vCenter proxy settings configuration is failing with "HTTPS cannot connect to the proxy"

Products

• VMware vCenter Server

Issue/Introduction

• Recently or in the past the vCenter proxy configured was disabled from the VAMI interface.
• When there is no proxy configured by default the proxy file should look like the example provided below :

root@example-vCenter[ / ]# cat /etc/sysconfig/proxy

# Enable a generation of the proxy settings to the profile.
# This setting allows to turn the proxy on and off while
# preserving the particular proxy setup.
#
PROXY_ENABLED="no"

# Some programs (e.g. wget) support proxies, if set in
# the environment.
# Example: HTTP_PROXY="http://proxy.provider.de:3128/"
HTTP_PROXY=""

# Example: HTTPS_PROXY="https://proxy.provider.de:3128/"
HTTPS_PROXY=""

# Example: FTP_PROXY="http://proxy.provider.de:3128/"
FTP_PROXY=""

# Example: GOPHER_PROXY="http://proxy.provider.de:3128/"
GOPHER_PROXY=""

# Example: SOCKS_PROXY="socks://proxy.example.com:8080"
SOCKS_PROXY=""

# Example: SOCKS5_SERVER="office-proxy.example.com:8881"
SOCKS5_SERVER=""

# Example: NO_PROXY="www.me.de, do.main, localhost"
NO_PROXY="localhost, 127.0.0.1"

Environment

• VMware vCenter Server 7.x
• VMware vCenter Server 8.x

Cause

• Whenever the proxy is being removed from the vCenter, it adds a comma before the localhost in the last line of the /etc/sysconfig/proxy file.
• A comma-separated list provides the right set of domain names, IP addresses or FQDNs which need to be bypassed.

Resolution

•    Remove the extra comma ( , ) and spacing before localhost from the last line of the proxy file right after the NO_PROXY=" pattern manually using vi editor
• • SSH into the vCenter appliance as the root user.
  • vi /etc/sysconfig/proxy
  • Press i to insert.
  • Navigate to the last line before localhost and remove the comma and spacing ( Once you are done the last line should look like this as seen below ) :
    • example : NO_PROXY="localhost, 127.0.0.1"
  • Press ecs key.
  • wq! and press enter.

OR 

• • SSH into the vCenter appliance as the root user.
  • sed -i 's/^NO_PROXY=", *\(.*\)/NO_PROXY="\1/' /etc/sysconfig/proxy

Note : Above command will remove any accidental leading comma with or without space right after the NO_PROXY=" pattern.

• Restart the vCenter applmgmt service :
  • service-control --restart applmgmt

• Try to Configure the proxy again from the VAMI interface.