summercms/docs/services/logging.md

title, description, section, order

title	description	section	order
Logging	Configure log channels in config/log.yaml, log through diary component loggers and keep credentials out of log records.	services	105

Logging

SummerCMS logs through the standard library's log/slog, configured by diary. Where a WinterCMS application lists channels in config/logging.php and calls Log::error, a SummerCMS application lists channels in config/log.yaml and logs through a component logger from diary.For. Every channel redacts credentials through sunscreen.

The application main that summer build generates calls diary.Bootstrap(os.Stderr, diary.Options{}) as the first statement of run, so even configuration errors are logged, and diary.Setup right after compass has loaded config/. From then on component loggers, slog.Default, the package-level slog functions and the standard log package all write through the configured channels.

Channels

A channel is a named destination with a driver:

Driver	Writes
console	One line per record to stderr. With format: auto (the default) the line is styled when stderr is a terminal (time, level, the component as a fixed-width prefix, the message, key=value attributes) and logfmt otherwise, for systemd and Docker; format: json writes JSON lines.
stderr	logfmt (the default) or JSON to stderr, never styled.
daily	One file per day, JSON by default or logfmt; see Daily files.
stack	Every record to each channel listed under channels.
null	Nothing.

Each channel may set its own level; a record reaches a channel when it passes both its component's level and the channel's level.

While a command shows a live view on the terminal (a spinner, a progress bar or the process view of bonfire.Process), styled console lines print above the view through bonfire.PrintAbove instead of being written into it, so log records from workers and other goroutines never tear the animation. Without a live view, and on channels that are not styled, lines are written directly as usual.

config/log.yaml

summer new writes this file, and an application without it gets the same values as framework defaults:

# config/log.yaml
default: stack
level: info
channels:
  stack:
    driver: stack
    channels: [console, daily]
  console:
    driver: console
    format: auto
  daily:
    driver: daily
    path: storage/logs/summer.log
    days: 14
    format: json
    level: warn
components:
  river: warn
  http: info

default names the channel every record goes to, level is the global minimum, channels defines the channels and components sets levels per component (the http: info line only spells out what level: info already gives). It is the shape of Laravel's config/logging.php (default, channels with a driver each, stack and daily drivers, days for retention), written in YAML. The framework defaults also define a stderr channel (logfmt) and a null channel, so default: stderr or default: null works without defining them.

Like any key, these can be overridden from the environment with a double underscore between path segments, and string values are accepted where YAML would give a number or a list:

SUMMER_LOG__CHANNELS__DAILY__DAYS=30
SUMMER_LOG__CHANNELS__STACK__CHANNELS=console,daily
SUMMER_LOG__COMPONENTS__RIVER=error

An override changes one key and keeps every other default. An unknown driver, format or level, a stack that names a missing channel or contains itself, and a daily path outside the application root stop the start-up with an error that names the key, for example diary: log.channels.daily.days must be a whole number of at least 0.

Component loggers

Code logs through the logger of its component:

// Before diary.Setup runs, records go to the process default logger.
// This one drops the time so the output is stable.
previous := slog.Default()
defer slog.SetDefault(previous)
slog.SetDefault(slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
	ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
		if len(groups) == 0 && a.Key == slog.TimeKey {
			return slog.Attr{}
		}
		return a
	},
})))

// After diary.Setup the same record reaches the configured channels and
// passes log.components.blog, else log.level.
blogLog.InfoContext(context.Background(), "post published", "id", 7)
// Output:
// level=INFO msg="post published" component=blog id=7

Every record carries the attribute component=blog, and passes the component's level: log.components.blog when it is set, log.level otherwise. The name is the plugin or module code without dots, because configuration keys split on dots (acme.blog would nest). Framework modules use their package name (cabana, lagoon, conga), River logs as river and GORM as db. diary.SetVerbosity lowers every component to info (1) or debug (2 and more) at runtime.

diary.For is safe in a package var block: before diary.Setup runs, its records go to the process default logger, and after it they reach the configured channels. Records logged through slog.Default carry no component and use log.level.

Daily files

A daily channel with path: storage/logs/summer.log writes storage/logs/summer-2026-10-21.log today and storage/logs/summer-2026-10-22.log after local midnight. A relative path resolves against the application root, the directory that holds config/, and may not leave it; an absolute path is used as given. Files are created with mode 0640 in directories created with mode 0750, because logs carry user identifiers, and a file is only created once a record reaches it. With days: 14 the files of today and the 13 days before are kept and older files of the same name pattern are deleted; other files in the directory are never touched. days: 0 keeps every file.

If the directory cannot be created or the file cannot be opened (a read-only container filesystem, missing permissions), the channel logs one warning from component diary on the console naming the path and the error, and is disabled. The start-up never fails because of a log file.

Redaction

Every channel, console, stderr, daily and null alike, is wrapped by sunscreen.Wrap, which rewrites every record before it is written:

• The value of an attribute whose key is one of sunscreen.RedactedKeys becomes [REDACTED], at any group depth and whatever the letter case: api_key, apikey, authorization, bearer, password, secret, token, webhook_secret, admin_password and the openai_api_key, anthropic_api_key and perplexity_api_key variants.
• The message, string values, error values and the formatted text of other values are passed through sunscreen.Scrub, which replaces Bearer <token>, sk- style API keys and x-api-key: <value>.
• slog.LogValuer values are resolved first, and maps such as http.Header are redacted key by key.

// Drop the time so the output is stable; a real application keeps it.
plain := slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
	ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
		if len(groups) == 0 && a.Key == slog.TimeKey {
			return slog.Attr{}
		}
		return a
	},
})
logger := slog.New(sunscreen.Wrap(plain))

logger.Info("vendor call failed",
	"api_key", "live-key-123",
	slog.Group("request", slog.String("Authorization", "Bearer abc.def")),
	"err", errors.New("401 for key sk-abcdefghijklmnopqrstuvwx"),
)
// Output:
// level=INFO msg="vendor call failed" api_key=[REDACTED] request.Authorization=[REDACTED] err="401 for key sk-[REDACTED]"

sunscreen.InstallDefault remains for programs that install their own default logger instead of diary.

Logging from a plugin

A plugin logs through its own component logger, named after its plugin code without dots, instead of the process default logger. The logger is safe to create in a package var block, before diary is set up:

// blogLog is the component logger of a blog plugin, created once in a
// package var block, before diary is set up.
var blogLog = diary.For("blog")

Its records carry component=blog, follow log.components.blog and go through the redacting channels.

Redaction is a safety net for mistakes, not a way to log secrets on purpose. Log identifiers and outcomes: the record id, the vendor, the status code, how long it took. Never log request arguments, tokens, credentials or request and response bodies, which can carry personal data the patterns do not recognise.

Request log

The router logs every request. Each request writes one Info record with the message http request from the component http once it has been served:

Attribute	Value
method	The request method.
pattern	The matched route, method and path pattern, for example GET /posts/{id}. Empty when no route matched.
status	The response status; a handler that writes without setting one counts as 200. A 5xx is logged as 499 (client closed request) only when the client had already gone away when the status was written and the handler did not panic: the error came from the cancellation, and no client received it. A 5xx written before the client went away keeps its status, and a recovered panic is always 500, so a search for 5xx records finds every real server error.
duration_ms	Time spent serving the request, in whole milliseconds.
request_id	The X-Request-Id request header, trimmed and cut to 128 bytes; absent when the header is empty. Set it in your reverse proxy to follow one request across the proxy's and the application's logs.
client_gone	true when the client went away before the request was served (its context ended with context.Canceled); absent otherwise.

The record carries the route pattern, never the URL path, the query string, request or response headers or the client address, because tokens travel in paths and query strings: share and invitation links carry them in the path. That holds for a request that reached no route too: a token route requested with another method gets a 405 from the router, and its trailing-slash variant a 404, before any route handler runs, so the path would carry the token. Grep for the empty pattern to find requests that reached no route; the client's own log (a browser, a proxy) shows which path it asked for.

The log is on by default, at Info, so the console shows it and the daily files keep what their level lets through. Silence it with the component level, or turn it off with http.access_log (environment SUMMER_HTTP__ACCESS_LOG=false):

# config/log.yaml
components:
  http: warn

# config/http.yaml
access_log: false

It goes to the published *slog.Logger when a plugin publishes one, else to the http component logger, so the redacting handler applies on every channel.

Panics

The router recovers a panicking handler and answers with an opaque 500: the JSON groups send {"error":true,"message":"Internal server error"} and the raw groups an empty body. The panic value never reaches the client. See Routing.