This is a Logz.io Fluentd solution for Kubernetes.

Fluentd DaemonSet

For Kubernetes, a DaemonSet ensures that some or all nodes run a copy of a pod. To collect logs, we'll use a Fluentd DaemonSet. Fluentd is flexible enough and has the proper plugins to distribute logs to different third parties, like Logz.io.

DaemonSet Content

This repository contains the configurations to deploy Fluentd as a DaemonSet. The Docker container image also comes pre-configured for Fluentd to gather all logs from the Kubernetes node environment and append the proper metadata to the logs.

Logging to Logz.io

DaemonSet configuration

The DaemonSet yaml file has two environment variables. Fluentd uses these variables when the container starts.

Environment variable	Description
LOGZIO_TOKEN	Logz.io account token
LOGZIO_URL	Logz.io listener url, If the account is in the EU region insert https://listener-eu.logz.io:8071. Otherwise, use https://listener.logz.io:8071. You can tell your account's region by checking your login URL - app.logz.io means you are in the US. app-eu.logz.io means you are in the EU

Logz.io endpoint configuration

Here you can configure Logz.io Fluentd endpoint shipping behavior.

Variable	Description	Default
endpoint_url	The url to Logz.io input	#{ENV['LOGZIO_URL']}?token=#{ENV['LOGZIO_TOKEN']}
output_include_time	To append a timestamp to your logs when they're processed, true. Otherwise, false.	true
buffer_type	Specifies which plugin to use as the backend	file
buffer_path	Path of the buffer	/var/log/Fluentd-buffers/stackdriver.buffer
buffer_queue_full_action	Controls the behavior when the queue becomes full	block
buffer_chunk_limit	Maximum size of a chunk allowed	2M
buffer_queue_limit	Maximum length of the output queue	6
flush_interval	Interval, in seconds, to wait before invoking the next buffer flush	5s
max_retry_wait	Maximum interval, in seconds, to wait between retries	30s
num_threads	Number of threads to flush the buffer	2

Disable systemd input

If you don't setup systemd in the container, fluentd shows following messages by default configuration.

[warn]: #0 [in_systemd_bootkube] Systemd::JournalError: No such file or directory retrying in 1s
[warn]: #0 [in_systemd_kubelet] Systemd::JournalError: No such file or directory retrying in 1s
[warn]: #0 [in_systemd_docker] Systemd::JournalError: No such file or directory retrying in 1s

You can suppress these messages by setting disable to FLUENTD_SYSTEMD_CONF environment variable in your kubernetes configuration.