CI: Use emulator acceleration

To take advantage of some of the new nested virtualization capabilities
of some of the images in Travis, you must be using the newest LTS
release of Ubuntu, 18.04 Bionic Beaver.

However, the Travis image of Bionic does not include support for JDK 8,
which we need to utilize the Android SDK manager. To circumvent this
issue, we change from the "android" language type to "generic", and take
care of both the JDK and the Android SDK ourselves.

As such, this commit makes the following changes:
* Switch `dist` from `trusty` to `bionic`
* Switch `language` from `android` to `generic`
* Enable the use of `sudo`
* Install libpulse0 for emulator audio
* Set up KVM inside the allocated Travis image
* Use Gravis repository to download and install Java
* Version android-wait-for-emulator in our repo
* Download and install the Android SDK ourselves
* Switch to `emulator-headless` for the x86 emulators

Since we're free to switch Java versions as we please, we can finally
support JDK 11 by switching to it after starting our emulator.

.travis.yml

@@ -1,17 +1,28 @@
-language: android
-dist: trusty
+sudo: true
+language: generic
+dist: bionic
 
-jdk:
-  - oraclejdk8
+addons:
+  apt:
+    packages:
+      - bridge-utils
+      - libpulse0
+      - libvirt-bin
+      - qemu-kvm
+      - virtinst
+      - ubuntu-vm-builder
 
 env:
   global:
-    - ADB_INSTALL_TIMEOUT=8
     - ABI=x86_64
+    - ADB_INSTALL_TIMEOUT=8
+    - ANDROID_HOME=${HOME}/android-sdk
+    - ANDROID_TOOLS_URL="https://dl.google.com/android/repository/sdk-tools-linux-4333796.zip"
     - EMU_FLAVOR=default # use google_apis flavor if no default flavor emulator
-    # PATH order is incredibly important. e.g. the 'emulator' script exists in more than one place!
-    - ANDROID_HOME=/usr/local/android-sdk
+    - GRAVIS="https://raw.githubusercontent.com/DanySK/Gravis-CI/master/"
+    - JDK="1.8"
     - TOOLS=${ANDROID_HOME}/tools
+    # PATH order is incredibly important. e.g. the 'emulator' script exists in more than one place!
     - PATH=${ANDROID_HOME}:${ANDROID_HOME}/emulator:${TOOLS}:${TOOLS}/bin:${ANDROID_HOME}/platform-tools:${PATH}
   matrix:
    #- API=15 # only runs locally. Create+Start once from AndroidStudio to init sdcard. Then only from command-line w/-engine classic
@@ -34,33 +45,44 @@ jobs:
   fast_finish: true  # We can report success without waiting for jobs that we
                      # allow / expect to fail.
   include:
-    - jdk: oraclejdk11
-      env: API=24
+    - env: API=24 JDK="1.11"
     # The test stage is implicit, we only need to define a post-test stage for codacy finalization
     - stage: finalize_coverage
       env: FINALIZE_COVERAGE=TRUE API=NONE
       install: skip
       script: echo finalize codacy coverage uploads
   allow_failures:
-    - jdk: oraclejdk11
+    - env: API=24 JDK="1.11"
     # API=28/Q are probably fixable but we don't need allow_failures to be on
     # in master to work through them.
     #- env: API=28
     #- env: API=Q
 
-android:
-  components:
-    # installing tools to start, then use `sdkmanager` below to get the rest
-    - tools
+before_install:
+  # Set up KVM
+  - sudo adduser $USER libvirt
+  - sudo adduser $USER kvm
 
-licenses:
-    - 'android-sdk-preview-license-.+'
-    - 'android-sdk-license-.+'
-    - 'google-gdk-license-.+'
+  # Set up JDK 8 for Android SDK
+  - curl "${GRAVIS}.install-jdk-travis.sh" --output ~/.install-jdk-travis.sh
+  - export TARGET_JDK="${JDK}"
+  - JDK="1.8"
+  - source ~/.install-jdk-travis.sh
+
+  # Set up Android SDK
+  - wget -q "${ANDROID_TOOLS_URL}" -O android-sdk-tools.zip
+  - unzip -q android-sdk-tools.zip -d ${ANDROID_HOME}
+  - rm android-sdk-tools.zip
+  
+  # Avoid harmless sdkmanager warning  
+  - mkdir ~/.android
+  - echo 'count=0' > ~/.android/repositories.cfg
+
+  # Accept all Android license agreements
+  - yes | sdkmanager --licenses
 
-# Emulator Management: Create, Start and Wait
 install:
-  - echo 'count=0' > /home/travis/.android/repositories.cfg # Avoid harmless sdkmanager warning
+  # Download SDK tools
   - echo y | sdkmanager "platform-tools" >/dev/null
   - echo y | sdkmanager "tools" >/dev/null # A second time per Travis docs, gets latest versions
   - echo y | sdkmanager "build-tools;28.0.3" >/dev/null # Implicit gradle dependency - gradle drives changes
@@ -69,11 +91,28 @@ install:
   - echo y | sdkmanager "emulator" >/dev/null
   - echo y | sdkmanager "extras;android;m2repository" >/dev/null
   - echo y | sdkmanager "system-images;android-$API;$EMU_FLAVOR;$ABI" >/dev/null # install our emulator
+
+  # Create an Android emulator
   - echo no | avdmanager create avd --force -n test -k "system-images;android-$API;$EMU_FLAVOR;$ABI" -c 10M
-  - emulator -verbose -avd test -no-accel -no-snapshot -no-window $AUDIO -camera-back none -camera-front none -selinux permissive -qemu -m 2048 &
-  - android-wait-for-emulator
+  - |
+    EMU_PARAMS="-verbose -no-snapshot -no-window -camera-back none -camera-front none -selinux permissive -qemu -m 2048"
+    EMU_COMMAND="emulator"
+    if [[ $ABI =~ "x86" ]]; then
+      EMU_COMMAND="emulator-headless"
+    fi
+    # This double "sudo" monstrosity is used to have Travis execute the
+    # emulator with its new group permissions and help preserve the rule
+    # of least privilege.
+    sudo -E sudo -u $USER -E bash -c "${ANDROID_HOME}/emulator/${EMU_COMMAND} -avd test ${AUDIO} ${EMU_PARAMS} &"
+
+  # Wait for emulator to be ready
+  - ./tools/android-wait-for-emulator.sh
   - adb shell input keyevent 82 &
 
+  # Switch back to our target JDK version to build and run tests
+  - JDK="${TARGET_JDK}"
+  - source ~/.install-jdk-travis.sh
+
 script:
   - ./gradlew jacocoTestReport # This produces an error while doing the API getprop on API 28...
 
@@ -82,6 +121,8 @@ after_success:
 
 before_cache:
   - rm -f $HOME/.gradle/caches/modules-2/modules-2.lock
+  - curl "${GRAVIS}.clean_gradle_cache.sh" --output ~/.clean_gradle_cache.sh
+  - bash ~/.clean_gradle_cache.sh
 
 cache:
   directories:
@@ -91,3 +132,4 @@ cache:
 notifications:
   email:
     - flerda+ankidroid-continuous@gmail.com
+

tools/android-wait-for-emulator.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+# Originally written by Ralf Kistner <ralf@embarkmobile.com>, but placed in the public domain
+
+set +e
+
+bootanim=""
+failcounter=0
+timeout_in_sec=600 # 10 minutes
+
+until [[ "$bootanim" =~ "stopped" ]]; do
+  bootanim=`adb -e shell getprop init.svc.bootanim 2>&1 &`
+  if [[ "$bootanim" =~ "device not found" || "$bootanim" =~ "device offline"
+    || "$bootanim" =~ "running" || "$bootanim" =~  "error: no emulators found" ]]; then
+    let "failcounter += 1"
+    echo "Waiting for emulator to start"
+    if [[ $failcounter -gt timeout_in_sec ]]; then
+      echo "Timeout ($timeout_in_sec seconds) reached; failed to start emulator"
+      exit 1
+    fi
+  fi
+  sleep 1
+done
+
+echo "Emulator is ready"
+