应用配置--容器化应用配置
容器化应用配置方法：
1.启动容器时直接向应用程序传递参数
2.将定义好的配置文件硬编码（嵌入）于镜像文件中
3.通过环境变量传递配置数据
4.基于存储卷传递配置文件
通过环境变量向容器注入配置信息
Kubernetes系统支持在为Pod资源配置容器时使用spec.containers.env为容器的环境变量传值从而完成应用的配置。
env字段，它的值由一个环境变量构建的列表。每个环境变量通常由name和value（或者valueFrom）字段构成。
value：环境变量的值（自定义的）；valueFrom：环境变量值的引用源，例如当前pod资源的名称，名称空间，标签等，不能与非空值的value字段同时使用；
valueFrom字段可引用的值有多种来源，包括当前pod资源的属性值，容器相关的系统资源配置，ConfigMap对象中的key以及Secert对象中的key，他们分别要使用不同的嵌套字段进行定义。
fieldRef：用于pod资源
configMapKeyRef：用于configMap
secretKeyRef：用于secret
resourceFieldRef：用于当前容器的特定系统资源的最小值（配额）或者最大值（限额），目前支持的引用包括limits.cpu、limits.memory、limits.ephemeral-storage(最小空间) 、requests.cpu、requests.memory、requests.ephemeral-storage
下面资源清单文件env-demo.yaml是定义pod资源
[root@k8s-master01 yaml]# cat env-demo.yaml apiVersion: v1 kind: Pod metadata: name: env-demo labels: purpose: demonstrate-environment-variables spec: containers: - name: env-demo-container image: busybox command: ["httpd"] args: ["-f"] env: - name: HELLO_WORLD value: just a demo - name: MY_NODE_NAME valueFrom: fieldRef: fieldPath: spec.nodeName - name: MY_NODE_IP valueFrom: fieldRef: fieldPath: status.hostIP - name: MY_POD_NAMESPACE valueFrom: fieldRef: fieldPath: metadata.namespace restartPolicy: OnFailure
[root@k8s-master01 yaml]# kubectl apply -f env-demo.yaml -n dev pod/env-demo created [root@k8s-master01 yaml]# kubectl get pods/env-demo Error from server (NotFound): pods "env-demo" not found [root@k8s-master01 yaml]# kubectl get pods/env-demo -n dev NAME READY STATUS RESTARTS AGE env-demo 1/1 Running 0 32s [root@k8s-master01 yaml]# kubectl get pods/env-demo -n dev -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES env-demo 1/1 Running 0 42s 10.244.2.7 k8s-node02 <none> <none> [root@k8s-master01 yaml]# kubectl exec env-demo printenv -n dev kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead. PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin HOSTNAME=env-demo MY_POD_NAMESPACE=dev HELLO_WORLD=just a demo MY_NODE_NAME=k8s-node02 MY_NODE_IP=192.168.3.22 KUBERNETES_SERVICE_PORT_HTTPS=443 KUBERNETES_PORT=tcp://10.96.0.1:443 KUBERNETES_PORT_443_TCP=tcp://10.96.0.1:443 KUBERNETES_PORT_443_TCP_PROTO=tcp KUBERNETES_PORT_443_TCP_PORT=443 KUBERNETES_PORT_443_TCP_ADDR=10.96.0.1 KUBERNETES_SERVICE_HOST=10.96.0.1 KUBERNETES_SERVICE_PORT=443 HOME=/root
[root@k8s-master01 yaml]# kubectl describe pod/env-demo -n dev Name: env-demo Namespace: dev Priority: 0 Node: k8s-node02/192.168.3.22 Start Time: Fri, 20 Aug 2021 10:04:26 +0800 Labels: purpose=demonstrate-environment-variables Annotations: <none> Status: Running IP: 10.244.2.7 IPs: IP: 10.244.2.7 Containers: env-demo-container: Container ID: docker://b473bd3b5edf257e58adaf14488d5a03e6c9972f05d0c47cc9cf598a52d1fa4c Image: busybox Image ID: docker-pullable://busybox@sha256:0f354ec1728d9ff32edcd7d1b8bbdfc798277ad36120dc3dc683be44524c8b60 Port: <none> Host Port: <none> Command: httpd Args: -f State: Running Started: Fri, 20 Aug 2021 10:04:32 +0800 Ready: True Restart Count: 0 Environment: HELLO_WORLD: just a demo MY_NODE_NAME: (v1:spec.nodeName) MY_NODE_IP: (v1:status.hostIP) MY_POD_NAMESPACE: dev (v1:metadata.namespace) Mounts: /var/run/secrets/kubernetes.io/serviceaccount from default-token-7p2m9 (ro) Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: default-token-7p2m9: Type: Secret (a volume populated by a Secret) SecretName: default-token-7p2m9 Optional: false QoS Class: BestEffort Node-Selectors: <none> Tolerations: node.kubernetes.io/not-ready:NoExecute op=Exists for 300s node.kubernetes.io/unreachable:NoExecute op=Exists for 300s Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 94s Successfully assigned dev/env-demo to k8s-node02 Normal Pulling 92s kubelet, k8s-node02 Pulling image "busybox" Normal Pulled 88s kubelet, k8s-node02 Successfully pulled image "busybox" in 3.374459704s Normal Created 88s kubelet, k8s-node02 Created container env-demo-container Normal Started 88s kubelet, k8s-node02 Started container env-demo-container
ConfigMap
configMap资源用于在运行时将配置文件、命令行参数、环境变量、端口号以及其他配置工作绑定至pod的容器和系统组件。
configMap资源用于存储和共享非敏感和未加密的配置信息。
下面是字面量(literal) 值数据源
创建configMap对象
[root@k8s-master01 yaml]# kubectl create configmap demoapp-config --from-literal=demoapp.host='0.0.0.0' --from-literal=demoapp.port='80' --namespace='dev' configmap/demoapp-config created
创建demoapp-config时传递了2个键值对。
[root@k8s-master01 yaml]# kubectl get configmaps demoapp-config -n dev -o yaml apiVersion: v1 data: demoapp.host: 0.0.0.0 demoapp.port: "80" kind: ConfigMap metadata: creationTimestamp: "2021-08-20T05:00:20Z" managedFields: - apiVersion: v1 fieldsType: FieldsV1 fieldsV1: f:data: .: {} f:demoapp.host: {} f:demoapp.port: {} manager: kubectl-create operation: Update time: "2021-08-20T05:00:20Z" name: demoapp-config namespace: dev resourceVersion: "394543" selfLink: /api/v1/namespaces/dev/configmaps/demoapp-config uid: af5e4b1e-5c24-477e-b271-9ac18b4dfc00
get configmap 命令输出的demoapp-config对象yaml格式信息可以看出，comfigmap资源没有spec和status字段，而是直接使用data字段嵌套键值信息。
所以，若是要基于配置清单创建configmap资源时仅仅需要指定 apiversion、kind、data、metadata这4个字段
下面是文件数据源
configmap资源也可以用于为应用程序提供大段配置，可以kubectl create configmap命令通过--from-file选项一次加载一个配置文件的内容为指定键的值，多个文件的加载可以重复使用。
先安装nginx
[root@k8s-master01 ~]# vim /etc/yum.repos.d/nginx.repo [nginx] name=nginx repo baseurl=http://nginx.org/packages/centos/$releasever/$basearch/ gpgcheck=0 enabled=1 yum install -y nginx
[root@k8s-master01 ~]# kubectl create configmap nginx-confs --from-file=/etc/nginx/conf.d/default.conf --namespace='dev' [root@k8s-master01 ~]# kubectl get configmap nginx-confs -n dev -o yaml apiVersion: v1 data: default.conf: |+ server { listen 80; server_name localhost; #access_log /var/log/nginx/host.access.log main; location / { root /usr/share/nginx/html; index index.html index.htm; } #error_page 404 /404.html; # redirect server error pages to the static page /50x.html # error_page 500 502 503 504 /50x.html; location = /50x.html { root /usr/share/nginx/html; } # proxy the PHP scripts to Apache listening on 127.0.0.1:80 # #location ~ \.php$ { # proxy_pass http://127.0.0.1; #} # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000 # #location ~ \.php$ { # root html; # fastcgi_pass 127.0.0.1:9000; # fastcgi_index index.php; # fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name; # include fastcgi_params; #} # deny access to .htaccess files, if Apache's document root # concurs with nginx's one # #location ~ /\.ht { # deny all; #} } kind: ConfigMap metadata: creationTimestamp: "2021-08-20T12:48:50Z" managedFields: - apiVersion: v1 fieldsType: FieldsV1 fieldsV1: f:data: .: {} f:default.conf: {} manager: kubectl-create operation: Update time: "2021-08-20T12:48:50Z" name: nginx-confs namespace: dev resourceVersion: "1926904" selfLink: /api/v1/namespaces/dev/configmaps/nginx-confs uid: 1498c8f3-9822-46b9-94f6-bc7676b0fc7a
上面是单个文件，对于配置文件比较多，且无需自定义键名的时候，可以直接把选项附加上一个路径
[root@k8s-master01 ~]# kubectl create configmap nginx-config-files --from-file=/etc/nginx/ configmap/nginx-config-files created [root@k8s-master01 ~]# kubectl describe configmap nginx-config-files Name: nginx-config-files Namespace: default Labels: <none> Annotations: <none> Data ==== fastcgi_params: ---- fastcgi_param QUERY_STRING $query_string; fastcgi_param REQUEST_METHOD $request_method; fastcgi_param CONTENT_TYPE $content_type; fastcgi_param CONTENT_LENGTH $content_length; fastcgi_param SCRIPT_NAME $fastcgi_script_name; fastcgi_param REQUEST_URI $request_uri; fastcgi_param DOCUMENT_URI $document_uri; fastcgi_param DOCUMENT_ROOT $document_root; fastcgi_param SERVER_PROTOCOL $server_protocol; fastcgi_param REQUEST_SCHEME $scheme; fastcgi_param HTTPS $https if_not_empty; fastcgi_param GATEWAY_INTERFACE CGI/1.1; fastcgi_param SERVER_SOFTWARE nginx/$nginx_version; fastcgi_param REMOTE_ADDR $remote_addr; fastcgi_param REMOTE_PORT $remote_port; fastcgi_param SERVER_ADDR $server_addr; fastcgi_param SERVER_PORT $server_port; fastcgi_param SERVER_NAME $server_name; # PHP only, required if PHP was built with --enable-force-cgi-redirect fastcgi_param REDIRECT_STATUS 200; mime.types: ---- types { text/html html htm shtml; text/css css; text/xml xml; image/gif gif; image/jpeg jpeg jpg; application/javascript js; application/atom+xml atom; application/rss+xml rss; text/mathml mml; text/plain txt; text/vnd.sun.j2me.app-descriptor jad; text/vnd.wap.wml wml; text/x-component htc; image/png png; image/svg+xml svg svgz; image/tiff tif tiff; image/vnd.wap.wbmp wbmp; image/webp webp; image/x-icon ico; image/x-jng jng; image/x-ms-bmp bmp; font/woff woff; font/woff2 woff2; application/java-archive jar war ear; application/json json; application/mac-binhex40 hqx; application/msword doc; application/pdf pdf; application/postscript ps eps ai; application/rtf rtf; application/vnd.apple.mpegurl m3u8; application/vnd.google-earth.kml+xml kml; application/vnd.google-earth.kmz kmz; application/vnd.ms-excel xls; application/vnd.ms-fontobject eot; application/vnd.ms-powerpoint ppt; application/vnd.oasis.opendocument.graphics odg; application/vnd.oasis.opendocument.presentation odp; application/vnd.oasis.opendocument.spreadsheet ods; application/vnd.oasis.opendocument.text odt; application/vnd.openxmlformats-officedocument.presentationml.presentation pptx; application/vnd.openxmlformats-officedocument.spreadsheetml.sheet xlsx; application/vnd.openxmlformats-officedocument.wordprocessingml.document docx; application/vnd.wap.wmlc wmlc; application/x-7z-compressed 7z; application/x-cocoa cco; application/x-java-archive-diff jardiff; application/x-java-jnlp-file jnlp; application/x-makeself run; application/x-perl pl pm; application/x-pilot prc pdb; application/x-rar-compressed rar; application/x-redhat-package-manager rpm; application/x-sea sea; application/x-shockwave-flash swf; application/x-stuffit sit; application/x-tcl tcl tk; application/x-x509-ca-cert der pem crt; application/x-xpinstall xpi; application/xhtml+xml xhtml; application/xspf+xml xspf; application/zip zip; application/octet-stream bin exe dll; application/octet-stream deb; application/octet-stream dmg; application/octet-stream iso img; application/octet-stream msi msp msm; audio/midi mid midi kar; audio/mpeg mp3; audio/ogg ogg; audio/x-m4a m4a; audio/x-realaudio ra; video/3gpp 3gpp 3gp; video/mp2t ts; video/mp4 mp4; video/mpeg mpeg mpg; video/quicktime mov; video/webm webm; video/x-flv flv; video/x-m4v m4v; video/x-mng mng; video/x-ms-asf asx asf; video/x-ms-wmv wmv; video/x-msvideo avi; } nginx.conf: ---- user nginx; worker_processes auto; error_log /var/log/nginx/error.log notice; pid /var/run/nginx.pid; events { worker_connections 1024; } http { include /etc/nginx/mime.types; default_type application/octet-stream; log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; access_log /var/log/nginx/access.log main; sendfile on; #tcp_nopush on; keepalive_timeout 65; #gzip on; include /etc/nginx/conf.d/*.conf; } scgi_params: ---- scgi_param REQUEST_METHOD $request_method; scgi_param REQUEST_URI $request_uri; scgi_param QUERY_STRING $query_string; scgi_param CONTENT_TYPE $content_type; scgi_param DOCUMENT_URI $document_uri; scgi_param DOCUMENT_ROOT $document_root; scgi_param SCGI 1; scgi_param SERVER_PROTOCOL $server_protocol; scgi_param REQUEST_SCHEME $scheme; scgi_param HTTPS $https if_not_empty; scgi_param REMOTE_ADDR $remote_addr; scgi_param REMOTE_PORT $remote_port; scgi_param SERVER_PORT $server_port; scgi_param SERVER_NAME $server_name; uwsgi_params: ---- uwsgi_param QUERY_STRING $query_string; uwsgi_param REQUEST_METHOD $request_method; uwsgi_param CONTENT_TYPE $content_type; uwsgi_param CONTENT_LENGTH $content_length; uwsgi_param REQUEST_URI $request_uri; uwsgi_param PATH_INFO $document_uri; uwsgi_param DOCUMENT_ROOT $document_root; uwsgi_param SERVER_PROTOCOL $server_protocol; uwsgi_param REQUEST_SCHEME $scheme; uwsgi_param HTTPS $https if_not_empty; uwsgi_param REMOTE_ADDR $remote_addr; uwsgi_param REMOTE_PORT $remote_port; uwsgi_param SERVER_PORT $server_port; uwsgi_param SERVER_NAME $server_name; Events: <none>
查看该对象的数据条目
[root@k8s-master01 ~]# kubectl get configmaps/nginx-config-files
NAME DATA AGE
nginx-config-files 5 4m10s #5条
基于字面量值和基于文件创建可以混合使用
[root@k8s-master01 ~]# kubectl create configmap nginx-config-literal --from-file=/etc/nginx/ --from-literal=nginx.host='0.0.0.0' --from-literal=nginx.port='8080' configmap/nginx-config-literal created [root@k8s-master01 ~]# kubectl get configmaps/nginx-config-literal NAME DATA AGE nginx-config-literal 7 20s #变成7条数据
通过环境变量引用configMao键值
[root@k8s-master01 yaml]# kubectl apply -f configmaps-env-demo.yaml -n dev pod/configmaps-env-demo created error: unable to recognize "configmaps-env-demo.yaml": no matches for kind "configMap" in version "v1" ## 错误原因是configMap的c没有大写 [root@k8s-master01 yaml]# cat configmaps-env-demo.yaml apiVersion : v1 kind: ConfigMap #注意不要忘记c大写 metadata: name: demoapp-config namespace: dev data: demoapp.port: "8080" demoapp.host: 0.0.0.0 --- apiVersion: v1 kind: Pod metadata: name: configmaps-env-demo namespace: dev spec: containers: - image: ikubernetes/demoapp:v1.0 name: demoapp env: - name: PORT valueFrom: configMapKeyRef: name: demoapp-config key: demoapp.port optional: false - name: HOST valueFrom: configMapKeyRef: name: demoapp-config key: demoapp.host optional: true [root@k8s-master01 yaml]# kubectl exec configmaps-env-demo -n dev -- netstat -tnl Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:8080 0.0.0.0:* LISTEN
浙公网安备 33010602011771号