~/.docker/config.json vs env variables

[collivier]

Documentation mentions the possibility to export both Docker Hub login and password which is more or less used for the private registry and skopeo:

• https://github.com/cnti-testcatalog/testsuite/blob/bb1634895c6f9f119cdd3e543d3e110b08227c19/cnf-testsuite.env.example
• https://github.com/cnti-testcatalog/testsuite/blob/bb1634895c6f9f119cdd3e543d3e110b08227c19/INSTALL.md

But, this env variables are not used for all the helm chart pulls which may require it too (ex bitnami as we have seen in gate).

So mainly 3 options:

• cnf-testsuite calls docker login if the env variables are set but that could erase a previous ~/.docker/config.json
• cnf-testsuite only copies the ~/.docker/config.json if it exists in cluster_tools and in the private registry (+ documentation updates to remove the env variables)
• documentation is updated to warn then enduser about ~/.docker/config.json may be needed when cnf-testsuite pulls the helm charts

Depending on the agreed solution, the workflow could be updated / enhanced.