27bb2da5ee
Nomad communicates with CSI plugin tasks via gRPC. The plugin supervisor hook uses this to ping the plugin for health checks which it emits as task events. After the first successful health check the plugin supervisor registers the plugin in the client's dynamic plugin registry, which in turn creates a CSI plugin manager instance that has its own gRPC client for fingerprinting the plugin and sending mount requests. If the plugin manager instance fails to connect to the plugin on its first attempt, it exits. The plugin supervisor hook is unaware that connection failed so long as its own pings continue to work. A transient failure during plugin startup may mislead the plugin supervisor hook into thinking the plugin is up (so there's no need to restart the allocation) but no fingerprinter is started. * Refactors the gRPC client to connect on first use. This provides the plugin manager instance the ability to retry the gRPC client connection until success. * Add a 30s timeout to the plugin supervisor so that we don't poll forever waiting for a plugin that will never come back up. Minor improvements: * The plugin supervisor hook creates a new gRPC client for every probe and then throws it away. Instead, reuse the client as we do for the plugin manager. * The gRPC client constructor has a 1 second timeout. Clarify that this timeout applies to the connection and not the rest of the client lifetime. |
||
|---|---|---|
| .. | ||
| fake | ||
| testing | ||
| client.go | ||
| client_test.go | ||
| plugin.go | ||