LoggingFormats.jl

This package is an aggregation of various useful format functions to use with the FormatLogger from the LoggingExtras package.

Currently, the following functors are available:

• JSON: output log events as JSON
• LogFmt: output log events formatted as logfmt
• Truncated: truncation of log messages

JSON: Output log events as JSON

LoggingFormats.JSON() is a function which formats the log message and the log metadata as JSON. Example:

julia> using LoggingFormats, LoggingExtras

julia> with_logger(FormatLogger(LoggingFormats.JSON(), stderr)) do
           @info "hello, world"
           @error "something is wrong"
       end
{"level":"info","msg":"hello, world","module":"Main","file":"REPL[10]","line":2,"group":"REPL[10]","id":"Main_6972c828","kwargs":{}}
{"level":"error","msg":"something is wrong","module":"Main","file":"REPL[10]","line":3,"group":"REPL[10]","id":"Main_2289c7f9","kwargs":{}}

LogFmt: Format log events as logfmt

LoggingFormats.LogFmt() is a function which formats the log message in the logfmt format. Example:

julia> using LoggingFormats, LoggingExtras

julia> with_logger(FormatLogger(LoggingFormats.LogFmt(), stderr)) do
           @info "hello, world"
           @error "something is wrong"
       end
level=info msg="hello, world" module=Main file="REPL[2]" line=2 group="REPL[2]" id=Main_6972c827
level=error msg="something is wrong" module=Main file="REPL[2]" line=3 group="REPL[2]" id=Main_2289c7f8

Truncated: Truncate long variables and messages

LoggingFormats.Truncated(max_var_len=5_000) is a function which formats data in similar manner as ConsoleLogger, but with truncation of string representation when it exceeds max_var_len. This format truncates the length of message itself, and truncates string representation of individual variables, but does not truncate the size of whole printed text.

See the examples:

julia> using LoggingFormats, LoggingExtras

julia> with_logger(FormatLogger(LoggingFormats.Truncated(30))) do
    short_var = "a"^5
    long_var = "a"^50
    @info "a short message" short_var long_var
    @info "a very long message "^20 short_var long_var
end
┌ Info: a short message
│   short_var = aaaaa
│   long_var = aaaaaaaaaaaa…
└ @ Main REPL[46]:4
┌ Info: a very long message a very lo…
│   short_var = aaaaa
│   long_var = aaaaaaaaaaaa…
└ @ Main REPL[46]:5