examples: RAG Chat UI (#3108)

This PR introduces a UI for a chat bot using the RAG service we
developed previously.

Testing done: ran locally

---------

Signed-off-by: Gabriel Georgiev <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

examples/rag-chat-api/README.md

@@ -21,3 +21,16 @@ Alternatively, you can use the Python script for easier access + string formatti
 ```
 python question.py "INPUT-QUESTION-HERE"
 ```
+
+### UI
+
+To run the UI, you need to install `streamlit`:
+```
+pip install streamlit
+```
+Note that newer versions of `streamlit` require Python 3.8+.
+
+Then, run the app:
+```
+streamlit run chat_app.py
+```

examples/rag-chat-api/chat_app.py

@@ -0,0 +1,29 @@
+# Copyright 2021-2024 VMware, Inc.
+# SPDX-License-Identifier: Apache-2.0
+import streamlit as st
+from question import get_api_response
+
+st.title("VDK Demo Chat Bot")
+
+# Initialize chat history
+if "messages" not in st.session_state:
+    st.session_state.messages = []
+
+# Display chat messages from history on app rerun
+for message in st.session_state.messages:
+    with st.chat_message(message["role"]):
+        st.markdown(message["content"])
+
+# React to user input
+if prompt := st.chat_input("What is up?"):
+    # Display user message in chat message container
+    st.chat_message("user").markdown(prompt)
+    # Add user message to chat history
+    st.session_state.messages.append({"role": "user", "content": prompt})
+
+    response = get_api_response(prompt)
+    # Display assistant response in chat message container
+    with st.chat_message("assistant"):
+        st.markdown(response)
+    # Add assistant response to chat history
+    st.session_state.messages.append({"role": "assistant", "content": response})

examples/rag-chat-api/question.py

@@ -5,16 +5,16 @@
 import requests
 
 
-def question():
-    if len(sys.argv) != 2:
-        print("Wrap your question in quotation marks")
-
+def get_api_response(question):
     headers = {"Content-Type": "application/json"}
-    data = {"question": sys.argv[1]}
+    data = {"question": question}
     res = requests.post("http://127.0.0.1:8000/question/", headers=headers, json=data)
 
-    print(res.text.replace("\\n", "\n").replace("\\t", "\t"))
+    return res.text.replace("\\n", "\n").replace("\\t", "\t")
 
 
 if __name__ == "__main__":
-    question()
+    if len(sys.argv) != 2:
+        print("Wrap your question in quotation marks")
+
+    print(get_api_response(sys.argv[1]))