Field-level parsing shared by the mesh status parsers.
Every mesh reports its peers in a different format, but the two fields the strategies read are read the same way everywhere: an address is only usable as a node name when it is a plain IPv4 address, and a mesh name is only a hostname up to its first dot.
Both functions accept any term. A daemon whose output does not match this library's expectations has to make a peer be skipped, not make the poll raise — the parsers promise never to raise, and that promise is only worth something if the helpers they are built from keep it too.
Summary
Functions
The hostname part of a mesh name: everything before the first dot.
Returns true when the value is a string holding a plain IPv4 address.
Functions
The hostname part of a mesh name: everything before the first dot.
Anything that is not a string becomes "", which no configured hostname
prefix can match (LibclusterMesh.Config refuses an empty prefix), so a
peer whose name field is missing is skipped rather than connected to under
a name it does not answer to.
iex> LibclusterMesh.Parse.hostname("myapp-1.example.ts.net.")
"myapp-1"
iex> LibclusterMesh.Parse.hostname("myapp-1")
"myapp-1"
iex> LibclusterMesh.Parse.hostname(nil)
""Returns true when the value is a string holding a plain IPv4 address.
Strict, so a prefix length or a zero-padded octet is not one — both appear in mesh output and neither is an address a node can be reached at.
iex> LibclusterMesh.Parse.ipv4?("100.64.0.2")
true
iex> LibclusterMesh.Parse.ipv4?("100.64.0.2/32")
false
iex> LibclusterMesh.Parse.ipv4?("fd00::2")
false
iex> LibclusterMesh.Parse.ipv4?(nil)
false