Pass more environment variables when pulling docker image

[duvallj]

Some background: I am working in a corporate environment where noexec and nodev are set on /tmp and all internet access must be done through a proxy. Usually when working with singularity, I am able to work around these restrictions by setting the appropriate environment variables (changing TMPDIR as well as the *_PROXY set of vars). However, when using Singularity-CRI, this does not work even when sycri has the correct environment due to

singularity-cri/pkg/image/image.go

Line 271 in 711792d

buildCmd.Env = []string{

. I will start working on a PR for this as soon as I submit the issue.

What are the steps to reproduce this issue?

1. Have a machine with noexec set on /tmp
2. Install sycri and crictl
3. Run sudo -E crictl -r unix:///var/run/singularity.sock pull docker://k8s.gcr.io/kube-apiserver:v1.18.5

What happens?

The image fails to pull.

What were you expecting to happen?

The image pull succeeds.

Any logs, error output, comments, etc?

FATA[0000] pulling image failed: rpc error: code = Internal desc = could not pull image: could not pull image: could not build image: WARNING: 'nodev' mount option set on /tmp, it could be a source of failure during build process
FATAL:   Unable to create build: 'noexec' mount option set on /tmp, temporary root filesystem won't be usable at this location

Environment?

OS distribution and version: CentOS Linux release 7.8.2003, kernel version 3.10.0-1127.13.1.el7.x86_64

go version: go1.14.4 linux/amd64

Singularity-CRI version: 1.0.0-beta.7

Singularity version: 3.5.3

Kubernetes version: 1.18.5