Added healthcheck endpoint /status

README.md

@@ -132,6 +132,45 @@ The following architectures are supported: `amd64`, `arm/v7`, and `arm64`. The f
 
 ## API Details
 
+### Health Checks
+
+You can perform status or health checks on your server configuration by accessing `/status`.
+
+| Path         | Method | Description |
+|------------- | ------ | ----------- |
+| `/status` |  GET  | Simply returns a server status.  The server http response code is a `200` if the server is working correcty and a `417` if there was an unexpected issue.  You can set the `Accept` header to `application/json` or `text/plain` for different response outputs.
+
+Below is a sample of just a simple text response:
+```bash
+# Request a general text response
+# Output will read `OK` if everything is fine, otherwise it will return
+# one or more of the following separated by a comma:
+#  - ATTACH_PERMISSION_ISSUE: Can not write attachments (likely a permission issue)
+#  - CONFIG_PERMISSION_ISSUE: Can not write configuration (likely a permission issue)
+curl -X GET http://localhost:8000/status
+```
+
+Below is a sample of a JSON response:
+```bash
+curl -X GET -H "Accept: application/json" http://localhost:8000/status
+```
+The above output may look like this:
+```json
+{
+  "config_lock": false,
+  "status": {
+    "can_write_config": true,
+    "can_write_attach": true,
+    "details": ["OK"]
+  }
+}
+```
+
+- The `config_lock` always cross references if the `APPRISE_CONFIG_LOCK` is enabled or not.
+- The `status.can_write_config` defines if the configuration directory is writable or not.  If the environment variable `APPRISE_STATEFUL_MODE` is set to `disabled`, this value will always read `false` and it will not impact the `status.details`
+- The `status.can_write_attach` defines if the attachment directory is writable or not.  If the environment variable `APPRISE_ATTACH_SIZE` or `APPRISE_MAX_ATTACHMENTS` is set to `0` (zero) or lower, this value will always read `false` and it will not impact the `status.details`.
+- The `status.details` identifies the overall status. If there is more then 1 issue to report here, they will all show in this list.  In a working orderly environment, this will always be set to `OK` and the http response type will be `200`.
+
 ### Stateless Solution
 
 Some people may wish to only have a sidecar solution that does require use of any persistent storage.  The following API endpoint can be used to directly send a notification of your choice to any of the [supported services by Apprise](https://github.com/caronc/apprise/wiki) without any storage based requirements:

apprise_api/api/templates/config.html

@@ -22,15 +22,15 @@ <h4>{% trans "Management for Config ID:" %} <code class="config-id">{{ key }}</c
       <h5>{% trans "Getting Started" %}</h5>
       <ol>
         <li>
-          {% blocktrans %}
-          Here is where you can store your Apprise configuration associated with the key <code>{{key}}</code>.
-          {% endblocktrans %}
-          For some examples on how to build a development environment around this, <strong><a href="{% url 'welcome'%}?key={{key}}">click here</a></strong>.
+          {% trans "Verify your Apprise API Status:" %} <strong><a href="{% url 'health' %}">click here</a></strong>
+        </li>
+        <li>
+          {% trans "Here is where you can store your Apprise configuration associated with the key:" %} <code>{{key}}</code>
+          {% trans "For some examples on how to build a development environment around this:" %} <strong><a href="{% url 'welcome'%}?key={{key}}">click here</a></strong>
         </li>
         <li>
           {% blocktrans %}
-          In the future you can return to this configuration screen at any time by placing the following into your
-          browser:
+          In the future you can return to this configuration screen at any time by placing the following into your browser:
           {% endblocktrans %}
           <code>{{request.scheme}}://{{request.META.HTTP_HOST}}{{BASE_URL}}/cfg/{{key}}</code>
         </li>

apprise_api/api/urls.py

@@ -29,6 +29,9 @@
     re_path(
         r'^$',
         views.WelcomeView.as_view(), name='welcome'),
+    re_path(
+        r'^status/?$',
+        views.HealthCheckView.as_view(), name='health'),
     re_path(
         r'^details/?$',
         views.DetailsView.as_view(), name='details'),

apprise_api/api/utils.py

@@ -229,6 +229,9 @@ def parse_attachments(attachment_payload, files_request):
         attachment_payload = (attachment_payload, )
         count += 1
 
+    if settings.APPRISE_ATTACH_SIZE <= 0:
+        raise ValueError("The attachment size is restricted to 0MB")
+
     if settings.APPRISE_MAX_ATTACHMENTS <= 0 or \
             (settings.APPRISE_MAX_ATTACHMENTS > 0 and
                 count > settings.APPRISE_MAX_ATTACHMENTS):
@@ -750,3 +753,65 @@ def send_webhook(payload):
         logger.debug('Socket Exception: %s' % str(e))
 
     return
+
+def healthcheck():
+    """
+    Runs a status check on the data and returns the statistics
+    """
+
+    # Some status variables we can flip
+    response = {
+        'can_write_config': False,
+        'can_write_attach': False,
+        'details': [],
+    }
+
+    if ConfigCache.mode != AppriseStoreMode.DISABLED:
+        # Update our Configuration Check Block
+        path = os.path.join(ConfigCache.root, '.tmp_healthcheck')
+        try:
+            os.makedirs(path, exist_ok=True)
+
+            # Write a small file
+            with tempfile.TemporaryFile(mode='w+b', dir=path) as fp:
+                # Test writing 1 block
+                fp.write(b'.')
+                # Read it back
+                fp.seek(0)
+                fp.read(1) == b'.'
+                # Toggle our status
+                response['can_write_config'] = True
+
+        except OSError:
+            # We can take an early exit
+            response['details'].append('CONFIG_PERMISSION_ISSUE')
+
+    if settings.APPRISE_MAX_ATTACHMENTS > 0 and settings.APPRISE_ATTACH_SIZE > 0:
+        # Test our ability to access write attachments
+
+        # Update our Configuration Check Block
+        path = os.path.join(settings.APPRISE_ATTACH_DIR, '.tmp_healthcheck')
+        try:
+            os.makedirs(path, exist_ok=True)
+
+            # Write a small file
+            with tempfile.TemporaryFile(mode='w+b', dir=path) as fp:
+                # Test writing 1 block
+                fp.write(b'.')
+                # Read it back
+                fp.seek(0)
+                fp.read(1) == b'.'
+                # Toggle our status
+                response['can_write_attach'] = True
+
+        except OSError:
+            # We can take an early exit
+            response['details'].append('ATTACH_PERMISSION_ISSUE')
+
+
+    if not response['details']:
+        response['details'].append('OK')
+
+    return response
+
+

apprise_api/api/views.py

@@ -40,6 +40,7 @@
 from .utils import ConfigCache
 from .utils import apply_global_filters
 from .utils import send_webhook
+from .utils import healthcheck
 from .forms import AddByUrlForm
 from .forms import AddByConfigForm
 from .forms import NotifyForm
@@ -116,6 +117,7 @@ class ResponseCode(object):
     not_found = 404
     method_not_allowed = 405
     method_not_accepted = 406
+    expectation_failed = 417
     failed_dependency = 424
     fields_too_large = 431
     internal_server_error = 500
@@ -136,6 +138,44 @@ def get(self, request):
         })
 
 
+@method_decorator((gzip_page, never_cache), name='dispatch')
+class HealthCheckView(View):
+    """
+    A Django view used to return a simple healthcheck
+    """
+
+    def get(self, request):
+        """
+        Handle a GET request
+        """
+        # Detect the format our incoming payload
+        json_payload = \
+            MIME_IS_JSON.match(
+                request.content_type
+                if request.content_type
+                else request.headers.get(
+                    'content-type', '')) is not None
+
+        # Detect the format our response should be in
+        json_response = True if json_payload \
+            and ACCEPT_ALL.match(request.headers.get('accept', '')) else \
+            MIME_IS_JSON.match(request.headers.get('accept', '')) is not None
+
+        # Run our healthcheck
+        response = healthcheck()
+
+        # Prepare our response
+        status = ResponseCode.okay if 'OK' in response['details'] else ResponseCode.expectation_failed
+        if not json_response:
+            response = ','.join(response['details'])
+
+        return HttpResponse(response, status=status, content_type='text/plain') \
+            if not json_response else JsonResponse({
+                'config_lock': settings.APPRISE_CONFIG_LOCK,
+                'status': response,
+            }, encoder=JSONEncoder, safe=False, status=status)
+
+
 @method_decorator((gzip_page, never_cache), name='dispatch')
 class DetailsView(View):
     """