Upload build metrics after a build is completed.

Soong now supports the ability to upload metrics to another location
by setting the ANDROID_ENABLE_METRICS_UPLOAD to an uploader that
accepts the upload.proto proto buffer message. When the environment
variable is set, a set of build metrics files (soong_metrics,
rbe_metrics.pb and build_error) is uploaded.

Bug: 140638454
Test: * Wrote unit test cases
      * Setup the uploader, built a succcessful and failed aosp_arm-eng
        target and monitor the uploading of the metrics.
Change-Id: I76a65739c557dc90345e098ca03119a950ece2d2
diff --git a/ui/build/upload_test.go b/ui/build/upload_test.go
new file mode 100644
index 0000000..adaa08d
--- /dev/null
+++ b/ui/build/upload_test.go
@@ -0,0 +1,120 @@
+// Copyright 2020 Google Inc. 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 build
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"android/soong/ui/logger"
+)
+
+func TestUploadMetrics(t *testing.T) {
+	ctx := testContext()
+	tests := []struct {
+		description string
+		uploader    string
+		createFiles bool
+		files       []string
+	}{{
+		description: "ANDROID_ENABLE_METRICS_UPLOAD not set",
+	}, {
+		description: "no metrics files to upload",
+		uploader:    "fake",
+	}, {
+		description: "non-existent metrics files no upload",
+		uploader:    "fake",
+		files:       []string{"metrics_file_1", "metrics_file_2", "metrics_file_3"},
+	}, {
+		description: "trigger upload",
+		uploader:    "echo",
+		createFiles: true,
+		files:       []string{"metrics_file_1", "metrics_file_2"},
+	}}
+
+	for _, tt := range tests {
+		t.Run(tt.description, func(t *testing.T) {
+			defer logger.Recover(func(err error) {
+				t.Fatalf("got unexpected error: %v", err)
+			})
+
+			outDir, err := ioutil.TempDir("", "")
+			if err != nil {
+				t.Fatalf("failed to create out directory: %v", outDir)
+			}
+			defer os.RemoveAll(outDir)
+
+			var metricsFiles []string
+			if tt.createFiles {
+				for _, f := range tt.files {
+					filename := filepath.Join(outDir, f)
+					metricsFiles = append(metricsFiles, filename)
+					if err := ioutil.WriteFile(filename, []byte("test file"), 0644); err != nil {
+						t.Fatalf("failed to create a fake metrics file %q for uploading: %v", filename, err)
+					}
+				}
+			}
+
+			config := Config{&configImpl{
+				environ: &Environment{
+					"OUT_DIR=" + outDir,
+					"ANDROID_ENABLE_METRICS_UPLOAD=" + tt.uploader,
+				},
+				buildDateTime: strconv.FormatInt(time.Now().UnixNano()/int64(time.Millisecond), 10),
+			}}
+
+			UploadMetrics(ctx, config, 1591031903, metricsFiles...)
+
+			if _, err := os.Stat(filepath.Join(outDir, uploadPbFilename)); err == nil {
+				t.Error("got true, want false for upload protobuf file to exist")
+			}
+		})
+	}
+}
+
+func TestUploadMetricsErrors(t *testing.T) {
+	expectedErr := "failed to write the marshaled"
+	defer logger.Recover(func(err error) {
+		got := err.Error()
+		if !strings.Contains(got, expectedErr) {
+			t.Errorf("got %q, want %q to be contained in error", got, expectedErr)
+		}
+	})
+
+	outDir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatalf("failed to create out directory: %v", outDir)
+	}
+	defer os.RemoveAll(outDir)
+
+	metricsFile := filepath.Join(outDir, "metrics_file_1")
+	if err := ioutil.WriteFile(metricsFile, []byte("test file"), 0644); err != nil {
+		t.Fatalf("failed to create a fake metrics file %q for uploading: %v", metricsFile, err)
+	}
+
+	config := Config{&configImpl{
+		environ: &Environment{
+			"ANDROID_ENABLE_METRICS_UPLOAD=fake",
+			"OUT_DIR=/bad",
+		}}}
+
+	UploadMetrics(testContext(), config, 1591031903, metricsFile)
+	t.Errorf("got nil, expecting %q as a failure", expectedErr)
+}