Deployment of the Python application fails because the installation of pip is getting stuck in air-gapped environments on TAP v1.6.

Products

• VMware Tanzu Application Service for VMs

Issue/Introduction

In air-gapped environments on TAP v1.6, the deployment of the Python application fails because the installation of pip becomes stuck during the build stage:

Paketo Buildpack for CA Certificates 3.6.1
https://github.com/paketo-buildpacks/ca-certificates
Launch Helper: Contributing to layer
Creating /layers/paketo-buildpacks_ca-certificates/helper/exec.d/ca-certificates-helper
Tanzu CPython Buildpack 1.8.5
Resolving CPython version
Candidate version sources (in priority order):
-> ""
<unknown> -> ""

Selected CPython version (using ): 3.10.11

Executing build process
Installing CPython 3.10.11
Completed in 1.539s

Generating SBOM for /layers/tanzu-buildpacks_cpython/cpython
Completed in 0s


Configuring build environment
PYTHONPATH -> "/layers/tanzu-buildpacks_cpython/cpython"
PYTHONPYCACHEPREFIX -> "/tmp"

Configuring launch environment
PYTHONPATH -> "/layers/tanzu-buildpacks_cpython/cpython"

Tanzu Pip Buildpack 0.16.7
Resolving Pip version
Candidate version sources (in priority order):
<unknown> -> ""

Selected Pip version (using <unknown>): 22.3.1

Executing build process
Installing Pip 22.3.1

 

Environment

Product Version: 1.6

Resolution

The root cause is two-fold:

First, the issue below describes what led to slow builds in airgapped environments. This was resolved by adding the --no-index flag to pip install (when the Pip buildpack is installing pip itself). Please kindly refer to Stop Checking PyPI Index during Installation

Secondly, the addition of the --no-index flag exposed a discrepancy in the build logic of the Pip buildpack in that a set of artifacts necessary for running pip install in later buildpacks was not being persisted throughout the build process. We stored those artifacts in a temporary directory which was cleaned up as soon as the Pip buildpack’s build phase completed. This worked before since the buildpack could always reach out to PyPI but the --no-index flag disabled that behaviour.
This, in turn, caused integration tests in the Tanzu Python buildpack to fail.

 

The fix is in tanzu-python buildpack v2.4.0 which is released as part of TAP 1.7.