Makefile,mkversion.sh: set tailscale versions at build time

While here, set the gradle versionName from the Makefile as well.

Updates tailscale/tailscale#486

Signed-off-by: Elias Naur <mail@eliasnaur.com>

Makefile

@@ -1,22 +1,29 @@
+# Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
 DEBUG_APK=tailscale-debug.apk
 RELEASE_AAB=tailscale-release.aab
 APPID=com.tailscale.ipn
 AAR=android/libs/ipn.aar
 KEYSTORE=tailscale.jks
 KEYSTORE_ALIAS=tailscale
+GIT_DESCRIBE=$(shell git describe --tags --long)
+VERSION_LONG=$(shell ./mkversion.sh long $(GIT_DESCRIBE))
+VERSION_SHORT=$(shell ./mkversion.sh short $(GIT_DESCRIBE))
 
 all: $(APK)
 
 aar:
 	mkdir -p android/libs
-	go run gioui.org/cmd/gogio -buildmode archive -target android -appid $(APPID) -o $(AAR) github.com/tailscale/tailscale-android/cmd/tailscale
+	go run gioui.org/cmd/gogio -ldflags "-X tailscale.com/version.LONG=$(VERSION_LONG) -X tailscale.com/version.SHORT=$(VERSION_SHORT)" -tags xversion -buildmode archive -target android -appid $(APPID) -o $(AAR) github.com/tailscale/tailscale-android/cmd/tailscale
 
 $(DEBUG_APK): aar
-	(cd android && ./gradlew assembleDebug)
+	(cd android && VERSION_LONG=$(VERSION_LONG) ./gradlew assembleDebug)
 	mv android/build/outputs/apk/debug/android-debug.apk $@
 	
 $(RELEASE_AAB): aar
-	(cd android && ./gradlew bundleRelease)
+	(cd android && VERSION_LONG=$(VERSION_LONG) ./gradlew bundleRelease)
 	mv ./android/build/outputs/bundle/release/android-release.aab $@
 
 release: $(RELEASE_AAB)

android/build.gradle

@@ -35,7 +35,7 @@ android {
         minSdkVersion 23
         targetSdkVersion 29
         versionCode 8
-        versionName getVersionName()
+        versionName System.getenv("VERSION_LONG")
     }
 	compileOptions {
 		sourceCompatibility 1.8

mkversion.sh

@@ -0,0 +1,97 @@
+#!/bin/sh
+
+# Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+set -eu
+
+mode=$1
+describe=$2
+
+long() {
+    ver="${describe#v}"
+    stem="${ver%%-*}"
+    case "$stem" in
+        *.*.*)
+            # Full SemVer, nothing to do.
+            semver="${stem}"
+        ;;
+        *.*)
+            # Old style major.minor, add a .0
+            semver="${stem}.0"
+            ;;
+        *)
+            echo "Unparseable version $stem" >&2
+            exit 1
+            ;;
+    esac
+    suffix="${ver#$stem}"
+    case "$suffix" in
+        -*-*)
+            # Has a change count in addition to the commit hash.
+        ;;
+        -*)
+            # Missing change count, add one.
+            suffix="-0${suffix}"
+            ;;
+        *)
+            echo "Unexpected version suffix" >&2
+            exit 1
+    esac
+    echo "${semver}${suffix}"
+}
+
+short() {
+    ver="$(long)"
+    case "$ver" in
+        *-*-*)
+            echo "${ver%-*}"
+            ;;
+        *-*)
+            echo "$ver"
+            ;;
+        *)
+            echo "Long version in invalid format" >&2
+            exit 1
+            ;;
+    esac
+}
+
+xcode() {
+    ver=$(short | sed -e 's/-/./')
+    major=$(echo "$ver" | cut -f1 -d.)
+    minor=$(echo "$ver" | cut -f2 -d.)
+    patch=$(echo "$ver" | cut -f3 -d.)
+    changecount=$(echo "$ver" | cut -f4 -d.)
+
+    # Apple version numbers must be major.minor.patch. We have 4 fields
+    # because we need major.minor.patch for go module compatibility, and
+    # changecount for automatic version numbering of unstable builds. To
+    # resolve this, for Apple builds, we combine changecount into patch:
+    patch=$((patch*10000 + changecount))
+
+    # CFBundleShortVersionString: the "short name" used in the App Store.
+    # eg. 0.92.98
+    echo "VERSION_NAME = $major.$minor.$patch"
+    # CFBundleVersion: the build number. Needs to be 3 numeric sections
+    # that increment for each release according to SemVer rules.
+    #
+    # We start counting at 100 because we submitted using raw build
+    # numbers before, and Apple doesn't let you start over.
+    # e.g. 0.98.3-123 -> 100.98.3123
+    major=$((major + 100))
+    echo "VERSION_ID = $major.$minor.$patch"
+}
+
+case "$mode" in
+    long)
+        long
+    ;;
+    short)
+        short
+    ;;
+    xcode)
+        xcode
+    ;;
+esac