promql  
http_requests_total  

promql  
rate(http_requests_total[5m])  

go  
httpRequests := prometheus.NewCounter(  
    prometheus.CounterOpts{  
        Name: "http_requests_total",  
        Help: "Total number of HTTP requests",  
    })  

promql  
node_memory_usage_bytes  

promql  
avg(node_cpu_seconds_total)  

go  
cpuUsage := prometheus.NewGauge(  
    prometheus.GaugeOpts{  
        Name: "cpu_usage_percentage",  
        Help: "Current CPU usage",  
    })  

promql  
http_request_duration_seconds_bucket  

promql  
histogram_quantile(0.95, rate(http_request_duration_seconds_bucket[5m]))  

go  
requestDuration := prometheus.NewHistogram(  
    prometheus.HistogramOpts{  
        Name:    "http_request_duration_seconds",  
        Help:    "Histogram of response time for HTTP requests",  
        Buckets: prometheus.DefBuckets,  
    })  

promql  
http_request_duration_seconds{quantile="0.99"}  

go  
requestSummary := prometheus.NewSummary(  
    prometheus.SummaryOpts{  
        Name:       "http_request_duration_seconds",  
        Help:       "Summary of response time for HTTP requests",  
        Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},  
    })  

sh  
kubectl top nodes  

NAME        CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%  
node-1      500m         25%    2Gi             50%  
node-2      1000m        50%    4Gi             80%  

sh  
kubectl top pods --all-namespaces  

NAMESPACE   POD            CPU(cores)   MEMORY(bytes)  
default     web-app-1      250m         256Mi  
default     web-app-2      300m         512Mi  
monitoring  prometheus-1   600m         1Gi  

sh  
kubectl describe node node-1  

Allocatable:  
  cpu:                4  
  memory:             8Gi  
  pods:               110  

sh  
kubectl describe pod my-pod  

Requests:  
  cpu:     500m  
  memory:  1Gi  
Limits:  
  cpu:     1  
  memory:  2Gi  

promql  
avg(rate(node_cpu_seconds_total[5m])) * 100  

promql  
avg(node_memory_Active_bytes) / avg(node_memory_MemTotal_bytes) * 100  

docker pull nginx:latest

docker images

FROM ubuntu:latest
RUN apt update && apt install -y nginx
CMD ["nginx", "-g", "daemon off;"]

docker build -t my-nginx .

docker run -d --name web -p 80:80 nginx

docker ps

docker stop web

git checkout feature-branch

git checkout main
git pull origin main

git checkout feature-branch
git rebase main

   git add <файл>
   

   git rebase --continue
   

git push origin feature-branch --force

ip route add 10.0.0.0/24 via 192.168.1.1

show mac address-table

kubectl taint nodes my-node key=value:NoSchedule

tolerations:
  - key: "key"
    operator: "Equal"
    value: "value"
    effect: "NoSchedule"

spec:
  nodeSelector:
    disktype: ssd

affinity:
  nodeAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
      nodeSelectorTerms:
        - matchExpressions:
            - key: region
              operator: In
              values:
                - us-east-1

apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: my-pdb
spec:
  maxUnavailable: 3
  selector:
    matchLabels:
      app: my-app

mount | grep acl

mount -o remount,acl /home

getfacl myfile.txt

# file: myfile.txt
# owner: user1
# group: users
user::rw-
user:john:r--
group::r--
mask::r--
other::---

setfacl -m u:john:rw myfile.txt

setfacl -m g:developers:x myfile.txt

setfacl -m o::rwx myfile.txt

setfacl -d -m u:john:rwx project/

setfacl -x u:john myfile.txt

setfacl -b myfile.txt

lsof | grep deleted

nginx     1234  www-data   4w   REG  8,1  5G   /var/log/nginx/access.log (deleted)

systemctl restart nginx

kill -HUP 1234  # Закрыть процесс (PID = 1234)

ls -l /proc/*/fd/ | grep deleted

lrwx------ 1 root root 64 Feb 21 14:23 /proc/5678/fd/4 -> /var/log/nginx/access.log (deleted)

> /proc/5678/fd/4

df -h
mount | grep /var/log

docker system df