added breaking changes feature

Signed-off-by: vl4deee11 <[email protected]>

Author: vl4deee11

cmd/postgres_exporter/pg_breaking_changes.go

@@ -0,0 +1,34 @@
+// Copyright 2021 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 (
+	"github.com/blang/semver"
+)
+
+type BreakingChanges struct {
+	Version string `yaml:"version"`
+	ver     semver.Version
+	Columns map[string]string `yaml:"columns"`
+}
+
+func (bc *BreakingChanges) parseVerTolerant() error {
+	bcVer, err := semver.ParseTolerant(bc.Version)
+	if err != nil {
+		return err
+	}
+
+	bc.ver = bcVer
+	return nil
+}

cmd/postgres_exporter/postgres_exporter.go

@@ -119,11 +119,12 @@ type Mapping map[string]MappingOptions
 
 // nolint: golint
 type UserQuery struct {
-	Query        string    `yaml:"query"`
-	Metrics      []Mapping `yaml:"metrics"`
-	Master       bool      `yaml:"master"`        // Querying only for master database
-	CacheSeconds uint64    `yaml:"cache_seconds"` // Number of seconds to cache the namespace result metrics for.
-	RunOnServer  string    `yaml:"runonserver"`   // Querying to run on which server version
+	Query           string            `yaml:"query"`
+	Metrics         []Mapping         `yaml:"metrics"`
+	BreakingChanges []BreakingChanges `yaml:"breakingChanges"`
+	Master          bool              `yaml:"master"`        // Querying only for master database
+	CacheSeconds    uint64            `yaml:"cache_seconds"` // Number of seconds to cache the namespace result metrics for.
+	RunOnServer     string            `yaml:"runonserver"`   // Querying to run on which server version
 }
 
 // nolint: golint
@@ -517,7 +518,7 @@ func makeQueryOverrideMap(pgVersion semver.Version, queryOverrides map[string][]
 	return resultMap
 }
 
-func parseUserQueries(content []byte) (map[string]intermediateMetricMap, map[string]string, error) {
+func parseUserQueries(content []byte, pgVersion semver.Version) (map[string]intermediateMetricMap, map[string]string, error) {
 	var userQueries UserQueries
 
 	err := yaml.Unmarshal(content, &userQueries)
@@ -532,6 +533,30 @@ func parseUserQueries(content []byte) (map[string]intermediateMetricMap, map[str
 	for metric, specs := range userQueries {
 		level.Debug(logger).Log("msg", "New user metric namespace from YAML metric", "metric", metric, "cache_seconds", specs.CacheSeconds)
 		newQueryOverrides[metric] = specs.Query
+		columnT := make(map[string]string)
+		for i := range specs.BreakingChanges {
+			if err := specs.BreakingChanges[i].parseVerTolerant(); err != nil {
+				return nil, nil, err
+			}
+
+			if pgVersion.GE(specs.BreakingChanges[i].ver) {
+				for t := range specs.BreakingChanges[i].Columns {
+					columnT[t] = specs.BreakingChanges[i].Columns[t]
+				}
+			}
+		}
+
+		// nolint: golint
+		// 2 because old - new
+		oldnew := make([]string, 0, 2*len(columnT))
+		for t := range columnT {
+			oldnew = append(oldnew, t, columnT[t])
+		}
+
+		r := strings.NewReplacer(oldnew...)
+
+		newQueryOverrides[metric] = r.Replace(newQueryOverrides[metric])
+
 		metricMap, ok := metricMaps[metric]
 		if !ok {
 			// Namespace for metric not found - add it.
@@ -571,7 +596,7 @@ func parseUserQueries(content []byte) (map[string]intermediateMetricMap, map[str
 // TODO: test code for all cu.
 // TODO: the YAML this supports is "non-standard" - we should move away from it.
 func addQueries(content []byte, pgVersion semver.Version, server *Server) error {
-	metricMaps, newQueryOverrides, err := parseUserQueries(content)
+	metricMaps, newQueryOverrides, err := parseUserQueries(content, pgVersion)
 	if err != nil {
 		return err
 	}

cmd/postgres_exporter/postgres_exporter_test.go

@@ -410,7 +410,7 @@ func (s *FunctionalSuite) TestBooleanConversionToValueAndString(c *C) {
 func (s *FunctionalSuite) TestParseUserQueries(c *C) {
 	userQueriesData, err := ioutil.ReadFile("./tests/user_queries_ok.yaml")
 	if err == nil {
-		metricMaps, newQueryOverrides, err := parseUserQueries(userQueriesData)
+		metricMaps, newQueryOverrides, err := parseUserQueries(userQueriesData, semver.Version{Major: 13})
 		c.Assert(err, Equals, nil)
 		c.Assert(metricMaps, NotNil)
 		c.Assert(newQueryOverrides, NotNil)

queries.yaml

@@ -159,8 +159,24 @@ pg_database:
         description: "Disk space used by the database"
 
 pg_stat_statements:
-  query: "SELECT t2.rolname, t3.datname, queryid, calls, total_time / 1000 as total_time_seconds, min_time / 1000 as min_time_seconds, max_time / 1000 as max_time_seconds, mean_time / 1000 as mean_time_seconds, stddev_time / 1000 as stddev_time_seconds, rows, shared_blks_hit, shared_blks_read, shared_blks_dirtied, shared_blks_written, local_blks_hit, local_blks_read, local_blks_dirtied, local_blks_written, temp_blks_read, temp_blks_written, blk_read_time / 1000 as blk_read_time_seconds, blk_write_time / 1000 as blk_write_time_seconds FROM pg_stat_statements t1 JOIN pg_roles t2 ON (t1.userid=t2.oid) JOIN pg_database t3 ON (t1.dbid=t3.oid) WHERE t2.rolname != 'rdsadmin'"
+  query: "SELECT t2.rolname, t3.datname, queryid, calls, total_time_T / 1000 as total_time_seconds, min_time_T / 1000 as min_time_seconds, max_time_T / 1000 as max_time_seconds, mean_time_T / 1000 as mean_time_seconds, stddev_time_T / 1000 as stddev_time_seconds, rows, shared_blks_hit, shared_blks_read, shared_blks_dirtied, shared_blks_written, local_blks_hit, local_blks_read, local_blks_dirtied, local_blks_written, temp_blks_read, temp_blks_written, blk_read_time / 1000 as blk_read_time_seconds, blk_write_time / 1000 as blk_write_time_seconds FROM pg_stat_statements t1 JOIN pg_roles t2 ON (t1.userid=t2.oid) JOIN pg_database t3 ON (t1.dbid=t3.oid) WHERE t2.rolname != 'rdsadmin'"
   master: true
+  breakingChanges:
+    # should be in asc order by version
+    - version: '9.4.0'
+      columns:
+        total_time_T: total_time
+        min_time_T: min_time
+        max_time_T: max_time
+        mean_time_T: mean_time
+        stddev_time_T: stddev_time
+    - version: '13.0.0'
+      columns:
+        total_time_T: total_exec_time
+        min_time_T: min_exec_time
+        max_time_T: max_exec_time
+        mean_time_T: mean_exec_time
+        stddev_time_T: stddev_exec_time
   metrics:
     - rolname:
         usage: "LABEL"