stern stern

Use this command to install stern:

winget install --id=stern.stern -e

Stern is a command-line tool designed to simplify log tailing across multiple pods and containers in Kubernetes. It enables users to monitor logs from various components simultaneously, making debugging and monitoring more efficient.

Key Features:

Multi-pod and Container Support: Tail logs from multiple pods and their respective containers in a single session.
Color-Coded Output: Logs are color-coded based on pod and container names for easier identification and quicker debugging.
Regex or Resource-Based Queries: Use regular expressions or Kubernetes resources (e.g., deployments, services) to filter logs, eliminating the need to specify exact pod IDs.
Dynamic Pod Management: Automatically adds new pods as they appear and removes deleted ones without manual intervention.
Container-Specific Filtering: Tail logs from specific containers within a pod using flags, allowing targeted monitoring.

Audience & Benefit:

Ideal for Kubernetes administrators and developers who need efficient debugging in complex environments. Stern helps save time by providing a unified view of logs across multiple components, reducing the likelihood of missing critical information during troubleshooting or monitoring.

Stern can be installed via winget on Windows, making it accessible to users familiar with package managers.

README

stern

Fork of discontinued wercker/stern

Stern allows you to tail multiple pods on Kubernetes and multiple containers within the pod. Each result is color coded for quicker debugging.

The query is a regular expression or a Kubernetes resource in the form / so the pod name can easily be filtered and you don't need to specify the exact id (for instance omitting the deployment id). If a pod is deleted it gets removed from tail and if a new pod is added it automatically gets tailed.

When a pod contains multiple containers Stern can tail all of them too without having to do this manually for each one. Simply specify the container flag to limit what containers to show. By default all containers are listened to.

Installation

Download binary

Download a binary release

Build from source

go install github.com/stern/stern@latest

asdf (Linux/macOS)

If you use asdf, you can install like this:

asdf plugin add stern
asdf install stern latest

Homebrew (Linux/macOS)

If you use Homebrew, you can install like this:

brew install stern

Krew (Linux/macOS/Windows)

If you use Krew which is the package manager for kubectl plugins, you can install like this:

kubectl krew install stern

WinGet (Windows)

If you're running on Windows, usually the actual best way is to use WinGet to install which is Windows' built-in package manager, you can install like this:

winget install stern.stern

Usage

stern pod-query [flags]

The pod-query is a regular expression or a Kubernetes resource in the form /.

The query is a regular expression when it is not a Kubernetes resource, so you could provide "web-\w" to tail web-backend and web-frontend pods but not web-123.

When the query is in the form (exact match), you can select all pods belonging to the specified Kubernetes resource, such as . Supported Kubernetes resources are , , , , , , and .

flag

default

purpose

--all-namespaces, -A

false

If present, tail across all namespaces. A specific namespace is ignored even if specified with --namespace.

--color

auto

Force set color output. 'auto': colorize if tty attached, 'always': always colorize, 'never': never colorize.

--completion

Output stern command-line completion code for the specified shell. Can be 'bash', 'zsh' or 'fish'.

--condition

The condition to filter on: [condition-name[=condition-value]. The default condition-value is true. Match is case-insensitive. Currently only supported with --tail=0 or --no-follow.

--config

~/.config/stern/config.yaml

Path to the stern config file

--container, -c

.*

Container name when multiple containers in pod. (regular expression)

--container-colors

Specifies the colors used to highlight container names. Use the same format as --pod-colors. Defaults to the values of --pod-colors if omitted, and must match its length.

--container-state

all

Tail containers with state in running, waiting, terminated, or all. 'all' matches all container states. To specify multiple states, repeat this or set comma-separated value.

--context

The name of the kubeconfig context to use

--diff-container, -d

false

Display different colors for different containers.

--ephemeral-containers

true

Include or exclude ephemeral containers.

--exclude, -e

[]

Log lines to exclude. (regular expression)

--exclude-container, -E

[]

Container name to exclude when multiple containers in pod. (regular expression)

--exclude-pod

[]

Pod name to exclude. (regular expression)

--field-selector

Selector (field query) to filter on. If present, default to ".*" for the pod-query.

--highlight, -H

[]

Log lines to highlight. (regular expression)

--include, -i

[]

Log lines to include. (regular expression)

--init-containers

true

Include or exclude init containers.

--kubeconfig

Path to the kubeconfig file to use for CLI requests.

--max-log-requests

-1

Maximum number of concurrent logs to request. Defaults to 50, but 5 when specifying --no-follow

--namespace, -n

Kubernetes namespace to use. Default to namespace configured in kubernetes context. To specify multiple namespaces, repeat this or set comma-separated value.

--no-follow

false

Exit when all logs have been shown.

--node

Node name to filter on.

--only-log-lines

false

Print only log lines

--output, -o

default

Specify predefined template. Currently support: [default, raw, json, extjson, ppextjson]

--pod-colors

Specifies the colors used to highlight pod names. Provide colors as a comma-separated list using SGR (Select Graphic Rendition) sequences, e.g., "91,92,93,94,95,96".

--prompt, -p

false

Toggle interactive prompt for selecting 'app.kubernetes.io/instance' label values.

--selector, -l

Selector (label query) to filter on. If present, default to ".*" for the pod-query.

--show-hidden-options

false

Print a list of hidden options.

--since, -s

48h0m0s

Return logs newer than a relative duration like 5s, 2m, or 3h.

--stdin

false

Parse logs from stdin. All Kubernetes related flags are ignored when it is set.

--tail

-1

The number of lines from the end of the logs to show. Defaults to -1, showing all logs.

--template

Template to use for log lines, leave empty to use --output flag.

--template-file, -T

Path to template to use for log lines, leave empty to use --output flag. It overrides --template option.

--timestamps, -t

Print timestamps with the specified format. One of 'default' or 'short' in the form '--timestamps=format' ('=' cannot be omitted). If specified but without value, 'default' is used.

--timezone

Local

Set timestamps to specific timezone.

--verbosity

0

Number of the log level verbosity

--version, -v

false

Print the version and exit.

output	description
`default`	Displays the namespace, pod and container, and decorates it with color depending on --color
`raw`	Only outputs the log message itself, useful when your logs are json and you want to pipe them to `jq`
`json`	Marshals the log struct to json. Useful for programmatic purposes
`extjson`	Outputs extended JSON with colorized pod/container names
`ppextjson`	Pretty-prints extended JSON with colorized pod/container names

property	type	description
`Message`	string	The log message itself
`NodeName`	string	The node name where the pod is scheduled on
`Namespace`	string	The namespace of the pod
`PodName`	string	The name of the pod
`ContainerName`	string	The name of the container
`Labels`	map[string]string	The labels of the pod
`Annotations`	map[string]string	The annotations of the pod

func	arguments	description
`json`	`object`	Marshal the object and output it as a json text
`color`	`color.Color, string`	Wrap the text in color (.ContainerColor and .PodColor provided)
`parseJSON`	`string`	Parse string as JSON
`tryParseJSON`	`string`	Attempt to parse string as JSON, return nil on failure
`extractJSONParts`	`string, ...string`	Parse string as JSON and concatenate the given keys.
`tryExtractJSONParts`	`string, ...string`	Attempt to parse string as JSON and concatenate the given keys. , return text on failure
`prettyJSON`	`any`	Parse input and emit it as pretty printed JSON, if parse fails output string as is.
`toRFC3339Nano`	`object`	Parse timestamp (string, int, json.Number) and output it using RFC3339Nano format
`toTimestamp`	`object, string [, string]`	Parse timestamp (string, int, json.Number) and output it using the given layout in the timezone that is optionally given (defaults to UTC).
`levelColor`	`string`	Print log level using appropriate color
`bunyanLevelColor`	`string`	Print bunyan numeric log level using appropriate color
`colorBlack`	`string`	Print text using black color
`colorRed`	`string`	Print text using red color
`colorGreen`	`string`	Print text using green color
`colorYellow`	`string`	Print text using yellow color
`colorBlue`	`string`	Print text using blue color
`colorMagenta`	`string`	Print text using magenta color
`colorCyan`	`string`	Print text using cyan color
`colorWhite`	`string`	Print text using white color
`colorCustom`	`string, int [, int]`	Print text using custom color, i.e. {{color "Hi" 3 96}} will print "Hi" as italic with cyan color

stern stern

Key Features:

Audience & Benefit:

README

stern

Installation

Download binary

Build from source

asdf (Linux/macOS)

Homebrew (Linux/macOS)

Krew (Linux/macOS/Windows)

WinGet (Windows)

Usage

cli flags

config file

templates

Log level verbosity

Max log requests

Customize highlight colors

Examples:

Completion

Running with container

Running in Kubernetes Pods

Contributing to this repository

`--no-follow`	default	behavior
specified	5	limits the number of concurrent logs to request
not specified	50	exits with an error when if it reaches the concurrent limit