corso/src/pkg/logger/example_logger_test.go
2024-01-29 18:26:45 +05:30

196 lines
7.1 KiB
Go

package logger_test
import (
"context"
"github.com/alcionai/corso/src/pkg/path"
)
// ---------------------------------------------------------------------------
// mock helpers
// ---------------------------------------------------------------------------
const itemID = "item_id"
var (
err error
itemPath, _ = path.Build("tid", "own", path.ExchangeService, path.ContactsCategory, false, "foo")
)
// ---------------------------------------------------------------------------
// examples
// ---------------------------------------------------------------------------
// ExampleSeed showcases seeding a logger into the context.
func Example_seed() {
// Before logging, a logger instance first needs to get seeded into
// the context. Seeding only needs to be done once. For example
// Corso's CLI layer seeds the logger in the cli initialization.
ctx := context.Background()
_ = ctx
// ls := logger.Settings{
// File: logger.Stderr,
// Level: logger.LLInfo,
// PIIHandling: logger.PIIPlainText,
// }
// ctx, log := logger.Seed(ctx, ls)
// // SDK consumers who configure their own zap logger can Set their logger
// // into the context directly, instead of Seeding a new one.
// ctx = logger.Set(ctx, log)
// // logs should always be flushed before exiting whichever func
// // seeded the logger.
// defer func() {
// _ = log.Sync() // flush all logs in the buffer
// }()
// // downstream, the logger will retrieve its configuration from
// // the context.
// func(ctx context.Context) {
// log := logger.Ctx(ctx)
// log.Info("hello, world!")
// }(ctx)
}
// ExampleLoggerStandards reviews code standards around logging in Corso.
func Example_logger_standards() {
// log := logger.Ctx(context.Background())
// // 1. Keep messages short. When possible, messages should state the current action.
// // Lowercase text, no ending punctuation.
// // This ensures logs are easy to scan, and simple to grok.
// //
// // preferred
// log.Info("getting item")
// // avoid
// log.Info("Getting one item from the service so that we can send it through the item feed.")
// // 2. Avoid statements like "unable to...", "failed to..", or "error when...".
// // Error level logs automatically imply a failure to do the action.
// //
// // preferred
// log.With("err", err).Error("connecting to repo")
// // avoid
// log.With("err", err).Error("unable to connect to repo")
// // 3. Do not fmt values into the message. Use With() or -w() to add structured data.
// // By keeping dynamic data in a structured format, we maximize log readability,
// // and make logs very easy to search or filter in bulk, and very easy to control pii.
// //
// // preferred
// log.With("err", err).Error("getting item")
// log.Errorw("getting item", "err", err)
// // avoid
// log.Errorf("getting item %s: %v", itemID, err)
// // 4. Give data keys reasonable namespaces. Use snake_case.
// // Overly generic keys can collide unexpectedly.
// //
// // preferred
// log.With("item_id", itemID).Info("getting item")
// // avoid
// log.With("id", itemID).Error("getting item")
// // 4. Avoid Warn-level logging. Prefer Info or Error.
// // Minimize confusion/contention about what level a log
// // "should be". Error during a failure, Info (or Debug)
// // otherwise.
// //
// // preferred
// log.With("err", err).Error("getting item")
// // avoid
// log.With("err", err).Warn("getting item")
// // 5. Avoid Panic/Fatal-level logging. Prefer Error.
// // Panic and Fatal logging can crash the application without
// // flushing buffered logs and finishing out other telemetry.
// //
// // preferred
// log.With("err", err).Error("connecting to repo")
// // avoid
// log.With("err", err).Panic("connecting to repo")
}
// ExampleLoggerCluesStandards reviews code standards around using the Clues package while logging.
func Example_logger_clues_standards() {
// ctx := clues.Add(context.Background(), "foo", "bar")
// log := logger.Ctx(ctx)
// // 1. Clues Ctx values are always added in .Ctx(); you don't
// // need to add them directly.
// //
// // preferred
// ctx = clues.Add(ctx, "item_id", itemID)
// logger.Ctx(ctx).Info("getting item")
// //
// // avoid
// ctx = clues.Add(ctx, "item_id", itemID)
// logger.Ctx(ctx).With(clues.In(ctx).Slice()...).Info("getting item")
// // 2. The last func to handle a context must add the clues to the error.
// //
// // preferred
// err := clues.WrapWC(ctx, err, "reason")
// // this dereference added for linter happiness
// _ = err
// // 3. Always extract structured data from errors.
// //
// // preferred
// log.With("error", err).Errorw("getting item", clues.InErr(err).Slice()...)
// //
// // avoid
// log.Errorw("getting item", "err", err)
// //
// // you can use the logger helper CtxErr() for the same results.
// // This helps to ensure all error values get packed into the logs
// // in the expected format.
// logger.CtxErr(ctx, err).Error("getting item")
// // 3. Protect pii in logs.
// // When it comes to protecting sensitive information, we only want
// // to hand loggers (and, by extension, clues errors) using one of
// // three approaches to securing values.
// //
// // First: plain, unhidden data. This can only be logged if we are
// // absolutely assured that this data does not expose sensitive
// // information for a user. Eg: internal ids and enums are fine to
// // log in plain text. Everything else must be considered wisely.
// //
// // Second: manually concealed values. Strings containing sensitive
// // info, and structs from external pacakges containing sensitive info,
// // can be logged by manually wrapping them with a clues.Hide() call.
// // Ex: clues.Hide(userName). This will hash the value according to
// // the user's hash algorithm configuration.
// //
// // Third: managed string concealers. Certain values have common
// // format and content, but appear commonly in the code as strings.
// // Examples include URLs and kopia repository paths. These values
// // may have a concealer built specifically for them to maximize the
// // data we can view when debugging, instead of hashing the complete
// // string. See graph/middleware.go LoggableURL{} and path/elements.go
// // LoggableDir{}.
// //
// // Fourth: structs that comply with clues.Concealer. The Concealer
// // interface requires a struct to comply with Conceal() (for cases
// // where the struct is handed to a clues aggregator directly), and
// // fmt's Format(state, verb), where the assumption is the standard
// // format writer will be replaced with a Conceal() call (for cases
// // where the struct is handed to some non-compliant formatter/printer).
// //
// // preferred
// log.With(
// // internal type, safe to log plainly
// "resource_type", resource.Users,
// // string containing sensitive info, wrap with Hide()
// "user_name", clues.Hide("your_user_name@microsoft.example"),
// // string partially concealed by a managed concealer.
// "request_url", graph.LoggableURL("https://corsobackup.io"),
// // a concealer-compliant struct, safe to add plainly
// "storage_path", itemPath)
}