Write k8s yaml

One 、 summary

K8s in , Support YAML and JSON Two formats to manage resource objects , But generally speaking JSON The format is more for api Message passing between interfaces , and YAML Format is a language that is specifically used to write configuration files , contrast JSON More concise and convenient , therefore , stay K8S It is commonly used in YAML File to manage resource objects

Two 、YAML Document basis

• YAML The rules of documentation ：

  1. Word in file Case sensitive
  2. yaml Indents are used in files to indicate hierarchical relationships , And only use Space
  3. The number of spaces used for indentation is not important , as long as Same level alignment that will do
  4. yaml Use... In the document # To represent a comment
  5. Indent one character after the character , Colon :、 comma ,、 Short cross bar - etc.
  6. --- Indicates the beginning of the file , utilize --- Multiple resources can be written to one yaml In file

• YAML The structure type of the file ：

  （1） Key value pair ——key:value：YAML The basic entry type in the file is Key value pair type , The format is ： key : value , Be careful There is a space between the colon and the value

  - for example ：
  apiVersion: apps/v1
  kind: Deployment
  # These two are key value pairs , There is a space between 
  - convert to json Format ：
  {
  
  "apiVersion": "apps/v1",
  "kind": "Deployment"
  }
  

  （2） list （ Array ）——list： The list will list some elements under the list name , In fact, it is an array , List with - start , There can be multiple lists , Note the indentation of each element in the list

  - for example ：
  args:
  - "test"
  - "aaaa"
  - "ccc"
  # Note that indents need to be the same 
  - convert to json Format
  {
  
  "args": [
  "test",
  "aaaa",
  "ccc"
  ]
  }
  

  （3） Dictionaries （ Map ）——map： The dictionary contains key value pairs 、 list , You can also nest dictionaries

  - for example ：
  metadata:
  labels:
  app: test
  name: test
  namespace: test
  # You can nest dictionaries 
  - convert to json Format
  {
  
  "metadata": {
  
  "labels": {
  
  "app": "test"
  },
  "name": "test",
  "namespace": "test"
  }
  }
  

• From the above structure type, we can see ,YAML Than JSON More concise , Easier to write

3、 ... and 、YAML Use

• stay K8S in ,Pod It's the smallest unit ,Pod All the information is recorded in one YAML In file
• Here's the definition PodYAML Some parameters of the file

- Required parameters ：

• One YAML In file , The following parameters must be written , Otherwise, an error will be reported ：

• That's what happened K8S Write a YAML Necessary parameters of the file

- spec.containers main parameter

• spec.containers It's a list list, The function is to define the relevant parameters of the container , Here is spec.containers Main parameters of

- spec.volumes main parameter

• spec.volumes It's a list list , Define parameters for synchronous storage , Here are the main parameters

- Extra parameter objects

• Except for the top containers Container settings and volumes Mount settings , There are several other parameters

Four 、Pod Complete definition file

apiVersion: v1 # Mandatory , Version number , for example v1, Version number must be available kubectl api-versions Query to .
kind: Pod # Mandatory , The type is Pod
metadata: # Mandatory , Metadata 
name: string # Mandatory ,Pod The name of 
namespace: string # Mandatory ,Pod The namespace to which it belongs , The default is "default", This is defined as string
labels: # Custom tag 
- name: string # Custom tag name 
annotations: # Custom comment list 
- name: string
spec: # Mandatory ,Pod Detailed definition of container in 
containers: # Mandatory ,Pod List of containers in 
- name: string # Mandatory , Container name , To comply with RFC 1035 standard 
image: string # Mandatory , Image name of the container 
imagePullPolicy: [ Always|Never|IfNotPresent ] # The strategy of getting images , Three strategies , The above parameters are described in detail 
command: [string] # Start command list of container , If not specified , Use the startup command used when packaging 
args: [string] # Start command parameter list of container 
workingDir: string # Working directory of the container 
volumeMounts: # Storage volume configuration mounted inside the container 
- name: string # quote pod The name of the defined shared storage volume , need volumes[] The volume name of the partial definition 
mountPath: string # The storage volume is in the container mount The absolute path of , Should be less than 512 character 
readOnly: boolean # Is it read-only mode 
ports: # List of port library numbers to be exposed 
- name: string # The name of the port 
containerPort: int # The port number the container needs to listen on 
hostPort: int # The port number that the host of the container needs to listen to , Default and Container identical 
protocol: string # Port agreement , Support TCP and UDP, Default TCP
env: # List of environment variables to be set before the container runs 
- name: string # Environment variable name 
value: string # The value of the environment variable 
resources: # Resource limits and request settings 
limits: # Resource limit settings 
cpu: string #Cpu The limitation of , Unit is core Count , Will be used for docker run --cpu-shares Parameters 
memory: string # Memory limit , The unit can be Mib/Gib, Will be used for docker run --memory Parameters 
requests: # Settings for resource requests 
cpu: string #Cpu request , Initial available number of container starts 
memory: string # Memory request , Initial available number of container starts 
livenessProbe: # Yes Pod Setting of health examination for each container inside , The container will restart automatically after several times of no response , The inspection methods are exec、httpGet and tcpSocket, Just set one of these methods for a container 
exec: # Yes Pod The in container inspection mode is set to exec The way 
command: [string] #exec A command or script that needs to be formulated 
httpGet: # Yes Pod The internal container health check method is set to HttpGet, Need to make Path、port
path: string
port: number
host: string
scheme: string
HttpHeaders:
- name: string
value: string
tcpSocket: # Yes Pod Internal container health check mode is set to tcpSocket The way 
port: number
initialDelaySeconds: 0 # Time of the first detection after the start of the container , The unit is in seconds 
timeoutSeconds: 0 # Timeout for container health probe to wait for response , Unit second , Default 1 second 
periodSeconds: 0 # Set the regular detection time for container monitoring and inspection , Unit second , Default 10 Seconds at a time 
successThreshold: 0
failureThreshold: 0
securityContext:
privileged: false
restartPolicy: [Always | Never | OnFailure] #Pod The restart strategy of , Three models , The above parameters are described in detail 
nodeSelector: obeject # Set up NodeSelector It means that you should Pod Schedule to include this label Of node On , With key：value The format of 
imagePullSecrets: #Pull Used when mirroring secret name , With key：secretkey Format designation 
- name: string
hostNetwork: false # Whether to use the host network mode , The default is false, If set to true, Indicates that the host network is used 
volumes: # In the pod List of shared storage volumes defined on 
- name: string # Shared storage volume name （volumes There are many types ）
emptyDir: {
} # The type is emtyDir The storage volume of , And Pod A temporary directory in the same lifecycle . Null value 
hostPath: string # The type is hostPath The storage volume of , Means mount Pod Directory of host 
path: string #Pod Directory of host , Will be used in the same period mount The catalog of 
secret: # The type is secret The storage volume of , Mount the cluster with the defined secre Object to the inside of the container 
scretname: string
items:
- key: string
path: string
configMap: # The type is configMap The storage volume of , Mount predefined configMap Object to the inside of the container 
name: string
items:
- key: string
path: string

5、 ... and 、Deployment Complete definition file

apiVersion: apps/v1
kind: Deployment
metadata:
spec:
minReadySeconds: <integer> # Set up pod The minimum number of seconds to be ready 
paused: <boolean> # Indicates that the deployment has been suspended and deploy The controller does not process the deployment 
progressDeadlineSeconds: <integer>
strategy: <Object> # Put the existing pod Replace with new pod Deployment strategy 
rollingUpdate: <Object> # Scroll through configuration parameters , Only if the type is RollingUpdate
maxSurge: <string> # The biggest cost of rolling update process is pod Number , It can be a number , It can also be a percentage 
maxUnavailable: <string> #
type: <string> # Deployment type ,Recreate,RollingUpdate
replicas: <integer> #pods Number of copies of 
selector: <Object> #pod tag chooser , matching pod label , By default pods The label of 
matchLabels: <map[string]string>
key1: value1
key2: value2
matchExpressions: <[]Object>
operator: <string> -required- # Set the relationship between a label key and a set of values ,In, NotIn, Exists and DoesNotExist
key: <string> -required-
values: <[]string>
revisionHistoryLimit: <integer> # Set the number of historical versions to keep , The default is 10
rollbackTo: <Object>
revision: <integer> # Set the version of the rollback , Set to 0 Then roll back to the previous version 
template: <Object> -required-
metadata:
spec:
containers: <[]Object> # Container configuration 
- name: <string> -required- # Container name 、DNS_LABEL
image: <string> # Mirror image 
imagePullPolicy: <string> # Mirror pull strategy ,Always、Never、IfNotPresent
ports: <[]Object>
- name: # Define the port name 
containerPort: # Exposed port of container 
protocol: TCP # or UDP
volumeMounts: <[]Object>
- name: <string> -required- # Set the volume name 
mountPath: <string> -required- # Set the path in the container to be mounted 
readOnly: <boolean> # Set whether it is read-only or not 
livenessProbe: <Object> # Ready to detect 
exec:
command: <[]string>
httpGet:
port: <string> -required-
path: <string>
host: <string>
httpHeaders: <[]Object>
name: <string> -required-
value: <string> -required-
scheme: <string>
initialDelaySeconds: <integer> # Set how many seconds to start detection 
failureThreshold: <integer> # Set the number of consecutive failed detections , Mark as failure , Three times by default 
successThreshold: <integer> # Set the minimum number of consecutive successful probes after failure , The default is 1
timeoutSeconds: <integer> # Set the number of seconds for the probe timeout , Default 1s
periodSeconds: <integer> # Set the frequency to perform the probe （ In seconds ）, Default 1s
tcpSocket: <Object> #TCPSocket The designation involves TCP Port operation 
port: <string> -required- # Exposed port of container 
host: <string> # Default pod Of IP
readinessProbe: <Object> # Same as livenessProbe
resources: <Object> # Resource allocation 
requests: <map[string]string> # Minimum resource allocation 
memory: "1024Mi"
cpu: "500m" #500m representative 0.5CPU
limits: <map[string]string> # Maximum resource allocation 
memory:
cpu:
volumes: <[]Object> # Data volume configuration 
- name: <string> -required- # Set the volume name , And volumeMounts The name corresponds to 
hostPath: <Object> # Set the mount host path 
path: <string> -required-
type: <string> # type ：DirectoryOrCreate、Directory、FileOrCreate、File、Socket、CharDevice、BlockDevice
- name: nfs
nfs: <Object> # Set up NFS The server 
server: <string> -required- # Set up NFS Server address 
path: <string> -required- # Set up NFS Server path 
readOnly: <boolean> # Set whether it is read-only or not 
- name: configmap
configMap:
name: <string> #configmap name 
defaultMode: <integer> # permissions 0~0777, Default 0664
optional: <boolean> # Specifies whether... Must be defined configmap Or its keys
items: <[]Object>
- key: <string> -required-
path: <string> -required-
mode: <integer>
restartPolicy: <string> # Restart strategy ,Always、OnFailure、Never
nodeName: <string>
nodeSelector: <map[string]string>
imagePullSecrets: <[]Object>
hostname: <string>
hostPID: <boolean>
status: <Object>