flux_dryrun · Kube Lint MCP: Risk & Policy

WHAT IT DOES

What flux_dryrun does on Kube Lint

AI agents invoke flux_dryrun to trigger actions in Kube Lint. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why flux_dryrun needs a policy

The tool executes kubectl commands (albeit with dry-run flags) which is an external operation that runs code/commands. Dry-run mode mitigates destructive risk by preventing actual cluster modifications, but execution of kubectl still constitutes the Execute category.

From the tool's definition Tool description states 'Validate FluxCD manifests with kubectl dry-run (client + server)', indicating execution of kubectl commands with dry-run mode.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

flux_dryrun Rate-limited

flux_dryrun stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "flux_dryrun": {
      "limits": [
        {
          "counter": "flux_dryrun_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Kube Lint, so you can run agents against it safely.

FAQ

Questions about flux_dryrun

What does the flux_dryrun tool do? +

Validate FluxCD manifests with kubectl dry-run (client + server).\n. It is categorised as a Execute tool in the Kube Lint MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on flux_dryrun? +

Register the Kube Lint MCP server in PolicyLayer and add a rule for flux_dryrun: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Kube Lint. Nothing to install.

What risk level is flux_dryrun? +

flux_dryrun is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit flux_dryrun? +

Yes. Add a rate_limit block to the flux_dryrun rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block flux_dryrun completely? +

Set action: deny in the PolicyLayer policy for flux_dryrun. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides flux_dryrun? +

flux_dryrun is provided by the Kube Lint MCP server (sophotechlabs/kube-lint-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.