- What's New
- Product Bulletin
- Service Overview
- Billing
- Getting Started
-
User Guide
-
UCS Clusters
- Overview
- Huawei Cloud Clusters
-
On-Premises Clusters
- Overview
- Service Planning for On-Premises Cluster Installation
- Registering an On-Premises Cluster
- Installing an On-Premises Cluster
- Managing an On-Premises Cluster
- Attached Clusters
- Multi-Cloud Clusters
- Single-Cluster Management
- Fleets
-
Cluster Federation
- Overview
- Enabling Cluster Federation
- Using kubectl to Connect to a Federation
- Upgrading a Federation
-
Workloads
- Workload Creation
-
Container Settings
- Setting Basic Container Information
- Setting Container Specifications
- Setting Container Lifecycle Parameters
- Setting Health Check for a Container
- Setting Environment Variables
- Configuring a Workload Upgrade Policy
- Configuring a Scheduling Policy (Affinity/Anti-affinity)
- Configuring Scheduling and Differentiation
- Managing a Workload
- ConfigMaps and Secrets
- Services and Ingresses
- MCI
- MCS
- DNS Policies
- Storage
- Namespaces
- Multi-Cluster Workload Scaling
- Adding Labels and Taints to a Cluster
- RBAC Authorization for Cluster Federations
- Image Repositories
- Permissions
-
Policy Center
- Overview
- Basic Concepts
- Enabling Policy Center
- Creating and Managing Policy Instances
- Example: Using Policy Center for Kubernetes Resource Compliance Governance
-
Policy Definition Library
- Overview
- k8spspvolumetypes
- k8spspallowedusers
- k8spspselinuxv2
- k8spspseccomp
- k8spspreadonlyrootfilesystem
- k8spspprocmount
- k8spspprivilegedcontainer
- k8spsphostnetworkingports
- k8spsphostnamespace
- k8spsphostfilesystem
- k8spspfsgroup
- k8spspforbiddensysctls
- k8spspflexvolumes
- k8spspcapabilities
- k8spspapparmor
- k8spspallowprivilegeescalationcontainer
- k8srequiredprobes
- k8srequiredlabels
- k8srequiredannotations
- k8sreplicalimits
- noupdateserviceaccount
- k8simagedigests
- k8sexternalips
- k8sdisallowedtags
- k8sdisallowanonymous
- k8srequiredresources
- k8scontainerratios
- k8scontainerrequests
- k8scontainerlimits
- k8sblockwildcardingress
- k8sblocknodeport
- k8sblockloadbalancer
- k8sblockendpointeditdefaultrole
- k8spspautomountserviceaccounttokenpod
- k8sallowedrepos
- Configuration Management
- Traffic Distribution
- Observability
- Container Migration
- Pipeline
- Error Codes
-
UCS Clusters
- Best Practices
-
API Reference
- Before You Start
- Calling APIs
-
API
- UCS Cluster
-
Fleet
- Adding a Cluster to a Fleet
- Removing a Cluster from a Fleet
- Registering a Fleet
- Deleting a Fleet
- Querying a Fleet
- Adding Clusters to a Fleet
- Updating Fleet Description
- Updating Permission Policies Associated with a Fleet
- Updating the Zone Associated with the Federation of a Fleet
- Obtaining the Fleet List
- Enabling Fleet Federation
- Disabling Cluster Federation
- Querying Federation Enabling Progress
- Creating a Federation Connection and Downloading kubeconfig
- Creating a Federation Connection
- Downloading Federation kubeconfig
- Permissions Management
- Using the Karmada API
- Appendix
-
FAQs
- About UCS
-
Billing
- How Is UCS Billed?
- What Status of a Cluster Will Incur UCS Charges?
- Why Am I Still Being Billed After I Purchase a Resource Package?
- How Do I Change the Billing Mode of a Cluster from Pay-per-Use to Yearly/Monthly?
- What Types of Invoices Are There?
- Can I Unsubscribe from or Modify a Resource Package?
-
Permissions
- How Do I Configure Access Permissions for Each Function of the UCS Console?
- What Can I Do If an IAM User Cannot Obtain Cluster or Fleet Information After Logging In to UCS?
- How Do I Restore ucs_admin_trust I Deleted or Modified?
- What Can I Do If I Cannot Associate the Permission Policy with a Fleet or Cluster?
- How Do I Clear RBAC Resources After a Cluster Is Unregistered?
- Policy Center
-
Fleets
- What Can I Do If Cluster Federation Verification Fails to Be Enabled for a Fleet?
- What Can I Do If an Abnormal, Federated Cluster Fails to Be Removed from the Fleet?
- What Can I Do If an Nginx Ingress Is in the Unready State After Being Deployed?
- What Can I Do If "Error from server (Forbidden)" Is Displayed When I Run the kubectl Command?
- Huawei Cloud Clusters
- Attached Clusters
-
On-Premises Clusters
- What Can I Do If an On-Premises Cluster Fails to Be Connected?
- How Do I Manually Clear Nodes of an On-Premises Cluster?
- How Do I Downgrade a cgroup?
- What Can I Do If the VM SSH Connection Times Out?
- How Do I Expand the Disk Capacity of the CIA Add-on in an On-Premises Cluster?
- What Can I Do If the Cluster Console Is Unavailable After the Master Node Is Shut Down?
- What Can I Do If a Node Is Not Ready After Its Scale-Out?
- How Do I Update the CA/TLS Certificate of an On-Premises Cluster?
- What Can I Do If an On-Premises Cluster Fails to Be Installed?
- Multi-Cloud Clusters
-
Cluster Federation
- What Can I Do If the Pre-upgrade Check of the Cluster Federation Fails?
- What Can I Do If a Cluster Fails to Be Added to a Federation?
- What Can I Do If Status Verification Fails When Clusters Are Added to a Federation?
- What Can I Do If an HPA Created on the Cluster Federation Management Plane Fails to Be Distributed to Member Clusters?
- What Can I Do If an MCI Object Fails to Be Created?
- What Can I Do If I Fail to Access a Service Through MCI?
- What Can I Do If an MCS Object Fails to Be Created?
- What Can I Do If an MCS or MCI Instance Fails to Be Deleted?
- Traffic Distribution
- Container Intelligent Analysis
- General Reference
Copied.
Setting Environment Variables
Scenario
An environment variable is a variable whose value can affect the way a running container will behave. You can modify environment variables even after workloads are deployed, increasing flexibility in workload configuration.
The function of setting environment variables on UCS is the same as that of specifying ENV in a Dockerfile.
After a container is started, do not modify configurations in the container. If configurations in the container are modified (for example, passwords, certificates, and environment variables of a containerized application are added to the container), the configurations will be lost after the container restarts and container services will become abnormal. An example scenario of container restart is pod rescheduling due to node anomalies.
Configurations must be imported to a container as arguments. Otherwise, configurations will be lost after the container restarts.
Environment variables can be set in the following modes:
- Custom: Enter a variable name and value.
- Added from ConfigMap: Import all keys in a ConfigMap as environment variables.
- Added from ConfigMap key: Import a key in a ConfigMap as the value of an environment variable. For example, if you import configmap_value of configmap_key in ConfigMap configmap-example as the value of environment variable key1, an environment variable named key1 with its value is configmap_value exists in the container.
- Added from secret: Import all keys in a secret as environment variables.
- Added from secret key: Import the value of a key in a secret as the value of an environment variable. For example, if you import secret_value of secret_key in secret secret-example as the value of environment variable key2, an environment variable named key2 with its value secret_value exists in the container.
- Variable Value/Reference: Use the field defined by a pod as the value of the environment variable, for example, the pod name.
- Resource Reference: Use the field defined by a container as the value of the environment variable, for example, the CPU limit of the container.
Adding Environment Variables
- When creating a workload, select Environment Variables under Container Settings.
- Set environment variables.
Figure 1 Adding environment variables
YAML Example
apiVersion: apps/v1 kind: Deployment metadata: name: env-example namespace: default spec: replicas: 1 selector: matchLabels: app: env-example template: metadata: labels: app: env-example spec: containers: - name: container-1 image: nginx:alpine imagePullPolicy: Always resources: requests: cpu: 250m memory: 512Mi limits: cpu: 250m memory: 512Mi env: - name: key # Custom value: value - name: key1 # Added from ConfigMap key valueFrom: configMapKeyRef: name: configmap-example key: key1 - name: key2 # Added from secret key valueFrom: secretKeyRef: name: secret-example key: key2 - name: key3 # Variable reference, which uses the field defined by a pod as the value of the environment variable. valueFrom: fieldRef: apiVersion: v1 fieldPath: metadata.name - name: key4 # Resource reference, which uses the field defined by a container as the value of the environment variable. valueFrom: resourceFieldRef: containerName: container1 resource: limits.cpu divisor: 1 envFrom: - configMapRef: # Added from ConfigMap name: configmap-example - secretRef: # Added from secret name: secret-example imagePullSecrets: - name: default-secret
Viewing Environment Variables
If the contents of configmap-example and secret-example are as follows:
$ kubectl get configmap configmap-example -oyaml apiVersion: v1 data: configmap_key: configmap_value kind: ConfigMap ... $ kubectl get secret secret-example -oyaml apiVersion: v1 data: secret_key: c2VjcmV0X3ZhbHVl # c2VjcmV0X3ZhbHVl is the value of secret_value in Base64 mode. kind: Secret ...
The environment variables in the pod are as follows:
$ kubectl get pod NAME READY STATUS RESTARTS AGE env-example-695b759569-lx9jp 1/1 Running 0 17m $ kubectl exec env-example-695b759569-lx9jp -- printenv / # env key=value # Custom environment variable key1=configmap_value # Added from ConfigMap key key2=secret_value # Added from secret key key3=env-example-695b759569-lx9jp # metadata.name defined by the pod key4=1 # limits.cpu defined by container1. The value is rounded up, in unit of cores. configmap_key=configmap_value # Added from ConfigMap. The key value in the original ConfigMap key is directly imported. secret_key=secret_value # Added from key. The key value in the original secret is directly imported.
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.
For any further questions, feel free to contact us through the chatbot.
Chatbot