Merge ~smoser/cloud-init:cleanup/remove-json-schema-from-tox-xenial into cloud-init:master

[Scott Moser]

tests: remove jsonschema from xenial tox environment.

Ubuntu 16.04 (xenial) does not have jsonschema installed by default. As
it is listed in requirements, the tox environment will always have it
installed.

Add the helper tools/pipremove that removes pip packages. Then use that
to remove jsonschema without noise of always running and ignoring a
'pip uninstall jsonschema'.

related https://code.launchpad.net/~smoser/cloud-init/+git/cloud-init/+merge/341997

to test that this works:
 tox-venv xenial pip install jsonschema
 tox -e xenial cloudinit/config/tests/test_snap.py

that will show:
  xenial runtests: commands[0] | python ./tools/pipremove jsonschema
  ./tools/pipremove removing package jsonschema
  Uninstalling jsonschema-2.6.0:
    Successfully uninstalled jsonschema-2.6.0
  xenial runtests: commands[1] | python -m nose cloudinit/config/tests/test_snap.py
  .........F.........FFFFFFFFF

[Server Team CI bot (server-team-bot)]

FAILED: Continuous integration, rev:d5f4efb75957b4c345ab79aa26880e358f7d6814
https://jenkins.ubuntu.com/server/job/cloud-init-ci/915/
Executed test runs:
    SUCCESS: Checkout
    FAILED: Unit & Style Tests

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/915/rebuild

review: Needs Fixing (continuous-integration)

[Scott Moser (smoser)]

Note that the failure jenkins saw is by design.
Trunk is busted and this exposes that fact.

[Server Team CI bot (server-team-bot)]

PASSED: Continuous integration, rev:ba4d474ee1e0f6fbc5fe17f314af0fda5b554471
https://jenkins.ubuntu.com/server/job/cloud-init-ci/918/
Executed test runs:
    SUCCESS: Checkout
    SUCCESS: Unit & Style Tests
    SUCCESS: Ubuntu LTS: Build
    SUCCESS: Ubuntu LTS: Integration
    SUCCESS: MAAS Compatability Testing
    IN_PROGRESS: Declarative: Post Actions

Click here to trigger a rebuild:
https://jenkins.ubuntu.com/server/job/cloud-init-ci/918/rebuild

review: Approve (continuous-integration)

[Chad Smith (chad.smith)]

+1

review: Approve

[Chad Smith (chad.smith)]

An upstream commit landed for this bug.

To view that commit see the following URL:
https://git.launchpad.net/cloud-init/commit/?id=68d798bb

diff --git a/tools/pipremove b/tools/pipremove
new file mode 100755
index 0000000..f8f4ff1
--- /dev/null
+++ b/tools/pipremove
@@ -0,0 +1,14 @@
+#!/usr/bin/python3
+import subprocess
+import sys
+
+for pkg in sys.argv[1:]:
+    try:
+        exec('import %s' % pkg)  # pylint: disable=W0122
+    except ImportError:
+        continue
+    sys.stderr.write("%s removing package %s\n" % (sys.argv[0], pkg))
+    ret = subprocess.Popen(['pip', 'uninstall', '--yes', pkg]).wait()
+    if ret != 0:
+        sys.stderr.write("Failed to uninstall %s (%d)\n" % (pkg, ret))
+        sys.exit(ret)
diff --git a/tox.ini b/tox.ini
index 1f990af..818ade3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -60,6 +60,9 @@ deps = sphinx
 commands = {envpython} -m sphinx {posargs:doc/rtd doc/rtd_html}
 
 [testenv:xenial]
+commands =
+  python ./tools/pipremove jsonschema
+  python -m nose {posargs:tests/unittests cloudinit}
 basepython = python3
 deps =
     # requirements