This projects provides example code to create an embedded etcd cluster in a Golang server.

The application can than use the cluster with a central key value storage acting as a shared distributed cluster state without depending on any extra database.

Every instance of a server, is treated as a node inside cluster. Each node have a pair of peer url and client url for internal communication between nodes. The transport.port configuration can be used to set this value of the peer port. By default it will use 2300. The client url is automatically configured by adding 1 to the peer url. Therefore when configuring multiple nodes in a cluster make sure to reserve 2 consecutive ports for each node.

Each instance of a server, require cluster.name and node.name to be set in order for the cluster to be configured accordingly and the node to join the desired cluster.

Discovery

By default, without additional configuration, a server will listen to all loopback addresses and ports 2300-2309 in order to find any node/cluster already running and join it if so.

In a use case where a 3 nodes cluster need to be boostrap from scratch, cluster.initial_master_nodes which correspond to all node.name that will be part of the cluster need to be specified.

If nodes are not port of the same network/host the discovery.seed_hosts need to be specifided in order for the cluster to listen to those IP addresses.

• Handle Node lifecycle:
  • Join
  • Remove
• Cluster teardown
• Cluster Storage Interface