Improve lint/vet reliability and refactor client runtime/bootstrap

1 files changed, 84 insertions, 0 deletions

diff --git a/internal/cli/runtime.go b/internal/cli/runtime.go
new file mode 100644
index 0000000..5e577c2
--- /dev/null
+++ b/internal/cli/runtime.go
@@ -0,0 +1,84 @@
+package cli
+
+import (
+	"context"
+	"net/http"
+	_ "net/http/pprof" // Register pprof handlers when runtime pprof endpoint is enabled.
+	"sync"
+
+	"github.com/mimecast/dtail/internal/io/dlog"
+	"github.com/mimecast/dtail/internal/profiling"
+	"github.com/mimecast/dtail/internal/source"
+)
+
+// ClientRuntime owns common client command runtime components.
+type ClientRuntime struct {
+	ctx            context.Context
+	cancel         context.CancelFunc
+	wg             sync.WaitGroup
+	profiler       *profiling.Profiler
+	profileEnabled bool
+}
+
+// NewClientRuntime starts logging and profiling for a client command.
+func NewClientRuntime(parent context.Context, profileFlags profiling.Flags, profileName string) *ClientRuntime {
+	if parent == nil {
+		parent = context.Background()
+	}
+	ctx, cancel := context.WithCancel(parent)
+	runtime := &ClientRuntime{
+		ctx:            ctx,
+		cancel:         cancel,
+		profiler:       profiling.NewProfiler(profileFlags.ToConfig(profileName)),
+		profileEnabled: profileFlags.Enabled(),
+	}
+
+	runtime.wg.Add(1)
+	dlog.Start(ctx, &runtime.wg, source.Client)
+	return runtime
+}
+
+// Context returns the runtime context.
+func (r *ClientRuntime) Context() context.Context {
+	return r.ctx
+}
+
+// Cancel cancels the runtime context.
+func (r *ClientRuntime) Cancel() {
+	r.cancel()
+}
+
+// StartPProf starts the pprof server if an address is provided.
+func (r *ClientRuntime) StartPProf(address string) {
+	if address == "" {
+		return
+	}
+
+	dlog.Client.Info("Starting PProf", address)
+	go func() {
+		if err := http.ListenAndServe(address, nil); err != nil {
+			dlog.Client.Error("PProf server exited", err)
+		}
+	}()
+}
+
+// LogStartupMetrics logs startup profiling metrics when enabled.
+func (r *ClientRuntime) LogStartupMetrics() {
+	if r.profileEnabled {
+		r.profiler.LogMetrics("startup")
+	}
+}
+
+// LogShutdownMetrics logs shutdown profiling metrics when enabled.
+func (r *ClientRuntime) LogShutdownMetrics() {
+	if r.profileEnabled {
+		r.profiler.LogMetrics("shutdown")
+	}
+}
+
+// Stop stops profiling and logging runtime goroutines.
+func (r *ClientRuntime) Stop() {
+	r.profiler.Stop()
+	r.cancel()
+	r.wg.Wait()
+}