PMM-11341 Auto discovery limit.

admin/commands/inventory/add_agent_postgres_exporter.go

@@ -56,6 +56,7 @@ type AddAgentPostgresExporterCommand struct {
 	SkipConnectionCheck bool              `help:"Skip connection check"`
 	PushMetrics         bool              `help:"Enables push metrics model flow, it will be sent to the server by an agent"`
 	DisableCollectors   []string          `help:"Comma-separated list of collector names to exclude from exporter"`
+	AutoDiscoveryLimit  int32             `default:"0" placeholder:"NUMBER" help:"Turn auto discovery off when total count of databases is bigger than limit"`
 	TLS                 bool              `help:"Use TLS to connect to the database"`
 	TLSSkipVerify       bool              `help:"Skip TLS certificates validation"`
 	TLSCAFile           string            `help:"TLS CA certificate file"`
@@ -99,6 +100,7 @@ func (cmd *AddAgentPostgresExporterCommand) RunCmd() (commands.Result, error) {
 			SkipConnectionCheck: cmd.SkipConnectionCheck,
 			PushMetrics:         cmd.PushMetrics,
 			DisableCollectors:   commands.ParseDisableCollectors(cmd.DisableCollectors),
+			AutoDiscoveryLimit:  cmd.AutoDiscoveryLimit,
 
 			TLS:           cmd.TLS,
 			TLSSkipVerify: cmd.TLSSkipVerify,

admin/commands/management/add_postgresql.go

@@ -73,6 +73,7 @@ type AddPostgreSQLCommand struct {
 	DisableQueryExamples bool              `name:"disable-queryexamples" help:"Disable collection of query examples"`
 	MetricsMode          string            `enum:"${metricsModesEnum}" default:"auto" help:"Metrics flow mode, can be push - agent will push metrics, pull - server scrape metrics from agent or auto - chosen by server"`
 	DisableCollectors    []string          `help:"Comma-separated list of collector names to exclude from exporter"`
+	AutoDiscoveryLimit   int32             `default:"0" placeholder:"NUMBER" help:"Turn auto discovery off when total count of databases is bigger than limit"`
 
 	AddCommonFlags
 	AddLogLevelNoFatalFlags
@@ -203,6 +204,7 @@ func (cmd *AddPostgreSQLCommand) RunCmd() (commands.Result, error) {
 			DisableQueryExamples: cmd.DisableQueryExamples,
 			MetricsMode:          pointer.ToString(strings.ToUpper(cmd.MetricsMode)),
 			DisableCollectors:    commands.ParseDisableCollectors(cmd.DisableCollectors),
+			AutoDiscoveryLimit:   cmd.AutoDiscoveryLimit,
 			LogLevel:             &cmd.AddLogLevel,
 		},
 		Context: commands.Ctx,

agent/serviceinfobroker/service_info_broker.go

@@ -222,9 +222,18 @@ func (sib *ServiceInfoBroker) getPostgreSQLInfo(ctx context.Context, dsn string,
 	var version string
 	if err = db.QueryRowContext(ctx, "SHOW /* agent='serviceinfobroker' */ SERVER_VERSION").Scan(&version); err != nil {
 		res.Error = err.Error()
+		return &res
 	}
-
 	res.Version = version
+
+	var databaseCount int32
+	databaseCountQuery := "SELECT /* agent='serviceinfobroker' */ count(datname) FROM pg_database WHERE datallowconn = true AND datistemplate = false AND datname != current_database()" //nolint:lll
+	if err = db.QueryRowContext(ctx, databaseCountQuery).Scan(&databaseCount); err != nil {
+		res.Error = err.Error()
+		return &res
+	}
+	res.DatabaseCount = databaseCount
+
 	return &res
 }
 

api/agentpb/agent.proto

@@ -444,6 +444,8 @@ message CheckConnectionResponse {
   message Stats {
     // A number of tables, 0 if unknown.
     int32 table_count = 1;
+    // A number of databases, 0 if unknown.
+    int32 database_count = 2;
   }
   // Error message if connection check failed.
   string error = 1;
@@ -472,6 +474,8 @@ message ServiceInfoResponse {
   int32 table_count = 2;
   // Database server version.
   string version = 3;
+  // A number of PostgreSQL databases, 0 if unknown.
+  int32 database_count = 4;
 }
 
 // JobStatusRequest is a ServerMessage asking pmm-agent for job status.

api/inventorypb/agents.proto

@@ -217,6 +217,8 @@ message PostgresExporter {
   string process_exec_path = 13;
   // Log level for exporter.
   LogLevel log_level = 14;
+  // Limit of databases for auto discovery.
+  int32 auto_discovery_limit = 16;
 }
 
 // ProxySQLExporter runs on Generic or Container Node and exposes ProxySQL Service metrics.
@@ -827,6 +829,8 @@ message AddPostgresExporterRequest {
   string agent_password = 14;
   // Log level for exporter.
   LogLevel log_level = 15;
+  // Limit of databases for auto discovery.
+  int32 auto_discovery_limit = 16;
 }
 
 message AddPostgresExporterResponse {

api/inventorypb/json/inventorypb.json

@@ -1329,6 +1329,12 @@
                   "type": "string",
                   "x-order": 13
                 },
+                "auto_discovery_limit": {
+                  "description": "Limit of databases for auto discovery.",
+                  "type": "integer",
+                  "format": "int32",
+                  "x-order": 15
+                },
                 "custom_labels": {
                   "description": "Custom user-assigned labels.",
                   "type": "object",
@@ -1433,6 +1439,12 @@
                       "type": "string",
                       "x-order": 0
                     },
+                    "auto_discovery_limit": {
+                      "description": "Limit of databases for auto discovery.",
+                      "type": "integer",
+                      "format": "int32",
+                      "x-order": 14
+                    },
                     "custom_labels": {
                       "description": "Custom user-assigned labels.",
                       "type": "object",
@@ -4406,6 +4418,12 @@
                       "type": "string",
                       "x-order": 0
                     },
+                    "auto_discovery_limit": {
+                      "description": "Limit of databases for auto discovery.",
+                      "type": "integer",
+                      "format": "int32",
+                      "x-order": 14
+                    },
                     "custom_labels": {
                       "description": "Custom user-assigned labels.",
                       "type": "object",
@@ -6570,6 +6588,12 @@
                       "type": "string",
                       "x-order": 0
                     },
+                    "auto_discovery_limit": {
+                      "description": "Limit of databases for auto discovery.",
+                      "type": "integer",
+                      "format": "int32",
+                      "x-order": 14
+                    },
                     "custom_labels": {
                       "description": "Custom user-assigned labels.",
                       "type": "object",
@@ -8168,6 +8192,12 @@
                         "type": "string",
                         "x-order": 0
                       },
+                      "auto_discovery_limit": {
+                        "description": "Limit of databases for auto discovery.",
+                        "type": "integer",
+                        "format": "int32",
+                        "x-order": 14
+                      },
                       "custom_labels": {
                         "description": "Custom user-assigned labels.",
                         "type": "object",
@@ -11849,6 +11879,12 @@
                   "type": "string",
                   "x-order": 2
                 },
+                "auto_discovery_limit": {
+                  "description": "Limit of databases for auto discovery.",
+                  "type": "integer",
+                  "format": "int32",
+                  "x-order": 9
+                },
                 "cluster": {
                   "description": "Cluster name.",
                   "type": "string",
@@ -11912,6 +11948,12 @@
                       "type": "string",
                       "x-order": 4
                     },
+                    "auto_discovery_limit": {
+                      "description": "Limit of databases for auto discovery.",
+                      "type": "integer",
+                      "format": "int32",
+                      "x-order": 12
+                    },
                     "cluster": {
                       "description": "Cluster name.",
                       "type": "string",
@@ -12685,6 +12727,12 @@
                       "type": "string",
                       "x-order": 4
                     },
+                    "auto_discovery_limit": {
+                      "description": "Limit of databases for auto discovery.",
+                      "type": "integer",
+                      "format": "int32",
+                      "x-order": 12
+                    },
                     "cluster": {
                       "description": "Cluster name.",
                       "type": "string",
@@ -13151,6 +13199,12 @@
                         "type": "string",
                         "x-order": 4
                       },
+                      "auto_discovery_limit": {
+                        "description": "Limit of databases for auto discovery.",
+                        "type": "integer",
+                        "format": "int32",
+                        "x-order": 12
+                      },
                       "cluster": {
                         "description": "Cluster name.",
                         "type": "string",