[FAB-2493] Package up GOLANG source precisely

This patch modifies the current GOLANG platform driver
for packaging the source code (used by the CLI, etc) to
be much more precise.  The current code more or less
grabs the entire GOPATH on the platform in which the
CLI is invoked.  The new code will only grab the bare
minimum of source files to build a specified package.

Fixes FAB-2493 for the fabric-peer component.

Change-Id: I048e4f654f2d13fe658dbe8153898020e2b2f4c7
Signed-off-by: Greg Haskins <gregory.haskins@gmail.com>

core/chaincode/platforms/golang/env.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2017 - Greg Haskins <gregory.haskins@gmail.com>
+
+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 golang
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type Env map[string]string
+
+func getEnv() Env {
+	env := make(Env)
+	for _, entry := range os.Environ() {
+		tokens := strings.Split(entry, "=")
+		if len(tokens) > 1 {
+			env[tokens[0]] = tokens[1]
+		}
+	}
+
+	return env
+}
+
+func flattenEnv(env Env) []string {
+	result := make([]string, 0)
+	for k, v := range env {
+		result = append(result, k+"="+v)
+	}
+
+	return result
+}
+
+type Paths map[string]bool
+
+func splitEnvPaths(value string) Paths {
+	_paths := filepath.SplitList(value)
+	paths := make(Paths)
+	for _, path := range _paths {
+		paths[path] = true
+	}
+	return paths
+}
+
+func flattenEnvPaths(paths Paths) string {
+
+	_paths := make([]string, 0)
+	for path, _ := range paths {
+		_paths = append(_paths, path)
+	}
+
+	return strings.Join(_paths, string(os.PathListSeparator))
+}

core/chaincode/platforms/golang/env_test.go

@@ -0,0 +1,29 @@
+/*
+Copyright 2017 - Greg Haskins <gregory.haskins@gmail.com>
+
+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 golang
+
+import (
+	"os"
+	"testing"
+
+	"github.com/docker/docker/pkg/testutil/assert"
+)
+
+func Test_splitEnvPath(t *testing.T) {
+	paths := splitEnvPaths("foo" + string(os.PathListSeparator) + "bar" + string(os.PathListSeparator) + "baz")
+	assert.Equal(t, len(paths), 3)
+}

core/chaincode/platforms/golang/list.go

@@ -0,0 +1,72 @@
+/*
+Copyright 2017 - Greg Haskins <gregory.haskins@gmail.com>
+
+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 golang
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+// Logic inspired by: https://dave.cheney.net/2014/09/14/go-list-your-swiss-army-knife
+func list(env Env, template, pkg string) ([]string, error) {
+
+	if env == nil {
+		env = getEnv()
+	}
+
+	var stdOut bytes.Buffer
+	var stdErr bytes.Buffer
+
+	cmd := exec.Command("go", "list", "-f", template, pkg)
+	cmd.Env = flattenEnv(env)
+	cmd.Stdout = &stdOut
+	cmd.Stderr = &stdErr
+	err := cmd.Start()
+
+	// Create a go routine that will wait for the command to finish
+	done := make(chan error, 1)
+	go func() {
+		done <- cmd.Wait()
+	}()
+
+	select {
+	case <-time.After(60 * time.Second):
+		if err = cmd.Process.Kill(); err != nil {
+			return nil, fmt.Errorf("go list: failed to kill: %s", err)
+		} else {
+			return nil, errors.New("go list: timeout")
+		}
+	case err = <-done:
+		if err != nil {
+			return nil, fmt.Errorf("go list: failed with error: \"%s\"\n%s", err, string(stdErr.Bytes()))
+		}
+
+		return strings.Split(string(stdOut.Bytes()), "\n"), nil
+	}
+}
+
+func listDeps(env Env, pkg string) ([]string, error) {
+	return list(env, "{{ join .Deps \"\\n\"}}", pkg)
+}
+
+func listImports(env Env, pkg string) ([]string, error) {
+	return list(env, "{{ join .Imports \"\\n\"}}", pkg)
+}

core/chaincode/platforms/golang/list_test.go

@@ -0,0 +1,26 @@
+/*
+Copyright 2017 - Greg Haskins <gregory.haskins@gmail.com>
+
+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 golang
+
+import "testing"
+
+func Test_listDeps(t *testing.T) {
+	_, err := listDeps(nil, "github.com/hyperledger/fabric/peer")
+	if err != nil {
+		t.Errorf("list failed: %s", err)
+	}
+}