Add kube profile spawner

kubespawner/spawner.py

@@ -21,6 +21,7 @@
 from kubernetes.client.rest import ApiException
 from kubernetes import client
 import escapism
+from jinja2 import Environment, BaseLoader
 
 from .clients import shared_client
 from kubespawner.traitlets import Callable
@@ -630,7 +631,7 @@ def _hub_connect_port_default(self):
         List of access modes the user has for the pvc.
 
         The access modes are:
-   
+
             - `ReadWriteOnce` – the volume can be mounted as read-write by a single node
             - `ReadOnlyMany` – the volume can be mounted read-only by many nodes
             - `ReadWriteMany` – the volume can be mounted as read-write by many nodes
@@ -649,7 +650,7 @@ def _hub_connect_port_default(self):
         The keys is name of hooks and there are only two hooks, postStart and preStop.
         The values are handler of hook which executes by Kubernetes management system when hook is called.
 
-        Below is an sample copied from 
+        Below is an sample copied from
         `Kubernetes doc <https://kubernetes.io/docs/tasks/configure-pod-container/attach-handler-lifecycle-event/>`_ ::
 
             lifecycle:
@@ -688,7 +689,7 @@ def _hub_connect_port_default(self):
                   add:
                   - NET_ADMIN
 
-        
+
         See https://kubernetes.io/docs/concepts/workloads/pods/init-containers/ for more
         info on what init containers are and why you might want to use them!
 
@@ -754,15 +755,15 @@ def _hub_connect_port_default(self):
         which follows spec at https://v1-6.docs.kubernetes.io/docs/api-reference/v1.6/#container-v1-core.
 
         One usage is setting crontab in a container to clean sensitive data with configuration below::
-        
+
             [
                 {
                     'name': 'crontab',
                     'image': 'supercronic',
                     'command': ['/usr/local/bin/supercronic', '/etc/crontab']
                 }
             ]
-        
+
         """
     )
 
@@ -800,6 +801,92 @@ def _hub_connect_port_default(self):
         """
         )
 
+    form_template = Unicode(
+        """<label for="profile">Please select a profile for your environment:</label>
+        <select class="form-control" name="profile" required autofocus>
+        {{ inputs }}
+        </select>
+        """,
+        config = True,
+        help = """Jinja2 template to use to construct options_form text. {inputs} is replaced with
+            the result of formatting inputs against each item in the profiles list."""
+        )
+
+    inputs = Unicode("""
+        <option value="{{ key }}" {{ first }} >{{ display }}</option>""",
+        config = True,
+        help = """Jinja template to construct {inputs} in form_template. This text will be formatted
+            against each item in the profiles list, in order, using the following key names:
+            ( display, key, type ) for the first three items in the tuple, and additionally
+            first = "checked" (taken from first_input) for the first item in the list, so that
+            the first item starts selected."""
+        )
+
+    first_input = Unicode('selected',
+        config=True,
+        help="Text to substitute as {first} in inputs"
+        )
+
+    options_form = Unicode()
+
+    profile_list = List(
+        trait = Dict(),
+        default_value = None,
+        minlen = 0,
+        config = True,
+        help = """
+            List of profiles to offer for selection by the user.
+
+            Signature is: List(Dict()), where each item is a dictionary that has two keys:
+            - 'display_name': the human readable display name (should be HTML safe)
+            - 'kubespawner_override': a dictionary with overrides to apply to the KubeSpawner
+              settings. Each value can be either the final value to change or a callable that
+              take the `KubeSpawner` instance as parameter and return the final value.
+
+            Example::
+
+                c.KubeSpawner.profile_list = [
+                    {
+                        'display_name': 'Training Env - Python',
+                        'kubespawner_override': {
+                            'singleuser_image_spec': 'training/python:label',
+                            'cpu_limit': 1,
+                            'mem_limit': '512M',
+                        }
+                    }, {
+                        'display_name': 'Training Env - Datascience',
+                        'kubespawner_override': {
+                            'singleuser_image_spec': 'training/datascience:label',
+                            'cpu_limit': 4,
+                            'mem_limit': '8G',
+                        }
+                    }, {
+                        'display_name': 'DataScience - Small instance',
+                        'kubespawner_override': {
+                            'singleuser_image_spec': 'datascience/small:label',
+                            'cpu_limit': 10,
+                            'mem_limit': '16G',
+                        }
+                    }, {
+                        'display_name': 'DataScience - Medium instance',
+                        'kubespawner_override': {
+                            'singleuser_image_spec': 'datascience/medium:label',
+                            'cpu_limit': 48,
+                            'mem_limit': '96G',
+                        }
+                    }, {
+                        'display_name': 'DataScience - Medium instance (GPUx2)',
+                        'kubespawner_override': {
+                            'singleuser_image_spec': 'datascience/medium:label',
+                            'cpu_limit': 48,
+                            'mem_limit': '96G',
+                            'extra_resource_guarantees': {"nvidia.com/gpu": "2"},
+                        }
+                    }
+                ]
+            """
+        )
+
     def _expand_user_properties(self, template):
         # Make sure username and servername match the restrictions for DNS labels
         safe_chars = set(string.ascii_lowercase + string.digits)
@@ -1127,3 +1214,67 @@ def get_args(self):
                 args[i] = '--hub-api-url="%s"' % (self.accessible_hub_api_url)
                 break
         return args
+
+    def _options_form_default(self):
+        '''
+        Build the form template according to the `profile_list` setting.
+
+        Returns:
+            None when no `profile_list` has been defined
+            The rendered template (using jinja2) when `profile_list` is defined.
+        '''
+        if not self.profile_list:
+            return
+        temp_keys = [
+            {
+                'display': p['display_name'],
+                'key': i,
+                'first': '',
+        } for i, p in enumerate(self.profile_list)]
+        temp_keys[0]['first'] = self.first_input
+        inputs_tpl = Environment(loader=BaseLoader).from_string(self.inputs)
+        text = ''.join([ inputs_tpl.render(**tk) for tk in temp_keys ])
+        rtemplate = Environment(loader=BaseLoader).from_string(self.form_template)
+        data = {
+            'inputs': text,
+        }
+        return rtemplate.render(**data)
+
+    def options_from_form(self, formdata):
+        """get the option selected by the user on the form
+
+        It actually reset the settings of kubespawner to each item found in the selected profile
+        (`kubespawner_override`).
+
+        Args:
+            formdata: user selection returned by the form
+
+        To access to the value, you can use the `get` accessor and the name of the html element,
+        for example::
+
+            formdata.get('profile',[0])
+
+        to get the value of the form named "profile", as defined in `form_template`::
+
+            <select class="form-control" name="profile"...>
+            </select>
+
+        Returns:
+            the selected user option
+        """
+
+        if not self.profile_list:
+            return formdata
+        # Default to first profile if somehow none is provided
+        selected_profile = int(formdata.get('profile',[0])[0])
+        options = self.profile_list[selected_profile]
+        self.log.debug("Applying KubeSpawner override for profile '%s'", options['display_name'])
+        kubespawner_override = options.get('kubespawner_override', {})
+        for k, v in kubespawner_override.items():
+            if callable(v):
+                v = v(self)
+                self.log.debug(".. overriding KubeSpawner value %s=%s (callable result)", k, v)
+            else:
+                self.log.debug(".. overriding KubeSpawner value %s=%s", k, v)
+            setattr(self, k, v)
+        return options

setup.py

@@ -8,6 +8,7 @@
         'pyYAML',
         'kubernetes==4.*',
         'escapism',
+        'jinja2',
     ],
     setup_requires=['pytest-runner'],
     tests_require=['pytest'],

tox.ini

@@ -2,7 +2,7 @@
 minversion = 1.6
 skipsdist = True
 
-envlist = py34
+envlist = py34,py35,py36
 
 [flake8]
 max-line-length = 100