Kubetail

Bash script that enables you to aggregate (tail/follow) logs from multiple pods into one stream. This is the same as running "kubectl logs -f " but for multiple pods.

Installation

Just download the kubetail file (or any of the releases) and you're good to go.

Homebrew

You can also install kubetail using brew:

$ brew tap johanhaleby/kubetail && brew install kubetail

Use brew install --HEAD kubetail to install the latest (unreleased) version.

Usage

First find the names of all your pods:

$ kubectl get pods

This will return a list looking something like this:

NAME                   READY     STATUS    RESTARTS   AGE
app1-v1-aba8y          1/1       Running   0          1d
app1-v1-gc4st          1/1       Running   0          1d
app1-v1-m8acl  	       1/1       Running   0          6d
app1-v1-s20d0  	       1/1       Running   0          1d
app2-v31-9pbpn         1/1       Running   0          1d
app2-v31-q74wg         1/1       Running   0          1d
my-demo-v5-0fa8o       1/1       Running   0          3h
my-demo-v5-yhren       1/1       Running   0          2h

To tail the logs of the two "app2" pods in one go simply do:

$ kubetail app2

To tail only a specific container from multiple pods specify the container like this:

$ kubetail app2 -c container1

You can repeat -c to tail multiple specific containers:

$ kubetail app2 -c container1 -c contianer2

Supply -h for help and addtional options:

$ kubetail -h

Colors

By using the -k argument you can specifiy how kubetail makes use of colors (only applicable when tailing multiple pods).

Value	Description
pod	Only the pod name is colorized but the logged text is using the terminal default color
line	The entire line is colorized (default)
false	Don't colorize the output at all

Example:

$ kubetail app2 -k false

Filtering / Highlighting etc

kubetail itself doesn't have filitering or highlighting capabilities built-in. If you're on MacOSX I recommend using iTerm2 which allows for continuous highlighting of search terms, good scrolling capabilities and multitab arrangements. Another useful feature of iTerm2 is the "timeline" (cmd + shift + e) which lets you display a timeline in your own local timezone next to the logs (that are typically in UTC).

If you're not using iTerm2 or think that kubetail is lacking in features there's a fork of kubetail made by Alan Stebbens that allows for richer configuration and uses multitail and bash-lib. Alan has been kind enough to provide a pull request but my current thinking is that I'd like kubetail to stay simple and small and not use any dependencies.

Known issues

When you press "ctrl+c" to end the log session you may end up with errors like this:

error: write /dev/stdout: broken pipe

I'm not quite sure why this happens, pull requests are welcome :)

See also: http://code.haleby.se/2015/11/13/tail-logs-from-multiple-pods-simultaneously-in-kubernetes/