From 713461df9847bd50d47b0df2b5a4f1f01206bdb8 Mon Sep 17 00:00:00 2001
From: Joe Adams <github@joeadams.io>
Date: Fri, 25 Feb 2022 11:45:15 -0500
Subject: [PATCH] WIP: Add prelim multi-target support
- Remove multi server support from new collector package
- Add http handler for multi-target support
Signed-off-by: Joe Adams <github@joeadams.io>
---
cmd/postgres_exporter/datasource.go | 6 ++
cmd/postgres_exporter/main.go | 25 ++++---
cmd/postgres_exporter/probe.go | 91 +++++++++++++++++++++++++
collector/collector.go | 44 +++++-------
collector/pg_database.go | 11 ++-
collector/pg_stat_bgwriter.go | 43 ++++--------
collector/probe.go | 90 +++++++++++++++++++++++++
collector/server.go | 100 ----------------------------
8 files changed, 239 insertions(+), 171 deletions(-)
create mode 100644 cmd/postgres_exporter/probe.go
create mode 100644 collector/probe.go
delete mode 100644 collector/server.go
diff --git a/cmd/postgres_exporter/datasource.go b/cmd/postgres_exporter/datasource.go
index 90d797b6..716138f3 100644
--- a/cmd/postgres_exporter/datasource.go
+++ b/cmd/postgres_exporter/datasource.go
@@ -162,6 +162,12 @@ func getDataSources() ([]string, error) {
uri = os.Getenv("DATA_SOURCE_URI")
}
+ // No datasources found. This allows us to support the multi-target pattern
+ // withouth an explicit datasource.
+ if uri == "" {
+ return []string{}, nil
+ }
+
dsn = "postgresql://" + ui + "@" + uri
return []string{dsn}, nil
diff --git a/cmd/postgres_exporter/main.go b/cmd/postgres_exporter/main.go
index 35db723a..2ec1bf26 100644
--- a/cmd/postgres_exporter/main.go
+++ b/cmd/postgres_exporter/main.go
@@ -85,16 +85,17 @@ func main() {
return
}
- dsn, err := getDataSources()
+ dsns, err := getDataSources()
if err != nil {
level.Error(logger).Log("msg", "Failed reading data sources", "err", err.Error())
os.Exit(1)
}
- if len(dsn) == 0 {
- level.Error(logger).Log("msg", "Couldn't find environment variables describing the datasource to use")
- os.Exit(1)
- }
+ // TODO(@sysadmind): Remove this with multi-target support
+ // if len(dsn) == 0 {
+ // level.Error(logger).Log("msg", "Couldn't find environment variables describing the datasource to use")
+ // os.Exit(1)
+ // }
opts := []ExporterOpt{
DisableDefaultMetrics(*disableDefaultMetrics),
@@ -106,7 +107,7 @@ func main() {
IncludeDatabases(*includeDatabases),
}
- exporter := NewExporter(dsn, opts...)
+ exporter := NewExporter(dsns, opts...)
defer func() {
exporter.servers.Close()
}()
@@ -115,6 +116,12 @@ func main() {
prometheus.MustRegister(exporter)
+ // TODO(@sysadmind): Remove this with multi-target support. We are removing multiple DSN support
+ dsn := ""
+ if len(dsns) > 0 {
+ dsn = dsns[0]
+ }
+
pe, err := collector.NewPostgresCollector(
logger,
dsn,
@@ -122,9 +129,9 @@ func main() {
)
if err != nil {
level.Error(logger).Log("msg", "Failed to create PostgresCollector", "err", err.Error())
- os.Exit(1)
+ } else {
+ prometheus.MustRegister(pe)
}
- prometheus.MustRegister(pe)
http.Handle(*metricPath, promhttp.Handler())
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
@@ -132,6 +139,8 @@ func main() {
w.Write(landingPage) // nolint: errcheck
})
+ http.HandleFunc("/probe", handleProbe(logger))
+
level.Info(logger).Log("msg", "Listening on address", "address", *listenAddress)
srv := &http.Server{Addr: *listenAddress}
if err := web.ListenAndServe(srv, *webConfig, logger); err != nil {
diff --git a/cmd/postgres_exporter/probe.go b/cmd/postgres_exporter/probe.go
new file mode 100644
index 00000000..c23777b4
--- /dev/null
+++ b/cmd/postgres_exporter/probe.go
@@ -0,0 +1,91 @@
+// Copyright 2022 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+ "net/http"
+ "time"
+
+ "github.com/go-kit/log"
+ "github.com/prometheus-community/postgres_exporter/collector"
+ "github.com/prometheus/client_golang/prometheus"
+ "github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+func handleProbe(logger log.Logger) http.HandlerFunc {
+ return func(w http.ResponseWriter, r *http.Request) {
+ ctx := r.Context()
+ params := r.URL.Query()
+ target := params.Get("target")
+ if target == "" {
+ http.Error(w, "target is required", http.StatusBadRequest)
+ return
+ }
+
+ // TODO: Timeout
+ // TODO: Auth Module
+
+ probeSuccessGauge := prometheus.NewGauge(prometheus.GaugeOpts{
+ Name: "probe_success",
+ Help: "Displays whether or not the probe was a success",
+ })
+ probeDurationGauge := prometheus.NewGauge(prometheus.GaugeOpts{
+ Name: "probe_duration_seconds",
+ Help: "Returns how long the probe took to complete in seconds",
+ })
+
+ tl := log.With(logger, "target", target)
+ _ = tl
+
+ start := time.Now()
+ registry := prometheus.NewRegistry()
+ registry.MustRegister(probeSuccessGauge)
+ registry.MustRegister(probeDurationGauge)
+
+ // TODO(@sysadmind): this is a temp hack until we have a proper auth module
+ target = "postgres://postgres:test@localhost:5432/circle_test?sslmode=disable"
+
+ // Run the probe
+ pc, err := collector.NewProbeCollector(tl, registry, target)
+ if err != nil {
+ probeSuccessGauge.Set(0)
+ probeDurationGauge.Set(time.Since(start).Seconds())
+ http.Error(w, err.Error(), http.StatusInternalServerError)
+ return
+ }
+ _ = ctx
+
+ // TODO: Which way should this be? Register or handle the collection manually?
+ // Also, what about the context?
+
+ // Option 1: Register the collector
+ registry.MustRegister(pc)
+
+ // Option 2: Handle the collection manually. This allows us to collect duration metrics.
+ // The collectors themselves already support their own duration metrics.
+ // err = pc.Update(ctx)
+ // if err != nil {
+ // probeSuccessGauge.Set(0)
+ // } else {
+ // probeSuccessGauge.Set(1)
+ // }
+
+ duration := time.Since(start).Seconds()
+ probeDurationGauge.Set(duration)
+
+ // TODO check success, etc
+ h := promhttp.HandlerFor(registry, promhttp.HandlerOpts{})
+ h.ServeHTTP(w, r)
+ }
+}
diff --git a/collector/collector.go b/collector/collector.go
index 58765b65..6d1a4dd1 100644
--- a/collector/collector.go
+++ b/collector/collector.go
@@ -15,6 +15,7 @@ package collector
import (
"context"
+ "database/sql"
"errors"
"fmt"
"sync"
@@ -58,7 +59,7 @@ var (
)
type Collector interface {
- Update(ctx context.Context, server *server, ch chan<- prometheus.Metric) error
+ Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error
}
func registerCollector(name string, isDefaultEnabled bool, createFunc func(logger log.Logger) (Collector, error)) {
@@ -86,13 +87,13 @@ type PostgresCollector struct {
Collectors map[string]Collector
logger log.Logger
- servers map[string]*server
+ db *sql.DB
}
type Option func(*PostgresCollector) error
// NewPostgresCollector creates a new PostgresCollector.
-func NewPostgresCollector(logger log.Logger, dsns []string, filters []string, options ...Option) (*PostgresCollector, error) {
+func NewPostgresCollector(logger log.Logger, dsn string, filters []string, options ...Option) (*PostgresCollector, error) {
p := &PostgresCollector{
logger: logger,
}
@@ -136,17 +137,18 @@ func NewPostgresCollector(logger log.Logger, dsns []string, filters []string, op
p.Collectors = collectors
- servers := make(map[string]*server)
- for _, dsn := range dsns {
- s, err := makeServer(dsn)
- if err != nil {
- return nil, err
- }
-
- servers[dsn] = s
+ if dsn == "" {
+ return nil, errors.New("empty dsn")
}
- p.servers = servers
+ db, err := sql.Open("postgres", dsn)
+ if err != nil {
+ return nil, err
+ }
+ db.SetMaxOpenConns(1)
+ db.SetMaxIdleConns(1)
+
+ p.db = db
return p, nil
}
@@ -160,32 +162,20 @@ func (p PostgresCollector) Describe(ch chan<- *prometheus.Desc) {
// Collect implements the prometheus.Collector interface.
func (p PostgresCollector) Collect(ch chan<- prometheus.Metric) {
ctx := context.TODO()
- wg := sync.WaitGroup{}
- wg.Add(len(p.servers))
- for _, s := range p.servers {
- go func(s *server) {
- p.subCollect(ctx, s, ch)
- wg.Done()
- }(s)
- }
- wg.Wait()
-}
-
-func (p PostgresCollector) subCollect(ctx context.Context, server *server, ch chan<- prometheus.Metric) {
wg := sync.WaitGroup{}
wg.Add(len(p.Collectors))
for name, c := range p.Collectors {
go func(name string, c Collector) {
- execute(ctx, name, c, server, ch, p.logger)
+ execute(ctx, name, c, p.db, ch, p.logger)
wg.Done()
}(name, c)
}
wg.Wait()
}
-func execute(ctx context.Context, name string, c Collector, s *server, ch chan<- prometheus.Metric, logger log.Logger) {
+func execute(ctx context.Context, name string, c Collector, db *sql.DB, ch chan<- prometheus.Metric, logger log.Logger) {
begin := time.Now()
- err := c.Update(ctx, s, ch)
+ err := c.Update(ctx, db, ch)
duration := time.Since(begin)
var success float64
diff --git a/collector/pg_database.go b/collector/pg_database.go
index 5868f66d..8fa4dab8 100644
--- a/collector/pg_database.go
+++ b/collector/pg_database.go
@@ -15,6 +15,7 @@ package collector
import (
"context"
+ "database/sql"
"github.com/go-kit/log"
"github.com/prometheus/client_golang/prometheus"
@@ -36,15 +37,11 @@ var pgDatabase = map[string]*prometheus.Desc{
"size_bytes": prometheus.NewDesc(
"pg_database_size_bytes",
"Disk space used by the database",
- []string{"datname", "server"}, nil,
+ []string{"datname"}, nil,
),
}
-func (PGDatabaseCollector) Update(ctx context.Context, server *server, ch chan<- prometheus.Metric) error {
- db, err := server.GetDB()
- if err != nil {
- return err
- }
+func (PGDatabaseCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
rows, err := db.QueryContext(ctx,
`SELECT pg_database.datname
,pg_database_size(pg_database.datname)
@@ -63,7 +60,7 @@ func (PGDatabaseCollector) Update(ctx context.Context, server *server, ch chan<-
ch <- prometheus.MustNewConstMetric(
pgDatabase["size_bytes"],
- prometheus.GaugeValue, float64(size), datname, server.GetName(),
+ prometheus.GaugeValue, float64(size), datname,
)
}
if err := rows.Err(); err != nil {
diff --git a/collector/pg_stat_bgwriter.go b/collector/pg_stat_bgwriter.go
index 7e7d09c7..f897dbe2 100644
--- a/collector/pg_stat_bgwriter.go
+++ b/collector/pg_stat_bgwriter.go
@@ -15,6 +15,7 @@ package collector
import (
"context"
+ "database/sql"
"time"
"github.com/go-kit/log"
@@ -38,77 +39,72 @@ var statBGWriter = map[string]*prometheus.Desc{
"checkpoints_timed": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "checkpoints_timed_total"),
"Number of scheduled checkpoints that have been performed",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"checkpoints_req": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "checkpoints_req_total"),
"Number of requested checkpoints that have been performed",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"checkpoint_write_time": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "checkpoint_write_time_total"),
"Total amount of time that has been spent in the portion of checkpoint processing where files are written to disk, in milliseconds",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"checkpoint_sync_time": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "checkpoint_sync_time_total"),
"Total amount of time that has been spent in the portion of checkpoint processing where files are synchronized to disk, in milliseconds",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"buffers_checkpoint": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "buffers_checkpoint_total"),
"Number of buffers written during checkpoints",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"buffers_clean": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "buffers_clean_total"),
"Number of buffers written by the background writer",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"maxwritten_clean": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "maxwritten_clean_total"),
"Number of times the background writer stopped a cleaning scan because it had written too many buffers",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"buffers_backend": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "buffers_backend_total"),
"Number of buffers written directly by a backend",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"buffers_backend_fsync": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "buffers_backend_fsync_total"),
"Number of times a backend had to execute its own fsync call (normally the background writer handles those even when the backend does its own write)",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"buffers_alloc": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "buffers_alloc_total"),
"Number of buffers allocated",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
"stats_reset": prometheus.NewDesc(
prometheus.BuildFQName(namespace, bgWriterSubsystem, "stats_reset_total"),
"Time at which these statistics were last reset",
- []string{"server"},
+ []string{},
prometheus.Labels{},
),
}
-func (PGStatBGWriterCollector) Update(ctx context.Context, server *server, ch chan<- prometheus.Metric) error {
- db, err := server.GetDB()
- if err != nil {
- return err
- }
-
+func (PGStatBGWriterCollector) Update(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
row := db.QueryRowContext(ctx,
`SELECT
checkpoints_timed
@@ -136,7 +132,7 @@ func (PGStatBGWriterCollector) Update(ctx context.Context, server *server, ch ch
var ba int
var sr time.Time
- err = row.Scan(&cpt, &cpr, &cpwt, &cpst, &bcp, &bc, &mwc, &bb, &bbf, &ba, &sr)
+ err := row.Scan(&cpt, &cpr, &cpwt, &cpst, &bcp, &bc, &mwc, &bb, &bbf, &ba, &sr)
if err != nil {
return err
}
@@ -145,67 +141,56 @@ func (PGStatBGWriterCollector) Update(ctx context.Context, server *server, ch ch
statBGWriter["checkpoints_timed"],
prometheus.CounterValue,
float64(cpt),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["checkpoints_req"],
prometheus.CounterValue,
float64(cpr),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["checkpoint_write_time"],
prometheus.CounterValue,
float64(cpwt),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["checkpoint_sync_time"],
prometheus.CounterValue,
float64(cpst),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["buffers_checkpoint"],
prometheus.CounterValue,
float64(bcp),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["buffers_clean"],
prometheus.CounterValue,
float64(bc),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["maxwritten_clean"],
prometheus.CounterValue,
float64(mwc),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["buffers_backend"],
prometheus.CounterValue,
float64(bb),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["buffers_backend_fsync"],
prometheus.CounterValue,
float64(bbf),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["buffers_alloc"],
prometheus.CounterValue,
float64(ba),
- server.GetName(),
)
ch <- prometheus.MustNewConstMetric(
statBGWriter["stats_reset"],
prometheus.CounterValue,
float64(sr.Unix()),
- server.GetName(),
)
return nil
diff --git a/collector/probe.go b/collector/probe.go
new file mode 100644
index 00000000..8aa18b92
--- /dev/null
+++ b/collector/probe.go
@@ -0,0 +1,90 @@
+// Copyright 2022 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package collector
+
+import (
+ "context"
+ "database/sql"
+ "fmt"
+ "strings"
+ "sync"
+
+ "github.com/go-kit/log"
+ "github.com/prometheus/client_golang/prometheus"
+)
+
+type ProbeCollector struct {
+ registry *prometheus.Registry
+ collectors map[string]Collector
+ logger log.Logger
+ db *sql.DB
+}
+
+func NewProbeCollector(logger log.Logger, registry *prometheus.Registry, dsn string) (*ProbeCollector, error) {
+ collectors := make(map[string]Collector)
+ initiatedCollectorsMtx.Lock()
+ defer initiatedCollectorsMtx.Unlock()
+ for key, enabled := range collectorState {
+ // TODO: Handle filters
+ // if !*enabled || (len(f) > 0 && !f[key]) {
+ // continue
+ // }
+ if !*enabled {
+ continue
+ }
+ if collector, ok := initiatedCollectors[key]; ok {
+ collectors[key] = collector
+ } else {
+ collector, err := factories[key](log.With(logger, "collector", key))
+ if err != nil {
+ return nil, err
+ }
+ collectors[key] = collector
+ initiatedCollectors[key] = collector
+ }
+ }
+
+ if !strings.HasPrefix(dsn, "postgres://") {
+ dsn = fmt.Sprintf("postgres://%s", dsn)
+ }
+
+ db, err := sql.Open("postgres", dsn)
+ if err != nil {
+ return nil, err
+ }
+ db.SetMaxOpenConns(1)
+ db.SetMaxIdleConns(1)
+
+ return &ProbeCollector{
+ registry: registry,
+ collectors: collectors,
+ logger: logger,
+ db: db,
+ }, nil
+}
+
+func (pc *ProbeCollector) Describe(ch chan<- *prometheus.Desc) {
+}
+
+func (pc *ProbeCollector) Collect(ch chan<- prometheus.Metric) {
+ wg := sync.WaitGroup{}
+ wg.Add(len(pc.collectors))
+ for name, c := range pc.collectors {
+ go func(name string, c Collector) {
+ execute(context.TODO(), name, c, pc.db, ch, pc.logger)
+ wg.Done()
+ }(name, c)
+ }
+ wg.Wait()
+}
diff --git a/collector/server.go b/collector/server.go
deleted file mode 100644
index fa490a2c..00000000
--- a/collector/server.go
+++ /dev/null
@@ -1,100 +0,0 @@
-// Copyright 2022 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package collector
-
-import (
- "database/sql"
- "fmt"
- "strings"
-
- "github.com/lib/pq"
-)
-
-type server struct {
- dsn string
- name string
- db *sql.DB
-}
-
-func makeServer(dsn string) (*server, error) {
- name, err := parseServerName(dsn)
- if err != nil {
- return nil, err
- }
- return &server{
- dsn: dsn,
- name: name,
- }, nil
-}
-
-func (s *server) GetDB() (*sql.DB, error) {
- if s.db != nil {
- return s.db, nil
- }
-
- db, err := sql.Open("postgres", s.dsn)
- if err != nil {
- return nil, err
- }
- db.SetMaxOpenConns(1)
- db.SetMaxIdleConns(1)
-
- s.db = db
-
- return s.db, nil
-}
-
-func (s *server) GetName() string {
- return s.name
-}
-
-func (s *server) String() string {
- return s.name
-}
-
-func parseServerName(url string) (string, error) {
- dsn, err := pq.ParseURL(url)
- if err != nil {
- dsn = url
- }
-
- pairs := strings.Split(dsn, " ")
- kv := make(map[string]string, len(pairs))
- for _, pair := range pairs {
- splitted := strings.SplitN(pair, "=", 2)
- if len(splitted) != 2 {
- return "", fmt.Errorf("malformed dsn %q", dsn)
- }
- // Newer versions of pq.ParseURL quote values so trim them off if they exist
- key := strings.Trim(splitted[0], "'\"")
- value := strings.Trim(splitted[1], "'\"")
- kv[key] = value
- }
-
- var fingerprint string
-
- if host, ok := kv["host"]; ok {
- fingerprint += host
- } else {
- fingerprint += "localhost"
- }
-
- if port, ok := kv["port"]; ok {
- fingerprint += ":" + port
- } else {
- fingerprint += ":5432"
- }
-
- return fingerprint, nil
-}