Add docs for CLI flags and feature flags

Signed-off-by: Mac Chaffee <machaffe@renci.org>

docs/spec/README.md

@@ -52,6 +52,42 @@ group of `HelmRelease` resources to be monitored using the [notification-control
 
 The API design of the controller can be found at [helm.toolkit.fluxcd.io/v2beta1](./v2beta1/helmreleases.md).
 
+## Configuration
+
+Here are the command line flags currently supported by the Helm Controller:
+
+```
+Usage of helm-controller:
+      --concurrent int                            The number of concurrent HelmRelease reconciles. (default 4)
+      --default-service-account string            Default service account used for impersonation.
+      --enable-leader-election                    Enable leader election for controller manager. Enabling this will ensure there is only one active controller manager.
+      --events-addr string                        The address of the events receiver.
+      --feature-gates mapStringBool               A comma separated list of key=value pairs defining the state of experimental features.
+      --graceful-shutdown-timeout duration        The duration given to the reconciler to finish before forcibly stopping.
+      --health-addr string                        The address the health endpoint binds to. (default ":9440")
+      --http-retry int                            The maximum number of retries when failing to fetch artifacts over HTTP. (default 9)
+      --insecure-kubeconfig-exec                  Allow use of the user.exec section in kubeconfigs provided for remote apply.
+      --insecure-kubeconfig-tls                   Allow that kubeconfigs provided for remote apply can disable TLS verification.
+      --kube-api-burst int                        The maximum burst queries-per-second of requests sent to the Kubernetes API. (default 100)
+      --kube-api-qps float32                      The maximum queries-per-second of requests sent to the Kubernetes API. (default 50)
+      --leader-election-lease-duration duration   Interval at which non-leader candidates will wait to force acquire leadership (duration string). (default 35s)
+      --leader-election-release-on-cancel         Defines if the leader should step down voluntarily on controller manager shutdown. (default true)
+      --leader-election-renew-deadline duration   Duration that the leading controller manager will retry refreshing leadership before giving up (duration string). (default 30s)
+      --leader-election-retry-period duration     Duration the LeaderElector clients should wait between tries of actions (duration string). (default 5s)
+      --log-encoding string                       Log encoding format. Can be 'json' or 'console'. (default "json")
+      --log-level string                          Log verbosity level. Can be one of 'trace', 'debug', 'info', 'error'. (default "info")
+      --max-retry-delay duration                  The maximum amount of time for which an object being reconciled will have to wait before a retry. (default 15m0s)
+      --metrics-addr string                       The address the metric endpoint binds to. (default ":8080")
+      --min-retry-delay duration                  The minimum amount of time for which an object being reconciled will have to wait before a retry. (default 750ms)
+      --no-cross-namespace-refs                   When set to true, references between custom resources are allowed only if the reference and the referee are in the same namespace.
+      --requeue-dependency duration               The interval at which failing dependencies are reevaluated. (default 30s)
+      --watch-all-namespaces                      Watch for custom resources in all namespaces, if set to false it will only watch the runtime namespace. (default true)
+```
+
+These are the currently supported feature gates (controlled by the `--feature-gates=<FlagName>=<true|false>` flag):
+
+* `CacheSecretsAndConfigMaps`: If enabled, Helm Controller will fetch all ConfigMaps and Secrets in the cluster and save them in a cache for faster access. This is disabled by default to reduce RAM usage and reduce cluster-wide RBAC requirements.
+
 ## Backward compatibility
 
 | Feature                                                             | Helm Controller          | Helm Operator      |

main.go

@@ -84,7 +84,7 @@ func main() {
 		leaderElectionOptions   leaderelection.Options
 		rateLimiterOptions      helper.RateLimiterOptions
 	)
-
+	// NOTE: If you add a new flag, remember to update docs/spec/README.md
 	flag.StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
 	flag.StringVar(&eventsAddr, "events-addr", "", "The address of the events receiver.")
 	flag.StringVar(&healthAddr, "health-addr", ":9440", "The address the health endpoint binds to.")