examples: adopt RAG examples for remote execution (#3117)

To be able to run the RAG DAG in a deployment we need non-local file
local storage.
The POC was build to pass data between jobs using a local file. Since I
want to deploy the jobs I need a way to pass data between them without
that since they do not share a file system. Postgres based storage was
created for that.

So moved created one and adopt it. 
It's currently copied in both jobs. I will refactor it away after this
PR.

I also ended up removing NLKT from everywhere. And also few doc fixes

examples/confluence-reader/common/database_storage.py

@@ -0,0 +1,90 @@
+# Copyright 2021-2024 VMware, Inc.
+# SPDX-License-Identifier: Apache-2.0
+import pickle
+from typing import Any
+from typing import List
+from typing import Optional
+from typing import Union
+
+from common.storage import IStorage
+from sqlalchemy import Column
+from sqlalchemy import create_engine
+from sqlalchemy import LargeBinary
+from sqlalchemy import MetaData
+from sqlalchemy import select
+from sqlalchemy import String
+from sqlalchemy import Table
+from sqlalchemy.exc import IntegrityError
+
+
+class DatabaseStorage(IStorage):
+    def __init__(self, connection_string: str):
+        self.engine = create_engine(connection_string)
+        self.metadata = MetaData()
+        self.table = Table(
+            "vdk_storage",
+            self.metadata,
+            Column("name", String, primary_key=True),
+            Column("content", LargeBinary),
+            Column("content_type", String),
+        )
+        self.metadata.create_all(self.engine)
+
+    def store(self, name: str, content: Union[str, bytes, Any]) -> None:
+        serialized_content, content_type = self._serialize_content(content)
+        ins = self.table.insert().values(
+            name=name, content=serialized_content, content_type=content_type
+        )
+        try:
+            with self.engine.connect() as conn:
+                conn.execute(ins)
+                conn.commit()
+        except IntegrityError:
+            # Handle duplicate name by updating existing content
+            upd = (
+                self.table.update()
+                .where(self.table.c.name == name)
+                .values(content=serialized_content, content_type=content_type)
+            )
+            with self.engine.connect() as conn:
+                conn.execute(upd)
+                conn.commit()
+
+    def retrieve(self, name: str) -> Optional[Union[str, bytes, Any]]:
+        sel = self.table.select().where(self.table.c.name == name)
+        with self.engine.connect() as conn:
+            result = conn.execute(sel).fetchone()
+            if result:
+                return self._deserialize_content(result.content, result.content_type)
+        return None
+
+    def list_contents(self) -> List[str]:
+        sel = select(self.table.c.name)
+        with self.engine.connect() as conn:
+            result = conn.execute(sel).fetchall()
+            return [row[0] for row in result]
+
+    def remove(self, name: str) -> bool:
+        del_stmt = self.table.delete().where(self.table.c.name == name)
+        with self.engine.connect() as conn:
+            result = conn.execute(del_stmt)
+            conn.commit()
+            return result.rowcount > 0
+
+    @staticmethod
+    def _serialize_content(content: Union[str, bytes, Any]) -> tuple[bytes, str]:
+        if isinstance(content, bytes):
+            return content, "bytes"
+        elif isinstance(content, str):
+            return content.encode(), "string"
+        else:
+            # Fallback to pickle for other types
+            return pickle.dumps(content), "pickle"
+
+    @staticmethod
+    def _deserialize_content(content: bytes, content_type: Optional[str]) -> Any:
+        if content_type == "pickle":
+            return pickle.loads(content)
+        if content_type == "string":
+            return content.decode()
+        return content

examples/confluence-reader/common/file_storage.py

@@ -0,0 +1,57 @@
+# Copyright 2021-2024 VMware, Inc.
+# SPDX-License-Identifier: Apache-2.0
+import json
+import os
+from typing import Any
+from typing import List
+from typing import Optional
+from typing import Union
+
+from storage import IStorage
+
+
+class FileStorage(IStorage):
+    def __init__(self, base_path: str):
+        self.base_path = base_path
+        if not os.path.exists(self.base_path):
+            os.makedirs(self.base_path)
+
+    def _get_file_path(self, name: str) -> str:
+        return os.path.join(self.base_path, name)
+
+    def store(
+        self,
+        name: str,
+        content: Union[str, bytes, Any],
+        content_type: Optional[str] = None,
+    ) -> None:
+        file_path = self._get_file_path(name)
+        with open(file_path, "w") as file:
+            if isinstance(content, (str, bytes)):
+                # Directly save strings and bytes
+                file.write(content if isinstance(content, str) else content.decode())
+            else:
+                # Assume JSON serializable for other types
+                json.dump(content, file)
+
+    def retrieve(self, name: str) -> Optional[Union[str, bytes, Any]]:
+        file_path = self._get_file_path(name)
+        if not os.path.exists(file_path):
+            return None
+        with open(file_path) as file:
+            try:
+                return json.load(file)
+            except json.JSONDecodeError:
+                # Content was not JSON, return as string
+                file.seek(0)
+                return file.read()
+
+    def list_contents(self) -> List[str]:
+        return os.listdir(self.base_path)
+
+    def remove(self, name: str) -> bool:
+        file_path = self._get_file_path(name)
+        if os.path.exists(file_path):
+            os.remove(file_path)
+            return True
+        return False

examples/confluence-reader/common/storage.py

@@ -0,0 +1,46 @@
+# Copyright 2021-2024 VMware, Inc.
+# SPDX-License-Identifier: Apache-2.0
+from typing import Any
+from typing import List
+from typing import Optional
+from typing import Union
+
+
+class IStorage:
+    def store(self, name: str, content: Union[str, bytes, Any]) -> None:
+        """
+        Stores the given content under the specified name. If the content is not a string or bytes,
+        the method tries to serialize it based on the content_type (if provided) or infers the type.
+
+        :param name: The unique name to store the content under.
+        :param content: The content to store. Can be of type str, bytes, or any serializable type.
+        """
+        pass
+
+    def retrieve(self, name: str) -> Optional[Union[str, bytes, Any]]:
+        """
+        Retrieves the content stored under the specified name. The method attempts to deserialize
+        the content to its original type if possible.
+
+        :param name: The name of the content to retrieve.
+        :return: The retrieved content, which can be of type str, bytes, or any deserialized Python object.
+                 Returns None if the content does not exist.
+        """
+        pass
+
+    def list_contents(self) -> List[str]:
+        """
+        Lists the names of all stored contents.
+
+        :return: A list of names representing the stored contents.
+        """
+        pass
+
+    def remove(self, name: str) -> bool:
+        """
+        Removes the content stored under the specified name.
+
+        :param name: The name of the content to remove.
+        :return: True if the content was successfully removed, False otherwise.
+        """
+        pass

examples/confluence-reader/fetch_confluence_space.py

@@ -3,12 +3,15 @@
 import json
 import logging
 import os
+import pathlib
 from datetime import datetime
 
+from common.database_storage import DatabaseStorage
 from confluence_document import ConfluenceDocument
 from langchain_community.document_loaders import ConfluenceLoader
 from vdk.api.job_input import IJobInput
 
+
 log = logging.getLogger(__name__)
 
 
@@ -109,17 +112,12 @@ def __init__(self, confluence_url, token, space_key):
         self.loader = ConfluenceLoader(url=self.confluence_url, token=self.token)
 
     def fetch_confluence_documents(self, cql_query):
-        try:
-            # TODO: think about configurable limits ? or some streaming solution
-            # How do we fit all documents in memory ?
-            raw_documents = self.loader.load(cql=cql_query, limit=50, max_pages=200)
-            return [
-                ConfluenceDocument(doc.metadata, doc.page_content)
-                for doc in raw_documents
-            ]
-        except Exception as e:
-            log.error(f"Error fetching documents from Confluence: {e}")
-            raise e
+        # TODO: think about configurable limits ? or some streaming solution
+        # How do we fit all documents in memory ?
+        raw_documents = self.loader.load(cql=cql_query, limit=50, max_pages=200)
+        return [
+            ConfluenceDocument(doc.metadata, doc.page_content) for doc in raw_documents
+        ]
 
     def fetch_updated_pages_in_confluence_space(
         self, last_date="1900-02-06 17:54", parent_page_id=None
@@ -147,9 +145,10 @@ def fetch_all_pages_in_confluence_space(self, parent_page_id=None):
 
 
 def get_value(job_input, key: str, default_value=None):
-    return job_input.get_arguments().get(
-        key, job_input.get_property(key, os.environ.get(key.upper(), default_value))
-    )
+    value = os.environ.get(key.upper(), default_value)
+    value = job_input.get_property(key, value)
+    value = job_input.get_secret(key, value)
+    return job_input.get_arguments().get(key, value)
 
 
 def set_property(job_input: IJobInput, key, value):
@@ -165,12 +164,20 @@ def run(job_input: IJobInput):
     token = get_value(job_input, "confluence_token")
     space_key = get_value(job_input, "confluence_space_key")
     parent_page_id = get_value(job_input, "confluence_parent_page_id")
-    last_date = get_value(job_input, "last_date", "1900-01-01 12:00")
-    data_file = get_value(
-        job_input,
-        "data_file",
-        os.path.join(job_input.get_temporary_write_directory(), "confluence_data.json"),
+    last_date = (
+        job_input.get_property(confluence_url, {})
+        .setdefault(space_key, {})
+        .setdefault(parent_page_id, {})
+        .get("last_date", "1900-01-01 12:00")
     )
+    data_file = os.path.join(
+        job_input.get_temporary_write_directory(), "confluence_data.json"
+    )
+    storage_name = get_value(job_input, "storage_name", "confluence_data")
+    storage = DatabaseStorage(get_value(job_input, "storage_connection_string"))
+    # TODO: this is not optimal . We just care about the IDs, we should not need to retrieve everything
+    data = storage.retrieve(storage_name)
+    pathlib.Path(data_file).write_text(data if data else "[]")
 
     confluence_reader = ConfluenceDataSource(confluence_url, token, space_key)
 
@@ -189,3 +196,8 @@ def run(job_input: IJobInput):
         data_file,
         confluence_reader.fetch_all_pages_in_confluence_space(parent_page_id),
     )
+
+    # TODO: it would be better to save each page in separate row.
+    # But that's quick solution for now to pass the data to the next job
+
+    storage.store(storage_name, pathlib.Path(data_file).read_text())

examples/confluence-reader/requirements.txt

@@ -5,3 +5,5 @@
 atlassian-python-api
 langchain_community
 lxml
+psycopg2-binary
+sqlalchemy