Pulish former wiki page as README.md

https://wiki.opnfv.org/display/functest/Write+your+own+Xtesting+driver

Change-Id: If135bf9d84e1c357911eb0b2331539844288969a
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

README.md

@@ -0,0 +1,198 @@
+# Xtesting in a nutshell
+
+Xtesting is a simple framework to assemble sparse test cases and to accelerate
+the adoption of continuous integration best practices. By managing all
+the interactions with the components (test scheduler, test results database,
+artifact repository), it allows the developer to work only on the test suites
+without diving into CI/CD.
+
+It asks for a few low constraints
+[quickly achievable](https://www.sdxcentral.com/articles/news/opnfvs-6th-release-brings-testing-capabilities-that-orange-is-already-using/2018/05/)
+to verify multiple components in the same CI/CD toolchain. Even more, it brings
+the capability to run third-party test cases in our CI toolchains and then to
+also rate network functions by the coverage.
+
+Please see
+[the Katacoda scenarios](https://www.katacoda.com/ollivier/courses/xtestingci)
+to try Xtesting. You will love them!
+
+## [Write your own Xtesting driver](https://www.katacoda.com/ollivier/courses/xtestingci/firstdriver)
+
+### dump all the following files in an empty dir
+
+weather.py
+
+```python
+#!/usr/bin/env python
+
+# pylint: disable=missing-docstring
+
+import json
+import os
+import sys
+import time
+
+import requests
+
+from xtesting.core import testcase
+
+
+class Weather(testcase.TestCase):
+
+    url = "https://samples.openweathermap.org/data/2.5/weather"
+    city_name = "London,uk"
+    app_key = "439d4b804bc8187953eb36d2a8c26a02"
+
+    def run(self, **kwargs):
+        try:
+            self.start_time = time.time()
+            req = requests.get("{}?q={}&&appid={}".format(
+                self.url, self.city_name, self.app_key))
+            req.raise_for_status()
+            data = req.json()
+            os.makedirs(self.res_dir, exist_ok=True)
+            with open('{}/dump.txt'.format(self.res_dir), 'w+') as report:
+                json.dump(data, report, indent=4, sort_keys=True)
+            for key in kwargs:
+                if data["main"][key] > kwargs[key]:
+                    self.result = self.result + 100/len(kwargs)
+            self.stop_time = time.time()
+        except Exception:  # pylint: disable=broad-except
+            print("Unexpected error:", sys.exc_info()[0])
+            self.result = 0
+            self.stop_time = time.time()
+```
+
+setup.py
+
+```python
+#!/usr/bin/env python
+
+# pylint: disable=missing-docstring
+
+import setuptools
+
+setuptools.setup(
+    setup_requires=['pbr>=2.0.0'],
+    pbr=True)
+```
+
+setup.cfg
+
+```
+[metadata]
+name = weather
+version = 1
+
+[files]
+packages = .
+
+[entry_points]
+xtesting.testcase =
+    weather = weather:Weather
+```
+
+requirements.txt
+
+```
+xtesting
+requests!=2.20.0,!=2.24.0 # Apache-2.0
+```
+
+testcases.yaml
+
+```yaml
+---
+tiers:
+    -
+        name: simple
+        order: 0
+        description: ''
+        testcases:
+            -
+                case_name: humidity
+                project_name: weather
+                criteria: 100
+                blocking: true
+                clean_flag: false
+                description: ''
+                run:
+                    name: weather
+                    args:
+                        humidity: 80
+            -
+                case_name: pressure
+                project_name: weather
+                criteria: 100
+                blocking: true
+                clean_flag: false
+                description: ''
+                run:
+                    name: weather
+                    args:
+                        pressure: 1000
+            -
+                case_name: temp
+                project_name: weather
+                criteria: 100
+                blocking: true
+                clean_flag: false
+                description: ''
+                run:
+                    name: weather
+                    args:
+                        temp: 280
+    -
+        name: combined
+        order: 1
+        description: ''
+        testcases:
+            -
+                case_name: half
+                project_name: weather
+                criteria: 50
+                blocking: true
+                clean_flag: false
+                description: ''
+                run:
+                    name: weather
+                    args:
+                        humidity: 90
+                        pressure: 1000
+                        temp: 280
+```
+
+Dockerfile
+
+```
+FROM alpine:3.12
+
+ADD . /src/
+RUN apk --no-cache add --update python3 py3-pip py3-wheel git && \
+    git init /src && pip3 install /src
+COPY testcases.yaml /usr/lib/python3.8/site-packages/xtesting/ci/testcases.yaml
+CMD ["run_tests", "-t", "all"]
+```
+
+### make world
+
+Deploy your own Xtesting toolchain
+
+```bash
+virtualenv xtesting
+. xtesting/bin/activate
+pip install ansible
+ansible-galaxy install collivier.xtesting
+ansible-galaxy collection install ansible.posix community.general community.grafana community.kubernetes
+ansible-playbook site.yml
+deactivate
+rm -r xtesting
+```
+
+Build your container
+
+```bash
+sudo docker build -t 127.0.0.1:5000/weather .
+```
+
+### That's all folks!