rollops-plugin-flagsmith

A Rollops feature-flag provider plugin backed by Flagsmith. As a rollout progresses, this plugin drives a Flagsmith flag's enabled state and rollout percentage to match — so a Flagsmith flag tracks a Rollops canary in lockstep.

It is a standalone binary that speaks the Rollops plugin protocol (manifest + gRPC, featureflag capability). Rollops launches it as a subprocess; it never needs to run as a service.

Install

go install github.com/klarlabs-studio/rollops-plugin-flagsmith/cmd/rollops-plugin-flagsmith@latest
# or build from source:
make build && make checksum   # prints the sha256 to pin

Place the binary somewhere the Rollops daemon can read but cannot be tampered with (a root-owned dir on a trusted mount — see the Rollops plugin security model), and note its sha256.

Configure

The plugin reads its Flagsmith credentials from its own environment — Rollops passes only the flag name, environment, and percentage, never secrets:

Env var	Meaning
FLAGSMITH_API_URL	Admin API base (default https://api.flagsmith.com/api/v1)
FLAGSMITH_TOKEN	Flagsmith Admin API token (required)
FLAGSMITH_PROJECT_ID	Numeric project id, for feature lookup (required)

Then reference it from a rollout:

spec:
  strategy:
    type: canary
    steps:
      - weight: 25
      - weight: 50
  featureFlags:
    plugin: /usr/local/lib/rollops/plugins/rollops-plugin-flagsmith
    sha256: <paste from `make checksum`>
    flag: checkout-redesign
    environment: <your Flagsmith environment API key>
    when: both

environment is the Flagsmith environment's API key. As the canary steps, the flag's value is set to the current percentage (25, 50, 100) and enabled follows the rollout; on promote it settles at 100%.

Semantics

Per ApplyFlag(flag, environment, percentage, disabled) the plugin:

1. resolves the feature id by name within FLAGSMITH_PROJECT_ID;
2. resolves the environment's feature-state id;
3. PATCHes it: enabled = !disabled, feature_state_value = percentage.

Your application reads the flag's value to gate on the current rollout percentage. (Flagsmith multivariate split is out of scope for v1; the value carries the percentage, which is the simplest provider-correct mapping.)

License

MIT.