Host Unable to Access Repository as Static IP Entry Present in Hosts File for the Domain

Problem

Host blocked from accessing the S3 bucket for https://s3-us-west-1.amazonaws.com/platform9-neutron/el7/ to download the required packages.

Environment

• Platform9 Managed OpenStack - All Versions

• Platform9 Managed Kubernetes - All Versions

Cause

1. IP address 54.231.237.25 mapped to the Domain Name s3-us-west-1.amazonaws.com on the host was not reachable.

None

[pf9@host ~]$ nmap -v -Pn s3-us-west-1.amazonaws.com
Starting Nmap 6.40 ( http://nmap.org ) at 2020-05-13 14:02 PDT
Initiating Connect Scan at 14:02
Scanning s3-us-west-1.amazonaws.com (54.231.237.25) [1000 ports]
Connect Scan Timing: About 15.50% done; ETC: 14:05 (0:02:49 remaining)
Connect Scan Timing: About 30.50% done; ETC: 14:05 (0:02:19 remaining)
Connect Scan Timing: About 45.50% done; ETC: 14:05 (0:01:49 remaining)
Connect Scan Timing: About 60.50% done; ETC: 14:05 (0:01:19 remaining)
Connect Scan Timing: About 75.50% done; ETC: 14:05 (0:00:49 remaining)
Completed Connect Scan at 14:05, 201.30s elapsed (1000 total ports)
Nmap scan report for s3-us-west-1.amazonaws.com (54.231.237.25)
Host is up.
All 1000 scanned ports on s3-us-west-1.amazonaws.com (54.231.237.25) are filtered
Read data files from: /usr/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 201.36 seconds

None

[pf9@host ~]$ nc -zv s3-us-west-1.amazonaws.com 80
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connection timed out.

None

[pf9@host ~]$ nc -zv 54.231.237.25 80
Ncat: Version 7.50 ( https://nmap.org/ncat )
Ncat: Connection timed out.

Resolution

The /etc/hosts file on the host had set endpoints with static IP addresses which conflicted with DNS resolution. On removal of the entries, the host was able to successfully download the packages.