Swap stats is not shown as part of the metrics/resource endpoint #129382
Description
What happened?
The following:
> kubectl get --raw "/api/v1/nodes/k8s-dev-worker/proxy/metrics/resource"
# HELP container_cpu_usage_seconds_total [STABLE] Cumulative cpu time consumed by the container in core-seconds
# TYPE container_cpu_usage_seconds_total counter
container_cpu_usage_seconds_total{container="kindnet-cni",namespace="kube-system",pod="kindnet-ndczz"} 1.121325 1735032838055
container_cpu_usage_seconds_total{container="kube-proxy",namespace="kube-system",pod="kube-proxy-l5jhs"} 1.100665 1735032838936
container_cpu_usage_seconds_total{container="metrics-server",namespace="kube-system",pod="metrics-server-8598789fdb-nw6cq"} 7.333964 1735032837430
# HELP container_memory_working_set_bytes [STABLE] Current working set of the container in bytes
# TYPE container_memory_working_set_bytes gauge
container_memory_working_set_bytes{container="kindnet-cni",namespace="kube-system",pod="kindnet-ndczz"} 3.2923648e+07 1735032838055
container_memory_working_set_bytes{container="kube-proxy",namespace="kube-system",pod="kube-proxy-l5jhs"} 4.0628224e+07 1735032838936
container_memory_working_set_bytes{container="metrics-server",namespace="kube-system",pod="metrics-server-8598789fdb-nw6cq"} 4.7026176e+07 1735032837430
# HELP container_start_time_seconds [STABLE] Start time of the container since unix epoch in seconds
# TYPE container_start_time_seconds gauge
container_start_time_seconds{container="kindnet-cni",namespace="kube-system",pod="kindnet-ndczz"} 1.7350309825441425e+09
container_start_time_seconds{container="kube-proxy",namespace="kube-system",pod="kube-proxy-l5jhs"} 1.7350309819809804e+09
container_start_time_seconds{container="metrics-server",namespace="kube-system",pod="metrics-server-8598789fdb-nw6cq"} 1.7350309993126562e+09
# HELP node_cpu_usage_seconds_total [STABLE] Cumulative cpu time consumed by the node in core-seconds
# TYPE node_cpu_usage_seconds_total counter
node_cpu_usage_seconds_total 71.41304 1735032832343
# HELP node_memory_working_set_bytes [STABLE] Current working set of the node in bytes
# TYPE node_memory_working_set_bytes gauge
node_memory_working_set_bytes 2.134016e+08 1735032832343
# HELP pod_cpu_usage_seconds_total [STABLE] Cumulative cpu time consumed by the pod in core-seconds
# TYPE pod_cpu_usage_seconds_total counter
pod_cpu_usage_seconds_total{namespace="kube-system",pod="kindnet-ndczz"} 1.145182 1735032830497
pod_cpu_usage_seconds_total{namespace="kube-system",pod="kube-proxy-l5jhs"} 1.108676 1735032837395
pod_cpu_usage_seconds_total{namespace="kube-system",pod="metrics-server-8598789fdb-nw6cq"} 7.336168 1735032831254
# HELP pod_memory_working_set_bytes [STABLE] Current working set of the pod in bytes
# TYPE pod_memory_working_set_bytes gauge
pod_memory_working_set_bytes{namespace="kube-system",pod="kindnet-ndczz"} 3.3222656e+07 1735032830497
pod_memory_working_set_bytes{namespace="kube-system",pod="kube-proxy-l5jhs"} 4.0914944e+07 1735032837395
pod_memory_working_set_bytes{namespace="kube-system",pod="metrics-server-8598789fdb-nw6cq"} 4.732928e+07 1735032831254
# HELP resource_scrape_error [STABLE] 1 if there was an error while getting container metrics, 0 otherwise
# TYPE resource_scrape_error gauge
resource_scrape_error 0
As can be seen, swap stats is not shown here:
> kubectl get --raw "/api/v1/nodes/k8s-dev-worker/proxy/metrics/resource" | grep -i swap
>
What did you expect to happen?
Swap to be included in metrics/resource endpoint stats.
How can we reproduce it (as minimally and precisely as possible)?
- Bring up a cluster
- Install metrics server
- Run
kubectl get --raw "/api/v1/nodes/<NODE-NAME>/proxy/metrics/resource" | grep -i swap
Anything else we need to know?
Swap stats were introduced in this PR: #118865.
It also shows the expected output.
Kubernetes version
$ kubectl version
Client Version: v1.32.0
Kustomize Version: v5.5.0
Server Version: v1.32.0
Cloud provider
Using a kind development cluster
OS version
# On Linux:
$ cat /etc/os-release
NAME="Fedora Linux"
VERSION="40 (Forty)"
ID=fedora
VERSION_ID=40
VERSION_CODENAME=""
PLATFORM_ID="platform:f40"
PRETTY_NAME="Fedora Linux 40 (Forty)"
ANSI_COLOR="0;38;2;60;110;180"
LOGO=fedora-logo-icon
CPE_NAME="cpe:/o:fedoraproject:fedora:40"
DEFAULT_HOSTNAME="fedora"
HOME_URL="https://fedoraproject.org/"
DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f40/system-administrators-guide/"
SUPPORT_URL="https://ask.fedoraproject.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=40
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=40
SUPPORT_END=2025-05-13
$ uname -a
Linux fedora40-eve 6.12.5-100.fc40.x86_64 #1 SMP PREEMPT_DYNAMIC Mon Dec 16 15:00:58 UTC 2024 x86_64 GNU/Linux
# On Windows:
C:\> wmic os get Caption, Version, BuildNumber, OSArchitecture
# paste output hereInstall tools
kind
Container runtime (CRI) and version (if applicable)
> crio version
Version: 1.31.3
GitCommit: 5865976a62cd3abd1b56ec21ea4fde19a730fe87
GitCommitDate: 2024-12-02T10:48:49Z
GitTreeState: dirty
BuildDate: 1970-01-01T00:00:00Z
GoVersion: go1.22.5
Compiler: gc
Platform: linux/amd64
Linkmode: static
BuildTags:
static
netgo
osusergo
exclude_graphdriver_btrfs
seccomp
apparmor
selinux
exclude_graphdriver_devicemapper
LDFlags: unknown
SeccompEnabled: true
AppArmorEnabled: false