This reverts commit c7b67d1.

This reverts commit 933f1af.

…sts execution

System tests running in docker are using the same virtual environment as
the host. If version of python in the virtual environment is not available
in the guest, it will use the default in the system, that is so far
Python 2.

fix 'str' does not support the buffer interface

* Run autopep on script/update_golang_x.py to fix make check
* Update travis to use Ubuntu Bionic

Some tests were requiring localhost to resolve to 127.0.0.1, but this is
not always the case. In some machines localhost resolve to other local
addresses as 127.0.1.1, or to [::1] if ipv4 is not available.

Localhost in travis resolves to 127.0.1.1, include this IP as alternate
name in certificates used for outputs testing.

Use python3 in the shebang for python scripts. python is going to be reserved for python2 in Ubuntu, and PEP394 mentions that python should be used in the shebang line only for scripts that are source compatible with both Python 2 and 3.

Document python requirement as >= 3.7.

On Linux, sys.platform doesn’t contain the major version anymore. It is now always ‘linux’, instead of ‘linux2’ or ‘linux3’ depending on the Linux version used to build Python. Replace sys.platform == ‘linux2’ with sys.platform.startswith(‘linux’), or directly sys.platform == ‘linux’ if you don’t need to support older Python versions.

Ref: https://docs.python.org/3.3/whatsnew/3.3.html#porting-python-code

This should fix test_management.py under Python3. An object was being returned but
the test was expecting to get a number. The format of the Elasticsearch response changed
for the "track_total_hits" enhancement, but this wasn't updated.

This has a few fixes to python system tests under libbeat/tests/system.

assert_docs_written_to_alias had an invalid assertion ever since Elasticsearch
changed the format of the hits count to allow for track_total_hits false. Many
tests were using this assertion even when not indexing any events so the hit
count would always be zero so I removed the assertion from those tests.

In other tests I was getting spurious failures because _search was being called
before the index was refreshed to allow the documents to be search able. So I
added an explicit /_refresh to fix the issue.

I changed create_kibana_space to allow a 409 response code so you can run the
tests more than once against a Kibana instance.

I fixed an assertion on the mode bits of a file since the format of octal numbers is
always prefixed with '0o' now.

And I fixed the libbeat keystore tests by encoding the secret string to binary
before calling os.write. This fixed this error:

```
======================================================================
ERROR: Add a secret to the store using stdin
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/akroh/go/src/github.com/elastic/beats/libbeat/tests/system/test_cmd_keystore.py", line 130, in test_keystore_add_secret_from_stdin
    exit_code = self.add_secret("willnotdelete")
  File "/Users/akroh/go/src/github.com/elastic/beats/libbeat/tests/system/keystore.py", line 29, in add_secret
    os.write(proc.stdin_write, value)
TypeError: a bytes-like object is required, not 'str'
```

…auditbeat-and-dashboards

Switch over to `python3 -m venv` instead of `virtualenv`. It's the recommended way to create virtual Python environments in 3.4 and above.

https://docs.python.org/3/library/venv.html

Remove any direct references to python to always allow
a specific python binary or version to be used.

It is failing with python 3 and we have another more complete build to
test this in Jenkins.

…nd-dashboards' into HEAD

This test was running with the unit test target and failing.

* Python3 Windows and Winlogbeat updates

This updates the Vagrantfile and addresses a few issues. I installed Python3 on Windows
via chocolotey and the python MSI and neither provided a `python3` command so I adjusted
the build tooling to use `python` on Windows.

Another issue I hit was that under Vagrant with the shared filesystem, `pip` would not
install into the virtual environment. It only will install when moving the PYTHON_ENV
off of the shared filesystem. So when provisining the Vagrant VM it will now put
PYTHON_ENV in C:\beats-python-env. Remember this if you need need to do a completely
clean build on Windows+Vagrant.

There were some encoding issues I found while reading output files containing unicode.
So I modified the libbeat's beat.py to specify `utf_8` encoding when opening output files.
I was seeing errors like:

```
======================================================================
ERROR: eventlogging - UTF-16 characters
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Gopath\src\github.com\elastic\beats\winlogbeat\tests\system\test_eventlogging.py", line 187, in test_utf16_characters
    evts = self.read_events(config={
  File "C:\Gopath\src\github.com\elastic\beats\winlogbeat\tests\system\winlogbeat.py", line 110, in read_events
    return self.read_output()
  File "C:\Gopath\src\github.com\elastic\beats\winlogbeat\tests\system\../../../libbeat/tests/system\beat\beat.py", line 260, in read_output
    for line in f:
  File "C:\Python38\lib\encodings\cp1252.py", line 23, in decode
    return codecs.charmap_decode(input,self.errors,decoding_table)[0]
UnicodeDecodeError: 'charmap' codec can't decode byte 0x8d in position 277: character maps to <undefined>
```

I bumped the Pillow version in the pip requirements because the newer version provides a
precompiled wheel for Python 3 on Windows. This avoids having to compiling it. I bumped
the Docker versions while debugging and just left them at the latest version since nothing broke.

I tested Winlogbeat and Metricbeat's `mage pythonUnitTest` on Windows 2019 and all tests passed.

Use the health check of the service for the docker health check,
and check the status code of the response.

Print nosetests output on builds.

Some versions of python cannot guarantee order of dictionaries, so same
dictionary can generate different documentation strings. Use a JSON
string so its representation doesn't depend on how python encodes it.

Also, fix versions in python-env for root directory.

…e-of-python3-branch

Replaces use of nosetests with mage wrapper in script for Windows CI workers.

Mage manages their own python virtual environments, this is preferred to directly
call python commands.

Installs python 3 using chocolatey, as it is still not available in Windows CI workers.

future was failing to install in Windows, but we don't actually need it anymore,
so it is removed.

…ch-again

Skip tests frequently failing in python 3 branch.
#16247

…nto HEAD