Fuzz testing jsonchema (#1499)

- Add `hypothesis` and `hypothesis-jsonschema`
- Add `hypothesis-slow` tox env to run slow tests
- Implement `JsonLocalResolver` to avoid `hypothesis-jsonschema` errors
- Add fuzz test covering `validate_cloudconfig_schema`

1 files changed, 37 insertions, 13 deletions

diff --git a/tox.ini b/tox.ini
index 26588585..1743b5e6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,13 @@
 [tox]
-envlist = py3, lowest-supported-dev, black, flake8, isort, mypy, pylint
+envlist =
+    py3,
+    lowest-supported-dev,
+    hypothesis-slow,
+    black,
+    flake8,
+    isort,
+    mypy,
+    pylint
 recreate = True
 
 [doc8]
@@ -15,6 +23,8 @@ passenv=
 [format_deps]
 black==22.3.0
 flake8==4.0.1
+hypothesis==6.31.6
+hypothesis_jsonschema==0.20.1
 isort==5.10.1
 mypy==0.950
 pylint==2.13.9
@@ -49,19 +59,23 @@ commands = {envpython} -m isort . --check-only
 
 [testenv:mypy]
 deps =
+    hypothesis=={[format_deps]hypothesis}
+    hypothesis_jsonschema=={[format_deps]hypothesis_jsonschema}
     mypy=={[format_deps]mypy}
+    pytest=={[format_deps]pytest}
     types-jsonschema=={[format_deps]types-jsonschema}
     types-oauthlib=={[format_deps]types-oauthlib}
     types-pyyaml=={[format_deps]types-PyYAML}
     types-requests=={[format_deps]types-requests}
     types-setuptools=={[format_deps]types-setuptools}
-    pytest=={[format_deps]pytest}
 commands = {envpython} -m mypy cloudinit/ tests/ tools/
 
 [testenv:check_format]
 deps =
     black=={[format_deps]black}
     flake8=={[format_deps]flake8}
+    hypothesis=={[format_deps]hypothesis}
+    hypothesis_jsonschema=={[format_deps]hypothesis_jsonschema}
     isort=={[format_deps]isort}
     mypy=={[format_deps]mypy}
     pylint=={[format_deps]pylint}
@@ -118,8 +132,17 @@ deps =
     -r{toxinidir}/test-requirements.txt
 commands = {envpython} -m pytest \
             --durations 10 \
-            {posargs:--cov=cloudinit --cov-branch \
-            tests/unittests}
+            -m "not hypothesis_slow" \
+            {posargs:--cov=cloudinit --cov-branch tests/unittests}
+
+[testenv:hypothesis-slow]
+deps =
+    hypothesis==6.31.6
+    hypothesis_jsonschema==0.20.1
+    -r{toxinidir}/test-requirements.txt
+commands = {envpython} -m pytest \
+            -m hypothesis_slow \
+            {posargs:--hypothesis-show-statistics tests/unittests}
 
 [lowest-supported-deps]
 # Tox is going to install requirements from pip. This is fine for
@@ -257,25 +280,26 @@ addopts = --strict
 log_format = %(asctime)s %(levelname)-9s %(name)s:%(filename)s:%(lineno)d %(message)s
 log_date_format = %Y-%m-%d %H:%M:%S
 markers =
-    allow_subp_for: allow subp usage for the given commands (disable_subp_usage)
+    adhoc: only run on adhoc basis, not in any CI environment (travis or jenkins)
     allow_all_subp: allow all subp usage (disable_subp_usage)
+    allow_subp_for: allow subp usage for the given commands (disable_subp_usage)
+    azure: test will only run on Azure platform
     ci: run this integration test as part of CI test runs
     ds_sys_cfg: a sys_cfg dict to be used by datasource fixtures
     ec2: test will only run on EC2 platform
     gce: test will only run on GCE platform
-    azure: test will only run on Azure platform
-    oci: test will only run on OCI platform
-    openstack: test will only run on openstack platform
+    hypothesis_slow: hypothesis test too slow to run as unit test
+    instance_name: the name to be used for the test instance
+    is_iscsi: whether is an instance has iscsi net cfg or not
     lxd_config_dict: set the config_dict passed on LXD instance creation
     lxd_container: test will only run in LXD container
     lxd_setup: specify callable to be called between init and start
     lxd_use_exec: `execute` will use `lxc exec` instead of SSH
     lxd_vm: test will only run in LXD VM
-    not_bionic: test cannot run on the bionic release
     no_container: test cannot run in a container
-    user_data: the user data to be passed to the test instance
-    instance_name: the name to be used for the test instance
+    not_bionic: test cannot run on the bionic release
+    oci: test will only run on OCI platform
+    openstack: test will only run on openstack platform
     ubuntu: this test should run on Ubuntu
     unstable: skip this test because it is flakey
-    adhoc: only run on adhoc basis, not in any CI environment (travis or jenkins)
-    is_iscsi: whether is an instance has iscsi net cfg or not
+    user_data: the user data to be passed to the test instance