Installation fails on master branch, works on release-2.28

[performance92]

What happened?

Hi,

I’m trying to install Kubernetes using the current master branch of Kubespray,
but the installation fails during the playbook execution.

When I switch to release-2.28 and run the same setup with the same environment,
the installation completes successfully.

This suggests that the current master branch may be broken or unstable for fresh installations.

Environment:

• OS: Ubuntu 22.04
• Ansible: (core 2.16.15)
• Python: (3.10.12)
• Installation method: containerized (Docker), but reproducible on host as well

Steps:

1. Clone kubespray repository (default branch: master)
2. Run standard cluster installation
3. Installation fails
4. Checkout release-2.28
5. Run the same steps → installation succeeds

I understand that master is a development branch, but at the moment it seems unusable
for clean installs. It might be helpful to document this or fix the regression.

Let me know if you need logs or more details.

Thanks.

What did you expect to happen?

I expected Kubespray to successfully complete a fresh Kubernetes cluster
installation when using the current master branch, as it is the default branch
of the repository.

At minimum, I expected the installation process to behave consistently with the
latest stable release branch.

How can we reproduce it (as minimally and precisely as possible)?

1. Clone the Kubespray repository using the default branch (master):
   git clone https://github.com/kubernetes-sigs/kubespray.git
   cd kubespray

2. Prepare a standard inventory based on inventory/sample.

3. Run the standard cluster installation playbook on Ubuntu 22.04
   with Ansible (no custom modifications).

4. The installation fails during playbook execution.

5. Checkout the release-2.28 branch:
   git checkout release-2.28

6. Run the same installation steps with the same environment.

7. The installation completes successfully.

OS

Ubuntu 22.04

Version of Ansible

ansible --version
ansible [core 2.16.15]
config file = /work/kubespray/ansible.cfg
configured module search path = ['/work/kubespray/library']
ansible python module location = /usr/local/lib/python3.10/dist-packages/ansible
ansible collection location = /root/.ansible/collections:/usr/share/ansible/collections
executable location = /usr/local/bin/ansible
python version = 3.10.12 (main, Nov 4 2025, 08:48:33) [GCC 11.4.0] (/usr/bin/python3)
jinja version = 3.1.6
libyaml = True

Version of Python

3.10.12

Version of Kubespray (commit)

master

Network plugin used

calico

Full inventory with variables

A timeout issue is occurring during the kubeadm installation on master nodes.

Command used to invoke ansible

ansible-playbook -i inventory/gardiyan/host.yml cluster.yml

Output of ansible run

A timeout issue is occurring during the kubeadm installation on master nodes.

Anything else we need to know

No response

[tico88612]

Could you paste the full log? Only reporting a timeout doesn't tell us where the error is.

[performance92]

Initialize first control plane node (1st try)] **************************************fatal: [gardiyan-master-node1]: FAILED! => changed=true cmd: - timeout - -k - 300s - 300s - /usr/local/bin/kubeadm - init - --config=/etc/kubernetes/kubeadm-config.yaml - --ignore-preflight-errors= - --skip-phases=addon/coredns - --upload-certs delta: '0:01:12.390036' end: '2026-01-10 01:39:25.071158' failed_when_result: true msg: non-zero return code rc: 1 start: '2026-01-10 01:38:12.681122' stderr: |- W0110 01:38:12.742218 12986 initconfiguration.go:361] [config] WARNING: Ignored configuration document with GroupVersionKind kubeadm.k8s.io/v1beta4, Kind=UpgradeConfiguration W0110 01:38:12.746056 12986 utils.go:69] The recommended value for "clusterDNS" in "KubeletConfiguration" is: [10.233.0.10]; the provided value is: [169.254.25.10] W0110 01:38:15.779917 12986 endpoint.go:56] [endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address W0110 01:38:16.279890 12986 endpoint.go:56] [endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address W0110 01:38:17.846787 12986 endpoint.go:56] [endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address W0110 01:38:17.954381 12986 endpoint.go:56] [endpoint] WARNING: port specified in controlPlaneEndpoint overrides bindPort in the controlplane address error: error execution phase upload-config/kubeadm: could not bootstrap the admin user in file admin.conf: unable to create ClusterRoleBinding: client rate limiter Wait returned an error: context deadline exceeded To see the stack trace of this error execute with --v=5 or higher stderr_lines: stdout: |- [init] Using Kubernetes version: v1.34.3 [preflight] Running pre-flight checks [preflight] Pulling images required for setting up a Kubernetes cluster [preflight] This might take a minute or two, depending on the speed of your internet connection [preflight] You can also perform this action beforehand using 'kubeadm config images pull' [certs] Using certificateDir folder "/etc/kubernetes/ssl" [certs] Generating "ca" certificate and key [certs] Generating "apiserver" certificate and key [certs] apiserver serving cert is signed for DNS names [gardiyan-master-node1 gardiyan-master-node2 gardiyan-master-node3 kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local lb-apiserver.kubernetes.local localhost] and IPs [10.233.0.1 172.16.18.150 127.0.0.1 ::1 172.16.18.100 10.0.0.2 10.0.0.3 172.16.18.151 172.16.18.152] [certs] Generating "apiserver-kubelet-client" certificate and key [certs] Generating "front-proxy-ca" certificate and key [certs] Generating "front-proxy-client" certificate and key [certs] External etcd mode: Skipping etcd/ca certificate authority generation [certs] External etcd mode: Skipping etcd/server certificate generation [certs] External etcd mode: Skipping etcd/peer certificate generation [certs] External etcd mode: Skipping etcd/healthcheck-client certificate generation [certs] External etcd mode: Skipping apiserver-etcd-client certificate generation [certs] Generating "sa" key and public key [kubeconfig] Using kubeconfig folder "/etc/kubernetes" [kubeconfig] Writing "admin.conf" kubeconfig file [kubeconfig] Writing "super-admin.conf" kubeconfig file [kubeconfig] Writing "kubelet.conf" kubeconfig file [kubeconfig] Writing "controller-manager.conf" kubeconfig file [kubeconfig] Writing "scheduler.conf" kubeconfig file [control-plane] Using manifest folder "/etc/kubernetes/manifests" [control-plane] Creating static Pod manifest for "kube-apiserver" [control-plane] Creating static Pod manifest for "kube-controller-manager" [control-plane] Creating static Pod manifest for "kube-scheduler" [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env" [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/instance-config.yaml" [patches] Applied patch of type "application/strategic-merge-patch+json" to target "kubeletconfiguration" [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml" [kubelet-start] Starting the kubelet [wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests" [kubelet-check] Waiting for a healthy kubelet at http://127.0.0.1:10248/healthz. This can take up to 4m0s [kubelet-check] The kubelet is healthy after 502.819314ms [control-plane-check] Waiting for healthy control plane components. This can take up to 4m0s [control-plane-check] Checking kube-apiserver at https://172.16.18.150:6443/livez [control-plane-check] Checking kube-controller-manager at https://[::]:10257/healthz [control-plane-check] Checking kube-scheduler at https://[::]:10259/livez [control-plane-check] kube-controller-manager is healthy after 2.347028978s [control-plane-check] kube-scheduler is healthy after 2.985836222s [control-plane-check] kube-apiserver is healthy after 5.002453635s stdout_lines: Friday 09 January 2026 22:39:25 +0000 (0:01:12.798) 0:15:06.501 ******** FAILED - RETRYING: [gardiyan-master-node1]: Kubeadm | Initialize first control plane node (retry) (2 retries left). FAILED - RETRYING: [gardiyan-master-node1]: Kubeadm | Initialize first control plane node (retry) (1 retries left). TASK [kubernetes/control-plane : Kubeadm | Initialize first control plane node (retry)] ****************************************fatal: [gardiyan-master-node1]: FAILED! => changed=true attempts: 2 cmd: - timeout - -k - 300s - 300s - /usr/local/bin/kubeadm - init - --config=/etc/kubernetes/kubeadm-config.yaml - --ignore-preflight-errors=FileAvailable--etc-kubernetes-manifests-kube-controller-manager.yaml,FileAvailable--etc-kubernetes-manifests-kube-scheduler.yaml,FileAvailable--etc-kubernetes-manifests-kube-apiserver.yaml,Port-10250 - --skip-phases=addon/coredns - --upload-certs delta: '0:00:00.267686' end: '2026-01-10 01:39:36.941117' failed_when_result: true msg: non-zero return code rc: 1 start: '2026-01-10 01:39:36.673431' stderr: |- W0110 01:39:36.734002 13560 initconfiguration.go:361] [config] WARNING: Ignored configuration document with GroupVersionKind kubeadm.k8s.io/v1beta4, Kind=UpgradeConfiguration W0110 01:39:36.738176 13560 utils.go:69] The recommended value for "clusterDNS" in "KubeletConfiguration" is: [10.233.0.10]; the provided value is: [169.254.25.10] [WARNING FileAvailable--etc-kubernetes-manifests-kube-apiserver.yaml]: /etc/kubernetes/manifests/kube-apiserver.yaml already exists [WARNING FileAvailable--etc-kubernetes-manifests-kube-controller-manager.yaml]: /etc/kubernetes/manifests/kube-controller-manager.yaml already exists [WARNING FileAvailable--etc-kubernetes-manifests-kube-scheduler.yaml]: /etc/kubernetes/manifests/kube-scheduler.yaml already exists [WARNING Port-10250]: Port 10250 is in use [preflight] Some fatal errors occurred: [ERROR Port-6443]: Port 6443 is in use [ERROR Port-10259]: Port 10259 is in use [ERROR Port-10257]: Port 10257 is in use [preflight] If you know what you are doing, you can make a check non-fatal with --ignore-preflight-errors=... error: error execution phase preflight: preflight checks failed To see the stack trace of this error execute with --v=5 or higher stderr_lines: stdout: |- [init] Using Kubernetes version: v1.34.3 [preflight] Running pre-flight checks stdout_lines: PLAY RECAP *********************************************************************************************************************gardiyan-master-node1 : ok=493 changed=75 unreachable=0 failed=1 skipped=584 rescued=1 ignored=1 gardiyan-master-node2 : ok=460 changed=72 unreachable=0 failed=0 skipped=512 rescued=0 ignored=1 gardiyan-master-node3 : ok=460 changed=72 unreachable=0 failed=0 skipped=512 rescued=0 ignored=1 gardiyan-worker-node1 : ok=354 changed=45 unreachable=0 failed=0 skipped=425 rescued=0 ignored=0 gardiyan-worker-node2 : ok=354 changed=45 unreachable=0 failed=0 skipped=425 rescued=0 ignored=0 gardiyan-worker-node3 : ok=354 changed=45 unreachable=0 failed=0 skipped=425 rescued=0 ignored=0 Friday 09 January 2026 22:39:36 +0000 (0:00:11.856) 0:15:18.358 ******** =============================================================================== kubernetes/control-plane : Kubeadm | Initialize first control plane node (1st try) ------------------------------------- 72.80s download : Download_container | Download image if required ------------------------------------------------------------- 35.05s download : Download_container | Download image if required ------------------------------------------------------------- 22.42s container-engine/runc : Download_file | Download item ------------------------------------------------------------------ 18.84s container-engine/containerd : Download_file | Download item ------------------------------------------------------------ 17.89s container-engine/crictl : Download_file | Download item ---------------------------------------------------------------- 17.54s container-engine/nerdctl : Download_file | Download item --------------------------------------------------------------- 16.89s download : Download_container | Download image if required ------------------------------------------------------------- 15.83s download : Download_container | Download image if required ------------------------------------------------------------- 15.01s download : Download_container | Download image if required ------------------------------------------------------------- 14.70s container-engine/validate-container-engine : Populate service facts ---------------------------------------------------- 14.37s download : Download_container | Download image if required ------------------------------------------------------------- 14.14s etcd : Gen_certs | Write etcd member/admin and kube_control_plane client certs to other etcd nodes --------------------- 14.07s download : Download_container | Download image if required ------------------------------------------------------------- 13.68s container-engine/crictl : Extract_file | Unpacking archive ------------------------------------------------------------- 13.66s download : Download_container | Download image if required ------------------------------------------------------------- 13.15s container-engine/nerdctl : Extract_file | Unpacking archive ------------------------------------------------------------ 13.00s kubernetes/control-plane : Kubeadm | Initialize first control plane node (retry) --------------------------------------- 11.86s download : Download_container | Download image if required ------------------------------------------------------------- 11.17s container-engine/containerd : Containerd | Unpack containerd archive ---------------------------------------------------- 9.35s root@9e199e1ace5d:/work/kubespray#

[performance92]

My server resources: master nodes 6 CPU 12 GB RAM 150 GB disk 1G network worker nodes 8 CPU 24 GB RAM 400 GB disk
I tried 3 times, but when I switched to release 2.28 branch, it completed without any problems. I don't understand if there is a problem with the versions or if there is a problem with the master branch.