mimetype without libmagic

Dockerfile

@@ -20,7 +20,7 @@ ARG TARGETARCH
 ARG TARGETVARIANT
 
 # Install system dependencies
-RUN apt-get update && apt-get install -y libmagic1 && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && rm -rf /var/lib/apt/lists/*
 RUN wget -O golang-migrate.deb https://github.com/golang-migrate/migrate/releases/download/v4.17.0/migrate.${TARGETOS}-${TARGETARCH}${TARGETVARIANT}.deb \
     && dpkg -i golang-migrate.deb \
     && rm golang-migrate.deb

README.md

@@ -109,14 +109,10 @@ pyenv activate opengpts
 Once your Python environment is set up, you can install the project dependencies:
 
 The backend service uses [poetry](https://python-poetry.org/docs/#installation) to manage dependencies.
-It assumes libmagic to be [installed](https://github.com/ahupp/python-magic?tab=readme-ov-file#installation) in your 
-host system.
 
 ```shell 
 pip install poetry
-pip install libmagic
 pip install langchain-community
-brew install libmagic
 ```
 
 **Install Postgres and the Postgres Vector Extension**

backend/Dockerfile

@@ -6,7 +6,7 @@ ARG TARGETARCH
 ARG TARGETVARIANT
 
 # Install system dependencies
-RUN apt-get update && apt-get install -y libmagic1 && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && rm -rf /var/lib/apt/lists/*
 RUN wget -O golang-migrate.deb https://github.com/golang-migrate/migrate/releases/download/v4.17.0/migrate.${TARGETOS}-${TARGETARCH}${TARGETVARIANT}.deb \
     && dpkg -i golang-migrate.deb \
     && rm golang-migrate.deb

backend/app/server.py

@@ -11,7 +11,7 @@
 from app.api import router as api_router
 from app.auth.handlers import AuthedUser
 from app.lifespan import lifespan
-from app.upload import ingest_runnable
+from app.upload import convert_ingestion_input_to_blob, ingest_runnable
 
 logger = logging.getLogger(__name__)
 
@@ -44,7 +44,8 @@ async def ingest_files(
         if thread is None:
             raise HTTPException(status_code=404, detail="Thread not found.")
 
-    return ingest_runnable.batch([file.file for file in files], config)
+    file_blobs = [convert_ingestion_input_to_blob(file) for file in files]
+    return ingest_runnable.batch(file_blobs, config)
 
 
 @app.get("/health")

backend/app/upload.py

@@ -9,9 +9,11 @@
 
 from __future__ import annotations
 
+import mimetypes
 import os
 from typing import BinaryIO, List, Optional
 
+from fastapi import UploadFile
 from langchain_community.vectorstores.pgvector import PGVector
 from langchain_core.document_loaders.blob_loaders import Blob
 from langchain_core.runnables import (
@@ -27,25 +29,52 @@
 from app.parsing import MIMETYPE_BASED_PARSER
 
 
-def _guess_mimetype(file_bytes: bytes) -> str:
-    """Guess the mime-type of a file."""
+def _guess_mimetype(file_name: str, file_bytes: bytes) -> str:
+    """Guess the mime-type of a file based on its name or bytes."""
+    # Guess based on the file extension
+    mime_type, _ = mimetypes.guess_type(file_name)
+
+    # Return detected mime type from mimetypes guess, unless it's None
+    if mime_type:
+        return mime_type
+
+    # Signature-based detection for common types
+    if file_bytes.startswith(b"%PDF"):
+        return "application/pdf"
+    elif file_bytes.startswith(
+        (b"\x50\x4B\x03\x04", b"\x50\x4B\x05\x06", b"\x50\x4B\x07\x08")
+    ):
+        return "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
+    elif file_bytes.startswith(b"\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1"):
+        return "application/msword"
+    elif file_bytes.startswith(b"\x09\x00\xff\x00\x06\x00"):
+        return "application/vnd.ms-excel"
+
+    # Check for CSV-like plain text content (commas, tabs, newlines)
     try:
-        import magic
-    except ImportError as e:
-        raise ImportError(
-            "magic package not found, please install it with `pip install python-magic`"
-        ) from e
+        decoded = file_bytes[:1024].decode("utf-8", errors="ignore")
+        if all(char in decoded for char in (",", "\n")) or all(
+            char in decoded for char in ("\t", "\n")
+        ):
+            return "text/csv"
+        elif decoded.isprintable() or decoded == "":
+            return "text/plain"
+    except UnicodeDecodeError:
+        pass
 
-    mime = magic.Magic(mime=True)
-    mime_type = mime.from_buffer(file_bytes)
-    return mime_type
+    return "application/octet-stream"
 
 
-def _convert_ingestion_input_to_blob(data: BinaryIO) -> Blob:
+def convert_ingestion_input_to_blob(file: UploadFile) -> Blob:
     """Convert ingestion input to blob."""
-    file_data = data.read()
-    mimetype = _guess_mimetype(file_data)
-    file_name = data.name
+    file_data = file.file.read()
+    file_name = file.filename
+
+    # Check if file_name is a valid string
+    if not isinstance(file_name, str):
+        raise TypeError(f"Expected string for file name, got {type(file_name)}")
+
+    mimetype = _guess_mimetype(file_name, file_data)
     return Blob.from_data(
         data=file_data,
         path=file_name,
@@ -104,10 +133,7 @@ def namespace(self) -> str:
             )
         return self.assistant_id if self.assistant_id is not None else self.thread_id
 
-    def invoke(
-        self, input: BinaryIO, config: Optional[RunnableConfig] = None
-    ) -> List[str]:
-        blob = _convert_ingestion_input_to_blob(input)
+    def invoke(self, blob: Blob, config: Optional[RunnableConfig] = None) -> List[str]:
         out = ingest_blob(
             blob,
             MIMETYPE_BASED_PARSER,

backend/pyproject.toml

@@ -22,7 +22,6 @@ tiktoken = "^0.5.1"
 langchain = ">=0.0.338"
 langgraph = "^0.0.38"
 pydantic = "<2.0"
-python-magic = "^0.4.27"
 langchain-openai = "^0.1.3"
 beautifulsoup4 = "^4.12.3"
 boto3 = "^1.34.28"

backend/tests/unit_tests/agent_executor/test_upload.py

@@ -1,8 +1,8 @@
 from io import BytesIO
 
 from langchain.text_splitter import RecursiveCharacterTextSplitter
-
-from app.upload import IngestRunnable, _guess_mimetype
+from fastapi import UploadFile
+from app.upload import IngestRunnable, _guess_mimetype, convert_ingestion_input_to_blob
 from tests.unit_tests.fixtures import get_sample_paths
 from tests.unit_tests.utils import InMemoryVectorStore
 
@@ -17,9 +17,15 @@ def test_ingestion_runnable() -> None:
         input_key="file_contents",
         assistant_id="TheParrot",
     )
-    data = BytesIO(b"test")
-    data.name = "filename"
-    ids = runnable.invoke(data)
+    # Simulate file data
+    file_data = BytesIO(b"test data")
+    file_data.seek(0)
+    # Create UploadFile object
+    file = UploadFile(filename="testfile.txt", file=file_data)
+
+    # Convert the file to blob
+    blob = convert_ingestion_input_to_blob(file)
+    ids = runnable.invoke(blob)
     assert len(ids) == 1
 
 
@@ -28,7 +34,7 @@ def test_mimetype_guessing() -> None:
     name_to_mime = {}
     for file in sorted(get_sample_paths()):
         data = file.read_bytes()
-        name_to_mime[file.name] = _guess_mimetype(data)
+        name_to_mime[file.name] = _guess_mimetype(file.name, data)
 
     assert {
         "sample.docx": (
@@ -38,6 +44,6 @@ def test_mimetype_guessing() -> None:
         "sample.html": "text/html",
         "sample.odt": "application/vnd.oasis.opendocument.text",
         "sample.pdf": "application/pdf",
-        "sample.rtf": "text/rtf",
+        "sample.rtf": "application/rtf",
         "sample.txt": "text/plain",
     } == name_to_mime