ConfigMap

镜像使用过程中,经常需要利用配置文件、启动脚步等方式来影响容器的运行方式,如果仅有少量配置,我们可以用环境变量的方式进行配置。然而对于一些较为复杂的配置,k8s提供了configmap解决方案
Configmap api 资源存储键/值对配置数据，pod 里面可以使用该数据.
ConfigMap和Secret类似,但是ConfigMap 可以更加方便的处理不包含敏感信息的字符串。
当CconfigMap 以数据卷的形式挂载进Pod的时，这时更新ConfigMap(或删除掉重建ConfigMap),Pod内挂载的配置新会热更新。这时可以增加一些监测配置文件变更脚本,然后reload 对应服务
ConfigMap的API概念上来说是很简单,ConfigMap的类型只是键值组。应当可以从不同角度配置.在一个Pod里面使用ConfigMap 大致三种方式。
1、命令行参数
2、环境变量
3、数据卷类型

变量设置成configMap

[root@k8s-master-001 ~]# kubectl  create configmap  test --from-literal=a=1  --from-literal=b=2
configmap/test created
[root@k8s-master-001 ~]# kubectl  get configmap test -o yaml
apiVersion: v1
data:
  a: "1"
  b: "2"
kind: ConfigMap
metadata:
  creationTimestamp: "2021-06-11T03:25:55Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:data:
        .: {}
        f:a: {}
        f:b: {}
    manager: kubectl
    operation: Update
    time: "2021-06-11T03:25:55Z"
  name: test
  namespace: kube-system
  resourceVersion: "52924439"
  selfLink: /api/v1/namespaces/kube-system/configmaps/test
  uid: 45cf5e6d-6b2d-43e6-85a5-ae0fe99cb4bf

nginx 配置文件设置configmap

#cat  nginx.conf
user  apps apps;
worker_processes 4;
worker_cpu_affinity 0001 0010 0100 1000; 
error_log  /apps/logs/nginx/nginx_error.log  error;
pid        /apps/logs/nginx/nginx.pid;

#Specifies the value for maximum file descriptors that can be opened by this process.
worker_rlimit_nofile 65535;

events
{
  use epoll;
  worker_connections 65535;
}

http
{
  include       mime.types;
  #geoip_city /usr/local/nginx/conf/GeoLiteCity.dat;
  #include geo.conf;
  default_type  application/octet-stream;

  #charset  gb2312;

  server_names_hash_bucket_size 128;
  client_header_buffer_size 4k;
  large_client_header_buffers 4 32k;
  client_max_body_size 80m;

  sendfile on;
  tcp_nopush     on;

  client_body_timeout  5;
  client_header_timeout 5;
  keepalive_timeout  5;
  send_timeout       5;

  open_file_cache max=65535 inactive=20s;
  open_file_cache_valid 30s;
  open_file_cache_min_uses 1;

  tcp_nodelay on;

  fastcgi_connect_timeout 300;
  fastcgi_send_timeout 300;
  fastcgi_read_timeout 300;
  fastcgi_buffer_size 64k;
  fastcgi_buffers 4 64k;
  fastcgi_busy_buffers_size 128k;
  fastcgi_temp_file_write_size 128k;

  client_body_buffer_size  512k;
  proxy_connect_timeout    5;
  proxy_read_timeout       60;
  proxy_send_timeout       5;
  proxy_buffer_size        16k;
  proxy_buffers            4 64k;
  proxy_busy_buffers_size 128k;
  proxy_temp_file_write_size 128k;

 
  gzip on;
  gzip_min_length  1k;
  gzip_buffers     4 16k;
  gzip_http_version 1.0;
  gzip_comp_level 2;
  gzip_types       text/plain application/x-javascript text/css application/xml text/javascript application/json application/javascript;
  gzip_vary on;

  #limit_zone  crawler  $binary_remote_addr  10m;
  proxy_temp_path   /dev/shm/temp;
  proxy_cache_path  /dev/shm/cache levels=2:2:2   keys_zone=cache_go:200m inactive=5d max_size=7g;

  log_format log_access "$remote_addr" "\t$remote_user" "\t$time_local" "\t$request" "\t$request_time" "\t$upstream_response_time" "\t$status" "\t$body_bytes_sent" "\t$http_referer" "\t$http_user_agent" "\t$http_x_forwarded_for" "\t$host" "\t$hostname" "\tCustomName1" "\t$http_Cdn_Src_Ip" "\t$http_Cdn_Src_Port" "\tCustomName4" "\tCustomName5" "\tCustomName6" "\tCustomName7" "\tCustomName8" "\t-";


   #Vhost server
   server{      
        listen  80 ;
        server_name _; 
        #index index.html index.php;
        proxy_read_timeout 600s;  
        location / {
          proxy_pass http://127.0.0.1:8080;
          proxy_set_header Host $host;
          proxy_set_header X-Real-IP $remote_addr;
          proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
          proxy_set_header X-Forwarded-Proto $scheme;
        }
       access_log  /apps/logs/nginx/access.log   log_access;
    } 
}
# kubectl create configmap nginxconfig --from-file nginx.conf 
# kubectl get configmap
# kubectl get configmap -o yaml

在rc配置文件中使用configmap

#cat nginx-rc-configmap.yaml   
apiVersion: v1
kind: ReplicationController
metadata:
  name: nginx
  labels:
    name: nginx
spec:
  replicas: 2
  selector:
    name: nginx
  template:
    metadata:
      labels: 
       name: nginx
    spec:
      containers:
      - name: nginx
        image: docker.io/nginx
        volumeMounts:
        - name: nginx
          mountPath: /apps/conf/nginx/nginx.conf
          subPath: nginx.conf
        ports:
        - containerPort: 80
      volumes:
      - name: nginx
        configMap:
         name: nginxconfig 
         items:
          - key: nginx.conf 
            path: nginx.conf

## kubectl create -f nginx-rc-configmap.yaml 

验证nginx配置文件

#  kubectl  get pod  -o wide -n default
NAME                             READY   STATUS    RESTARTS   AGE    IP           NODE        NOMINATED NODE   READINESS GATES
nginx-2kkk7                      1/1     Running   0          23m    10.80.27.3   k8s-node-001   <none>           <none>
nginx-fp22n                      1/1     Running   0          23m    10.80.58.7   k8s-node-002   <none>           <none>

#   kubectl exec -it nginx-2kkk7    -n default -- cat /apps/conf/nginx/nginx.conf