Pickle conversion now requires `--trust-remote-code`. (#1704)

# What does this PR do?

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Fixes # (issue)


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docs/source/_toctree.yml

@@ -23,6 +23,8 @@
     title: All TGI CLI  options
   - local: basic_tutorials/non_core_models
     title: Non-core Model Serving
+  - local: basic_tutorials/safety
+    title: Safety
   title: Tutorials
 - sections:
   - local: conceptual/streaming

docs/source/basic_tutorials/safety.md

@@ -0,0 +1,31 @@
+# Model safety.
+
+[Pytorch uses pickle](https://pytorch.org/docs/master/generated/torch.load.html) by default meaning that for quite a long while
+*Every* model using that format is potentially executing unintended code while purely loading the model.
+
+There is a big red warning on Python's page for pickle [link](https://docs.python.org/3/library/pickle.html) but for quite a while
+this was ignored by the community. Now that AI/ML is getting used much more ubiquitously we need to switch away from this format.
+
+HuggingFace is leading the effort here by creating a new format which contains pure data ([safetensors](https://github.com/huggingface/safetensors))
+and moving slowly but surely all the libs to make use of it by default.
+The move is intentionnally slow in order to make breaking changes as little impact as possible on users throughout.
+
+
+# TGI 2.0
+
+Since the release of TGI 2.0, we take the opportunity of this major version increase to break backward compatibility for these pytorch
+models (since they are a huge security risk for anyone deploying them).
+
+
+From now on, TGI will not convert automatically pickle files without having `--trust-remote-code` flag or `TRUST_REMOTE_CODE=true` in the environment variables.
+This flag is already used for community defined inference code, and is therefore quite representative of the level of confidence you are giving the model providers.
+
+
+If you want to use a model that uses pickle, but you still do not want to trust the authors entirely we recommend making a convertion on our space made for that.
+
+https://huggingface.co/spaces/safetensors/convert
+
+This space will create a PR on the original model, which you are use directly regardless of merge status from the original authors. Just use
+```
+docker run .... --revision refs/pr/#ID # Or use REVISION=refs/pr/#ID in the environment
+```

server/text_generation_server/cli.py

@@ -249,6 +249,13 @@ def download_weights(
         local_pt_files = utils.download_weights(pt_filenames, model_id, revision)
 
     if auto_convert:
+        if not trust_remote_code:
+            logger.warning(
+                f"🚨🚨BREAKING CHANGE in 2.0🚨🚨: Safetensors conversion is disabled without `--trust-remote-code` because "
+                f"Pickle files are unsafe and can essentially contain remote code execution!"
+                f"Please check for more information here: https://huggingface.co/docs/text-generation-inference/basic_tutorials/safety",
+            )
+
         logger.warning(
             f"No safetensors weights found for model {model_id} at revision {revision}. "
             f"Converting PyTorch weights to safetensors."