Fix etc hosts for cluster nodes

Drop non systemd OS types support

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

Add section describing Kargo vs Kops

Fix etcd cert generation to support large deployments

Due to bash max args limits, we should pass all node filenames and
base64-encoded tar data through stdin/stdout instead.

Fixes #832

Add yaml/json loader for inventory

Systemd units, limits, and bin path fixes

Rework wildcards matching all nodes

* Add restart for weave service unit
* Reuse docker_bin_dir everythere
* Limit systemd managed docker containers by CPU/RAM. Do not configure native
  systemd limits due to the lack of consensus in the kernel community
  requires out-of-tree kernel patches.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

Fix creation and sync of etcd certs

Admin certs only go to etcd nodes
Only generate cert-data for nodes that need sync

Fix calico-rr to use etcd certs instead of kube certs

* Re-enable ansible_ssh_pipelining as expected for the cluster.yml
* Do not use 'all' wildcasts for hosts, limit only to k8s-cluster, etcd,
  calico-rr groups instead. Other nodes in inventory are out of Kargo
  scope and it's up to users how to manage them.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

Rework CI triggers/pipeline

* Run CI triggers in one step
* Run all test matrix for triggers
* Switch back to g1-small

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

Rework ignore_errors to report no reds

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

Do not forward private domains for upstream resolvers

Also fix kube log level 4 to log dnsmasq queries.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

Add inventory builder python script

Includes tox support for running unit tests.
Small note added to getting-started guide for using
inventory_builder.py

Also adds manual-only unit test.

Adjust etcd server certificates

ETCD doesn't need cert/key options set. It only requires peer
cert options.

workaround case for etcdctl not yet being installed, only allow for return code of 0 (no error)

Document commonly used Kargo vars

Fix Flannel network on CoreOS

Individual etcd ssl certs

    Resolves: #748

Raise ansible forks for CI test config