sandbox pause/resume fail with "Content-Length is required" (HTTP 411)

[pratikbin]

Summary

createos sandbox pause and createos sandbox resume fail on every sandbox, addressed by name or by ID. The API returns HTTP 411 Length Required.

$ createos sandbox pause bench-2
  ERROR  Content-Length is required
  Hint: Check that the value you provided is correct and try again.

Root cause

lifecyclePOST() in internal/api/sandbox.go builds the request with no .SetBody(...):

func (c *SandboxClient) lifecyclePOST(ctx context.Context, id, path string) (*SandboxView, error) {
	var envelope Response[SandboxView]
	resp, err := c.Client.R().
		SetContext(ctx).
		SetPathParam("id", id).
		SetResult(&envelope).
		Post(path)
	...

Both PauseSandbox and ResumeSandbox call this helper, so both endpoints fail.

Over HTTP/2, a Go client request with no body sends no Content-Length header — it signals end of body with END_STREAM instead, which is valid HTTP/2. The API requires Content-Length on every POST and rejects the request with 411 before it reaches route logic. Other lifecycle calls that already set a body (CreateSandbox, ForkSandbox, AttachDisk, …) are unaffected.

Repro

$ createos --debug sandbox pause sb-01m0vyh91ayt2sardrn3b0vz8q
~~~ REQUEST ~~~
POST  /v1/sandboxes/sb-01m0vyh91ayt2sardrn3b0vz8q/pause  HTTP/1.1
BODY   :
***** NO CONTENT *****
------------------------------------------------------------------------------
~~~ RESPONSE ~~~
STATUS       : 411 Length Required
BODY         :
{
   "status": "fail",
   "data": "Content-Length is required"
}

Identical failure for resume (POST /v1/sandboxes/{id}/resume).

Fix (verified against the live API)

Give the request a body:

resp, err := c.Client.R().
    SetContext(ctx).
    SetPathParam("id", id).
    SetBody(map[string]any{}).
    SetResult(&envelope).
    Post(path)

Built and ran this exact change locally against api.sb.createos.sh:

• pause returned 200 OK, sandbox reached paused.
• resume returned 200 OK with status:"resuming", and the sandbox settled into running.

Version

Version: dev
Channel: stable
Commit:  unknown

Built from main at b6f98bb ("fix(sandbox): pin ssh known_hosts to sandbox id (#76)").

Also noticed while restoring test state (separate, lower confidence)

After the fix, one resume briefly read back status:"paused" on the first poll or two before settling into resuming → running within ~11s. Might be read-path eventual consistency rather than a real regression — did not chase further, flagging in case it's already on your radar.