Use Aki's solution

.travis.yml

@@ -1,20 +1,31 @@
 sudo: required  # Needed to install a recent version of OpenJDK as well as Python 3.7
+dist: xenial
 
-language: java
+language: python
+
+env:
+  JAVA_HOME=/usr/lib/jvm/java-8-oracle
 
 matrix:
   fast_finish: true
   include:
     - python: 3.6
       env:
         TOXENV=py36
-      jdk: openjdk7
     - python: 3.7
-      dist: xenial  # from https://github.com/travis-ci/travis-ci/issues/9815#issuecomment-401756442
-      group: edge   # see https://github.com/travis-ci/travis-ci/issues/10212#issuecomment-429422646
       env:
         TOXENV=py37
-      jdk: openjdk8
+
+
+before_install:
+    # Install oracle java 8, because jarsigner in openjdk 11.0.1+13 breaks
+    # integration tests.
+    # https://github.com/mozilla-releng/signingscript/issues/80
+    - sudo add-apt-repository -y ppa:webupd8team/java
+    - sudo apt-get update
+    - echo debconf shared/accepted-oracle-license-v1-1 select true | sudo debconf-set-selections
+    - echo debconf shared/accepted-oracle-license-v1-1 seen true | sudo debconf-set-selections
+    - sudo apt-get install oracle-java8-installer
 
 install:
     - travis_retry pip install tox

pushapkscript/test/integration/test_integration_script.py

@@ -15,6 +15,12 @@
 test_data_dir = os.path.join(this_dir, '..', 'data')
 
 
+def _get_java_path(tool_name):
+    if os.environ.get('JAVA_HOME'):
+        return os.path.join(os.environ['JAVA_HOME'], 'bin', tool_name)
+    return tool_name
+
+
 class KeystoreManager(object):
     def __init__(self, test_data_dir, certificate_alias='nightly', keystore_password='12345678'):
         self.keystore_path = os.path.join(test_data_dir, 'keystore')
@@ -23,7 +29,7 @@ def __init__(self, test_data_dir, certificate_alias='nightly', keystore_password
 
     def add_certificate(self, certificate_path):
         subprocess.run([
-            'keytool', '-import', '-noprompt',
+            _get_java_path('keytool'), '-import', '-noprompt',
             '-keystore', self.keystore_path, '-storepass', self.keystore_password,
             '-file', certificate_path, '-alias', self.certificate_alias
         ])
@@ -49,6 +55,7 @@ def _generate_json(self):
             "schema_file": "{project_data_dir}/pushapk_task_schema.json",
             "verbose": true,
 
+            "jarsigner_binary": "{binary}",
             "jarsigner_key_store": "{keystore_path}",
             "jarsigner_certificate_alias": "{certificate_alias}",
             "google_play_accounts": {{
@@ -60,7 +67,7 @@ def _generate_json(self):
             "taskcluster_scope_prefix": "project:releng:googleplay:"
         }}'''.format(
             work_dir=self.work_dir, test_data_dir=self.test_data_dir, project_data_dir=project_data_dir,
-            keystore_path=self.keystore_manager.keystore_path,
+            binary=_get_java_path('jarsigner'), keystore_path=self.keystore_manager.keystore_path,
             certificate_alias=self.keystore_manager.certificate_alias
         ))