Route Configuration
Overview
The Route Controller manages network routes for pod communication in VPC environments. It ensures proper connectivity between nodes and pods across the cluster by configuring routes in Linode VPC.
Prerequisites
- Kubernetes cluster running in Linode VPC
- CCM with route controller enabled
- Proper API permissions
Configuration
Enable Route Controller
- Via Helm chart in
values.yaml:
routeController:
vpcNames: "vpc-prod,vpc-staging" # Comma separated names of VPCs managed by CCM
clusterCIDR: "10.0.0.0/8" # Pod CIDR range
configureCloudRoutes: true # Enable route controller
- Via command line flags in CCM deployment:
spec:
template:
spec:
containers:
- name: ccm-linode
args:
- --configure-cloud-routes=true
- --vpc-names=vpc-prod,vpc-staging
- --cluster-cidr=10.0.0.0/8
Environment Variables
| Variable |
Default |
Description |
LINODE_ROUTES_CACHE_TTL_SECONDS |
60 |
Default timeout of route cache in seconds |
Route Management
Automatic Operations
The Route Controller:
- Creates routes for pod CIDR ranges assigned to nodes
- Updates routes when nodes are added/removed
- Manages route tables in specified VPCs
- Handles route cleanup during node removal
- Maintains route cache for performance
Route Types
-
Pod CIDR Routes
- Created for each node's pod CIDR allocation
- Target is node's private IP address
- Automatically managed based on node lifecycle
-
VPC Routes
- Managed within specified VPCs
- Enables cross-node pod communication
- Automatically updated with topology changes
Best Practices
CIDR Planning
- Ensure pod CIDR range doesn't overlap with node's VPC ip-address
- Plan for future cluster growth
- Document CIDR allocations
VPC Configuration
- Use clear, descriptive VPC names
- Configure proper VPC security settings
- Ensure proper API permissions
Troubleshooting
Common Issues
-
Route Creation Failures
- Verify API permissions
- Check for CIDR conflicts
- Validate VPC configuration
- Ensure node private IPs are configured
-
Pod Communication Issues
- Verify route table entries
- Check VPC network ACLs
- Validate node networking
- Confirm pod CIDR assignments