From 5bc427fee0e919901129bec25c5ee96311077d04 Mon Sep 17 00:00:00 2001
From: Christian Boettcher <c.boettcher@fz-juelich.de>
Date: Tue, 7 Dec 2021 09:57:53 +0100
Subject: [PATCH] add basic client for datacat + first tests
---
.gitignore | 5 +-
datacat_integration/connection.py | 106 ++++++++++++++++++++++++++++++
tests/test_connection.py | 46 +++++++++++++
3 files changed, 155 insertions(+), 2 deletions(-)
create mode 100644 datacat_integration/connection.py
create mode 100644 tests/test_connection.py
diff --git a/.gitignore b/.gitignore
index e14035c..7e667c3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,5 +7,6 @@ __pycache__/
.coverage
coverage.xml
-# vs-code specific, individual files
-settings.json
\ No newline at end of file
+# local env files
+settings.json
+testing-authentication.env
\ No newline at end of file
diff --git a/datacat_integration/connection.py b/datacat_integration/connection.py
new file mode 100644
index 0000000..ddaa6bf
--- /dev/null
+++ b/datacat_integration/connection.py
@@ -0,0 +1,106 @@
+from typing import Dict
+import uuid
+import json
+
+from urllib.parse import urljoin
+
+import requests
+
+class DataCatalogEntry:
+ """A datatype representing an entry in the datacatalog."""
+ name: str = ""
+ url: str = ""
+ metadata: Dict[str, str] = {}
+
+ def __init__(self, name: str, url: str, metadata: Dict[str, str]):
+ self.name = name
+ self.url = url
+ self.metadata = metadata
+
+ def json(self):
+ """returns a json-compatible representation of the object."""
+ return json.dumps(
+ {
+ "name" : self.name,
+ "url" : self.url,
+ "metadata" : self.metadata
+ }
+ )
+
+ def from_json(data: json):
+ """returns a DataCatalogEntry object from the given json string"""
+ dict_data = json.loads(data)
+ return DataCatalogEntry(dict_data['name'], dict_data['url'], dict_data['metadata'])
+
+
+
+class DataCatConnection:
+ """An API to the DataCatalog. An instance of this class contains connection data for a single DataCatalog-server with a single user/pass login."""
+ def __init__(
+ self,
+ catalog_url: str = "",
+ username: str = "",
+ password: str = ""
+ ):
+ self.url = catalog_url
+ self.user = username
+ self._password = password
+ self.refresh_token()
+
+
+ def refresh_token(self): # POST /token
+ """Refresh the stored token by retrieving a new one from the server."""
+ data = {
+ "username" : self.user,
+ "password" : self._password
+ }
+ headers = {
+ 'accept' : 'application/json'
+ }
+ response = requests.post(urljoin(self.url, 'token'), data=data, headers=headers)
+ if response.ok:
+ self._auth_token = response.json()['access_token']
+ return self._auth_token
+ else:
+ raise ConnectionError('Could not authenticate with the DataCatalog.')
+
+ def get_token(self): # GET /me with auth and refresh if error
+ """Checks if the current token is valid. If yes, return it, else refresh it and return a new one."""
+ headers = {
+ 'accept' : 'application/json',
+ 'Authorization' : 'Bearer {}'.format(self._auth_token)
+ }
+ if requests.get(urljoin(self.url, 'me'), headers=headers).ok:
+ return self._auth_token
+ else:
+ return self.refresh_token()
+
+
+ def get_object(self, datacat_type: str, oid: uuid): # GET /<type>/<oid>
+ """Returns a json of the given object from the server."""
+ headers = {
+ 'accept' : 'application/json'
+ }
+ url = urljoin(self.url, "{}/{}".format(datacat_type, oid))
+ return requests.get(url, headers=headers).json()
+
+ def create_object(self, datacat_type: str, object: DataCatalogEntry): # POST /<type>
+ """Creates a new object in the datacatalog. Returns the oid of successful."""
+ headers = {
+ 'accept' : 'application/json',
+ 'Content-Type' : 'application/json',
+ 'Authorization' : 'Bearer {}'.format(self._auth_token)
+ }
+ response = requests.post(urljoin(self.url, datacat_type), headers=headers, data=object.json())
+ if response.ok:
+ return response.json()[0]
+ else:
+ raise ConnectionError(response.text)
+
+ def list_type(self, datacat_type: str):
+ """lists all elements of the given type"""
+ headers = {
+ 'accept' : 'application/json'
+ }
+ url = urljoin(self.url, datacat_type)
+ return requests.get(url, headers=headers).json()
\ No newline at end of file
diff --git a/tests/test_connection.py b/tests/test_connection.py
new file mode 100644
index 0000000..49e239a
--- /dev/null
+++ b/tests/test_connection.py
@@ -0,0 +1,46 @@
+from unittest import TestCase
+import os
+
+from datacat_integration.connection import DataCatalogEntry, DataCatConnection
+
+
+class EntryTest(TestCase):
+ def setUp(self) -> None:
+ self.json_string = '{ "name" : "foo", "url" : "bar", "metadata" : { "key1" : "val1", "key2" : "val2" } }'
+ self.entry : DataCatalogEntry = DataCatalogEntry("foo", "bar", {"key1" : "val1", "key2" : "val2"})
+
+ def test_create_entry_from_json(self):
+ entry_from_json = DataCatalogEntry.from_json(self.json_string)
+ self.assertDictEqual(self.entry.metadata, entry_from_json.metadata)
+ self.assertEqual(self.entry.name, entry_from_json.name)
+ self.assertEqual(self.entry.url, entry_from_json.url)
+
+ def test_create_json_from_entry(self):
+ json_from_entry = self.entry.json()
+ self.assertEqual(json_from_entry.replace(" ", ""), self.json_string.replace(" ", ""))
+
+class ConnectionTest(TestCase):
+
+ def setUp(self) -> None:
+ self.url = os.getenv('DATACAT_URL')
+ self.user = os.getenv('DATACAT_LOGIN')
+ self.password = os.getenv('DATACAT_PASSWORD')
+ # if these are not set, connection can not be properly tested
+ self.assertIsNotNone(self.url)
+ self.assertIsNotNone(self.user)
+ self.assertIsNotNone(self.password)
+
+ def test_create_token(self):
+ pass
+
+ def test_update_token(self):
+ pass
+
+ def test_get_object(self):
+ pass
+
+ def test_create_object(self):
+ pass # TODO
+
+ def test_list_objects(self):
+ pass
\ No newline at end of file
--
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