Puree
Description
Puree is a log aggregator which provides the following features.
- Filtering: Log entries can be processed before being sent. You can add common parameters, do random sampling, ...
- Buffering: Log entries are stored in a buffer until it's time to send them.
- Batching: Multiple log entries are grouped and sent in one request.
- Retrying: Automatically retry to send after some backoff time if a transmission error occurred.
Puree helps you unify your logging infrastructure.
Currently in development so the interface might change.
Installation
Carthage
github "cookpad/Puree-Swift"
CocoaPods
use_frameworks!
pod 'Puree', '~> 5.0'Swift PM
The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler. It is in early development, but Puree-Swift does support its use on supported platforms.
Once you have your Swift package set up, adding Puree-Swift as a dependency is as easy as adding it to the dependencies value of your Package.swift.
dependencies: [
.package(url: "https://github.com/cookpad/Puree-Swift.git", .upToNextMinor(from: "5.2.0"))
]Usage
Define your own Filter/Output
Filter
A Filter should convert any objects into LogEntry.
import Foundation
import Puree
struct PVLogFilter: Filter {
let tagPattern: TagPattern
init(tagPattern: TagPattern) {
self.tagPattern = tagPattern
}
func convertToLogs(_ payload: [String: Any]?, tag: String, captured: String?, logger: Logger) -> Set<LogEntry> {
let currentDate = logger.currentDate
let userData: Data?
if let payload = payload {
userData = try! JSONSerialization.data(withJSONObject: payload)
} else {
userData = nil
}
let log = LogEntry(tag: tag,
date: currentDate,
userData: userData)
return [log]
}
}Output
An Output should emit log entries to wherever they need.
The following ConsoleOutput will output logs to the standard output.
class ConsoleOutput: Output {
let tagPattern: TagPattern
required init(logStore: LogStore, tagPattern: TagPattern) {
self.tagPattern = tagPattern
}
func emit(log: LogEntry) {
if let userData = log.userData {
let jsonObject = try! JSONSerialization.jsonObject(with: userData)
print(jsonObject)
}
}
}BufferedOutput
If you use BufferedOutput instead of raw Output, log entries are buffered and emitted on a routine schedule.
class LogServerOutput: BufferedOutput {
override func write(_ chunk: BufferedOutput.Chunk, completion: @escaping (Bool) -> Void) {
let payload = chunk.logs.flatMap { log in
if let userData = log.userData {
return try? JSONSerialization.jsonObject(with: userData, options: [])
}
return nil
}
if let data = try? JSONSerialization.data(withJSONObject: payload, options: []) {
let task = URLSession.shared.uploadTask(with: request, from: data)
task.resume()
}
}
}Make logger and post log
After implementing filters and outputs, you can configure the routing with Logger.Configuration.
import Puree
let configuration = Logger.Configuration(filterSettings: [
FilterSetting {
PVLogFilter(tagPattern: TagPattern(string: "pv.**")!)
}
],
outputSettings: [
OutputSetting {
PVLogOutput(logStore: $0, tagPattern: TagPattern(string: "activity.**")!)
},
OutputSetting {
ConsoleOutput(logStore: $0, tagPattern: TagPattern(string: "pv.**")!)
},
OutputSetting {
LogServerOutput(logStore: $0, tagPattern: TagPattern(string: "pv.**")!)
},
])
let logger = try! Logger(configuration: configuration)
logger.postLog(["page_name": "top", "user_id": 100], tag: "pv.top")Using this configuration, the expected result is as follows:
| tag name | -> [ Filter Plugin ] | -> [ Output Plugin ] |
|---|---|---|
| pv.recipe.list | -> [ PVLogFilter ] |
-> [ ConsoleOutput ], [ LogServerOutput ] |
| pv.recipe.detail | -> [ PVLogFilter ] |
-> [ ConsoleOutput ], [ LogServerOutput ] |
| activity.recipe.tap | -> ( no filter ) | -> [ ConsoleOutput ] |
| event.special | -> ( no filter ) | -> ( no output ) |
We recommend suspending loggers while the application is in the background.
class AppDelegate: UIApplicationDelegate {
func applicationDidEnterBackground(_ application: UIApplication) {
logger.suspend()
}
func applicationWillEnterForeground(_ application: UIApplication) {
logger.resume()
}
}Tag system
Tag
A tag is consisted of multiple term delimited by ..
For example activity.recipe.view, pv.recipe_detail.
You can choose your tags logged freely.
Pattern
Filter, Output and BufferedOutput plugins are applied to log entries with a matching tag.
You can specify tag pattern for plugin reaction rules.
Simple pattern
Pattern aaa.bbb matches tag aaa.bbb, doesn't match tag aaa.ccc (Perfect matching).
Wildcard
Pattern aaa.* matches tags aaa.bbb and aaa.ccc, but not aaa or aaa.bbb.ccc (single term).
Pattern aaa.** matches tags aaa, aaa.bbb and aaa.bbb.ccc, but not xxx.yyy.zzz (zero or more terms).
Log Store
In the case an application couldn't send log entries (e.g. network connection unavailable), Puree stores the unsent entries.
By default, Puree stores them in local files in the Library/Caches directory.
You can also define your own custom log store backed by any storage (e.g. Core Data, Realm, YapDatabase, etc.).
See the LogStore protocol for more details.