mirror of https://github.com/hashicorp/consul
95 lines
2.6 KiB
Go
95 lines
2.6 KiB
Go
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package agent
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import (
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"context"
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"net"
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"sync"
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"time"
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"github.com/hashicorp/go-hclog"
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"golang.org/x/sync/errgroup"
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)
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// apiServers is a wrapper around errgroup.Group for managing go routines for
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// long running agent components (ex: http server, dns server). If any of the
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// servers fail, the failed channel will be closed, which will cause the agent
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// to be shutdown instead of running in a degraded state.
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//
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// This struct exists as a shim for using errgroup.Group without making major
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// changes to Agent. In the future it may be removed and replaced with more
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// direct usage of errgroup.Group.
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type apiServers struct {
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logger hclog.Logger
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group *errgroup.Group
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servers []apiServer
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// failed channel is closed when the first server goroutines exit with a
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// non-nil error.
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failed <-chan struct{}
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}
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type apiServer struct {
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// Protocol supported by this server. One of: dns, http, https
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Protocol string
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// Addr the server is listening on
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Addr net.Addr
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// Run will be called in a goroutine to run the server. When any Run exits
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// with a non-nil error, the failed channel will be closed.
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Run func() error
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// Shutdown function used to stop the server
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Shutdown func(context.Context) error
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}
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// NewAPIServers returns an empty apiServers that is ready to Start servers.
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func NewAPIServers(logger hclog.Logger) *apiServers {
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group, ctx := errgroup.WithContext(context.TODO())
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return &apiServers{
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logger: logger,
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group: group,
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failed: ctx.Done(),
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}
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}
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func (s *apiServers) Start(srv apiServer) {
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srv.logger(s.logger).Info("Starting server")
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s.servers = append(s.servers, srv)
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s.group.Go(srv.Run)
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}
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func (s apiServer) logger(base hclog.Logger) hclog.Logger {
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return base.With(
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"protocol", s.Protocol,
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"address", s.Addr.String(),
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"network", s.Addr.Network())
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}
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// Shutdown all the servers and log any errors as warning. Each server is given
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// 1 second, or until ctx is cancelled, to shutdown gracefully.
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func (s *apiServers) Shutdown(ctx context.Context) {
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shutdownGroup := new(sync.WaitGroup)
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for i := range s.servers {
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server := s.servers[i]
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shutdownGroup.Add(1)
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go func() {
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defer shutdownGroup.Done()
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logger := server.logger(s.logger)
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logger.Info("Stopping server")
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ctx, cancel := context.WithTimeout(ctx, time.Second)
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defer cancel()
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if err := server.Shutdown(ctx); err != nil {
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logger.Warn("Failed to stop server")
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}
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}()
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}
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s.servers = nil
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shutdownGroup.Wait()
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}
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// WaitForShutdown waits until all server goroutines have exited. Shutdown
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// must be called before WaitForShutdown, otherwise it will block forever.
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func (s *apiServers) WaitForShutdown() error {
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return s.group.Wait()
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}
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