plaklet

plaklet is a small, single-shot task executor built on kloset. It reads one task description as JSON on stdin, runs it (backup, check, …) against kloset connectors linked into the binary, and streams the result back as JSON on stdout.

It is the execution engine that a driver spawns to actually do work — for example plakar-edge, which forwards tasks from a control plane to a remote network. plaklet itself is control-plane-agnostic: it has no dependency on plakman, only on kloset and a set of built-in connectors.

Protocol

plaklet reads a single ExecPayload object on stdin and writes a stream of ExecReply objects (one JSON object per line) on stdout, ending with a terminal success or failure. The shapes are defined in protocol.go.

// stdin — one ExecPayload
{
  "op": "backup",
  "task_config": { "tags": "nightly", "ignore": "*.tmp" },
  "source": {                       // resolved connector configuration
    "integration": { "name": "fs", "version": "1.1.2" },
    "fields": [ { "key": "location", "val": "fs:///data" } ]
  },
  "target": {
    "integration": { "name": "fs", "version": "1.1.2" },
    "fields": [ { "key": "location", "val": "fs:///backups/store" } ]
  }
}

// stdout — a stream of ExecReply, terminal reply last
{"type":"report","report":{ "type":"backup", "backup": { … } }}
{"type":"success"}

Connector secrets are expected to be already resolved into literal field values before the payload reaches plaklet.

Operations

Op	Needs	Description
backup	source + target	Snapshot a source into a store
check	source (a store)	Verify every snapshot in a store
restore	source (a store) + target (a destination)	Export a snapshot to a destination
sync	source + target (both stores)	Copy snapshots from one store to another

restore and sync select snapshots via task_config: snapshot (a specific ID), latest ("true"), and tags (comma-separated). restore requires exactly one match; sync copies every match the target does not already have.

Remaining operations (prune, maintenance) follow the same pattern and can be added in their own files.

Connectors

The backends are linked in-process (see connectors.go) — the same set the public plakar CLI ships: fs, http, ptar, stdio, tar. Add an integration subpackage import to support more.

Build & run

go build -o plaklet .

plaklet -cache /var/cache/plaklet -quiet < payload.json

Flag	Default	Meaning
-cache	(required)	Cache directory (pebble state cache)
-cpu	GOMAXPROCS-1	Number of CPUs to use
-concurrency	NumCPU	Max backup/scan worker concurrency
-quiet	false	Quiet
-pkg		Reserved; connectors are linked in-process