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Use net.Listen func to ensure the port is free #6990

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Merged
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Jul 4, 2021
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Use net.Listen func to ensure the port is free #6990

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8 changes: 4 additions & 4 deletions internal/net/net.go
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Original file line number Diff line number Diff line change
Expand Up @@ -29,12 +29,12 @@ func IsIPV6(ip _net.IP) bool {

// IsPortAvailable checks if a TCP port is available or not
func IsPortAvailable(p int) bool {
conn, err := _net.Dial("tcp", fmt.Sprintf(":%v", p))
ln, err := _net.Listen("tcp", fmt.Sprintf(":%v", p))
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Cant it be a problem if we try to bind nginx to a specific IP, but here you check all the interfaces?

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https://kubernetes.github.io/ingress-nginx/user-guide/nginx-configuration/configmap/#bind-address <- we should probably check against this address specifically:

  1. If it does not exists, we may try binding to every address
  2. If this exists, then we should try to bind specifically to this address

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Yes, you are right, I just did a workaround let it can run in my cluster. I will try to change it under your suggested.

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@rikatz but the function was use in init check, so it will change so many things.

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hum indeed, this value is in ConfigMap and it's not a flag...

OK, so overall this problem would still happen if we have something listening in the port, I think we can go forward with this one.

if err != nil {
return true
return false
}
defer conn.Close()
return false
defer ln.Close()
return true
}

// IsIPv6Enabled checks if IPV6 is enabled or not and we have
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