promtail -help

Usage of config-file-loader:
  -check-syntax
    	Validate the config file of its syntax
  -client.batch-size-bytes int
    	Maximum batch size to accrue before sending (deprecated). (default 1048576)
  -client.batch-wait duration
    	Maximum wait period before sending batch (deprecated). (default 1s)
  -client.drop-rate-limited-batches
    	Do not retry batches that have been rate limited by Loki (deprecated).
  -client.external-labels value
    	list of external labels to add to each log (e.g: --client.external-labels=lb1=v1,lb2=v2) (deprecated).
  -client.max-backoff duration
    	Maximum backoff time between retries (deprecated). (default 5m0s)
  -client.max-retries int
    	Maximum number of retires when sending batches (deprecated). (default 10)
  -client.min-backoff duration
    	Initial backoff time between retries (deprecated). (default 500ms)
  -client.tenant-id string
    	Tenant ID to use when pushing logs to Loki (deprecated).
  -client.timeout duration
    	Maximum time to wait for server to respond to a request (deprecated). (default 10s)
  -client.url value
    	URL of log server (deprecated).
  -config.expand-env
    	Expands ${var} in config according to the values of the environment variables.
  -config.file string
    	yaml file to load
  -dry-run
    	Start Promtail but print entries instead of sending them to Loki.
  -file-watch.max_poll_frequency duration
    	Maximum period to poll for file changes (default 250ms)
  -file-watch.min_poll_frequency duration
    	Minimum period to poll for file changes (default 250ms)
  -inspect
    	Allows for detailed inspection of pipeline stages
  -limit.readline-burst int
    	The cap in the quantity of burst lines that this instance of Promtail may push to Loki. (default 10000)
  -limit.readline-rate float
    	The rate limit in log lines per second that this instance of Promtail may push to Loki. (default 10000)
  -limit.readline-rate-drop
    	When true, exceeding the rate limit causes this instance of Promtail to discard log lines, rather than sending them to Loki. (default true)
  -limit.readline-rate-enabled
    	When true, enforces rate limiting on this instance of Promtail.
  -log-config-reverse-order
    	Dump the entire Loki config object at Info log level with the order reversed, reversing the order makes viewing the entries easier in Grafana.
  -log.format value
    	Output log messages in the given format. Valid formats: [logfmt, json] (default logfmt)
  -log.level value
    	Only log messages with the given severity or above. Valid levels: [debug, info, warn, error] (default info)
  -max-line-size value
    	Maximum log line byte size allowed without dropping. Example: 256kb, 2M. 0 to disable.
  -max-line-size-truncate
    	Whether to truncate lines that exceed max_line_size. No effect if max_line_size is disabled
  -max-streams int
    	Maximum number of active streams. 0 to disable.
  -positions.file string
    	Location to read/write positions from. (default "/var/log/positions.yaml")
  -positions.ignore-invalid-yaml
    	whether to ignore & later overwrite positions files that are corrupted
  -positions.sync-period duration
    	Period with this to sync the position file. (default 10s)
  -print-config-stderr
    	Dump the entire Loki config object to stderr
  -server.disable
    	Disable the http and grpc server.
  -server.enable-runtime-reload
    	Enable reload via HTTP request.
  -server.graceful-shutdown-timeout duration
    	Timeout for graceful shutdowns (default 30s)
  -server.grpc-conn-limit int
    	Maximum number of simultaneous grpc connections, <=0 to disable
  -server.grpc-listen-address string
    	gRPC server listen address.
  -server.grpc-listen-network string
    	gRPC server listen network (default "tcp")
  -server.grpc-listen-port int
    	gRPC server listen port. (default 9095)
  -server.grpc-max-concurrent-streams uint
    	Limit on the number of concurrent streams for gRPC calls (0 = unlimited) (default 100)
  -server.grpc-max-recv-msg-size-bytes int
    	Limit on the size of a gRPC message this server can receive (bytes). (default 4194304)
  -server.grpc-max-send-msg-size-bytes int
    	Limit on the size of a gRPC message this server can send (bytes). (default 4194304)
  -server.grpc-tls-ca-path string
    	GRPC TLS Client CA path.
  -server.grpc-tls-cert-path string
    	GRPC TLS server cert path.
  -server.grpc-tls-client-auth string
    	GRPC TLS Client Auth type.
  -server.grpc-tls-key-path string
    	GRPC TLS server key path.
  -server.grpc.keepalive.max-connection-age duration
    	The duration for the maximum amount of time a connection may exist before it will be closed. Default: infinity (default 2562047h47m16.854775807s)
  -server.grpc.keepalive.max-connection-age-grace duration
    	An additive period after max-connection-age after which the connection will be forcibly closed. Default: infinity (default 2562047h47m16.854775807s)
  -server.grpc.keepalive.max-connection-idle duration
    	The duration after which an idle connection should be closed. Default: infinity (default 2562047h47m16.854775807s)
  -server.grpc.keepalive.min-time-between-pings duration
    	Minimum amount of time a client should wait before sending a keepalive ping. If client sends keepalive ping more often, server will send GOAWAY and close the connection. (default 5m0s)
  -server.grpc.keepalive.ping-without-stream-allowed
    	If true, server allows keepalive pings even when there are no active streams(RPCs). If false, and client sends ping when there are no active streams, server will send GOAWAY and close the connection.
  -server.grpc.keepalive.time duration
    	Duration after which a keepalive probe is sent in case of no activity over the connection., Default: 2h (default 2h0m0s)
  -server.grpc.keepalive.timeout duration
    	After having pinged for keepalive check, the duration after which an idle connection should be closed, Default: 20s (default 20s)
  -server.http-conn-limit int
    	Maximum number of simultaneous http connections, <=0 to disable
  -server.http-idle-timeout duration
    	Idle timeout for HTTP server (default 2m0s)
  -server.http-listen-address string
    	HTTP server listen address.
  -server.http-listen-network string
    	HTTP server listen network, default tcp (default "tcp")
  -server.http-listen-port int
    	HTTP server listen port. (default 80)
  -server.http-read-timeout duration
    	Read timeout for HTTP server (default 30s)
  -server.http-tls-ca-path string
    	HTTP TLS Client CA path.
  -server.http-tls-cert-path string
    	HTTP server cert path.
  -server.http-tls-client-auth string
    	HTTP TLS Client Auth type.
  -server.http-tls-key-path string
    	HTTP server key path.
  -server.http-write-timeout duration
    	Write timeout for HTTP server (default 30s)
  -server.log-request-at-info-level-enabled
    	Optionally log requests at info level instead of debug level. Applies to request headers as well if server.log-request-headers is enabled.
  -server.log-request-headers
    	Optionally log request headers.
  -server.log-request-headers-exclude-list string
    	Comma separated list of headers to exclude from loggin. Only used if server.log-request-headers is true.
  -server.log-source-ips-enabled
    	Optionally log the source IPs.
  -server.log-source-ips-header string
    	Header field storing the source IPs. Only used if server.log-source-ips-enabled is true. If not set the default Forwarded, X-Real-IP and X-Forwarded-For headers are used
  -server.log-source-ips-regex string
    	Regex for matching the source IPs. Only used if server.log-source-ips-enabled is true. If not set the default Forwarded, X-Real-IP and X-Forwarded-For headers are used
  -server.path-prefix string
    	Base path to serve all API routes from (e.g. /v1/)
  -server.profiling_enabled
    	Enable the /debug/fgprof and /debug/pprof endpoints for profiling.
  -server.register-instrumentation
    	Register the intrumentation handlers (/metrics etc). (default true)
  -server.tls-cipher-suites string
    	Comma-separated list of cipher suites to use. If blank, the default Go cipher suites is used.
  -server.tls-min-version string
    	Minimum TLS version to use. Allowed values: VersionTLS10, VersionTLS11, VersionTLS12, VersionTLS13. If blank, the Go TLS minimum version is used.
  -stdin
    	Set to true to pipe logs to promtail.
  -target.sync-period duration
    	Period to resync directories being watched and files being tailed. (default 10s)
  -tracing.enabled
    	Set to false to disable tracing. (default true)
  -version
    	Print this builds version information

promtail -version

Promtail, /etc/promtail/config.yml, promtail [ -check-syntax, | -version | -help ]