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Secure Installs

Installing Python packages securely is a best practice recommended by pip. This page describes how to apply these practices when installing MLflow and its dependencies.

Hash-Checking Mode​

pip's hash-checking mode verifies that every downloaded package matches a known SHA256 hash, protecting against tampering and man-in-the-middle attacks.

Generating Hashed Requirements​

Use pip-compile to resolve all dependencies and generate hashes:

bash
pip install pip-tools
pip-compile --generate-hashes --output-file=requirements.txt requirements.in

Where requirements.in pins your direct dependencies:

text
mlflow==3.10.1

The generated requirements.txt will include hashes for every package:

text
mlflow==3.10.1 \
    --hash=sha256:abc123... \
    --hash=sha256:def456...
numpy==2.2.4 \
    --hash=sha256:789abc...

Installing with Hash Verification​

bash
pip install --require-hashes -r requirements.txt

All packages (including transitive dependencies) must be pinned with == and have at least one hash. A partially-hashed requirements file is rejected by pip to prevent a malicious package from slipping through an unhashed entry.

Disabling Source Distributions​

To further reduce risk, use --only-binary :all: to prevent pip from running arbitrary build code (e.g., via setup.py or PEP 517 build backends) during installation:

bash
pip install --require-hashes --only-binary :all: -r requirements.txt

Filtering by Upload Time​

Both pip and uv support filtering packages by their upload date, ensuring that dependency resolution only considers packages published before a known point in time. This protects against newly published malicious versions and enables reproducible builds.

Choosing a date

Use an absolute timestamp set to the last date you audited or verified your dependencies. This ensures reproducible installs. Relative durations like "7 days" are convenient for rolling policies but produce different results over time.

pip​

pip's --uploaded-prior-to option accepts an ISO 8601 datetime:

bash
# Replace with a date you trust (e.g., the last date you verified your dependencies)
pip install --uploaded-prior-to="2026-03-01T00:00:00Z" mlflow

This only applies to packages from remote indexes (not local files or VCS requirements), and the index must provide upload-time metadata (PyPI does).

uv​

uv provides the equivalent exclude-newer setting:

bash
# Absolute timestamp - best for reproducible builds (replace with your own trusted date)
uv pip install --exclude-newer "2026-03-01T00:00:00Z" mlflow

# Relative duration - useful for rolling policies (e.g., always exclude packages newer than 7 days)
uv pip install --exclude-newer "7 days" mlflow

For one-off tool invocations with uvx:

bash
# Absolute timestamp - best for reproducible builds (replace with your own trusted date)
uvx --exclude-newer "2026-03-01T00:00:00Z" mlflow server

# Relative duration - useful for rolling policies (e.g., always exclude packages newer than 7 days)
uvx --exclude-newer "7 days" mlflow server