renaming plugins -> inputs

plugins/inputs/postgresql/README.md

@@ -0,0 +1,30 @@
+# PostgreSQL plugin
+
+This postgresql plugin provides metrics for your postgres database. It currently works with postgres versions 8.1+. It uses data from the built in _pg_stat_database_ view. The metrics recorded depend on your version of postgres. See table:
+```
+pg version      9.2+   9.1   8.3-9.0   8.1-8.2   7.4-8.0(unsupported)
+---             ---    ---   -------   -------   -------
+datid*           x      x       x         x
+datname*         x      x       x         x
+numbackends      x      x       x         x         x
+xact_commit      x      x       x         x         x
+xact_rollback    x      x       x         x         x
+blks_read        x      x       x         x         x
+blks_hit         x      x       x         x         x
+tup_returned     x      x       x
+tup_fetched      x      x       x
+tup_inserted     x      x       x
+tup_updated      x      x       x
+tup_deleted      x      x       x
+conflicts        x      x
+temp_files       x
+temp_bytes       x
+deadlocks        x
+blk_read_time    x
+blk_write_time   x
+stats_reset*     x      x
+```
+
+_* value ignored and therefore not recorded._
+
+More information about the meaning of these metrics can be found in the [PostgreSQL Documentation](http://www.postgresql.org/docs/9.2/static/monitoring-stats.html#PG-STAT-DATABASE-VIEW)

plugins/inputs/postgresql/postgresql.go

@@ -0,0 +1,151 @@
+package postgresql
+
+import (
+	"bytes"
+	"database/sql"
+	"fmt"
+	"strings"
+
+	"github.com/influxdb/telegraf/plugins/inputs"
+
+	_ "github.com/lib/pq"
+)
+
+type Postgresql struct {
+	Address        string
+	Databases      []string
+	OrderedColumns []string
+}
+
+var ignoredColumns = map[string]bool{"datid": true, "datname": true, "stats_reset": true}
+
+var sampleConfig = `
+  # specify address via a url matching:
+  #   postgres://[pqgotest[:password]]@localhost[/dbname]?sslmode=[disable|verify-ca|verify-full]
+  # or a simple string:
+  #   host=localhost user=pqotest password=... sslmode=... dbname=app_production
+  #
+  # All connection parameters are optional.
+  #
+  # Without the dbname parameter, the driver will default to a database
+  # with the same name as the user. This dbname is just for instantiating a
+  # connection with the server and doesn't restrict the databases we are trying
+  # to grab metrics for.
+  #
+  address = "host=localhost user=postgres sslmode=disable"
+
+  # A list of databases to pull metrics about. If not specified, metrics for all
+  # databases are gathered.
+  # databases = ["app_production", "testing"]
+`
+
+func (p *Postgresql) SampleConfig() string {
+	return sampleConfig
+}
+
+func (p *Postgresql) Description() string {
+	return "Read metrics from one or many postgresql servers"
+}
+
+func (p *Postgresql) IgnoredColumns() map[string]bool {
+	return ignoredColumns
+}
+
+var localhost = "host=localhost sslmode=disable"
+
+func (p *Postgresql) Gather(acc inputs.Accumulator) error {
+	var query string
+
+	if p.Address == "" || p.Address == "localhost" {
+		p.Address = localhost
+	}
+
+	db, err := sql.Open("postgres", p.Address)
+	if err != nil {
+		return err
+	}
+
+	defer db.Close()
+
+	if len(p.Databases) == 0 {
+		query = `SELECT * FROM pg_stat_database`
+	} else {
+		query = fmt.Sprintf(`SELECT * FROM pg_stat_database WHERE datname IN ('%s')`,
+			strings.Join(p.Databases, "','"))
+	}
+
+	rows, err := db.Query(query)
+	if err != nil {
+		return err
+	}
+
+	defer rows.Close()
+
+	// grab the column information from the result
+	p.OrderedColumns, err = rows.Columns()
+	if err != nil {
+		return err
+	}
+
+	for rows.Next() {
+		err = p.accRow(rows, acc)
+		if err != nil {
+			return err
+		}
+	}
+
+	return rows.Err()
+}
+
+type scanner interface {
+	Scan(dest ...interface{}) error
+}
+
+func (p *Postgresql) accRow(row scanner, acc inputs.Accumulator) error {
+	var columnVars []interface{}
+	var dbname bytes.Buffer
+
+	// this is where we'll store the column name with its *interface{}
+	columnMap := make(map[string]*interface{})
+
+	for _, column := range p.OrderedColumns {
+		columnMap[column] = new(interface{})
+	}
+
+	// populate the array of interface{} with the pointers in the right order
+	for i := 0; i < len(columnMap); i++ {
+		columnVars = append(columnVars, columnMap[p.OrderedColumns[i]])
+	}
+
+	// deconstruct array of variables and send to Scan
+	err := row.Scan(columnVars...)
+
+	if err != nil {
+		return err
+	}
+
+	// extract the database name from the column map
+	dbnameChars := (*columnMap["datname"]).([]uint8)
+	for i := 0; i < len(dbnameChars); i++ {
+		dbname.WriteString(string(dbnameChars[i]))
+	}
+
+	tags := map[string]string{"server": p.Address, "db": dbname.String()}
+
+	fields := make(map[string]interface{})
+	for col, val := range columnMap {
+		_, ignore := ignoredColumns[col]
+		if !ignore {
+			fields[col] = *val
+		}
+	}
+	acc.AddFields("postgresql", fields, tags)
+
+	return nil
+}
+
+func init() {
+	inputs.Add("postgresql", func() inputs.Input {
+		return &Postgresql{}
+	})
+}

plugins/inputs/postgresql/postgresql_test.go

@@ -0,0 +1,146 @@
+package postgresql
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/influxdb/telegraf/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPostgresqlGeneratesMetrics(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	p := &Postgresql{
+		Address: fmt.Sprintf("host=%s user=postgres sslmode=disable",
+			testutil.GetLocalHost()),
+		Databases: []string{"postgres"},
+	}
+
+	var acc testutil.Accumulator
+
+	err := p.Gather(&acc)
+	require.NoError(t, err)
+
+	availableColumns := make(map[string]bool)
+	for _, col := range p.OrderedColumns {
+		availableColumns[col] = true
+	}
+
+	intMetrics := []string{
+		"xact_commit",
+		"xact_rollback",
+		"blks_read",
+		"blks_hit",
+		"tup_returned",
+		"tup_fetched",
+		"tup_inserted",
+		"tup_updated",
+		"tup_deleted",
+		"conflicts",
+		"temp_files",
+		"temp_bytes",
+		"deadlocks",
+		"numbackends",
+	}
+
+	floatMetrics := []string{
+		"blk_read_time",
+		"blk_write_time",
+	}
+
+	metricsCounted := 0
+
+	for _, metric := range intMetrics {
+		_, ok := availableColumns[metric]
+		if ok {
+			assert.True(t, acc.HasIntField("postgresql", metric))
+			metricsCounted++
+		}
+	}
+
+	for _, metric := range floatMetrics {
+		_, ok := availableColumns[metric]
+		if ok {
+			assert.True(t, acc.HasFloatField("postgresql", metric))
+			metricsCounted++
+		}
+	}
+
+	assert.True(t, metricsCounted > 0)
+	assert.Equal(t, len(availableColumns)-len(p.IgnoredColumns()), metricsCounted)
+}
+
+func TestPostgresqlTagsMetricsWithDatabaseName(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	p := &Postgresql{
+		Address: fmt.Sprintf("host=%s user=postgres sslmode=disable",
+			testutil.GetLocalHost()),
+		Databases: []string{"postgres"},
+	}
+
+	var acc testutil.Accumulator
+
+	err := p.Gather(&acc)
+	require.NoError(t, err)
+
+	point, ok := acc.Get("postgresql")
+	require.True(t, ok)
+
+	assert.Equal(t, "postgres", point.Tags["db"])
+}
+
+func TestPostgresqlDefaultsToAllDatabases(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	p := &Postgresql{
+		Address: fmt.Sprintf("host=%s user=postgres sslmode=disable",
+			testutil.GetLocalHost()),
+	}
+
+	var acc testutil.Accumulator
+
+	err := p.Gather(&acc)
+	require.NoError(t, err)
+
+	var found bool
+
+	for _, pnt := range acc.Points {
+		if pnt.Measurement == "postgresql" {
+			if pnt.Tags["db"] == "postgres" {
+				found = true
+				break
+			}
+		}
+	}
+
+	assert.True(t, found)
+}
+
+func TestPostgresqlIgnoresUnwantedColumns(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping integration test in short mode")
+	}
+
+	p := &Postgresql{
+		Address: fmt.Sprintf("host=%s user=postgres sslmode=disable",
+			testutil.GetLocalHost()),
+	}
+
+	var acc testutil.Accumulator
+
+	err := p.Gather(&acc)
+	require.NoError(t, err)
+
+	for col := range p.IgnoredColumns() {
+		assert.False(t, acc.HasMeasurement(col))
+	}
+}