A log file highlighter
- πͺ΅ View (or
tail
) any log file of any format - π° No setup or config required
- π Highlights numbers, dates, IP-addresses, UUIDs, URLs and more
- βοΈ All highlight groups are customizable
- 𧬠Easy to integrate with other commands
- π Uses
less
under the hood - π¦ Powered by the
manifold
crate
- Overview
- Usage
- Installing
- Highlight Groups
- Watching folders
- Customizing Highlight Groups
- Working with
stdin
andstdout
- Using the pager
less
- Settings
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.
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
kubectl logs [pod name] --follow | tspin
# Capture the stdout of another command and view in `less`
tspin --listen-command 'kubectl logs -f pod_name'
# 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
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
.
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.
Create a theme.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 theme.toml
file. For example, to edit the date
highlight group, add the following to your theme.toml
:
[date]
style = { fg = "green" }
Expand the section below to see the default config for the highlight groups:
Default highlight groups settings
[date]
date = { fg = "magenta" }
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" }
[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" }
[json]
key = { fg = "yellow" }
quote_token = { fg = "yellow", faint = true }
curly_bracket = { faint = true }
square_bracket = { faint = true }
comma = { faint = true }
colon = { faint = true }
To individually disable or enable highlight groups, use the --enable
and --disable
flags:
# Enable only the url highlight group, disabling the rest
tspin application.log --enable=url
# Disable the numbers highlight group, keeping the rest
tspin application.log --disable=numbers
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 }
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.
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]]
regex = 'Started (.*)\.'
style = { fg = "red" }
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
To capture the output of a command and view it in less
, use the --listen-command
flag:
tspin --listen-command 'kubectl logs -f pod_name'
This will run the command kubectl logs -f pod_name
in the background and pipe the output to tailspin
. The output
will be displayed in less
, allowing you to navigate and search through the logs.
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 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
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.
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.
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.
-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
--no-builtin-keywords Disable the highlighting of booleans, nulls, log severities and common REST verbs
--enable=[HIGHLIGHT_GROUP] Enable one or more highlight groups, disabling the rest
--disable=[HIGHLIGHT_GROUP] Disable one or more highlight groups, enabling the rest