refactor(mk): move build rules into separate scripts (#855)

See https://github.com/ooni/probe/issues/2218

MOBILE/android/createpom

@@ -0,0 +1,4 @@
+#!/bin/bash
+set -euo pipefail
+__version=$(date -u +%Y.%m.%d-%H%M%S)
+cat ./MOBILE/android/template.pom | sed -e "s/@VERSION@/$__version/g" > ./MOBILE/android/oonimkall.pom

MOBILE/android/ensure

@@ -0,0 +1,38 @@
+#!/bin/bash
+
+set -euo pipefail
+
+__install_extra="build-tools;32.0.0 platforms;android-31"
+
+__ndk_version="23.1.7779620"
+
+GOOS=$(go env GOOS)
+case $GOOS in
+linux)
+	__sdk_dir=$HOME/Android/Sdk
+	;;
+darwin)
+	__sdk_dir=$HOME/Library/Android/sdk
+	;;
+*)
+	echo "FATAL: unsupported operating system" 1>&2
+	exit 1
+	;;
+esac
+
+ANDROID_HOME=${ANDROID_HOME:-$__sdk_dir}
+if [[ ! -d $ANDROID_HOME ]]; then
+	echo "FATAL: expected to find android SDK at $ANDROID_HOME, but found nothing" 1>&2
+	echo "HINT: run ./MOBILE/android/setup to (re)install the SDK" 1>&2
+	exit 1
+fi
+
+__sdkmanager=$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager
+if [[ ! -x $__sdkmanager ]]; then
+	echo "FATAL: expected to find sdkmanager at $__sdkmanager, but found nothing" 1>&2
+	echo "HINT: run ./MOBILE/android/setup to (re)install the SDK" 1>&2
+	exit 1
+fi
+
+set -x
+echo "Yes" | $__sdkmanager --install $__install_extra "ndk;$__ndk_version"

MOBILE/android/setup

@@ -0,0 +1,52 @@
+#!/bin/bash
+
+set -euo pipefail
+
+GOOS=$(go env GOOS)
+case $GOOS in
+linux)
+	__sdk_dir=$HOME/Android/Sdk
+	;;
+darwin)
+	__sdk_dir=$HOME/Library/Android/sdk
+	;;
+*)
+	echo "FATAL: unsupported operating system" 1>&2
+	exit 1
+	;;
+esac
+
+ANDROID_HOME=${ANDROID_HOME:-$__sdk_dir}
+
+__clitools_version=8512546
+__clitools_file=commandlinetools-linux-${__clitools_version}_latest.zip
+__clitools_sha256=2ccbda4302db862a28ada25aa7425d99dce9462046003c1714b059b5c47970d8
+
+printf "checking for curl... "
+command -v curl || {
+	echo "not found"
+	exit 1
+}
+printf "checking for shasum... "
+command -v shasum || {
+	echo "not found"
+	exit 1
+}
+printf "checking for unzip... "
+command -v unzip || {
+	echo "not found"
+	exit 1
+}
+
+set -x
+rm -rf $ANDROID_HOME/cmdline-tools/latest
+curl -fsSLO https://dl.google.com/android/repository/$__clitools_file
+echo "$__clitools_sha256  $__clitools_file" >__SHA256
+shasum --check __SHA256
+rm -f __SHA256
+unzip $__clitools_file
+rm $__clitools_file
+mkdir -p $ANDROID_HOME/cmdline-tools
+# See https://stackoverflow.com/a/61176718 to understand why
+# we need to reorganize the directories like this:
+mv cmdline-tools $ANDROID_HOME/cmdline-tools/latest

MOBILE/gomobile

@@ -0,0 +1,61 @@
+#!/bin/bash
+
+set -euo pipefail
+
+if [[ $# -ne 2 ]]; then
+	echo "" 1>&2
+	echo "Calls gomobile for either Android or iOS to build PACKAGE." 1>&2
+	echo "" 1>&2
+	echo "usage: $0 TARGET PACKAGE" 1>&2
+	echo "" 1>&2
+	echo "TARGET must be one of: android, ios." 1>&2
+	echo "" 1>&2
+	echo "Features:" 1>&2
+	echo "" 1>&2
+	echo "* automatically sets -tags=ooni_psiphon_config when possible;" 1>&2
+	echo "" 1>&2
+	echo "* if GOLANG_EXTRA_FLAGS is set, pass it to the Go compiler." 1>&2
+	echo "" 1>&2
+	echo "Example:" 1>&2
+	echo "" 1>&2
+	echo "  ./MOBILE/gomobile android ./pkg/oonimkall" 1>&2
+	echo "" 1>&2
+	exit 1
+fi
+
+TARGET=$1
+PACKAGE=$2
+
+if [[ $TARGET == "android" ]]; then
+	EXT="aar"
+elif [[ $TARGET == "ios" ]]; then
+	EXT="xcframework"
+else
+	echo "FATAL: unsupported target: $TARGET" 1>&2
+	exit 1
+fi
+
+if [[ -f ./internal/engine/psiphon-config.json.age &&
+	-f ./internal/engine/psiphon-config.key ]]; then
+	OONI_PSIPHON_TAGS=ooni_psiphon_config
+else
+	OONI_PSIPHON_TAGS=""
+fi
+
+PRODUCT=$(basename $PACKAGE)
+
+function cleanup() {
+	# Undoes the effects of go-getting golang.org/x/mobile/cmd/gomobile
+	go mod tidy
+}
+trap cleanup EXIT
+
+set -x
+go install golang.org/x/mobile/cmd/gomobile@latest
+$(go env GOPATH)/bin/gomobile init
+# Adding gomobile to go.mod as documented by golang.org/wiki/Mobile
+go get -d golang.org/x/mobile/cmd/gomobile
+
+$(go env GOPATH)/bin/gomobile bind -target $TARGET \
+	-o ./MOBILE/$TARGET/$PRODUCT.$EXT -tags="$OONI_PSIPHON_TAGS" \
+	-ldflags '-s -w' ${GOLANG_EXTRA_FLAGS:-} $PACKAGE

MOBILE/ios/check-xcode-version

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+set -euo pipefail
+
+EXPECTED_XCODE_VERSION=${EXPECTED_XCODE_VERSION:-13.4.1}
+
+printf "checking for xcodebuild... "
+command -v xcodebuild || {
+	echo "not found"
+	exit 1
+}
+
+printf "checking for Xcode version... "
+__XCODEVERSION_REAL=$(xcodebuild -version | grep ^Xcode | awk '{print $2}')
+echo $__XCODEVERSION_REAL
+[[ "$EXPECTED_XCODE_VERSION" = "$__XCODEVERSION_REAL" ]] || {
+	echo "fatal: Xcode version must be $EXPECTED_XCODE_VERSION instead of $__XCODEVERSION_REAL"
+	exit 1
+}

MOBILE/ios/createpodspec

@@ -0,0 +1,6 @@
+#!/bin/bash
+set -euo pipefail
+__version=$(date -u +%Y.%m.%d-%H%M%S)
+__release=$(git describe --tags || echo '0.0.0-dev')
+cat ./MOBILE/ios/template.podspec | sed -e "s/@VERSION@/$__version/g" \
+	-e "s/@RELEASE@/$__release/g" >./MOBILE/ios/oonimkall.podspec

MOBILE/ios/zipframework

@@ -0,0 +1,7 @@
+#!/bin/bash
+set -euxo pipefail
+(
+	cd ./MOBILE/ios
+	rm -rf oonimkall.xcframework.zip
+	zip -yr oonimkall.xcframework.zip oonimkall.xcframework
+)