Generate time-plus-random Proxmox VMIDs instead of calling `/cluster/nextid` by Copilot · Pull Request #489 · mieweb/opensource-server

Copilot · 2026-10-01T22:01:46Z

Proxmox's /cluster/nextid endpoint returns the same ID to callers that ask at the same time. When two container-creation jobs run concurrently, both get one ID, and the slower createLxc call fails with a CTID conflict.

This PR has the manager generate the VMID itself, so no coordination or retries are needed.

Changes

utils/vmid.js (new): generateVmid() builds an ID in the style of UUIDv7, packed into Proxmox's VMID range of 100–999999999:
```
VMID = 100 + (epochSeconds % 9999) * 100000 + crypto.randomInt(100000)
```
- The high digits are a time slot of one second. The slots cycle about every 2.8 h.
- The low 5 digits are random, from a CSPRNG.
- The largest possible value is 999,899,999.
ProxmoxApi.nextId(): returns generateVmid() and no longer makes an HTTP call. Callers don't change.
bin/create-container.js: only the comment and log text change.
Tests: utils/__tests__/vmid.test.js checks the range bounds, that IDs randomize within one second, and that IDs from different seconds never overlap.

Collision properties

Scenario	Probability
Two allocations in the same second	1 / 100,000
Allocations in different seconds, within one cycle	0
New ID vs. N existing containers	≈ N / 10⁹

Review notes

The generator doesn't check which VMIDs are already in use, and a failed create isn't retried; the issue asked for neither. A collision still fails the job the same way it does today, just much less often.
Docker nodes still let Docker assign the ID. DummyApi is unchanged.

Fixes [Bug]: Container creation CTID conflict #488

Co-authored-by: runleveldev <44057501+runleveldev@users.noreply.github.com>

Copilot

Copilot review overview

🟢 Approval recommended

The implementation matches the accepted probabilistic design, with only minor documentation clarifications remaining.

Review effort: Balanced
Findings: 1

Open (1)

Qualify collision estimate for uneven VMID time-slot distribution · New

What changed in this PR

Replaces Proxmox’s /cluster/nextid calls with locally generated VMIDs to reduce concurrent container-creation conflicts reported in #488.

Changes:

Adds a time-slot and cryptographic-random VMID generator.
Connects Proxmox allocation to the generator and adds tests.
Updates allocation comments and log text without changing Docker behavior.

File	Description
`create-a-container/utils/vmid.js`	Adds local VMID generation.
`create-a-container/utils/proxmox-api.js`	Replaces the allocation HTTP request.
`create-a-container/utils/__tests__/vmid.test.js`	Tests bounds, randomness, and adjacent-second separation.
`create-a-container/bin/create-container.js`	Updates allocation comments and logging.

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+  const timeSlot = Math.floor(now / 1000) % TIME_SLOTS;
+  return VMID_MIN + timeSlot * RANDOM_SPACE + crypto.randomInt(RANDOM_SPACE);


Copilot

Copilot review overview

🟡 Changes recommended

Conflict detection misses response-body error text, causing affected collisions to fail without retrying.

Review effort: Balanced
Findings: 2

Open (2)

Detect VMID conflicts in response body fields · New
Qualify collision estimate for uneven VMID time-slot distribution

cmyers-mieweb

Approved, we will need to see how the retry logic added works within the ongoing environment once this is merged to spot for any creation bugs. Only other thing I can think is check logic if the job-runner already has an ID it is using in an ongoing build, though the event in itself after the randomization makes it rare.

runleveldev · 2026-10-02T13:48:54Z

@copilot resolve merge conlficts

…-creation-ctid-conflict # Conflicts: # create-a-container/bin/create-container.js # create-a-container/utils/proxmox-api.js Co-authored-by: runleveldev <44057501+runleveldev@users.noreply.github.com>

Copilot · 2026-10-02T13:55:35Z

@copilot resolve merge conlficts

Resolved the conflicts and merged latest main in 1688958, preserving volume provisioning and VMID retries. All 58 targeted tests pass; review and CodeQL found no issues. The full manager suite failed in unchanged MCP proxy tests and then aborted with a SQLite closed-handle error.

Copilot

Copilot review overview

🟢 Approval recommended

No blocking issues remain; the PR description needs only a non-blocking clarification of retry behavior.

Review effort: Balanced
Findings: 1

Open (1)

Qualify collision estimate for uneven VMID time-slot distribution

Resolved since last review (1)

Detect VMID conflicts in response body fields

Initial plan

ccaaa0c

Copilot AI assigned Copilot and runleveldev Oct 1, 2026

Copilot started work on behalf of runleveldev October 1, 2026 22:02 View session

Copilot AI linked an issue Oct 1, 2026 that may be closed by this pull request

[Bug]: Container creation CTID conflict #488

Closed

Generate pseudo-random time+random VMIDs instead of /cluster/nextid

c1ccd3c

Co-authored-by: runleveldev <44057501+runleveldev@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix container creation CTID conflict due to race condition~~ Generate time-plus-random Proxmox VMIDs instead of calling /cluster/nextid Oct 1, 2026

Copilot AI requested a review from runleveldev October 1, 2026 22:05

Copilot finished work on behalf of runleveldev October 1, 2026 22:05

runleveldev requested a balanced review from Copilot October 1, 2026 22:07

runleveldev marked this pull request as ready for review October 1, 2026 22:07

runleveldev approved these changes Oct 1, 2026

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Copilot started reviewing on behalf of runleveldev October 1, 2026 22:07 View session

Copilot AI reviewed Oct 1, 2026

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Comment thread create-a-container/utils/vmid.js

Comment on lines +21 to +22

const timeSlot = Math.floor(now / 1000) % TIME_SLOTS;

return VMID_MIN + timeSlot * RANDOM_SPACE + crypto.randomInt(RANDOM_SPACE);

Retry container create/clone with a new VMID on conflict

45448bf

Copilot AI balanced review requested due to automatic review settings October 1, 2026 22:27

Copilot started reviewing on behalf of runleveldev October 1, 2026 22:28 View session

Copilot AI reviewed Oct 1, 2026

View reviewed changes

Comment thread create-a-container/utils/vmid.js

cmyers-mieweb approved these changes Oct 1, 2026

View reviewed changes

Copilot started work on behalf of runleveldev October 2, 2026 13:49 View session

Merge remote-tracking branch 'origin/main' into copilot/fix-container…

1688958

…-creation-ctid-conflict # Conflicts: # create-a-container/bin/create-container.js # create-a-container/utils/proxmox-api.js Co-authored-by: runleveldev <44057501+runleveldev@users.noreply.github.com>

Copilot AI balanced review requested due to automatic review settings October 2, 2026 13:54

Copilot started reviewing on behalf of runleveldev October 2, 2026 13:54 View session

Copilot finished work on behalf of runleveldev October 2, 2026 13:56

Copilot AI requested a review from runleveldev October 2, 2026 13:56

runleveldev merged commit 21462f2 into main Oct 2, 2026
8 checks passed

runleveldev deleted the copilot/fix-container-creation-ctid-conflict branch October 2, 2026 13:57

Copilot AI reviewed Oct 2, 2026

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Generate time-plus-random Proxmox VMIDs instead of calling `/cluster/nextid` - #489

Generate time-plus-random Proxmox VMIDs instead of calling `/cluster/nextid`#489
runleveldev merged 4 commits into
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		const timeSlot = Math.floor(now / 1000) % TIME_SLOTS;
		return VMID_MIN + timeSlot * RANDOM_SPACE + crypto.randomInt(RANDOM_SPACE);

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