18 stable releases
3.0.2 | Aug 17, 2024 |
---|---|
3.0.1 | Apr 1, 2024 |
3.0.0 | Jan 21, 2024 |
2.4.0 | Jan 11, 2024 |
1.3.0 | Jul 31, 2023 |
#158 in HTTP server
486 downloads per month
4MB
3K
SLoC
A log file highlighter
Features
- 🪵 View (or
tail
) any log file of any format - 🍰 No setup or config required
- 🌈 Highlights numbers, dates, IP-addresses, UUIDs, URLs and more
- ⚙️ All highlight groups are customizable
- 🧬 Easy to integrate with other commands
- 🔍 Uses
less
under the hood for scrollback, search and filtering
Table of Contents
- Overview
- Usage
- Installing
- Highlight Groups
- Watching folders
- Customizing Highlight Groups
- Working with
stdin
andstdout
- Using the pager
less
- Settings
Overview
tailspin
works by reading through a log file line by line, running a series of regexes
against each line. The regexes recognize patterns you expect to find in a logfile, like dates, numbers, severity
keywords and more.
tailspin
does not make any assumptions on the format or position of the items it wants to highlight. For this reason,
it requires no configuration and the highlighting will work consistently across different logfiles.
Usage
The binary name for tailspin
is tspin
.
# Read from file and view in `less`
tspin application.log
# Read from file and print to stdout
tspin application.log --print
# Read from stdin and print to stdout
echo "2021-01-01 12:00:00 [INFO] This is a log message" | tspin
# Read from another command and print to stdout
kubectl logs [pod name] --follow | tspin
Installing
Package Managers
# Homebrew
brew install tailspin
# Cargo
cargo install tailspin
# Archlinux
pacman -S tailspin
# Nix
nix-shell -p tailspin
# NetBSD
pkgin install tailspin
# FreeBSD
pkg install tailspin
From Source
cargo install --path .
Binary will be placed in ~/.cargo/bin
, make sure you add the folder to your PATH
environment variable.
[!IMPORTANT] When building from source, make sure that you are using the latest version of
less
.
Highlight Groups
Dates
Keywords
URLs
Numbers
IP Addresses
Quotes
Unix file paths
HTTP methods
UUIDs
Key-value pairs
Pointer addresses
Unix processes
Watching folders
tailspin
can listen for newline entries in a given folder. Watching folders is useful for monitoring log files that
are rotated.
When watching folders, tailspin
will start in follow mode (abort with Ctrl + C) and will only print
newline entries which arrive after the initial start.
Customizing Highlight Groups
Overview
Create config.toml
in ~/.config/tailspin
to customize highlight groups.
Styles have the following shape:
style = { fg = "color", bg = "color", italic = false, bold = false, underline = false }
To edit the different highlight groups, include them in your config.toml
file. For example, to edit the date
highlight group, add the following to your config.toml
:
[date]
style = { fg = "green" }
Expand the section below to see the default config for the highlight groups:
Default highlight groups settings
[date]
number = { fg = "magenta" }
separator = { faint = true }
[date_word] # e.g. "Jan 01", "Mon Feb 28"
day = { fg = "magenta" }
month = { fg = "magenta" }
number = { fg = "magenta" }
[time]
time = { fg = "blue" }
zone = { fg = "red" }
separator = { faint = true }
[[keywords]]
words = ['null', 'true', 'false']
style = { fg = "red", italic = true }
[[keywords]]
words = ['GET']
style = { fg = "black", bg = "green" }
border = true
[url]
http = { fg = "red", faint = true }
https = { fg = "green", faint = true }
host = { fg = "blue", faint = true }
path = { fg = "blue" }
query_params_key = { fg = "magenta" }
query_params_value = { fg = "cyan" }
symbols = { fg = "red" }
[number]
style = { fg = "cyan" }
[ip]
number = { fg = "blue", italic = true }
letter = { fg = "magenta", italic = true }
separator = { fg = "red" }
[quotes]
style = { fg = "yellow" }
token = '"'
[path]
segment = { fg = "green", italic = true }
separator = { fg = "yellow" }
[uuid]
number = { fg = "blue", italic = true }
letter = { fg = "magenta", italic = true }
separator = { fg = "red" }
[pointer]
number = { fg = "blue", italic = true }
letter = { fg = "magenta", italic = true }
separator = { fg = "red" }
[key_value]
key = { faint = true }
separator = { fg = "white" }
[process]
name = { fg = "green" }
separator = { fg = "red" }
id = { fg = "yellow" }
Disabling Highlight Groups
To disable a highlight group, set the disabled
field for that group to true:
[date]
disabled = true
Adding Keywords via config.toml
To add custom keywords, either include them in the list of keywords or add new entries:
[[keywords]]
words = ['MyCustomKeyword']
style = { fg = "green" }
[[keywords]]
words = ['null', 'true', 'false']
style = { fg = "red", italic = true }
Adding Keywords from the command line
Sometimes it is more convenient to add highlight groups on the fly without having to edit a TOML. To add highlights from
the command line, use the --words-[red|green|yellow|blue|magenta|cyan]
flag followed by a comma separated list
of words to be highlighted.
Custom regex highlighters
When you need more control over the highlighting, you can use the regex highlighter. This highlighter allows you to specify a regex and a style to be applied to the matched text.
It supports one capture group ()
. When found, it will apply the style to the captured text.
[[regexps]]
regular_expression = 'Started (.*)\.'
style = { fg = "red" }
Working with stdin
and stdout
By default, tailspin
will open a file in the pager less
. However, if you pipe something into tailspin
, it will
print the highlighted output directly to stdout
. This is similar to running tspin [file] --print
.
To let tailspin
highlight the logs of different commands, you can pipe the output of those commands into tailspin
like so:
journalctl -f | tspin
cat /var/log/syslog | tspin
kubectl logs -f pod_name | tspin
Using the pager less
Overview
tailspin
uses less
as its pager to view the highlighted log files. You can get more info on less
via the man
command (man less
) or by hitting the h button to access the help screen.
Navigating
Navigating within less
uses a set of keybindings that may be familiar to users of vim
or other vi
-like
editors. Here's a brief overview of the most useful navigation commands:
- j/k: Scroll one line up / down
- d/u: Scroll one half-page up / down
- g/G: Go to the top / bottom of the file
Follow mode
When you run tailspin
with the -f
or --follow
flag, it will scroll to the bottom and print new lines to the screen
as they're added to the file.
To stop following the file, interrupt with Ctrl + C. This will stop the tailing, but keep the file open, allowing you to review the existing content.
To resume following the file from within less
, press Shift + F.
Search
Use / followed by your search query. For example, /ERROR
finds the first occurrence of
ERROR.
After the search, n finds the next instance, and N finds the previous instance.
Filtering
less
allows filtering lines by a keyword, using & followed by the pattern. For instance, &ERROR
shows
only lines with ERROR.
To only show lines containing either ERROR
or WARN
, use a regular expression: &\(ERROR\|WARN\)
.
To clear the filter, use & with no pattern.
Settings
-f, --follow Follow the contents of the file
-e, --start-at-end Start at the end of the file
-p, --print Print the output to stdout
-c, --listen-command [CMD] Listen the output (stdout) of the provided command
--config-path [PATH] Use the configuration file from the provided path
--words-[COLOR] [WORDS] Highlight the provided words with the given color
--disable-builtin-keywords Disable the highlighting of all builtin groups
--disable-booleans Disable the highlighting of booleans and nulls
--disable-severity Disable the highlighting of severity levels
--disable-rest Disable the highlighting of REST verbs
Dependencies
~15–27MB
~424K SLoC