Rollout Strategies

Vexil supports progressive rollouts to safely deploy flag changes.

Strategies

Immediate (default)

The flag value changes instantly for all targeted workloads:

spec:
  rollout:
    strategy: immediate

Canary

Gradually increase the percentage of workloads receiving the new value:

spec:
  defaultValue: "true"
  rollout:
    strategy: canary
    steps:
      - percentage: 10
        duration: "1h"
      - percentage: 25
        duration: "2h"
      - percentage: 50
        duration: "4h"
      - percentage: 100
        duration: "0s"

This rolls out the flag to:

1. 10% of targeted workloads for 1 hour
2. 25% for 2 hours
3. 50% for 4 hours
4. 100% (complete)

Linear

Automatically increase the percentage at regular intervals:

spec:
  rollout:
    strategy: linear
    steps:
      - percentage: 100
        duration: "1h"    # reaches 100% over 1 hour

Monitoring Rollouts

Check rollout progress:

kubectl get featureflag new-checkout -o wide

The PHASE column shows RollingOut during a rollout, and the status includes rolloutProgress (0-100).

Aborting a Rollout

To abort a rollout, disable the flag:

kubectl patch featureflag new-checkout \
  -p '{"spec":{"disabled":true}}' --type=merge

The flag phase changes to Disabled and the previous value is restored.