Host Naming Convention

Overview

Onagre enforces strict validation for hostnames, fully qualified domain names (FQDNs), and IP addresses to ensure compatibility with networking standards. Hosts must adhere to one of the following formats:

IPv4 Address (RFC 791)
IPv6 Address (RFC 4291)
Hostname (RFC 1035)

Hostname Validation Examples

Hostname	Valid?	Explanation
`example.com`	✅ Yes	Valid domain name.
`sub.domain.com`	✅ Yes	Valid subdomain.
`localhost`	✅ Yes	Common local hostname.
`a-b-c123.net`	✅ Yes	Valid use of letters, numbers, and hyphens.
`-invalid.com`	❌ No	Cannot start with a hyphen (`-`).
`verylonglabelnameover63characterslong.example.com`	❌ No	A label exceeds 63 characters.
`example..com`	❌ No	Double dots `..` are not allowed.
`example.com-`	❌ No	Cannot end with a hyphen (`-`).
`_invalid.com`	❌ No	Underscores (`_`) are not allowed in hostnames.
`123..example.com`	❌ No	Consecutive dots are not valid.

Fully Qualified Domain Name (FQDN) Examples

FQDN	Valid?	Explanation
`server.example.com`	✅ Yes	Common fully qualified domain name.
`my-host.example.net`	✅ Yes	Valid use of hyphen in a subdomain.
`api.sub.example.org`	✅ Yes	Valid multiple subdomain levels.
`web1.example.co.uk`	✅ Yes	Valid domain with country code TLD.
`12345.example.com`	✅ Yes	Hostnames can be fully numeric.
`host..example.com`	❌ No	Double dots `..` are not valid.
`invalid.-example.com`	❌ No	A label cannot start with a hyphen (`-`).
`sub_domain.example.com`	❌ No	Underscores (`_`) are not allowed.
`ex@mple.com`	❌ No	Special characters are not allowed.
`veryverylonghostnameover63characterslong.example.com`	❌ No	A label exceeds the 63-character limit.

IPv4 Validation Examples

IPv4 Address	Valid?	Explanation
`192.168.1.1`	✅ Yes	Common private address.
`127.0.0.1`	✅ Yes	Loopback address (localhost).
`300.168.1.1`	❌ No	`300` exceeds the valid range (`0-255`).
`192.168.1.256`	❌ No	`256` exceeds the valid range (`0-255`).
`192.168.01.1`	❌ No	Leading zeroes are not allowed (`01`).
`192.168.1`	❌ No	Incomplete (missing an octet).
`192.168.1.1.1`	❌ No	Too many octets (should have 4).
`192.168..1.1`	❌ No	Double `..` is not allowed.
`abc.def.gha.bcd`	❌ No	Contains invalid characters (letters).

IPv6 Validation Examples

IPv6 Address	Valid?	Explanation
`2001:db8::ff00:42:8329`	✅ Yes	Valid IPv6 address using `::`.
`2001:0db8:85a3:0000:0000:8a2e:0370:7334`	✅ Yes	Fully expanded IPv6 address.
`::1`	✅ Yes	Loopback address (equivalent to `127.0.0.1` in IPv4).
`::`	✅ Yes	Unspecified address (default).
`fe80::1`	✅ Yes	Valid link-local address.
`2001:db8:::1`	❌ No	Too many colons (`:::` is not allowed).
`2001:ghij::1`	❌ No	Contains non-hexadecimal letters (`g`-`j`).
`2001::12345`	❌ No	A segment exceeds `ffff` (max `0-FFFF`).
`1234::5678::9abc`	❌ No	Double `::` is not allowed in multiple places.
`::ffff:192.168.1.256`	❌ No	Invalid embedded IPv4 (`256`).

Summary

Onagre follows strict hostname, FQDN, and IP validation rules based on networking standards. Ensuring that all inputs conform to these guidelines prevents misconfigurations and enhances reliability within the platform.