kubeadm during initialization of master and slave nodes need to make
several API calls directly to the node where it is running or master.
In environments with http/https proxies, user might accidentally
have configuration where connections to API would go over proxy instead
of directly.
User can re-run kubeadm with corrected NO_PROXY variable. Example:
$ NO_PROXY=* kubeadm join ...
Automatic merge from submit-queue
kubeadm: added unit test for app/preflight pkg
Added unit test for kubeadm/app/preflight package testing functionality of checks.go.
This PR is part of the ongoing effort to add tests (#35025)
/cc @pires @jbeda
Packages may auto-create directories in /etc/kubernetes, and users also
need files such as cloud-config.json to be present and preserved at
their default locations in /etc/kubernetes. As such this modifies
pre-flight checks to only require the absence of the files and
directories we explicitly create in kubeadm.
Reset is similarly modified to not wipe out /etc/kubernetes entirely.
When resetting directories we also now preserve the directory itself,
but delete it's contents.
Also adds tests for reset command logic specifically for /etc/kubernetes
cleanup, to ensure user files are not inadvertently wiped out.
Add skip-preflight-checks to known flags.
Fix bug with preflight checks not returning system is-active as errors.
Fix error handling to use correct function.
Includes checks for verifying services exist and are enabled, ports are
open, directories do not exist or are empty, and required binaries are
in the path.
Checks that user running kubeamd init and join is root and will only execute
command if user is root. Moved away from using kubectl error handling to
having kubeadm handle its own errors. This should allow kubeadm to have
more meaningful errors, exit codes, and logging for specific kubeadm use
cases.
