mirror of https://github.com/hashicorp/consul
90 lines
2.2 KiB
Go
90 lines
2.2 KiB
Go
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package controller
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import (
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"context"
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"sync"
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"sync/atomic"
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"github.com/hashicorp/go-hclog"
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"github.com/hashicorp/consul/internal/resource"
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)
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// Manager is responsible for scheduling the execution of controllers.
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type Manager struct {
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logger hclog.Logger
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raftLeader atomic.Bool
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mu sync.Mutex
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running bool
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controllers []Controller
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leaseChans []chan struct{}
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}
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// NewManager creates a Manager. logger will be used by the Manager, and as the
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// base logger for controllers when one is not specified using WithLogger.
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func NewManager(logger hclog.Logger) *Manager {
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return &Manager{logger: logger}
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}
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// Register the given controller to be executed by the Manager. Cannot be called
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// once the Manager is running.
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func (m *Manager) Register(ctrl Controller) {
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m.mu.Lock()
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defer m.mu.Unlock()
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if m.running {
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panic("cannot register additional controllers after calling Run")
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}
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m.controllers = append(m.controllers, ctrl)
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}
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// Run the Manager and start executing controllers until the given context is
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// canceled. Cannot be called more than once.
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func (m *Manager) Run(ctx context.Context) {
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m.mu.Lock()
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defer m.mu.Unlock()
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if m.running {
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panic("cannot call Run more than once")
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}
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m.running = true
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for _, desc := range m.controllers {
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runner := &controllerRunner{
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ctrl: desc,
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logger: m.logger.With("managed_type", resource.ToGVK(desc.managedType)),
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}
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go newSupervisor(runner.run, m.newLeaseLocked()).run(ctx)
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}
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}
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// SetRaftLeader notifies the Manager of Raft leadership changes. Controllers
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// are currently only executed on the Raft leader, so calling this method will
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// cause the Manager to spin them up/down accordingly.
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func (m *Manager) SetRaftLeader(leader bool) {
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m.raftLeader.Store(leader)
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m.mu.Lock()
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defer m.mu.Unlock()
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for _, ch := range m.leaseChans {
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select {
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case ch <- struct{}{}:
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default:
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// Do not block if there's nothing receiving on ch (because the supervisor is
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// busy doing something else). Note that ch has a buffer of 1, so we'll never
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// miss the notification that something has changed so we need to re-evaluate
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// the lease.
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}
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}
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}
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func (m *Manager) newLeaseLocked() Lease {
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ch := make(chan struct{}, 1)
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m.leaseChans = append(m.leaseChans, ch)
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return &raftLease{m: m, ch: ch}
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}
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