timber-logging-to-file

Simple library which save encrypted timber logs to file. Best way to verify what's happen when tester have hard to reproduce error and Crashlytics doesn't contain enough information. In difficult examples it is possible to use it in production.

Add dependency to gradle

implementation("com.github.markowanga:timber-logging-to-file:1.3.0")

Basic usage of library

Library provide simple Timber.Tree called LogToFileTimberTree.

Below example shows how to plant LogToFileTimberTree:

fun initLogger() {
    Timber.plant(
        LogToFileTimberTree(ExternalLogStorageProvider(context).getStorageDirectory())
    )
}

Encrypted logs

Sometimes logs contain any secure data and user cannot have access to read it. Library contain simple TextCrypt class which can encrypt logs before append to file. There are two TextCrypters implemented in library, of course the interface can be implemented with other custom crypt methods.

Logs are saved to file line by line, it means that each line should be decoded separately.

Base64TextCrypt

The simple encryption -- easy to decode, but simple user can't read it.

Example of use:

fun initLogger() {
    Timber.plant(
        LogToFileTimberTree(
            ExternalLogStorageProvider(context).getStorageDirectory(),
            Base64TextCrypt()
        )
    )
}

CipherTextCrypt

More advanced TextCrypt. It uses javax.crypto.Cipher with AES/ECB/PKCS5Padding transformation. Logs are protected by password.

Example of use:

fun initLogger() {
    Timber.plant(
        LogToFileTimberTree(
            ExternalLogStorageProvider(context).getStorageDirectory(),
            CipherTextCrypt("test1234test1234")
        )
    )
}

Log file names

Library support file name based on current date and any variant can be implemented.

There are two implemented LogFileNameProvider in library

DailyLogFileNameProvider

The best way to divide logs for days

class DailyLogFileNameProvider(
    private val dateTimeFormatter: DateTimeFormatter = DEFAULT_FORMATTER,
    prefix: String = DEFAULT_PREFIX,
    extension: String = DEFAULT_EXTENSION
) : LogFileNameProvider(prefix, extension) { /**/ }

ConstantDateTimeLogFileNameProvider

The best way to divide logs per constant date – ex. datetime when application starts

class ConstantDateTimeLogFileNameProvider(
    private val dateTime: LocalDateTime = LocalDateTime.now(),
    private val dateTimeFormatter: DateTimeFormatter = DEFAULT_FORMATTER,
    prefix: String = DEFAULT_PREFIX,
    extension: String = DEFAULT_EXTENSION
) : LogFileNameProvider(prefix, extension) { /**/ }

Where to find files with logs

There are two type of paths provided by implementation of StorageProvider

InternalLogStorageProvider

InternalLogStorageProvider(context).getStorageDirectory()

It's classic internal memory of android app, it isn't available to read in release mode

ExternalLogStorageProvider

ExternalLogStorageProvider(context).getStorageDirectory()

External location of files – default Location is Android/data/{applicationId}/files/app-logs.