Infra Requirements
Overview
This page discusses the infrastructure requirements for DIGIT services. It also explains why DIGIT services are containerised and deployed on Kubernetes.
Requirements
DIGIT Infra is abstracted to Kubernetes which is an open-source containers orchestration platform that helps in abstracting a variety of infra types that are being available across each state, like Physical, VMs, on-premises clouds(VMware, OpenStack, Nutanix, etc.), commercial clouds (Google, AWS, Azure, etc.), SDC and NIC into a standard infra type. Essentially it unifies various infra types into a standard and single type of infrastructure and thus DIGIT becomes multi-cloud supported, portable, extensible, high-performant and scalable containerized workloads and services. This facilitates both declarative configuration and automation. Kubernetes services, eco-system, support and tools are widely available.
The basic need to provision Kubernetes Cluster
Kubernetes as such is a set of components that designated jobs of scheduling, controlling, monitoring
Master Cluster
3 or more machines running one of:
Ubuntu 16.04+
Debian 9
CentOS 7
RHEL 7
Container Linux (tested with 1576.4.0)
4 GB or more of RAM per machine (any less will leave little room for your apps)
2 CPUs or more
User Cluster
3 or more machines running one of:
Ubuntu 16.04+
Debian 9
CentOS 7
RHEL 7
Container Linux (tested with 1576.4.0)
2 GB or more of RAM per machine (any less will leave little room for your apps)
2 CPUs or more
Full network connectivity between all machines in the cluster (public or private network is fine)
Unique hostname, MAC address, and product_uuid for every node. Click here for more details.
Certain ports are open on your machines. See below for more details
Swap disabled. You MUST disable swap in order for the Kubelet to work properly
Verify the MAC Address and product_uuid
Are Unique for Every Node
product_uuid
Are Unique for Every NodeYou can get the MAC address of the network interfaces using the command
ip link
orifconfig -a
The product_uuid can be checked by using the command
sudo cat /sys/class/dmi/id/product_uuid
It is very likely that hardware devices will have unique addresses, although some virtual machines may have identical values. Kubernetes uses these values to uniquely identify the nodes in the cluster. If these values are not unique to each node, the installation process may fail.
Check Network Adapters
If you have more than one network adapter, and your Kubernetes components are not reachable on the default route, we recommend you add IP route(s) so Kubernetes cluster addresses go via the appropriate adapter.
Check Required Ports
Master Cluster Master Node(s)
Worker Node(s)& User Cluster Worker Nodes
** Default port range for NodePort Services.
Any port numbers marked with * are overridable, so you will need to ensure any custom ports you provide are also open.
Complete Infra Specifications
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