Improper PID permission prevents `nginx` startup on OpenShift

Summary

Improper PID permission prevents nginx startup when running as random UID on OpenShift.

Steps to reproduce

• Reference the existing Ironbank image in a deployment manifest
• Apply/create the deployment on OpenShift 4.6.z+
• Observe failed container startup and error msg: nginx: [emerg] open() "/tmp/nginx.pid" failed (13: Permission denied)

What is the current bug behavior?

nginx container fails to start with error:

2021/07/01 13:24:26 [emerg] 1#1: open() "/tmp/nginx.pid" failed (13: Permission denied)
nginx: [emerg] open() "/tmp/nginx.pid" failed (13: Permission denied)

What is the expected correct behavior?

Standard log output should appear and the pod should remain in a "Running" state:

[jrmorgan@ahub openshift-nginx-sidecar]# oc logs sidecar-7dcf9cbb95-c99q4 -c nginx
10.128.2.1 - - [01/Jul/2021:13:29:52 +0000] "GET / HTTP/1.1" 200 9593 "-" "" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:89.0) Gecko/20100101 Firefox/89.0" "192.168.1.177" "sidecar-sidecar.apps.vmx.int.shifti.us" sn="localhost" rt=0.024 ua="[::1]:8888, 127.0.0.1:8888" us="502, 200" ut="0.000, 0.024" ul="0, 9593" cs=- 67933c3d8ff6a8a3edfc4986585207f0
10.128.2.1 - - [01/Jul/2021:13:29:52 +0000] "GET /flasgger_static/swagger-ui.css HTTP/1.1" 200 47921 "http://sidecar-sidecar.apps.vmx.int.shifti.us/" "" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:89.0) Gecko/20100101 Firefox/89.0" "192.168.1.177" "sidecar-sidecar.apps.vmx.int.shifti.us" sn="localhost" rt=0.011 ua="127.0.0.1:8888" us="200" ut="0.010" ul="81499" cs=- c92eff50f69cd51b749d9dc3816954ce

Relevant logs and/or screenshots

When attempting to run the container on OpenShift 4.6.z an error may be encountered due to current pid permissions and the assigned project uid range:

## Error message:
[jrmorgan@ahub openshift-nginx-sidecar]# oc logs sidecar-7dcf9cbb95-6gfhh -c nginx
2021/07/01 13:24:26 [emerg] 1#1: open() "/tmp/nginx.pid" failed (13: Permission denied)
nginx: [emerg] open() "/tmp/nginx.pid" failed (13: Permission denied)

## project uid range:
[jrmorgan@ahub openshift-nginx-sidecar]# oc describe project sidecar
Name:                   sidecar
Created:                43 hours ago
Labels:                 <none>
Annotations:            openshift.io/description=
...
                        openshift.io/sa.scc.supplemental-groups=1000610000/10000
                        openshift.io/sa.scc.uid-range=1000610000/10000

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)

Defintion of Done

• Bug has been identified and corrected within the container