Postgres exporter changes for tx duration

.github/CODEOWNERS

@@ -0,0 +1 @@
+* @percona/pmm-review-exporters

.github/dependabot.yml

@@ -1,6 +1,19 @@
+---
 version: 2
 updates:
   - package-ecosystem: "gomod"
     directory: "/"
     schedule:
-      interval: "monthly"
+      interval: "weekly"
+  - package-ecosystem: "gomod"
+    directory: "/tools"
+    schedule:
+      interval: "weekly"
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"

.github/workflows/go.yml

@@ -0,0 +1,56 @@
+name: Go
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - v[0-9]+.[0-9]+.[0-9]+*
+  pull_request:
+
+jobs:
+  test:
+    name: Test
+    strategy:
+      matrix:
+        postgresql-image:
+          - postgres:10
+          - postgres:11
+          - postgres:12
+          - postgres:13
+          - postgres:14
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version-file: ${{ github.workspace }}/go.mod
+
+    - name: Run checks
+      run: |
+        go build -modfile=tools/go.mod -o bin/golangci-lint github.com/golangci/golangci-lint/cmd/golangci-lint
+        go build -modfile=tools/go.mod -o bin/reviewdog github.com/reviewdog/reviewdog/cmd/reviewdog
+        bin/golangci-lint run -c=.golangci.yml --out-format=line-number | env REVIEWDOG_GITHUB_API_TOKEN=${{ secrets.GITHUB_TOKEN }} bin/reviewdog -f=golangci-lint -level=error -reporter=github-pr-review
+
+    - name: Run Tests
+      run: |
+        sudo chown 999:999 testdata/ssl/server/*
+        sudo chmod 600 testdata/ssl/server/*
+        docker compose up -d
+        make
+        make test
+      env:
+        POSTGRESQL_IMAGE: ${{ matrix.postgresql-image }}
+
+    - name: Run debug commands on failure
+      if: ${{ failure() }}
+      run: |
+        env | sort
+        go env | sort
+        git status
+        docker --version
+        docker compose --version
+        docker compose logs

.github/workflows/golangci-lint.yml

@@ -20,13 +20,15 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608 # v4.1.0
       - name: install Go
-        uses: actions/setup-go@6edd4406fa81c3da01a34fa6f6343087c207a568 # v3.5.0
+        uses: actions/setup-go@0a12ed9d6a96ab950c8f026ed9f722fe0da7ef32 # v5.0.2
         with:
-          go-version: 1.20.x
+          go-version-file: ${{ github.workspace }}/go.mod
+
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'
+
       - name: Lint
-        uses: golangci/golangci-lint-action@3a919529898de77ec3da873e3063ca4b10e7f5cc # v3.7.0
+        uses: golangci/golangci-lint-action@2226d7cb06a077cd73e56eedd38eecad18e5d837 # v6.5.0
         with:
           version: v1.54.2

.gitignore

@@ -20,3 +20,6 @@
 /.metrics.*.removed
 /tools/src
 /vendor
+/percona_tests/assets/postgres_exporter
+/percona_tests/assets/postgres_exporter_percona
+/percona_tests/assets/metrics.*

CHANGELOG.md

@@ -81,6 +81,11 @@ params. See the Multi-Target Support section of the README.
 * [BUGFIX] Fix checkpoint_write_time value type #666
 * [BUGFIX] Fix checkpoint_sync_time value type #667
 
+## 0.11.1 / 2022-08-01
+
+* [BUGFIX] Fix checkpoint_write_time value type #666
+* [BUGFIX] Fix checkpoint_sync_time value type #667
+
 ## 0.11.0 / 2022-07-28
 
 NOTE: pg_stat_bgwriter counter metrics had the `_total` suffix added #556

Makefile

@@ -8,3 +8,10 @@ DOCKER_REPO  ?= prometheuscommunity
 include Makefile.common
 
 DOCKER_IMAGE_NAME       ?= postgres-exporter
+
+GO_BUILD_LDFLAGS = -X github.com/prometheus/common/version.Version=$(shell cat VERSION) -X github.com/prometheus/common/version.Revision=$(shell git rev-parse HEAD) -X github.com/prometheus/common/version.Branch=$(shell git describe --always --contains --all) -X github.com/prometheus/common/version.BuildUser= -X github.com/prometheus/common/version.BuildDate=$(shell date +%FT%T%z) -s -w
+
+export PMM_RELEASE_PATH?=.
+
+release:
+	go build -ldflags="$(GO_BUILD_LDFLAGS)" -o $(PMM_RELEASE_PATH)/postgres_exporter ./cmd/postgres_exporter

Makefile.common

@@ -58,7 +58,7 @@ endif
 PROMU_VERSION ?= 0.15.0
 PROMU_URL     := https://github.com/prometheus/promu/releases/download/v$(PROMU_VERSION)/promu-$(PROMU_VERSION).$(GO_BUILD_PLATFORM).tar.gz
 
-SKIP_GOLANGCI_LINT :=
+SKIP_GOLANGCI_LINT ?= $(CI)
 GOLANGCI_LINT :=
 GOLANGCI_LINT_OPTS ?=
 GOLANGCI_LINT_VERSION ?= v1.54.2
@@ -106,7 +106,7 @@ endif
 %: common-% ;
 
 .PHONY: common-all
-common-all: precheck style check_license lint yamllint unused build test
+common-all: precheck style lint unused build test
 
 .PHONY: common-style
 common-style:
@@ -118,17 +118,6 @@ common-style:
 		exit 1; \
 	fi
 
-.PHONY: common-check_license
-common-check_license:
-	@echo ">> checking license header"
-	@licRes=$$(for file in $$(find . -type f -iname '*.go' ! -path './vendor/*') ; do \
-               awk 'NR<=3' $$file | grep -Eq "(Copyright|generated|GENERATED)" || echo $$file; \
-       done); \
-       if [ -n "$${licRes}" ]; then \
-               echo "license header checking failed:"; echo "$${licRes}"; \
-               exit 1; \
-       fi
-
 .PHONY: common-deps
 common-deps:
 	@echo ">> getting dependencies"

cmd/postgres_exporter/datasource.go

@@ -48,22 +48,16 @@ func (e *Exporter) discoverDatabaseDSNs() []string {
 			level.Error(logger).Log("msg", "Unable to parse DSN as either URI or connstring", "dsn", loggableDSN(dsn))
 			continue
 		}
-
-		server, err := e.servers.GetServer(dsn)
-		if err != nil {
-			level.Error(logger).Log("msg", "Error opening connection to database", "dsn", loggableDSN(dsn), "err", err)
-			continue
-		}
 		dsns[dsn] = struct{}{}
 
 		// If autoDiscoverDatabases is true, set first dsn as master database (Default: false)
-		server.master = true
+		e.masterDSN = dsn
 
-		databaseNames, err := queryDatabases(server)
+		databaseNames, err := e.getDatabaseNames(dsn)
 		if err != nil {
-			level.Error(logger).Log("msg", "Error querying databases", "dsn", loggableDSN(dsn), "err", err)
 			continue
 		}
+
 		for _, databaseName := range databaseNames {
 			if contains(e.excludeDatabases, databaseName) {
 				continue
@@ -74,7 +68,11 @@ func (e *Exporter) discoverDatabaseDSNs() []string {
 			}
 
 			if dsnURI != nil {
-				dsnURI.Path = databaseName
+				if dsnURI.Host == "" && strings.HasPrefix(dsnURI.Path, "/") {
+					dsnURI.Path = "/" + databaseName
+				} else {
+					dsnURI.Path = databaseName
+				}
 				dsn = dsnURI.String()
 			} else {
 				// replacing one dbname with another is complicated.
@@ -95,15 +93,40 @@ func (e *Exporter) discoverDatabaseDSNs() []string {
 	return result
 }
 
-func (e *Exporter) scrapeDSN(ch chan<- prometheus.Metric, dsn string) error {
-	server, err := e.servers.GetServer(dsn)
+func (e *Exporter) getDatabaseNames(dsn string) ([]string, error) {
+	if e.connSema != nil {
+		if err := e.connSema.Acquire(e.ctx, 1); err != nil {
+			level.Warn(logger).Log("msg", "Failed to acquire semaphore", "err", err)
+			return nil, err
+		}
+		defer e.connSema.Release(1)
+	}
 
+	server, err := e.GetServer(dsn)
+	if err != nil {
+		level.Error(logger).Log("msg", "Error opening connection to database", "dsn", loggableDSN(dsn), "err", err)
+		return nil, err
+	}
+	defer server.Close()
+
+	dbNames, err := queryDatabases(e.ctx, server)
+	if err != nil {
+		level.Error(logger).Log("msg", "Error querying databases", "dsn", loggableDSN(dsn), "err", err)
+		return nil, err
+	}
+
+	return dbNames, nil
+}
+
+func (e *Exporter) scrapeDSN(ch chan<- prometheus.Metric, dsn string) error {
+	server, err := e.GetServer(dsn)
 	if err != nil {
 		return &ErrorConnectToServer{fmt.Sprintf("Error opening connection to database (%s): %s", loggableDSN(dsn), err.Error())}
 	}
+	defer server.Close()
 
 	// Check if autoDiscoverDatabases is false, set dsn as master database (Default: false)
-	if !e.autoDiscoverDatabases {
+	if !e.autoDiscoverDatabases || e.masterDSN == dsn {
 		server.master = true
 	}