Merge remote-tracking branch 'server/main' into add_server

Add server to basyx-python-sdk.

server/Dockerfile

@@ -0,0 +1,14 @@
+FROM tiangolo/uwsgi-nginx:python3.11
+
+# Should match client_body_buffer_size defined in nginx/body-buffer-size.conf
+ENV NGINX_MAX_UPLOAD 1M
+
+# object stores aren't thread-safe yet
+# https://github.com/eclipse-basyx/basyx-python-sdk/issues/205
+ENV UWSGI_CHEAPER 0
+ENV UWSGI_PROCESSES 1
+
+RUN pip install --no-cache-dir git+https://github.com/rwth-iat/basyx-python-sdk@feature/http_api
+
+COPY ./app /app
+COPY ./nginx /etc/nginx/conf.d

server/README.md

@@ -0,0 +1,71 @@
+# Eclipse BaSyx Python SDK - HTTP Server
+
+This repository contains a Dockerfile to spin up an exemplary HTTP/REST server following the [Specification of the AAS Part 2 API][6] with ease.
+The server currently implements the following interfaces:
+
+- [Asset Administration Shell Repository Service][4]
+- [Submodel Repository Service][5]
+
+It uses the [HTTP API][1] and the [AASX][7], [JSON][8], and [XML][9] Adapters of the [BaSyx Python SDK][3], to serve regarding files from a given directory.
+The files are only read, chages won't persist.
+
+Alternatively, the container can also be told to use the [Local-File Backend][2] instead, which stores AAS and Submodels as individual JSON files and allows for persistent changes (except supplementary files, i.e. files referenced by `File` submodel elements).
+See [below](#options) on how to configure this.
+
+## Building
+The container image can be built via:
+```
+$ docker buildx build -t basyx-python-sdk-http-server .
+```
+
+## Running
+
+### Storage
+The container needs to be provided with the directory `/storage` to store AAS and Submodel files: AASX, JSON, XML or JSON files of Local-File Backend.
+
+This directory can be mapped via the `-v` option from another image or a local directory.
+To map the directory `storage` inside the container, `-v ./storage:/storage` can be used.
+The directory `storage` will be created in the current working directory, if it doesn't already exist.
+
+### Port
+The HTTP server inside the container listens on port 80 by default.
+To expose it on the host on port 8080, use the option `-p 8080:80` when running it.
+
+### Options
+The container can be configured via environment variables:
+- `API_BASE_PATH` determines the base path under which all other API paths are made available.
+  Default: `/api/v3.0`
+- `STORAGE_TYPE` can be one of `LOCAL_FILE_READ_ONLY` or `LOCAL_FILE_BACKEND`:
+  - When set to `LOCAL_FILE_READ_ONLY` (the default), the server will read and serve AASX, JSON, XML files from the storage directory.
+    The files are not modified, all changes done via the API are only stored in memory.
+  - When instead set to `LOCAL_FILE`, the server makes use of the [LocalFileBackend][2], where AAS and Submodels are persistently stored as JSON files.
+    Supplementary files, i.e. files referenced by `File` submodel elements, are not stored in this case.
+- `STORAGE_PATH` sets the directory to read the files from *within the container*. If you bind your files to a directory different from the default `/storage`, you can use this variable to adjust the server accordingly.
+
+### Running Examples
+
+Putting it all together, the container can be started via the following command:
+```
+$ docker run -p 8080:80 -v ./storage:/storage basyx-python-sdk-http-server
+```
+
+Since Windows uses backslashes instead of forward slashes in paths, you'll have to adjust the path to the storage directory there:
+```
+> docker run -p 8080:80 -v .\storage:/storage basyx-python-sdk-http-server
+```
+
+Per default, the server will use the `LOCAL_FILE_READ_ONLY` storage type and serve the API under `/api/v3.0` and read files from `/storage`. If you want to change this, you can do so like this:
+```
+$ docker run -p 8080:80 -v ./storage2:/storage2 -e API_BASE_PATH=/api/v3.1 -e STORAGE_TYPE=LOCAL_FILE_BACKEND -e STORAGE_PATH=/storage2 basyx-python-sdk-http-server
+```
+
+
+[1]: https://github.com/eclipse-basyx/basyx-python-sdk/pull/238
+[2]: https://basyx-python-sdk.readthedocs.io/en/latest/backend/local_file.html
+[3]: https://github.com/eclipse-basyx/basyx-python-sdk
+[4]: https://app.swaggerhub.com/apis/Plattform_i40/AssetAdministrationShellRepositoryServiceSpecification/V3.0.1_SSP-001
+[5]: https://app.swaggerhub.com/apis/Plattform_i40/SubmodelRepositoryServiceSpecification/V3.0.1_SSP-001
+[6]: https://industrialdigitaltwin.org/content-hub/aasspecifications/idta_01002-3-0_application_programming_interfaces
+[7]: https://basyx-python-sdk.readthedocs.io/en/latest/adapter/aasx.html#adapter-aasx
+[8]: https://basyx-python-sdk.readthedocs.io/en/latest/adapter/json.html
+[9]: https://basyx-python-sdk.readthedocs.io/en/latest/adapter/xml.html

server/app/main.py

@@ -0,0 +1,46 @@
+import os
+import pathlib
+import sys
+
+from basyx.aas import model, adapter
+from basyx.aas.adapter import aasx
+
+from basyx.aas.backend.local_file import LocalFileObjectStore
+from basyx.aas.adapter.http import WSGIApp
+
+storage_path = os.getenv("STORAGE_PATH", "storage")
+storage_type = os.getenv("STORAGE_TYPE", "LOCAL_FILE_READ_ONLY")
+base_path = os.getenv("API_BASE_PATH")
+
+wsgi_optparams = {}
+
+if base_path is not None:
+    wsgi_optparams["base_path"] = base_path
+
+if storage_type == "LOCAL_FILE_BACKEND":
+    application = WSGIApp(LocalFileObjectStore(storage_path), aasx.DictSupplementaryFileContainer(), **wsgi_optparams)
+
+elif storage_type in "LOCAL_FILE_READ_ONLY":
+    object_store: model.DictObjectStore = model.DictObjectStore()
+    file_store: aasx.DictSupplementaryFileContainer = aasx.DictSupplementaryFileContainer()
+
+    for file in pathlib.Path(storage_path).iterdir():
+        if not file.is_file():
+            continue
+        print(f"Loading {file}")
+
+        if file.suffix.lower() == ".json":
+            with open(file) as f:
+                adapter.json.read_aas_json_file_into(object_store, f)
+        elif file.suffix.lower() == ".xml":
+            with open(file) as f:
+                adapter.xml.read_aas_xml_file_into(object_store, file)
+        elif file.suffix.lower() == ".aasx":
+            with aasx.AASXReader(file) as reader:
+                reader.read_into(object_store=object_store, file_store=file_store)
+
+    application = WSGIApp(object_store, file_store, **wsgi_optparams)
+
+else:
+    print(f"STORAGE_TYPE must be either LOCAL_FILE or LOCAL_FILE_READ_ONLY! Current value: {storage_type}",
+          file=sys.stderr)

server/nginx/body-buffer-size.conf

@@ -0,0 +1,6 @@
+# While the Dockerfile sets client_max_body_size, it doesn't
+# allow us to define client_body_buffer_size, which is 16k
+# by default. This results in temporary buffer files being
+# created, in case the request body exceeds this limit. Thus,
+# we override it here to match client_max_body_size.
+client_body_buffer_size 1M;

server/nginx/cors-header.conf

@@ -0,0 +1 @@
+add_header Access-Control-Allow-Origin *;