k8stail

tail -f experience for Kubernetes Pods

As you know, kubectl logs can stream only ONE pod at the same time. k8stail enables you to watch log streams of ALL pods in the specified namespace or labels in real time, like tail -f.

Table of Contents

• Requirements
• Installation
  • Using Homebrew (OS X only)
  • Precompiled binary
  • From source
  • Run in a Docker container
• Usage
  • kubeconfig file
  • Options
• Development
• Author
• License

Requirements

Kubernetes 1.3 or above

Installation

Using Homebrew (OS X only)

Formula is available at dtan4/homebrew-dtan4.

$ brew tap dtan4/dtan4
$ brew install k8stail

Precompiled binary

Precompiled binaries for Windows, OS X, Linux are available at Releases.

From source

$ go get -d github.com/dtan4/k8stail
$ cd $GOPATH/src/github.com/dtan4/k8stail
$ make deps
$ make install

Run in a Docker container

Docker image is no longer provided officially. If you'd like to run k8sec in Docker image, see Dockerfile and build image by yourself.

docker build -t k8stail .

Usage

Logs of all pods, all containers in pod in the specified namespace are streaming. When new pod is added, logs of the pod also appears. To stop streaming and exit, press Ctrl-C.

$ k8stail --namespace awesome-app
Namespace: awesome-app
Labels:
----------
Pod awesome-app-web-4212725599-67vd4 has detected
Pod awesome-app-web-4212725599-6pduy has detected
Pod awesome-app-web-4212725599-lbuny has detected
Pod awesome-app-web-4212725599-mh3g1 has detected
Pod awesome-app-web-4212725599-pvjsm has detected
[awesome-app-web-4212725599-mh3g1][web]  | creating base compositions...
[awesome-app-web-4212725599-zei9h][web]  |    (47.1ms)  CREATE TABLE "schema_migrations" ("version" character varying NOT NULL)
[awesome-app-web-4212725599-zei9h][web]  |    (45.1ms)  CREATE UNIQUE INDEX  "unique_schema_migrations" ON "schema_migrations"  ("version")
[awesome-app-web-4212725599-zei9h][web]  |   ActiveRecord::SchemaMigration Load (1.8ms)  SELECT "schema_migrations".* FROM "schema_migrations"
[awesome-app-web-4212725599-zei9h][web]  | Migrating to CreatePosts (20160218082522)

With --timestamps option, log timestamp is printed together.

$ k8stail --namespace awesome-app --timestamps
Namespace: awesome-app
Labels:
----------
Pod awesome-app-web-4212725599-67vd4 has detected
Pod awesome-app-web-4212725599-6pduy has detected
Pod awesome-app-web-4212725599-lbuny has detected
Pod awesome-app-web-4212725599-mh3g1 has detected
Pod awesome-app-web-4212725599-pvjsm has detected
[awesome-app-web-4212725599-mh3g1][web] 2016-11-15T10:57:22.178667425Z  | creating base compositions...
[awesome-app-web-4212725599-zei9h][web] 2016-11-15T10:57:22.309011520Z  |    (47.1ms)  CREATE TABLE "schema_migrations" ("version" character varying NOT NULL)
[awesome-app-web-4212725599-zei9h][web] 2016-11-15T10:57:22.309053601Z  |    (45.1ms)  CREATE UNIQUE INDEX  "unique_schema_migrations" ON "schema_migrations"  ("version")
[awesome-app-web-4212725599-zei9h][web] 2016-11-15T10:57:22.463700110Z  |   ActiveRecord::SchemaMigration Load (1.8ms)  SELECT "schema_migrations".* FROM "schema_migrations"
[awesome-app-web-4212725599-zei9h][web] 2016-11-15T10:57:22.463743373Z  | Migrating to CreatePosts (20160218082522)

With --labels option, you can filter pods to watch.

$ k8stail --namespace awesome-app --labels name=awesome-app-web
Namespace: awesome-app
Labels:    name=awesome-app-web
----------
Pod awesome-app-web-4212725599-67vd4 has detected
Pod awesome-app-web-4212725599-6pduy has detected
Pod awesome-app-web-4212725599-lbuny has detected
Pod awesome-app-web-4212725599-mh3g1 has detected
Pod awesome-app-web-4212725599-pvjsm has detected
[awesome-app-web-4212725599-mh3g1][web]  | creating base compositions...
[awesome-app-web-4212725599-zei9h][web]  |    (47.1ms)  CREATE TABLE "schema_migrations" ("version" character varying NOT NULL)
[awesome-app-web-4212725599-zei9h][web]  |    (45.1ms)  CREATE UNIQUE INDEX  "unique_schema_migrations" ON "schema_migrations"  ("version")
[awesome-app-web-4212725599-zei9h][web]  |   ActiveRecord::SchemaMigration Load (1.8ms)  SELECT "schema_migrations".* FROM "schema_migrations"
[awesome-app-web-4212725599-zei9h][web]  | Migrating to CreatePosts (20160218082522)

kubeconfig file

k8stail uses ~/.kube/config as default. You can specify another path by KUBECONFIG environment variable or --kubeconfig option. --kubeconfig option always overrides KUBECONFIG environment variable.

$ KUBECONFIG=/path/to/kubeconfig k8stail
# or
$ k8stail --kubeconfig=/path/to/kubeconfig

Options

Option	Description	Required	Default
--context=CONTEXT	Kubernetes context
--debug	Debug mode using pprof (http://localhost:6060)		false
--kubeconfig=KUBECONFIG	Path of kubeconfig		~/.kube/config
--labels=LABELS	Label filter query (e.g. app=APP,role=ROLE)
--namespace=NAMESPACE	Kubernetes namespace		default
--timestamps	Include timestamps on each line		false
-h, -help	Print command line usage
-v, -version	Print version

Development

Go 1.7 or above is required.

Clone this repository and build using make.

$ go get -d github.com/dtan4/k8stail
$ cd $GOPATH/src/github.com/dtan4/k8stail
$ make

Author

Daisuke Fujita (@dtan4)

License