Bogdan Dobrelya b8bc8eee41 Add download_always_pull check and sha256 for docker images

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

2016-12-20 17:02:09 +01:00

Large deployments of K8s

For a large scaled deployments, consider the following configuration changes:

Tune ansible settings for forks and timeout vars to fit large numbers of nodes being deployed.
Override containers' foo_image_repo vars to point to intranet registry.
Override the download_run_once: true and/or download_localhost: true. See download modes for details.
Adjust the retry_stagger global var as appropriate. It should provide sane load on a delegate (the first K8s master node) then retrying failed push or download operations.
Tune parameters for DNS related applications (dnsmasq daemon set, kubedns replication controller). Those are dns_replicas, dns_cpu_limit, dns_cpu_requests, dns_memory_limit, dns_memory_requests. Please note that limits must always be greater than or equal to requests.

For example, when deploying 200 nodes, you may want to run ansible with --forks=50, --timeout=600 and define the retry_stagger: 60.