diff --git a/bp2build/Android.bp b/bp2build/Android.bp
index 9b66354..337fe86 100644
--- a/bp2build/Android.bp
+++ b/bp2build/Android.bp
@@ -19,6 +19,7 @@
     deps: [
         "soong-android",
         "soong-android-soongconfig",
+        "soong-shared",
         "soong-apex",
         "soong-bazel",
         "soong-cc",
@@ -27,6 +28,7 @@
         "soong-genrule",
         "soong-python",
         "soong-sh",
+        "soong-ui-metrics",
     ],
     testSrcs: [
         "android_app_certificate_conversion_test.go",
diff --git a/bp2build/build_conversion.go b/bp2build/build_conversion.go
index eb60cd1..54b59af 100644
--- a/bp2build/build_conversion.go
+++ b/bp2build/build_conversion.go
@@ -259,7 +259,7 @@
 
 	// Simple metrics tracking for bp2build
 	metrics := CodegenMetrics{
-		ruleClassCount: make(map[string]int),
+		ruleClassCount: make(map[string]uint64),
 	}
 
 	dirs := make(map[string]bool)
diff --git a/bp2build/metrics.go b/bp2build/metrics.go
index b3d5afb..68ac544 100644
--- a/bp2build/metrics.go
+++ b/bp2build/metrics.go
@@ -2,34 +2,52 @@
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 	"strings"
 
 	"android/soong/android"
+	"android/soong/shared"
+	"android/soong/ui/metrics/bp2build_metrics_proto"
 )
 
 // Simple metrics struct to collect information about a Blueprint to BUILD
 // conversion process.
 type CodegenMetrics struct {
 	// Total number of Soong modules converted to generated targets
-	generatedModuleCount int
+	generatedModuleCount uint64
 
 	// Total number of Soong modules converted to handcrafted targets
-	handCraftedModuleCount int
+	handCraftedModuleCount uint64
 
 	// Total number of unconverted Soong modules
-	unconvertedModuleCount int
+	unconvertedModuleCount uint64
 
 	// Counts of generated Bazel targets per Bazel rule class
-	ruleClassCount map[string]int
+	ruleClassCount map[string]uint64
 
+	// List of modules with unconverted deps
+	// NOTE: NOT in the .proto
 	moduleWithUnconvertedDepsMsgs []string
 
+	// List of converted modules
 	convertedModules []string
 }
 
+// Serialize returns the protoized version of CodegenMetrics: bp2build_metrics_proto.Bp2BuildMetrics
+func (metrics *CodegenMetrics) Serialize() bp2build_metrics_proto.Bp2BuildMetrics {
+	return bp2build_metrics_proto.Bp2BuildMetrics{
+		GeneratedModuleCount:   metrics.generatedModuleCount,
+		HandCraftedModuleCount: metrics.handCraftedModuleCount,
+		UnconvertedModuleCount: metrics.unconvertedModuleCount,
+		RuleClassCount:         metrics.ruleClassCount,
+		ConvertedModules:       metrics.convertedModules,
+	}
+}
+
 // Print the codegen metrics to stdout.
 func (metrics *CodegenMetrics) Print() {
-	generatedTargetCount := 0
+	generatedTargetCount := uint64(0)
 	for _, ruleClass := range android.SortedStringKeys(metrics.ruleClassCount) {
 		count := metrics.ruleClassCount[ruleClass]
 		fmt.Printf("[bp2build] %s: %d targets\n", ruleClass, count)
@@ -45,6 +63,40 @@
 		strings.Join(metrics.moduleWithUnconvertedDepsMsgs, "\n\t"))
 }
 
+const bp2buildMetricsFilename = "bp2build_metrics.pb"
+
+// fail prints $PWD to stderr, followed by the given printf string and args (vals),
+// then the given alert, and then exits with 1 for failure
+func fail(err error, alertFmt string, vals ...interface{}) {
+	cwd, wderr := os.Getwd()
+	if wderr != nil {
+		cwd = "FAILED TO GET $PWD: " + wderr.Error()
+	}
+	fmt.Fprintf(os.Stderr, "\nIn "+cwd+":\n"+alertFmt+"\n"+err.Error()+"\n", vals...)
+	os.Exit(1)
+}
+
+// Write the bp2build-protoized codegen metrics into the given directory
+func (metrics *CodegenMetrics) Write(dir string) {
+	if _, err := os.Stat(dir); os.IsNotExist(err) {
+		// The metrics dir doesn't already exist, so create it (and parents)
+		if err := os.MkdirAll(dir, 0755); err != nil { // rx for all; w for user
+			fail(err, "Failed to `mkdir -p` %s", dir)
+		}
+	} else if err != nil {
+		fail(err, "Failed to `stat` %s", dir)
+	}
+	metricsFile := filepath.Join(dir, bp2buildMetricsFilename)
+	if err := metrics.dump(metricsFile); err != nil {
+		fail(err, "Error outputting %s", metricsFile)
+	}
+	if _, err := os.Stat(metricsFile); err != nil {
+		fail(err, "MISSING BP2BUILD METRICS OUTPUT: Failed to `stat` %s", metricsFile)
+	} else {
+		fmt.Printf("\nWrote bp2build metrics to: %s\n", metricsFile)
+	}
+}
+
 func (metrics *CodegenMetrics) IncrementRuleClassCount(ruleClass string) {
 	metrics.ruleClassCount[ruleClass] += 1
 }
@@ -53,12 +105,18 @@
 	metrics.unconvertedModuleCount += 1
 }
 
-func (metrics *CodegenMetrics) TotalModuleCount() int {
+func (metrics *CodegenMetrics) TotalModuleCount() uint64 {
 	return metrics.handCraftedModuleCount +
 		metrics.generatedModuleCount +
 		metrics.unconvertedModuleCount
 }
 
+// Dump serializes the metrics to the given filename
+func (metrics *CodegenMetrics) dump(filename string) (err error) {
+	ser := metrics.Serialize()
+	return shared.Save(&ser, filename)
+}
+
 type ConversionType int
 
 const (
diff --git a/cmd/soong_build/main.go b/cmd/soong_build/main.go
index c81d4bc..f07eafa 100644
--- a/cmd/soong_build/main.go
+++ b/cmd/soong_build/main.go
@@ -537,6 +537,7 @@
 	// for queryview, since that's a total repo-wide conversion and there's a
 	// 1:1 mapping for each module.
 	metrics.Print()
+	writeBp2BuildMetrics(&metrics, configuration)
 
 	ninjaDeps = append(ninjaDeps, codegenContext.AdditionalNinjaDeps()...)
 	ninjaDeps = append(ninjaDeps, symlinkForestDeps...)
@@ -546,3 +547,13 @@
 	// Create an empty bp2build marker file.
 	touch(shared.JoinPath(topDir, bp2buildMarker))
 }
+
+// Write Bp2Build metrics into $LOG_DIR
+func writeBp2BuildMetrics(metrics *bp2build.CodegenMetrics, configuration android.Config) {
+	metricsDir := configuration.Getenv("LOG_DIR")
+	if len(metricsDir) < 1 {
+		fmt.Fprintf(os.Stderr, "\nMissing required env var for generating bp2build metrics: LOG_DIR\n")
+		os.Exit(1)
+	}
+	metrics.Write(metricsDir)
+}
diff --git a/shared/Android.bp b/shared/Android.bp
index deb17f8..3c84f55 100644
--- a/shared/Android.bp
+++ b/shared/Android.bp
@@ -9,11 +9,13 @@
         "env.go",
         "paths.go",
         "debug.go",
+        "proto.go",
     ],
     testSrcs: [
         "paths_test.go",
     ],
     deps: [
         "soong-bazel",
+        "golang-protobuf-proto",
     ],
 }
diff --git a/shared/proto.go b/shared/proto.go
new file mode 100644
index 0000000..232656b
--- /dev/null
+++ b/shared/proto.go
@@ -0,0 +1,41 @@
+// Copyright 2021 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 shared
+
+import (
+	"io/ioutil"
+	"os"
+
+	"google.golang.org/protobuf/proto"
+)
+
+// Save takes a protobuf message, marshals to an array of bytes
+// and is then saved to a file.
+func Save(pb proto.Message, filepath string) (err error) {
+	data, err := proto.Marshal(pb)
+	if err != nil {
+		return err
+	}
+	tempFilepath := filepath + ".tmp"
+	if err := ioutil.WriteFile(tempFilepath, []byte(data), 0644 /* rw-r--r-- */); err != nil {
+		return err
+	}
+
+	if err := os.Rename(tempFilepath, filepath); err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/ui/build/config.go b/ui/build/config.go
index c306633..4c26d3e 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -1255,16 +1255,22 @@
 	return c.metricsUploader
 }
 
-// LogsDir returns the logs directory where build log and metrics
-// files are located. By default, the logs directory is the out
+// LogsDir returns the absolute path to the logs directory where build log and
+// metrics files are located. By default, the logs directory is the out
 // directory. If the argument dist is specified, the logs directory
 // is <dist_dir>/logs.
 func (c *configImpl) LogsDir() string {
+	dir := c.OutDir()
 	if c.Dist() {
 		// Always write logs to the real dist dir, even if Bazel is using a rigged dist dir for other files
-		return filepath.Join(c.RealDistDir(), "logs")
+		dir = filepath.Join(c.RealDistDir(), "logs")
 	}
-	return c.OutDir()
+	absDir, err := filepath.Abs(dir)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "\nError making log dir '%s' absolute: %s\n", dir, err.Error())
+		os.Exit(1)
+	}
+	return absDir
 }
 
 // BazelMetricsDir returns the <logs dir>/bazel_metrics directory
diff --git a/ui/build/soong.go b/ui/build/soong.go
index ae9a2ce..5360342 100644
--- a/ui/build/soong.go
+++ b/ui/build/soong.go
@@ -373,6 +373,7 @@
 	soongBuildEnv.Set("BAZEL_OUTPUT_BASE", filepath.Join(config.BazelOutDir(), "output"))
 	soongBuildEnv.Set("BAZEL_WORKSPACE", absPath(ctx, "."))
 	soongBuildEnv.Set("BAZEL_METRICS_DIR", config.BazelMetricsDir())
+	soongBuildEnv.Set("LOG_DIR", config.LogsDir())
 
 	// For Soong bootstrapping tests
 	if os.Getenv("ALLOW_MISSING_DEPENDENCIES") == "true" {
diff --git a/ui/metrics/Android.bp b/ui/metrics/Android.bp
index 96f6389..3ba3907 100644
--- a/ui/metrics/Android.bp
+++ b/ui/metrics/Android.bp
@@ -25,6 +25,7 @@
         "soong-ui-metrics_proto",
         "soong-ui-bp2build_metrics_proto",
         "soong-ui-tracer",
+        "soong-shared",
     ],
     srcs: [
         "metrics.go",
diff --git a/ui/metrics/metrics.go b/ui/metrics/metrics.go
index f1bb862..80f8c1a 100644
--- a/ui/metrics/metrics.go
+++ b/ui/metrics/metrics.go
@@ -32,12 +32,12 @@
 // of what an event is and how the metrics system is a stack based system.
 
 import (
-	"io/ioutil"
 	"os"
 	"runtime"
 	"strings"
 	"time"
 
+	"android/soong/shared"
 	"google.golang.org/protobuf/proto"
 
 	soong_metrics_proto "android/soong/ui/metrics/metrics_proto"
@@ -196,7 +196,7 @@
 	}
 	m.metrics.HostOs = proto.String(runtime.GOOS)
 
-	return save(&m.metrics, out)
+	return shared.Save(&m.metrics, out)
 }
 
 // SetSoongBuildMetrics sets the metrics collected from the soong_build
@@ -228,25 +228,5 @@
 
 // Dump saves the collected CUJs metrics to the raw protobuf file.
 func (c *CriticalUserJourneysMetrics) Dump(filename string) (err error) {
-	return save(&c.cujs, filename)
-}
-
-// save takes a protobuf message, marshals to an array of bytes
-// and is then saved to a file.
-func save(pb proto.Message, filename string) (err error) {
-	data, err := proto.Marshal(pb)
-	if err != nil {
-		return err
-	}
-
-	tempFilename := filename + ".tmp"
-	if err := ioutil.WriteFile(tempFilename, []byte(data), 0644 /* rw-r--r-- */); err != nil {
-		return err
-	}
-
-	if err := os.Rename(tempFilename, filename); err != nil {
-		return err
-	}
-
-	return nil
+	return shared.Save(&c.cujs, filename)
 }