}

vendor/github.com/google/go-containerregistry/v1/tarball/write.go

@@ -32,20 +32,24 @@ type WriteOptions struct {
 	// TODO(mattmoor): Whether to store things compressed?
 }
 
-// Write saves the image as the given tag in a tarball at the given path.
-func Write(p string, tag name.Tag, img v1.Image, wo *WriteOptions) error {
-	// Write in the compressed format.
-	// This is a tarball, on-disk, with:
-	// One manifest.json file at the top level containing information about several images.
-	// One file for each layer, named after the layer's SHA.
-	// One file for the config blob, named after its SHA.
-
+// WriteToFile writes in the compressed format to a tarball, on disk.
+// This is just syntactic sugar wrapping tarball.Write with a new file.
+func WriteToFile(p string, tag name.Tag, img v1.Image, wo *WriteOptions) error {
 	w, err := os.Create(p)
 	if err != nil {
 		return err
 	}
 	defer w.Close()
 
+	return Write(tag, img, wo, w)
+}
+
+// Write the contents of the image to the provided reader, in the compressed format.
+// The contents are written in the following format:
+// One manifest.json file at the top level containing information about several images.
+// One file for each layer, named after the layer's SHA.
+// One file for the config blob, named after its SHA.
+func Write(tag name.Tag, img v1.Image, wo *WriteOptions, w io.Writer) error {
 	tf := tar.NewWriter(w)
 	defer tf.Close()
 
@@ -58,7 +62,7 @@ func Write(p string, tag name.Tag, img v1.Image, wo *WriteOptions) error {
 	if err != nil {
 		return err
 	}
-	if err := writeFile(tf, cfgName.String(), bytes.NewReader(cfgBlob), int64(len(cfgBlob))); err != nil {
+	if err := writeTarEntry(tf, cfgName.String(), bytes.NewReader(cfgBlob), int64(len(cfgBlob))); err != nil {
 		return err
 	}
 
@@ -94,10 +98,9 @@ func Write(p string, tag name.Tag, img v1.Image, wo *WriteOptions) error {
 			return err
 		}
 
-		if err := writeFile(tf, layerFiles[i], r, blobSize); err != nil {
+		if err := writeTarEntry(tf, layerFiles[i], r, blobSize); err != nil {
 			return err
 		}
-
 	}
 
 	// Generate the tar descriptor and write it.
@@ -112,10 +115,11 @@ func Write(p string, tag name.Tag, img v1.Image, wo *WriteOptions) error {
 	if err != nil {
 		return err
 	}
-	return writeFile(tf, "manifest.json", bytes.NewReader(tdBytes), int64(len(tdBytes)))
+	return writeTarEntry(tf, "manifest.json", bytes.NewReader(tdBytes), int64(len(tdBytes)))
 }
 
-func writeFile(tf *tar.Writer, path string, r io.Reader, size int64) error {
+// write a file to the provided writer with a corresponding tar header
+func writeTarEntry(tf *tar.Writer, path string, r io.Reader, size int64) error {
 	hdr := &tar.Header{
 		Mode:     0644,
 		Typeflag: tar.TypeReg,