Description

Drycc (pronounced DAY-iss) is an open source PaaS that makes it easy to deploy and manage applications on your own servers. Drycc builds on Kubernetes to provide a lightweight, Heroku-inspired workflow.

About

This is an centos7 based image for running fluentd. It is built for the purpose of running on a kubernetes cluster.

This work is based on the docker-fluentd and docker-fluentd-kubernetes images by the fabric8 team. This image is in with drycc v2 to send all log data to the logger component.

Configuration

Support containerd log format

By default, fluent parses logs in docker json format. If you use containerd, you only need to set the following environment variables

• CONTAINER_TAIL_PARSER_TYPE="/^(?<time>.+) (?<stream>stdout|stderr)( (?<tags>.))? (?<log>.*)$/"

Support exclude specific container logs

You can exclude container logs from /var/log/containers/ with CONTAINER_TAIL_EXCLUDE_PATH.

• CONTAINER_TAIL_EXCLUDE_PATH='["/var/log/containers/coredns-*", "/var/log/containers/ingress-nginx-*"]'

Enable more verbose logging

By default we do not capture kubernetes system logs. However, it is possible to tell fluentd to capture those logs just by specifying a few new environment variables.

• CAPTURE_START_SCRIPT
• CAPTURE_DOCKER_LOG
• CAPTURE_ETCD_LOG
• CAPTURE_KUBELET_LOG
• CAPTURE_KUBE_API_LOG
• CAPTURE_CONTROLLER_LOG
• CAPTURE_SCHEDULER_LOG

Set a variable's value to a non-empty string such as "true" to capture that log. Make these changes to the tpl/drycc-logger-fluentd-daemon.yaml file in the Workflow chart directory.

Drop Fluentd Logs

To turn off log collection of fluentd's own logs to avoid infinite loops set the following environment variable to a non-empty string value

• DROP_FLUENTD_LOGS

Disable Drycc Output

To turn off the drycc output plugin set the following environment variable to a non-empty string value

• DISABLE_DRYCC_OUTPUT

Disable sending log data to redis

To turn off sending log data to redis set the following environment variable to "false"

• SEND_LOGS_TO_REDIS

Plugins

fluent-plugin-kubernetes_metadata_filter

This plugin is used to decorate all log entries with kubernetes metadata.

fluent-plugin-elasticsearch

Allows fluentd to send log data to an elastic search cluster. You must specify an ELASTICSEARCH_HOST environment variable for this plugin to work.

• ELASTICSEARCH_HOST="some.host"
• ELASTICSEARCH_SCHEME="http/https"
• ELASTICSEARCH_PORT="9200"
• ELASTICSEARCH_USER="username"
• ELASTICSEARCH_PASSWORD="password"
• ELASTICSEARCH_LOGSTASH_FORMAT="true/false" - Creates indexes in the format index_prefix-YYYY.MM.DD
• ELASTICSEARCH_TARGET_INDEX_KEY="kubernetes.namespace_name" - Allows the index name to come from within the log message map. See example message format below. This allows the user to have an index per namespace, container name, or other dynamic value.
• ELASTICSEARCH_TARGET_TYPE_KEY="some.key" - Allows the user to set _type to a custom value found in the map.
• ELASTICSEARCH_INCLUDE_TAG_KEY="true/false" - Merge the fluentd tag back into the log message map.
• ELASTICSEARCH_INDEX_NAME="fluentd" - Set the index name where all events will be sent.
• ELASTICSEARCH_LOGSTASH_PREFIX="logstash" - Set the logstash prefix variable which is used when you want to use logstash format without specifying ELASTICSEARCH_TARGET_INDEX_KEY.
• ELASTICSEARCH_TIME_KEY="" - specify where the plugin can find the timestamp used for the @timestamp field
• ELASTICSEARCH_TIME_KEY_FORMAT="" - specify the format of ELASTICSEARCH_TIME_KEY
• ELASTICSEARCH_TIME_KEY_EXCLUDE_TIMESTAMP="" - If ELASTICSEARCH_TIME_KEY specified dont set ``@timestamp
• ELASTICSEARCH_400_REASON="true" - You can set this true to capture the 400 error reasons without all the other debug logs.

fluent-plugin-remote_syslog

This plugin allows fluentd to send data to a remote syslog endpoint like papertrail. You can configure fluentd to talk to multiple remote syslog endpoints by using the following scheme:

• SYSLOG_HOST_1=some.host
• SYSLOG_PORT_1=514
• SYSLOG_HOST_2=some.other.host
• SYSLOG_PORT_2=52232

You can also set SYSLOG_HOST and SYSLOG_PORT.

fluent-plugin-sumologic

This plugin allows for fluentd to send all log data to a sumologic endpoint. You can configure it using the following environment variables:

• SUMOLOGIC_COLLECTOR_URL
• SUMOLOGIC_ENDPOINT
• SUMOLOGIC_HOST
• SUMOLOGIC_PORT : defaults to 80 (unless IS_HTTPS is set and then its 443)
• IS_HTTPS

fluent-plugin-gelf-hs

This plugin allows for fluentd to send all log data to a remote graylog endpoint. You can configure it using the following environment variables:

• GELF_HOST=some.host
• GELF_PORT=12201
• GELF_PROTOCOL="udp/tcp"
• GELF_TLS="true/false"
• GELF_TLS_OPTIONS_CERT="-----BEGIN CERTIFICATE-----\n[...]\n-----END CERTIFICATE-----"
• GELF_TLS_OPTIONS_KEY="-----BEGIN PRIVATE KEY-----\n[...]\n-----END PRIVATE KEY-----"
• GELF_TLS_OPTIONS_ALL_CIPHERS="true/false"
• GELF_TLS_OPTIONS_TLS_VERSION=":TLSv1/:TLSv1_1/:TLSv1_2"
• GELF_TLS_OPTIONS_NO_DEFAULT_CA="true/false"

Drycc Output

Drycc output is a custom fluentd plugin that was written to forward data directly to drycc components while filtering out data that we did not care about. We have 2 pieces of information we care about currently.

Logs from applications that are written to stdout within the container and the controller logs that represent actions against those applications. These logs are sent to an internal messaging system (REIDS) on a configurable topic. The logger component then reads those messages and stores the data in an ring buffer.

The stream these messages are put on are configurable via environment variables.

• REDIS_LOG_STREAM

Custom Plugins

If you need something beyond the plugins that come pre-installed in the image, it is possible to set some environment variables to install and configure custom plugins as well.

To install a custom plugin, simply set a FLUENTD_PLUGIN_# environment variable. For multiple plugins simply increment the trailing number. FLUENTD_PLUGIN_1=some-fluentd-plugin

To configure your custom plugins, use either the CUSTOM_STORE_# or CUSTOM_FILTER_# environment variables

• CUSTOM_STORE_1="configuration text"
• CUSTOM_FILTER_1="configuration text"

If you need the build tools available for installing your plugin, this can be enabled with another environment variable INSTALL_BUILD_TOOLS="true"