fix: Miscellaneous bug fixes for MLflow client upgrade (#487)

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**What this PR does / why we need it**:
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the problem you're trying to solve. --->

This PR contains miscellaneous bug fixes, following
#465

**Which issue(s) this PR fixes**:
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*Automatically closes linked issue when PR is merged.
Usage: `Fixes #<issue number>`, or `Fixes (paste link of issue)`.
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1. Correcting the `protobuf` version range that the SDK can work with
2. Updating Pyfunc user docs to elaborate on the Protobuf compatibility
3. Correcting the `sed` command for fixing the `mlflow` dependency in
the conda env file (example test below)

![Screenshot 2023-11-09 at 7 07 23
AM](https://github.com/caraml-dev/merlin/assets/23465343/d5e9fb72-6cd5-450d-9f70-dec633de5716)

**Does this PR introduce a user-facing change?**:
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```release-note
Update protobuf dependency range and docs
```

**Checklist**

- [ ] Added unit test, integration, and/or e2e tests
- [x] Tested locally
- [x] Updated documentation
- [ ] Update Swagger spec if the PR introduce API changes
- [ ] Regenerated Golang and Python client if the PR introduce API
changes

docs/user-guide/examples/pyfunc_model.md

@@ -2,6 +2,19 @@
 
 Try out the notebooks below to learn how to deploy PyFunc Models to Merlin.
 
+**Note on compatibility**: The Pyfunc servers are compatible with `protobuf>=3.12.0,<5.0.0`. Users whose models have a strong dependency on Protobuf `3.x.x` are advised to pin the library version in their conda environment, when submitting the model version. If using Protobuf `3.x.x`, users can do one of the following:
+* Use `protobuf>=3.20.0` - these versions support simplified class definitions and this is the recommended approach.
+* If you must use `protobuf>=3.12.0,<3.20.0`, other packages used in the Pyfunc server need to be downgraded as well. Please pin the following in your model’s conda environment:
+```yaml
+dependencies:
+  - pip:
+    - protobuf==3.15.6 # Example older protobuf version
+    - caraml-upi-protos<=0.3.6
+    - grpcio<1.49.0
+    - grpcio-reflection<1.49.0
+    - grpcio-health-checking<1.49.0
+```
+
 ## Deploy PyFunc Model
 
 {% embed url="https://github.com/caraml-dev/merlin/blob/main/examples/pyfunc/Pyfunc.ipynb" %}

python/batch-predictor/docker/app.Dockerfile

@@ -24,6 +24,6 @@ ARG GOOGLE_APPLICATION_CREDENTIALS
 RUN if [[ ! -z "$GOOGLE_APPLICATION_CREDENTIALS" ]]; then gcloud auth activate-service-account --key-file=${GOOGLE_APPLICATION_CREDENTIALS}; fi
 RUN gsutil -m cp -r ${MODEL_URL} .
 RUN /bin/bash -c ". activate ${CONDA_ENVIRONMENT} && \
-    sed -i 's/mlflow\(\s*==\s*[^ ]*\)\{0,1\}/mlflow==1.26.1/g' ${HOME}/model/conda.yaml && \
+    sed -i 's/mlflow[><=]\{0,1\}.*$/mlflow==1.26.1/g' ${HOME}/model/conda.yaml && \
     conda env update --name ${CONDA_ENVIRONMENT} --file ${HOME}/model/conda.yaml && \
     python ${HOME}/merlin-spark-app/main.py --dry-run-model ${HOME}/model"

python/pyfunc-server/docker/Dockerfile

@@ -24,7 +24,7 @@ WORKDIR /pyfunc-server
 RUN if [ ! -z "$GOOGLE_APPLICATION_CREDENTIALS" ]; then gcloud auth activate-service-account --key-file=${GOOGLE_APPLICATION_CREDENTIALS}; fi
 RUN gsutil cp -r ${MODEL_URL} .
 RUN /bin/bash -c ". activate merlin-model && \
-    sed -i 's/mlflow\(\s*==\s*[^ ]*\)\{0,1\}/mlflow==1.26.1/g' model/conda.yaml && \
+    sed -i 's/mlflow[><=]\{0,1\}.*$/mlflow==1.26.1/g' model/conda.yaml && \
     conda env update --name merlin-model --file model/conda.yaml && \
     python -m pyfuncserver --model_dir model --dry_run"
 

python/sdk/setup.py

@@ -30,7 +30,7 @@
     "cookiecutter>=1.7.2",
     "docker>=4.2.1",
     "google-cloud-storage>=1.19.0",
-    "protobuf>=3.0.0,<5.0.0",
+    "protobuf>=3.12.0,<5.0.0", # Determined by the mlflow dependency
     "mlflow>=1.26.1,<2.0.0",
     "PyPrind>=2.11.2",
     "python_dateutil>=2.5.3",