Move monitor.Diagnostics to its own package

I was trying to create a Diagnostics Client in the tsdb package, but
IIRC importing `monitor` caused an import cycle of:
tsdb -> monitor -> cluster -> tsdb.

Moving Diagnostics to its own package will allow further use of
diagnostics.Client without running into import cycles.

monitor/build_info.go

@@ -1,5 +1,7 @@
 package monitor
 
+import "github.com/influxdata/influxdb/monitor/diagnostics"
+
 // system captures build diagnostics
 type build struct {
 	Version string
@@ -8,7 +10,7 @@ type build struct {
 	Time    string
 }
 
-func (b *build) Diagnostics() (*Diagnostic, error) {
+func (b *build) Diagnostics() (*diagnostics.Diagnostics, error) {
 	diagnostics := map[string]interface{}{
 		"Version":    b.Version,
 		"Commit":     b.Commit,
@@ -16,5 +18,5 @@ func (b *build) Diagnostics() (*Diagnostic, error) {
 		"Build Time": b.Time,
 	}
 
-	return DiagnosticFromMap(diagnostics), nil
+	return DiagnosticsFromMap(diagnostics), nil
 }

monitor/diagnostics/diagnostics.go

@@ -0,0 +1,41 @@
+package diagnostics // import "github.com/influxdata/influxdb/monitor/diagnostics"
+
+// Client is the interface modules implement if they register diagnostics with monitor.
+type Client interface {
+	Diagnostics() (*Diagnostics, error)
+}
+
+// The ClientFunc type is an adapter to allow the use of
+// ordinary functions as Diagnostics clients.
+type ClientFunc func() (*Diagnostics, error)
+
+// Diagnostics calls f().
+func (f ClientFunc) Diagnostics() (*Diagnostics, error) {
+	return f()
+}
+
+// Diagnostics represents a table of diagnostic information. The first value
+// is the name of the columns, the second is a slice of interface slices containing
+// the values for each column, by row. This information is never written to an InfluxDB
+// system and is display-only. An example showing, say, connections follows:
+//
+//     source_ip    source_port       dest_ip     dest_port
+//     182.1.0.2    2890              127.0.0.1   38901
+//     174.33.1.2   2924              127.0.0.1   38902
+type Diagnostics struct {
+	Columns []string
+	Rows    [][]interface{}
+}
+
+// NewDiagnostic initialises a new Diagnostics with the specified columns.
+func NewDiagnostics(columns []string) *Diagnostics {
+	return &Diagnostics{
+		Columns: columns,
+		Rows:    make([][]interface{}, 0),
+	}
+}
+
+// AddRow appends the provided row to the Diagnostics' rows.
+func (d *Diagnostics) AddRow(r []interface{}) {
+	d.Rows = append(d.Rows, r)
+}

monitor/go_runtime.go

@@ -2,12 +2,14 @@ package monitor
 
 import (
 	"runtime"
+
+	"github.com/influxdata/influxdb/monitor/diagnostics"
 )
 
 // goRuntime captures Go runtime diagnostics
 type goRuntime struct{}
 
-func (g *goRuntime) Diagnostics() (*Diagnostic, error) {
+func (g *goRuntime) Diagnostics() (*diagnostics.Diagnostics, error) {
 	diagnostics := map[string]interface{}{
 		"GOARCH":     runtime.GOARCH,
 		"GOOS":       runtime.GOOS,
@@ -15,5 +17,5 @@ func (g *goRuntime) Diagnostics() (*Diagnostic, error) {
 		"version":    runtime.Version(),
 	}
 
-	return DiagnosticFromMap(diagnostics), nil
+	return DiagnosticsFromMap(diagnostics), nil
 }

monitor/network.go

@@ -2,12 +2,14 @@ package monitor
 
 import (
 	"os"
+
+	"github.com/influxdata/influxdb/monitor/diagnostics"
 )
 
 // network captures network diagnostics
 type network struct{}
 
-func (n *network) Diagnostics() (*Diagnostic, error) {
+func (n *network) Diagnostics() (*diagnostics.Diagnostics, error) {
 	h, err := os.Hostname()
 	if err != nil {
 		return nil, err
@@ -17,5 +19,5 @@ func (n *network) Diagnostics() (*Diagnostic, error) {
 		"hostname": h,
 	}
 
-	return DiagnosticFromMap(diagnostics), nil
+	return DiagnosticsFromMap(diagnostics), nil
 }

monitor/service.go

@@ -14,6 +14,7 @@ import (
 	"github.com/influxdata/influxdb"
 	"github.com/influxdata/influxdb/cluster"
 	"github.com/influxdata/influxdb/models"
+	"github.com/influxdata/influxdb/monitor/diagnostics"
 	"github.com/influxdata/influxdb/services/meta"
 )
 
@@ -25,46 +26,6 @@ const (
 	MonitorRetentionPolicyDuration = 7 * 24 * time.Hour
 )
 
-// DiagsClient is the interface modules implement if they register diags with monitor.
-type DiagsClient interface {
-	Diagnostics() (*Diagnostic, error)
-}
-
-// The DiagsClientFunc type is an adapter to allow the use of
-// ordinary functions as Diagnostis clients.
-type DiagsClientFunc func() (*Diagnostic, error)
-
-// Diagnostics calls f().
-func (f DiagsClientFunc) Diagnostics() (*Diagnostic, error) {
-	return f()
-}
-
-// Diagnostic represents a table of diagnostic information. The first value
-// is the name of the columns, the second is a slice of interface slices containing
-// the values for each column, by row. This information is never written to an InfluxDB
-// system and is display-only. An example showing, say, connections follows:
-//
-//     source_ip    source_port       dest_ip     dest_port
-//     182.1.0.2    2890              127.0.0.1   38901
-//     174.33.1.2   2924              127.0.0.1   38902
-type Diagnostic struct {
-	Columns []string
-	Rows    [][]interface{}
-}
-
-// NewDiagnostic initialises a new Diagnostic with the specified columns.
-func NewDiagnostic(columns []string) *Diagnostic {
-	return &Diagnostic{
-		Columns: columns,
-		Rows:    make([][]interface{}, 0),
-	}
-}
-
-// AddRow appends the provided row to the Diagnostic's rows.
-func (d *Diagnostic) AddRow(r []interface{}) {
-	d.Rows = append(d.Rows, r)
-}
-
 // Monitor represents an instance of the monitor system.
 type Monitor struct {
 	// Build information for diagnostics.
@@ -77,7 +38,7 @@ type Monitor struct {
 	done chan struct{}
 	mu   sync.Mutex
 
-	diagRegistrations map[string]DiagsClient
+	diagRegistrations map[string]diagnostics.Client
 
 	storeCreated           bool
 	storeEnabled           bool
@@ -109,7 +70,7 @@ type Monitor struct {
 func New(c Config) *Monitor {
 	return &Monitor{
 		done:              make(chan struct{}),
-		diagRegistrations: make(map[string]DiagsClient),
+		diagRegistrations: make(map[string]diagnostics.Client),
 		storeEnabled:      c.StoreEnabled,
 		storeDatabase:     c.StoreDatabase,
 		storeInterval:     time.Duration(c.StoreInterval),
@@ -158,7 +119,7 @@ func (m *Monitor) SetLogger(l *log.Logger) {
 }
 
 // RegisterDiagnosticsClient registers a diagnostics client with the given name and tags.
-func (m *Monitor) RegisterDiagnosticsClient(name string, client DiagsClient) {
+func (m *Monitor) RegisterDiagnosticsClient(name string, client diagnostics.Client) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	m.diagRegistrations[name] = client
@@ -287,11 +248,11 @@ func (m *Monitor) Statistics(tags map[string]string) ([]*Statistic, error) {
 // Diagnostics fetches diagnostic information for each registered
 // diagnostic client. It skips any clients that return an error when
 // retrieving their diagnostics.
-func (m *Monitor) Diagnostics() (map[string]*Diagnostic, error) {
+func (m *Monitor) Diagnostics() (map[string]*diagnostics.Diagnostics, error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 
-	diags := make(map[string]*Diagnostic, len(m.diagRegistrations))
+	diags := make(map[string]*diagnostics.Diagnostics, len(m.diagRegistrations))
 	for k, v := range m.diagRegistrations {
 		d, err := v.Diagnostics()
 		if err != nil {
@@ -420,8 +381,8 @@ func (s *Statistic) valueNames() []string {
 	return a
 }
 
-// DiagnosticFromMap returns a Diagnostic from a map.
+// DiagnosticsFromMap returns a Diagnostics from a map.
-func DiagnosticFromMap(m map[string]interface{}) *Diagnostic {
+func DiagnosticsFromMap(m map[string]interface{}) *diagnostics.Diagnostics {
 	// Display columns in deterministic order.
 	sortedKeys := make([]string, 0, len(m))
 	for k := range m {
@@ -429,7 +390,7 @@ func DiagnosticFromMap(m map[string]interface{}) *Diagnostic {
 	}
 	sort.Strings(sortedKeys)
 
-	d := NewDiagnostic(sortedKeys)
+	d := diagnostics.NewDiagnostics(sortedKeys)
 	row := make([]interface{}, len(sortedKeys))
 	for i, k := range sortedKeys {
 		row[i] = m[k]

monitor/statement_executor.go

@@ -6,13 +6,14 @@ import (
 
 	"github.com/influxdata/influxdb/influxql"
 	"github.com/influxdata/influxdb/models"
+	"github.com/influxdata/influxdb/monitor/diagnostics"
 )
 
 // StatementExecutor translates InfluxQL queries to Monitor methods.
 type StatementExecutor struct {
 	Monitor interface {
 		Statistics(map[string]string) ([]*Statistic, error)
-		Diagnostics() (map[string]*Diagnostic, error)
+		Diagnostics() (map[string]*diagnostics.Diagnostics, error)
 	}
 }
 

monitor/system.go

@@ -3,6 +3,8 @@ package monitor
 import (
 	"os"
 	"time"
+
+	"github.com/influxdata/influxdb/monitor/diagnostics"
 )
 
 var startTime time.Time
@@ -14,7 +16,7 @@ func init() {
 // system captures system-level diagnostics
 type system struct{}
 
-func (s *system) Diagnostics() (*Diagnostic, error) {
+func (s *system) Diagnostics() (*diagnostics.Diagnostics, error) {
 	diagnostics := map[string]interface{}{
 		"PID":         os.Getpid(),
 		"currentTime": time.Now().UTC(),
@@ -22,5 +24,5 @@ func (s *system) Diagnostics() (*Diagnostic, error) {
 		"uptime":      time.Since(startTime).String(),
 	}
 
-	return DiagnosticFromMap(diagnostics), nil
+	return DiagnosticsFromMap(diagnostics), nil
 }

services/graphite/service.go

@@ -14,7 +14,7 @@ import (
 
 	"github.com/influxdata/influxdb"
 	"github.com/influxdata/influxdb/cluster"
-	"github.com/influxdata/influxdb/monitor"
+	"github.com/influxdata/influxdb/monitor/diagnostics"
 	"github.com/influxdata/influxdb/services/meta"
 	"github.com/influxdata/influxdb/tsdb"
 )
@@ -76,7 +76,7 @@ type Service struct {
 	done chan struct{}
 
 	Monitor interface {
-		RegisterDiagnosticsClient(name string, client monitor.DiagsClient)
+		RegisterDiagnosticsClient(name string, client diagnostics.Client)
 		DeregisterDiagnosticsClient(name string)
 	}
 	PointsWriter interface {
@@ -374,16 +374,15 @@ func (s *Service) processBatches(batcher *tsdb.PointBatcher) {
 }
 
 // Diagnostics returns diagnostics of the graphite service.
-func (s *Service) Diagnostics() (*monitor.Diagnostic, error) {
+func (s *Service) Diagnostics() (*diagnostics.Diagnostics, error) {
 	s.tcpConnectionsMu.Lock()
 	defer s.tcpConnectionsMu.Unlock()
 
-	d := &monitor.Diagnostic{
+	d := &diagnostics.Diagnostics{
 		Columns: []string{"local", "remote", "connect time"},
 		Rows:    make([][]interface{}, 0, len(s.tcpConnections)),
 	}
 	for _, v := range s.tcpConnections {
-		_ = v
 		d.Rows = append(d.Rows, []interface{}{v.conn.LocalAddr().String(), v.conn.RemoteAddr().String(), v.connectTime})
 	}
 	return d, nil

services/hh/service.go

@@ -14,7 +14,7 @@ import (
 
 	"github.com/influxdata/influxdb"
 	"github.com/influxdata/influxdb/models"
-	"github.com/influxdata/influxdb/monitor"
+	"github.com/influxdata/influxdb/monitor/diagnostics"
 	"github.com/influxdata/influxdb/services/meta"
 )
 
@@ -46,7 +46,7 @@ type Service struct {
 	MetaClient  metaClient
 
 	Monitor interface {
-		RegisterDiagnosticsClient(name string, client monitor.DiagsClient)
+		RegisterDiagnosticsClient(name string, client diagnostics.Client)
 		DeregisterDiagnosticsClient(name string)
 	}
 }
@@ -188,11 +188,11 @@ func (s *Service) WriteShard(shardID, ownerID uint64, points []models.Point) err
 }
 
 // Diagnostics returns diagnostic information.
-func (s *Service) Diagnostics() (*monitor.Diagnostic, error) {
+func (s *Service) Diagnostics() (*diagnostics.Diagnostics, error) {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	d := &monitor.Diagnostic{
+	d := &diagnostics.Diagnostics{
 		Columns: []string{"node", "active", "last modified", "head", "tail"},
 		Rows:    make([][]interface{}, 0, len(s.processors)),
 	}