[*] update environment variables documentation, closes #424

docker/bootstrap/init_dbs.sh

@@ -20,9 +20,3 @@ GRANT EXECUTE ON FUNCTION get_load_average() TO pgwatch3;
 COMMENT ON FUNCTION get_load_average() is 'created for pgwatch3';
 COMMIT;
 EOSQL
-
-if [ "$PW3_PG_SCHEMA_TYPE" == "timescale" ] ; then
-    psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname "pgwatch3_metrics" <<-EOSQL
-        CREATE EXTENSION timescaledb;
-EOSQL
-fi

docs/ENV_VARIABLES.md

@@ -5,38 +5,10 @@ Some variables influence multiple components. Command line parameters override e
 ## Docker image specific
 
 - **PW3_TESTDB** When set, the config DB itself will be added to monitoring as "test". Default: -
-- **PW3_PG_SCHEMA_TYPE** Enables to choose different metric storage models for the "pgwatch3" image - [metric-time|metric-dbname-time]. Default: metric-time
 
 ## Gatherer daemon
 
-- **PW3_GROUP** Logical grouping/sharding key to monitor a subset of configured hosts. Default: -
-- **PW3_PG_METRIC_STORE_CONN_STR** Postgres metric store connection string. Default: -
-- **PW3_JSON_STORAGE_FILE** File to store metric values. Default: -
-- **PW3_PG_RETENTION_DAYS** Effective when PW3_DATASTORE=postgres. Default: 14
-- **PW3_CONFIG** Connection string (`postgresql://user:pwd@host/db`), file or folder of YAML (.yaml/.yml) files containing info on which DBs to monitor and where to store metrics
-- **PW3_METRICS_FOLDER** File mode. Folder of metrics definitions
-- **PW3_BATCHING_MAX_DELAY_MS** Max milliseconds to wait for a batched metrics flush. Default: 250
-- **PW3_INTERNAL_STATS_PORT** Port for inquiring monitoring status in JSON format. Default: 8081
-- **PW3_CONN_POOLING** Enable re-use of metrics fetching connections. "off" means reconnect every time. Default: off
-- **PW3_AES_GCM_KEYPHRASE** Keyphrase for encryption/decpyption of connect string passwords.
-- **PW3_AES_GCM_KEYPHRASE_FILE** File containing a keyphrase for encryption/decpyption of connect string passwords.
-- **PW3_AES_GCM_PASSWORD_TO_ENCRYPT** A special mode, returns the encrypted plain-text string and quits. Keyphrase(file) must be set
-- **PW3_PROMETHEUS_PORT** Prometheus port. Effective with --datastore=prometheus. Default: 9187
-- **PW3_PROMETHEUS_LISTEN_ADDR** Network interface to listen on. Default: "0.0.0.0"
-- **PW3_PROMETHEUS_NAMESPACE** Prefix for all non-process (thus Postgres) metrics. Default: "pgwatch3"
-- **PW3_PROMETHEUS_ASYNC_MODE** Gather in background as with other storages and cache last fetch results for each metric in memory. Default: false
-- **PW3_ADD_SYSTEM_IDENTIFIER** Add system identifier to each captured metric (PG10+). Default: false
-- **PW3_SYSTEM_IDENTIFIER_FIELD** Control name of the "system identifier" field. Default: sys_id
-- **PW3_SERVERS_REFRESH_LOOP_SECONDS** Sleep time for the main loop. Default: 120
-- **PW3_VERSION** Show Git build version and exit.
-- **PW3_PING** Try to connect to all configured DB-s, report errors and then exit.
-- **PW3_INSTANCE_LEVEL_CACHE_MAX_SECONDS** Max allowed staleness for instance level metric data shared between DBs of an instance. Affects 'continuous' host types only. Set to 0 to disable. Default: 30
-- **PW3_DIRECT_OS_STATS** Extract OS related psutil statistics not via PL/Python wrappers but directly on host, i.e. assumes "push" setup. Default: off.
-- **PW3_MIN_DB_SIZE_MB** Smaller size DBs will be ignored and not monitored until they reach the threshold. Default: 0 (no size-based limiting).
-- **PW3_MAX_PARALLEL_CONNECTIONS_PER_DB** Max parallel metric fetches per DB. Note the multiplication effect on multi-DB instances. Default: 2
-- **PW3_EMERGENCY_PAUSE_TRIGGERFILE** When the file exists no metrics will be temporarily fetched / scraped. Default: /tmp/pgwatch3-emergency-pause
-- **PW3_NO_HELPER_FUNCTIONS** Ignore metric definitions using helper functions (in form get_smth()) and don't also roll out any helpers automatically. Default: false
-- **PW3_TRY_CREATE_LISTED_EXTS_IF_MISSING** Try creating the listed extensions (comma sep.) on first connect for all monitored DBs when missing. Main usage - pg_stat_statements. Default: ""
+See `pgwatch3 --help` output for details.
 
 ## Grafana
 

src/config/cmdoptions.go

@@ -74,6 +74,7 @@ type Options struct {
 	WebUI        WebUIOpts       `group:"WebUI"`
 	Version      bool            `long:"version" mapstructure:"version" description:"Show Git build version and exit" env:"PW3_VERSION"`
 	Ping         bool            `long:"ping" mapstructure:"ping" description:"Try to connect to all configured DB-s, report errors and then exit" env:"PW3_PING"`
+	Help         bool
 }
 
 // New returns a new instance of CmdOptions
@@ -82,12 +83,17 @@ func New(writer io.Writer) (*Options, error) {
 	parser := flags.NewParser(cmdOpts, flags.HelpFlag)
 	var err error
 	if _, err = parser.Parse(); err != nil {
-		if !flags.WroteHelp(err) {
-			parser.WriteHelp(writer)
-			return cmdOpts, err
+		if flagsErr, ok := err.(*flags.Error); ok && flagsErr.Type == flags.ErrHelp {
+			cmdOpts.Help = true
 		}
 	}
-	return cmdOpts, validateConfig(cmdOpts)
+	if err == nil {
+		err = validateConfig(cmdOpts)
+	}
+	if !flags.WroteHelp(err) {
+		parser.WriteHelp(writer)
+	}
+	return cmdOpts, err
 }
 
 // Verbose returns true if the debug log is enabled

src/main.go

@@ -192,11 +192,13 @@ func main() {
 	defer cancel()
 
 	if opts, err = config.New(os.Stdout); err != nil {
-		exitCode.Store(ExitCodeConfigError)
-		fmt.Print(err)
+		if !opts.Help {
+			exitCode.Store(ExitCodeConfigError)
+		}
+		fmt.Println(err)
 		return
 	}
-	if opts.VersionOnly() {
+	if opts.VersionOnly() || opts.Help {
 		printVersion()
 		return
 	}