Error while run k8scp.sh

ricascross

Hi,
I follow all the steps from the guide. I am running ubuntu in docker container and when run "bash k8scp.sh | tee cp.out" I get an error that cannot connect to container.d as you can see below:

[init] Using Kubernetes version: v1.32.1
[preflight] Running pre-flight checks
W0413 21:02:11.037647 6593 checks.go:1080] [preflight] WARNING: Couldn't create the interface used for talking to the container runtime: failed to create new CRI runtime service: validate service connection: validate CRI v1 runtime API for endpoint "unix:///var/run/containerd/containerd.sock": rpc error: code = Unavailable desc = connection error: desc = "transport: Error while dialing: dial unix /var/run/containerd/containerd.sock: connect: no such file or directory"
[WARNING SystemVerification]: mkdir /sys/fs/cgroup/freezer-test707063798: read-only file system
[preflight] The system verification failed. Printing the output from the verification:
KERNEL_VERSION: 6.5.0-15-generic
OS: Linux
CGROUPS_CPU: enabled
CGROUPS_CPUSET: enabled
CGROUPS_DEVICES: enabled
CGROUPS_FREEZER: missing
CGROUPS_MEMORY: enabled
CGROUPS_PIDS: enabled
CGROUPS_HUGETLB: enabled
CGROUPS_IO: enabled
error execution phase preflight: [preflight] Some fatal errors occurred:
[ERROR SystemVerification]: failed to parse kernel config: unable to load kernel module: "configs", output: "", err: exec: "modprobe": executable file not found in $PATH
[ERROR SystemVerification]: missing required cgroups: freezer
[preflight] If you know what you are doing, you can make a check non-fatal with --ignore-preflight-errors=...
To see the stack trace of this error execute with --v=5 or higher
cp: cannot stat '/etc/kubernetes/admin.conf': No such file or directory
chown: cannot access '/root/.kube/config': No such file or directory
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
100 52.8M 100 52.8M 0 0 16.3M 0 0:00:03 0:00:03 --:--:-- 24.9M
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
100 92 100 92 0 0 108 0 --:--:-- --:--:-- --:--:-- 0
cilium-linux-arm64.tar.gz: OK
cilium

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Installing Cilium, this may take a bit...

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ℹ️ Using Cilium version 1.16.1

Error: Unable to install Cilium: Kubernetes cluster unreachable: Get "http://localhost:8080/version": dial tcp 127.0.0.1:8080: connect: connection refused
⏭️ Skipping auto kube-proxy detection

Cilium install finished. Continuing with script.

--2025-04-13 21:02:19-- https://get.helm.sh/helm-v3.14.1-linux-amd64.tar.gz
Resolving get.helm.sh (get.helm.sh)... 13.107.246.64
Connecting to get.helm.sh (get.helm.sh)|13.107.246.64|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 16132188 (15M) [application/x-tar]
Saving to: 'helm-v3.14.1-linux-amd64.tar.gz'

helm-v3.14.1-linux-amd64.tar.gz 100%[==================================================================================>] 15.38M 2.99MB/s in 6.8s

2025-04-13 21:02:28 (2.28 MB/s) - 'helm-v3.14.1-linux-amd64.tar.gz' saved [16132188/16132188]

E0413 21:02:54.869242 6652 memcache.go:265] "Unhandled Error" err="couldn't get current server API group list: Get \"http://localhost:8080/api?timeout=32s\": dial tcp 127.0.0.1:8080: connect: connection refused"
E0413 21:02:54.870709 6652 memcache.go:265] "Unhandled Error" err="couldn't get current server API group list: Get \"http://localhost:8080/api?timeout=32s\": dial tcp 127.0.0.1:8080: connect: connection refused"
E0413 21:02:54.872299 6652 memcache.go:265] "Unhandled Error" err="couldn't get current server API group list: Get \"http://localhost:8080/api?timeout=32s\": dial tcp 127.0.0.1:8080: connect: connection refused"
E0413 21:02:54.873849 6652 memcache.go:265] "Unhandled Error" err="couldn't get current server API group list: Get \"http://localhost:8080/api?timeout=32s\": dial tcp 127.0.0.1:8080: connect: connection refused"
E0413 21:02:54.875261 6652 memcache.go:265] "Unhandled Error" err="couldn't get current server API group list: Get \"http://localhost:8080/api?timeout=32s\": dial tcp 127.0.0.1:8080: connect: connection refused"
The connection to the server localhost:8080 was refused - did you specify the right host or port?
debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 78.)
debconf: falling back to frontend: Readline
Setting up readline-common (8.1.2-1) ...
Setting up iso-codes (4.9.0-1) ...
Setting up libpolkit-gobject-1-0:arm64 (0.105-33) ...
Setting up libgdbm6:arm64 (1.23-1) ...

chrispokorni

Hi @ricascross,

Docker is known to set limitations especially on the networking that is required by a distributed Kubernetes cluster when hosted in containers. Also, resource requirements configuration, critical for Kubernetes nodes, can be challenging when working with a containerized environment - including CPU, Memory, and storage disk space.
The course materials have been tested on VMs, both local and cloud.
If the Docker runtime is the only virtualization method available to you, then "kind" (Kubernetes in Docker) or "minikube" (with the Docker driver) may be suited for your needs, since both tools are capable of properly configuring the Docker environment to host a distributed cluster in containers. This, however, is not a recommendation. I would still encourage you to deploy your cluster on a set of VMs.
While the Docker runtime configuration is automated by both kind and minikube to support the hosting of Kubernetes nodes in containers, not all lab exercises can be reproduced in such a limited environment.

Regards,
-Chris

ricascross

Thank you for your answer. I tried AWS VM but in free tier is not working too because 2 cpus is required

chrispokorni

Hi @ricascross,

Local VMs can also be used for the lab environment. Hypervisors such as VirtualBox, QEMU/KVM, VMware, and others can be used for this purpose. However, your host workstation should support the CPU, RAM, and storage disk requirements of the two VMs, on top of the host OS and hypervisor resource requirements.

Regards,
-Chris

ricascross

Thank you Chris, for supporting me.