[receiver/postgresql] Use postgres database when listing (#13931)

* update postgresqlreceiver to use postgres database for listing

receiver/postgresqlreceiver/client.go

@@ -103,7 +103,9 @@ func sslConnectionString(tls configtls.TLSClientSetting) string {
 }
 
 func newPostgreSQLClient(conf postgreSQLConfig) (*postgreSQLClient, error) {
- dbField := ""
+ // postgres will assume the supplied user as the database name if none is provided,
+ // so we must specify a databse name even when we are just collecting the list of databases.
+ dbField := "dbname=postgres"
  if conf.database != "" {
  dbField = fmt.Sprintf("dbname=%s ", conf.database)
  }
@@ -118,7 +120,7 @@ func newPostgreSQLClient(conf postgreSQLConfig) (*postgreSQLClient, error) {
  host = fmt.Sprintf("/%s", host)
  }
 
- connStr := fmt.Sprintf("port=%s host=%s user=%s password=%s %s%s", port, host, conf.username, conf.password, dbField, sslConnectionString(conf.tls))
+ connStr := fmt.Sprintf("port=%s host=%s user=%s password=%s %s %s", port, host, conf.username, conf.password, dbField, sslConnectionString(conf.tls))
 
  conn, err := pq.NewConnector(connStr)
  if err != nil {

receiver/postgresqlreceiver/integration_test.go

@@ -57,8 +57,8 @@ func TestPostgreSQLIntegration(t *testing.T) {
  cfg := f.CreateDefaultConfig().(*Config)
  cfg.Endpoint = net.JoinHostPort(hostname, "15432")
  cfg.Databases = []string{"otel"}
- cfg.Username = "otel"
- cfg.Password = "otel"
+ cfg.Username = "otelu"
+ cfg.Password = "otelp"
  cfg.Insecure = true
  return cfg
  },
@@ -71,8 +71,8 @@ func TestPostgreSQLIntegration(t *testing.T) {
  cfg := f.CreateDefaultConfig().(*Config)
  cfg.Endpoint = net.JoinHostPort(hostname, "15432")
  cfg.Databases = []string{"otel", "otel2"}
- cfg.Username = "otel"
- cfg.Password = "otel"
+ cfg.Username = "otelu"
+ cfg.Password = "otelp"
  cfg.Insecure = true
  return cfg
  },
@@ -85,8 +85,8 @@ func TestPostgreSQLIntegration(t *testing.T) {
  cfg := f.CreateDefaultConfig().(*Config)
  cfg.Endpoint = net.JoinHostPort(hostname, "15432")
  cfg.Databases = []string{}
- cfg.Username = "otel"
- cfg.Password = "otel"
+ cfg.Username = "otelu"
+ cfg.Password = "otelp"
  cfg.Insecure = true
  return cfg
  },
@@ -103,8 +103,8 @@ func TestPostgreSQLIntegration(t *testing.T) {
  cfg := f.CreateDefaultConfig().(*Config)
  cfg.Endpoint = net.JoinHostPort(hostname, "15432")
  cfg.Databases = []string{}
- cfg.Username = "otel"
- cfg.Password = "otel"
+ cfg.Username = "otelu"
+ cfg.Password = "otelp"
  cfg.Insecure = true
  return cfg
  },

receiver/postgresqlreceiver/testdata/integration/init.sql

@@ -1,5 +1,5 @@
-CREATE USER otel WITH PASSWORD 'otel';
-GRANT SELECT ON pg_stat_database TO otel;
+CREATE USER otelu WITH PASSWORD 'otelp';
+GRANT SELECT ON pg_stat_database TO otelu;
 
 CREATE TABLE table1 (
  id serial PRIMARY KEY

unreleased/postgres-list-postgres-user.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: postgresqlreceiver
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Uses the postgres databasename when retrieving database inventory information
+
+# One or more tracking issues related to the change
+issues: [13641]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: