Modified the Dockerfile to use numeric UID

[Rchanger]

#766
Fix: modified the docker file to use numeric UID.

USE 101

Reason for change:

when we set the RunAsNonRoot field of a security context, k8s internal logic checks the container for numeric UID instead of a username, and if it doesnot found any numeric UID it throughs error container has runAsNonRoot and image has non-numeric user (terrascan), cannot verify user is non-root

Tested the changes for Use cases

• Admission controller webhook with plane YAML files
• Admission controller with Helm
• Admission controller with argoCD

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information

[codecov]

Codecov Report

Merging #773 (60dc1e5) into master (01c8d78) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #773   +/-   ##
=======================================
  Coverage   73.78%   73.78%           
=======================================
  Files         110      110           
  Lines        3285     3285           
=======================================
  Hits         2424     2424           
  Misses        677      677           
  Partials      184      184           

[devang-gaur]

Built the docker file and by default whoami returns 'terrascan'.

$ docker exec -it c7dfa4829a14 /bin/sh
/ $ whoami
terrascan
/ $ ps aux
PID   USER     TIME  COMMAND
    1 terrasca  0:03 /go/bin/terrascan server --log-type json
   17 terrasca  0:00 /bin/sh
   24 terrasca  0:00 ps aux