* nebula-cert: support reading CA passphrase from env
This patch extends the `nebula-cert` command to support reading
the CA passphrase from the environment variable `CA_PASSPHRASE`.
Currently `nebula-cert` depends in an interactive session to obtain
the CA passphrase. This presents a challenge for automation tools like
ansible. With this change, ansible can store the CA passphrase in a
vault and supply it to `nebula-cert` via the `CA_PASSPHRASE`
environment variable for non-interactive signing.
Signed-off-by: Hal Martin <1230969+halmartin@users.noreply.github.com>
* name the variable NEBULA_CA_PASSPHRASE
---------
Signed-off-by: Hal Martin <1230969+halmartin@users.noreply.github.com>
Co-authored-by: JackDoan <me@jackdoan.com>
