Use FastAPI to provide rest endpoints (#135)

* simple fastapi setup

* squashing commits; rebased onto master and modified some vscode settings. WIP.

* made application compatible with config changes

* moved starting the app into blueapi/service/main instead of cli. Added deprecation message for worker.

* responded to comments

* added some cli tests. Intend to add more...

* added mock as dependency to pass tests

* added more tests for cli and modified existing rest tests

* changed run to serve instead

* made teardown handler do nothing if handler not set

* removed redundant comment

* removed redundant string concatenation in test

* moved assert statement

* made minor changes in response to comments; using functools wraps and .json() instead of literal_eval in tests

* fixed minor issues; param ingestion for cli.py::run_plan and made fixtures for tests

* moved common parts of tests to conftest.py, made session scope fixtures

* fixed linting

* made minor changes in response to comments; changed dependencies

* modified pyproject toml to include all fastapi dependencies

* removed redundant fake_cli file which I just used for testing. Changed error message for deprecated worker command

* fixing tests

* added extra test for the handler

* made suggested changes

* Update src/blueapi/service/main.py

Co-authored-by: Callum Forrester <29771545+callumforrester@users.noreply.github.com>

* modified docs

---------

Co-authored-by: Callum Forrester <29771545+callumforrester@users.noreply.github.com>

.devcontainer/Dockerfile

@@ -34,4 +34,4 @@ ENV PATH=/venv/bin:$PATH
 
 # change this entrypoint if it is not the same as the repo
 ENTRYPOINT ["blueapi"]
-CMD ["worker"]
+CMD ["serve"]

.vscode/launch.json

@@ -4,6 +4,18 @@
     // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
     "version": "0.2.0",
     "configurations": [
+        {
+            "name": "Debug Rest Service",
+            "type": "python",
+            "request": "launch",
+            "module": "uvicorn",
+            "args": [
+                "src.blueapi.rest.main:app",
+                "--reload"
+            ],
+            "jinja": true,
+            "justMyCode": true
+        },
         {
             "name": "Debug Unit Test",
             "type": "python",
@@ -22,13 +34,13 @@
             },
         },
         {
-            "name": "Worker Service",
+            "name": "Run Service",
             "type": "python",
             "request": "launch",
             "justMyCode": false,
             "module": "blueapi.cli",
             "args": [
-                "worker"
+                "serve"
             ]
         },
         {
@@ -68,4 +80,4 @@
             ]
         }
     ]
-}
+}

.vscode/settings.json

@@ -13,5 +13,5 @@
         "source.organizeImports": true
     },
     "esbonio.server.enabled": true,
-    "esbonio.sphinx.confDir": ""
-}
+    "esbonio.sphinx.confDir": "",
+}

docs/developer/tutorials/dev-run.rst

@@ -44,7 +44,7 @@ Start the worker from the command line or vscode:
 
         .. code:: shell
 
-            blueapi worker
+            blueapi serve
 
     .. tab-item:: VSCode
 

pyproject.toml

@@ -22,6 +22,9 @@ dependencies = [
     "scanspec",
     "PyYAML",
     "click",
+    "fastapi[all]",
+    "uvicorn",
+    "requests",
 ]
 dynamic = ["version"]
 license.file = "LICENSE"
@@ -44,6 +47,9 @@ dev = [
     "tox-direct",
     "types-mock",
     "types-PyYAML",
+    "types-requests",
+    "types-urllib3",
+    "mock",
 ]
 
 [project.scripts]

src/blueapi/__init__.py

@@ -3,4 +3,5 @@
 __version__ = version("blueapi")
 del version
 
+
 __all__ = ["__version__"]

src/blueapi/cli/cli.py

@@ -1,27 +1,32 @@
 import json
 import logging
+from functools import wraps
 from pathlib import Path
+from pprint import pprint
 from typing import Optional
 
 import click
+import requests
+from requests.exceptions import ConnectionError
 
 from blueapi import __version__
 from blueapi.config import ApplicationConfig, ConfigLoader
-from blueapi.messaging import StompMessagingTemplate
-
-from .amq import AmqClient
-from .updates import CliEventRenderer
+from blueapi.service.main import start
 
 
 @click.group(invoke_without_command=True)
 @click.version_option(version=__version__, prog_name="blueapi")
 @click.option("-c", "--config", type=Path, help="Path to configuration YAML file")
 @click.pass_context
-def main(ctx, config: Optional[Path]) -> None:
+def main(ctx: click.Context, config: Optional[Path]) -> None:
     # if no command is supplied, run with the options passed
+
     config_loader = ConfigLoader(ApplicationConfig)
     if config is not None:
-        config_loader.use_values_from_yaml(config)
+        if config.exists():
+            config_loader.use_values_from_yaml(config)
+        else:
+            raise FileNotFoundError(f"Cannot find file: {config}")
 
     ctx.ensure_object(dict)
     ctx.obj["config"] = config_loader.load()
@@ -30,58 +35,74 @@ def main(ctx, config: Optional[Path]) -> None:
         print("Please invoke subcommand!")
 
 
-@main.command(name="worker")
+@main.command(name="serve")
 @click.pass_obj
-def start_worker(obj: dict) -> None:
-    from blueapi.service import start
+def start_application(obj: dict):
+    start(obj["config"])
 
-    config: ApplicationConfig = obj["config"]
-    start(config)
+
+@main.command(name="worker", deprecated=True)
+@click.pass_obj
+def deprecated_start_application(obj: dict):
+    print("Please use serve command instead.\n")
+    start(obj["config"])
 
 
 @main.group()
 @click.pass_context
-def controller(ctx) -> None:
+def controller(ctx: click.Context) -> None:
     if ctx.invoked_subcommand is None:
         print("Please invoke subcommand!")
         return
 
     ctx.ensure_object(dict)
     config: ApplicationConfig = ctx.obj["config"]
     logging.basicConfig(level=config.logging.level)
-    client = AmqClient(StompMessagingTemplate.autoconfigured(config.stomp))
-    ctx.obj["client"] = client
-    client.app.connect()
+
+
+def check_connection(func):
+    @wraps(func)
+    def wrapper(*args, **kwargs):
+        try:
+            func(*args, **kwargs)
+        except ConnectionError:
+            print("Failed to establish connection to FastAPI server.")
+
+    return wrapper
 
 
 @controller.command(name="plans")
-@click.pass_context
-def get_plans(ctx) -> None:
-    client: AmqClient = ctx.obj["client"]
-    plans = client.get_plans()
-    print("PLANS")
-    for plan in plans.plans:
-        print("\t" + plan.name)
+@check_connection
+@click.pass_obj
+def get_plans(obj: dict) -> None:
+    config: ApplicationConfig = obj["config"]
+
+    resp = requests.get(f"http://{config.api.host}:{config.api.port}/plans")
+    print(f"Response returned with {resp.status_code}: ")
+    pprint(resp.json())
 
 
 @controller.command(name="devices")
-@click.pass_context
-def get_devices(ctx) -> None:
-    client: AmqClient = ctx.obj["client"]
-    print(client.get_devices().devices)
+@check_connection
+@click.pass_obj
+def get_devices(obj: dict) -> None:
+    config: ApplicationConfig = obj["config"]
+
+    resp = requests.get(f"http://{config.api.host}:{config.api.port}/devices")
+    print(f"Response returned with {resp.status_code}: ")
+    pprint(resp.json())
 
 
 @controller.command(name="run")
 @click.argument("name", type=str)
 @click.option("-p", "--parameters", type=str, help="Parameters as valid JSON")
-@click.pass_context
-def run_plan(ctx, name: str, parameters: str) -> None:
-    client: AmqClient = ctx.obj["client"]
-    renderer = CliEventRenderer()
-    client.run_plan(
-        name,
-        json.loads(parameters),
-        renderer.on_worker_event,
-        renderer.on_progress_event,
-        timeout=120.0,
+@check_connection
+@click.pass_obj
+def run_plan(obj: dict, name: str, parameters: str) -> None:
+    config: ApplicationConfig = obj["config"]
+
+    resp = requests.put(
+        f"http://{config.api.host}:{config.api.port}/task/{name}",
+        json={"name": name, "params": json.loads(parameters)},
     )
+    print(f"Response returned with {resp.status_code}: ")

src/blueapi/config.py

@@ -35,6 +35,11 @@ class LoggingConfig(BlueapiBaseModel):
     level: LogLevel = "INFO"
 
 
+class RestConfig(BlueapiBaseModel):
+    host: str = "localhost"
+    port: int = 8000
+
+
 class ApplicationConfig(BlueapiBaseModel):
     """
     Config for the worker application as a whole. Root of
@@ -44,13 +49,15 @@ class ApplicationConfig(BlueapiBaseModel):
     stomp: StompConfig = Field(default_factory=StompConfig)
     env: EnvironmentConfig = Field(default_factory=EnvironmentConfig)
     logging: LoggingConfig = Field(default_factory=LoggingConfig)
+    api: RestConfig = Field(default_factory=RestConfig)
 
     def __eq__(self, other: object) -> bool:
         if isinstance(other, ApplicationConfig):
             return (
                 (self.stomp == other.stomp)
                 & (self.env == other.env)
                 & (self.logging == other.logging)
+                & (self.api == other.api)
             )
         return False
 

src/blueapi/service/__init__.py

@@ -1,4 +1,3 @@
-from .app import start
 from .model import DeviceModel, PlanModel
 
-__all__ = ["start", "PlanModel", "DeviceModel"]
+__all__ = ["PlanModel", "DeviceModel"]