Specifying this new flag will automatically hash the configmap/secret
contents with sha256 and append the first 40 hex-encoded bits of the
hash to the name of the configmap/secret. This is especially useful for
workflows that generate configmaps/secrets from files (e.g.
--from-file).
Note that vowels and vowel-like characters in the hash are remapped to
consonants to make it more difficult to accidentally form bad words.
See this Google doc for more background:
https://docs.google.com/document/d/1x1fJ3pGRx20ujR-Y89HUAw8glUL8-ygaztLkkmQeCdU/edit
The POSIX standard restricts environment variable names to uppercase
letters, digits, and the underscore character in shell contexts only.
For generic application usage, it is stated that all other characters
shall be tolerated.
This change relaxes the rules to some degree. Namely, we stop requiring
environment variable names to be strict C_IDENTIFIERS and start
permitting lowercase, dot, and dash characters.
Public container images using environment variable names beyond the
shell-only context can benefit from this relaxation. Elasticsearch is
one popular example.
Lukasz Zajaczkowski