Config option is not working with containerd

[gerijani]

Contributing guidelines and issue reporting guide

• I've read the contributing guidelines and wholeheartedly agree. I've also read the issue reporting guide.

Well-formed report checklist

• I have found a bug that the documentation does not mention anything about my problem
• I have found a bug that there are no open or closed issues that are related to my problem
• I have provided version/information about my environment and done my best to provide a reproducer

Description of bug

Bug description

Setting a specific namespace for buildkit to be work in has no affect:

[worker.containerd]
   namespace = "default"

After restarting containerd service recreates the buildkit ns:

>nerdctl namespace ls:

NAME        CONTAINERS    IMAGES    VOLUMES    LABELS
buildkit    0             0         0 <-------newly created
default     0             0         0

Reproduction

On Ubuntu 24.04 LTS deploy containerd from a default repo:
containerd/noble-updates,now 1.7.24-0ubuntu1~24.04.1

Install buildkit from tar.gz https://github.com/moby/buildkit/releases/download/v0.19.0/buildkit-v0.19.0.linux-amd64.tar.gz
Using examples from https://github.com/moby/buildkit/tree/13c7eaaf858b82b733339e362e89be5c8d5658f5/examples/systemd/system to run it as systemd service.

Restarting service always recreates namespace as in systemd service status shows at "==>":

❯ sudo systemctl status buildkit.service
● buildkit.service - BuildKit
     Loaded: loaded (/etc/systemd/system/buildkit.service; enabled; preset: enabled)
     Active: active (running) since Tue 2025-02-18 16:48:33 CET; 14min ago
TriggeredBy: ● buildkit.socket
       Docs: https://github.com/moby/buildkit
   Main PID: 3243 (buildkitd)
      Tasks: 10 (limit: 19039)
     Memory: 11.1M ()
     CGroup: /system.slice/buildkit.service
             └─3243 /opt/containerd/bin/buildkitd --oci-worker-snapshotter=stargz

Feb 18 16:48:33 Lenovo-15411 systemd[1]: Starting buildkit.service - BuildKit...
Feb 18 16:48:33 Lenovo-15411 buildkitd[3243]: time="2025-02-18T16:48:33+01:00" level=warning msg="using host network as the default"
Feb 18 16:48:33 Lenovo-15411 buildkitd[3243]: time="2025-02-18T16:48:33+01:00" level=info msg="found worker \"d60hrjule1t19212upz7e754r\", labels=map[org.mobyproject.buildkit.worker.executor:oci org.mobyproje......>
Feb 18 16:48:33 Lenovo-15411 buildkitd[3243]: time="2025-02-18T16:48:33+01:00" level=warning msg="using host network as the default"
Feb 18 16:48:33 Lenovo-15411 buildkitd[3243]: time="2025-02-18T16:48:33+01:00" level=info msg="found worker \"qdhl3ohp0yaf2f0irlefbz64d\", 
==>
 labels=map[org.mobyproject.buildkit.worker.containerd.namespace:buildkit.......>

Feb 18 16:48:33 Lenovo-15411 buildkitd[3243]: time="2025-02-18T16:48:33+01:00" level=info msg="found 2 workers, default=\"d60hrjule1t19212upz7e754r\""
Feb 18 16:48:33 Lenovo-15411 buildkitd[3243]: time="2025-02-18T16:48:33+01:00" level=warning msg="currently, only the default worker can be used."
Feb 18 16:48:33 Lenovo-15411 buildkitd[3243]: time="2025-02-18T16:48:33+01:00" level=info msg="running server on /run/buildkit/buildkitd.sock"
Feb 18 16:48:33 Lenovo-15411 systemd[1]: Started buildkit.service - BuildKit

[AkihiroSuda]

The config path might be incorrect?

buildkit/docs/buildkitd.toml.md

Lines 9 to 10 in 4712052

	The file path is `/etc/buildkit/buildkitd.toml` for rootful mode,
	`~/.config/buildkit/buildkitd.toml` for rootless mode.

[gerijani]

The config path might be incorrect?

buildkit/docs/buildkitd.toml.md

Lines 9 to 10 in 4712052

The file path is /etc/buildkit/buildkitd.toml for rootful mode,
~/.config/buildkit/buildkitd.toml for rootless mode.

Nope. It's ok.

❯ sudo ls -l /etc/buildkit/buildkitd.toml
-rw-r--r-- 1 root root 804 Feb 19 17:21 /etc/buildkit/buildkitd.toml
❯ sudo cat /etc/buildkit/buildkitd.toml
# root is where all buildkit state is stored.
root = "/var/lib/buildkit"
# insecure-entitlements allows insecure entitlements, disabled by default.
insecure-entitlements = [ "network.host", "security.insecure" ]

[log]
  # log formatter: json or text
  format = "text"

[worker.containerd]
  address = "/run/containerd/containerd.sock"
  enabled = true
  platforms = [ "linux/amd64", "linux/arm64" ]
  namespace = "default"

[worker.containerd.runtime]
  name = "io.containerd.runc.v2"
  path = "/usr/bin/runc"
  options = { BinaryName = "runc" }

[[worker.containerd.gcpolicy]]
    reservedSpace = 512000000
    keepDuration = 172800
    filters = [ "type==source.local", "type==exec.cachemount", "type==source.git.checkout"]
[[worker.containerd.gcpolicy]]
    all = true
    reservedSpace = 1024000000