Crash less when docker fails

.dockerignore

@@ -8,7 +8,7 @@
 **/.ipynb_checkpoints
 /build
 *.egg-info
-/dist
+dist
 **/.DS_Store
 **/npm-debug.log
 **/.cache/

nbmolviz/mdtconfig/docker.py

@@ -23,8 +23,14 @@
 from .images import DockerImageStatus
 
 
+SPINNER = '<div class="nbv-loader" />'
+CONNECTED = '<span style="color:green">connected</span>'
+DISCONNECTED = '<span style="color:red">disconnected</span>'
+
 class DockerConfig(VBox):
     def __init__(self):
+        self.client = None
+        self.warning = ipy.HTML(description='<b>Engine status:</b>', value=SPINNER)
         self.devmode_label = ipy.Label('Use local docker images (developer mode)',
                                        layout=ipy.Layout(width='100%'))
         self.devmode_button = ipy.Checkbox(value=mdt.compute.config.devmode,
@@ -40,31 +46,29 @@ def __init__(self):
         self.engine_config_value = ipy.Text('blank', layout=ipy.Layout(width='100%'))
         self.engine_config_value.add_class('nbv-monospace')
 
-        self.image_box = ipy.Box(children=(DockerImageStatus(),))
+        self.image_box = ipy.Box()
 
         self._reset_config_button = ipy.Button(description='Reset',
                                                tooltip='Reset to applied value')
         self._apply_changes_button = ipy.Button(description='Apply',
                                                 tooltip='Apply for this session')
         self._save_changes_button = ipy.Button(description='Make default',
                                                tooltip='Make this the default for new sessions')
-        self._test_button = ipy.Button(description='Test connection',
-                                       tooltip='Test connection to docker engine')
         self._reset_config_button.on_click(self.reset_config)
         self._apply_changes_button.on_click(self.apply_config)
         self._save_changes_button.on_click(self.save_config)
-        self._test_button.on_click(self.test_connection)
 
-        self.children = [VBox([self.engine_config_description,
+        self.children = [self.warning,
+                         VBox([self.engine_config_description,
                                self.engine_config_value]),
                          HBox([self._reset_config_button,
                                self._apply_changes_button,
-                               self._test_button,
                                self._save_changes_button]),
                          HBox([self.devmode_button, self.devmode_label]),
                          self.image_box]
         self.reset_config()
         super().__init__(children=self.children)
+        self.connect_to_engine()
 
     def reset_config(self, *args):
         """ Reset configuration in UI widget to the stored values
@@ -74,19 +78,24 @@ def reset_config(self, *args):
     def set_devmode(self, *args):
         self.image_box.children = ()
         mdt.compute.config.devmode = self.devmode_button.value
-        self.image_box.children = (DockerImageStatus(),)
+        self.image_box.children = (DockerImageStatus(self.client),)
 
     def apply_config(self, *args):
         mdt.compute.config['default_docker_host'] = self.engine_config_value.value
-        mdt.compute.reset_compute_engine()
-
-    def test_connection(self, *args):
-        self.apply_config()
-        engine = mdt.compute.default_engine
-        if engine is None:
-            raise ValueError('Failed to create compute engine with current configuration')
-        engine.test_connection()
-        print("SUCCESS: %s is accepting jobs" % engine)
+        self.connect_to_engine()
+
+    def connect_to_engine(self, *args):
+        self.warning.value = SPINNER
+        self.client = None
+        try:
+            mdt.compute.reset_compute_engine()
+            self.client = mdt.compute.get_engine().client
+            self.client.ping()
+        except (mdt.exceptions.DockerError, AttributeError):
+            self.warning.value = DISCONNECTED
+        else:
+            self.image_box.children = (DockerImageStatus(self.client),)
+            self.warning.value = CONNECTED
 
     def save_config(self, *args):
         mdt.compute.update_saved_config(dockerhost=self.engine_config_value.value)

nbmolviz/mdtconfig/images.py

@@ -29,13 +29,14 @@
 
 
 class DockerImageStatus(ipy.VBox):
-    def __init__(self):
+    def __init__(self, client):
+        self.client = client
 
         images = self._get_images()
         self.header = ipy.HTML(
                 '<span class="nbv-table-header" style="width:950px"">Image status</span>',
                 layout=ipy.Layout(align_items='flex-end'))
-        super().__init__([self.header] + [DockerImageView(im) for im in sorted(images)])
+        super().__init__([self.header] + [DockerImageView(im, client) for im in sorted(images)])
 
     def _get_images(self):
         return set(p.get_docker_image_path()
@@ -46,8 +47,9 @@ class DockerImageView(ipy.HBox):
     LOADER = "<div class='nbv-loader' />"
     DMKDIR = os.path.join(os.path.dirname(os.path.dirname(mdt.__file__)), 'DockerMakefiles')
 
-    def __init__(self, image):
+    def __init__(self, image, client):
         self._err = False
+        self._client = client
         self.image = image
         self.status = ipy.HTML(layout=ipy.Layout(width="20px"))
         self.html = ipy.HTML(value=image, layout=ipy.Layout(width="400px"))
@@ -59,7 +61,6 @@ def __init__(self, image):
         else:
             self.button.on_click(self.pull)
         self._reactivate_button()
-        self._client = mdt.compute.get_engine().client
         self._set_status_value()
         super().__init__(children=[self.status, self.html, self.button, self.msg])
 
@@ -138,26 +139,34 @@ def _disable_button(self, description):
 
     def _reactivate_button(self):
         self.button.disabled = False
-        if mdt.compute.config.devmode:
-            self.button.description = 'Rebuild image'
+        if self._client is None:
+            self.button.description = 'no connection'
+            self.button.disabled = True
+            self.button.style.button_color = '#FAFAFA'
         else:
-            self.button.description = 'Pull image'
-        self.button.style.font_weight = '400'
-        self.button.style.button_color = '#9feeb2'
+            if mdt.compute.config.devmode:
+                self.button.description = 'Rebuild image'
+            else:
+                self.button.description = 'Pull image'
+            self.button.style.font_weight = '400'
+            self.button.style.button_color = '#9feeb2'
 
 
     def _set_status_value(self):
         from docker import errors
 
-        try:
-            imginfo = self._client.inspect_image(self.image)
-        except errors.ImageNotFound:
-            if self._err:
-                self.status.value = WARNING
-            else:
-                self.status.value = MISSING
+        if self._client is None:
+            self.status.value = 'n/a'
         else:
-            self.status.value = INSTALLED
+            try:
+                imginfo = self._client.inspect_image(self.image)
+            except errors.ImageNotFound:
+                if self._err:
+                    self.status.value = WARNING
+                else:
+                    self.status.value = MISSING
+            else:
+                self.status.value = INSTALLED
 
     def _watch_pull_logs(self, stream):
         found = set()