# Fluentd

[Fluentd](https://www.fluentd.org/) is an open source data collector, which lets you unify the data collection and consumption for a better use and understanding of data.

## TL;DR;

```console
$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/fluentd
```

## Introduction

This chart bootstraps a [Fluentd](https://github.com/bitnami/bitnami-docker-fluentd) deployment on a [Kubernetes](http://kubernetes.io) cluster using the [Helm](https://helm.sh) package manager.

Bitnami charts can be used with [Kubeapps](https://kubeapps.com/) for deployment and management of Helm Charts in clusters.

## Prerequisites

- Kubernetes 1.12+
- Helm 2.11+ or Helm 3.0-beta3+
- PV provisioner support in the underlying infrastructure

> Note: Please, note that the forwarder runs the container as root by default setting the `forwarder.securityContext.runAsUser` to `0` (_root_ user)

## Installing the Chart

To install the chart with the release name `my-release`:

```console
$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/fluentd
```

These commands deploy Fluentd on the Kubernetes cluster in the default configuration. The [Parameters](#parameters) section lists the parameters that can be configured during installation.

> **Tip**: List all releases using `helm list`

## Uninstalling the Chart

To uninstall/delete the `my-release` resources:

```console
$ helm delete my-release
```

The command removes all the Kubernetes components associated with the chart and deletes the release. Use the option `--purge` to delete all history too.

## Parameters

The following tables lists the configurable parameters of the kibana chart and their default values.

| Parameter                                       | Description                                                                                                    | Default                                                                                                 |
|-------------------------------------------------|----------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------|
| `global.imageRegistry`                          | Global Docker image registry                                                                                   | `nil`                                                                                                   |
| `global.imagePullSecrets`                       | Global Docker registry secret names as an array                                                                | `[]` (does not add image pull secrets to deployed pods)                                                 |
| `image.registry`                                | Fluentd image registry                                                                                         | `docker.io`                                                                                             |
| `image.repository`                              | Fluentd image name                                                                                             | `bitnami/fluentd`                                                                                       |
| `image.tag`                                     | Fluentd image tag                                                                                              | `{TAG_NAME}`                                                                                            |
| `image.pullPolicy`                              | Fluentd image pull policy                                                                                      | `IfNotPresent`                                                                                          |
| `image.pullSecrets`                             | Specify docker-registry secret names as an array                                                               | `[]` (does not add image pull secrets to deployed pods)                                                 |
| `nameOverride`                                  | String to partially override fluentd.fullname template with a string (will prepend the release name)           | `nil`                                                                                                   |
| `fullnameOverride`                              | String to fully override fluentd.fullname template with a string                                               | `nil`                                                                                                   |
| `clusterDomain`                                 | Kubernetes DNS domain name to use                                                                              | `cluster.local`                                                                                         |
| `forwarder.enabled`                             | Enable Fluentd forwarder                                                                                       | `true`                                                                                                  |
| `forwarder.daemonUser`                          | Fluentd forwarder daemon system user                                                                           | `root`                                                                                                  |
| `forwarder.daemonGroup`                         | Fluentd forwarder daemon system group                                                                          | `root`                                                                                                  |
| `forwarder.securityContext.enabled`             | Enable security context for forwarder pods                                                                     | `true`                                                                                                  |
| `forwarder.securityContext.fsGroup`             | Group ID for forwarder's containers filesystem                                                                 | `0`                                                                                                     |
| `forwarder.securityContext.runAsUser`           | User ID for forwarder's containers                                                                             | `0`                                                                                                     |
| `forwarder.configFile`                          | Name of the config file that will be used by Fluentd at launch under the `/opt/bitnami/fluentd/conf` directory | `fluentd.conf`                                                                                          |
| `forwarder.configMap`                           | Name of the config map that contains the Fluentd configuration files                                           | `nil`                                                                                                   |
| `forwarder.extraArgs`                           | Extra arguments for the Fluentd command line                                                                   | `nil`                                                                                                   |
| `forwarder.extraEnv`                            | Extra environment variables to pass to the container                                                           | `[]`                                                                                                    |
| `forwarder.containerPorts`                      | Ports the forwarder containers will listen on                                                                  | `Check values.yaml`                                                                                     |
| `forwarder.service.type`                        | Kubernetes service type (`ClusterIP`, `NodePort`, or `LoadBalancer`) for the forwarders                        | `ClusterIP`                                                                                             |
| `forwarder.service.ports`                       | Array containing the forwarder service ports                                                                   | `Check values.yaml file`                                                                                |
| `forwarder.service.loadBalancerIP`              | loadBalancerIP if service type is `LoadBalancer`                                                               | `nil`                                                                                                   |
| `forwarder.service.loadBalancerSourceRanges`    | Addresses that are allowed when service is LoadBalancer                                                        | `[]`                                                                                                    |
| `forwarder.service.clusterIP`                   | Static clusterIP or None for headless services                                                                 | `nil`                                                                                                   |
| `forwarder.service.annotations`                 | Annotations for the forwarder service                                                                          | `{}`                                                                                                    |
| `forwarder.livenessProbe.enabled`               | Enable liveness probes for the forwarder                                                                       | `true`                                                                                                  |
| `forwarder.livenessProbe.initialDelaySeconds`   | Delay before liveness probe is initiated                                                                       | `60`                                                                                                    |
| `forwarder.livenessProbe.periodSeconds`         | How often to perform the probe                                                                                 | `10`                                                                                                    |
| `forwarder.livenessProbe.timeoutSeconds`        | When the probe times out                                                                                       | `5`                                                                                                     |
| `forwarder.livenessProbe.failureThreshold`      | Minimum consecutive failures for the probe to be considered failed after having succeeded.                     | `6`                                                                                                     |
| `forwarder.livenessProbe.successThreshold`      | Minimum consecutive successes for the probe to be considered successful after having failed.                   | `1`                                                                                                     |
| `forwarder.readinessProbe.enabled`              | Enable readiness probes for the forwarder                                                                      | `true`                                                                                                  |
| `forwarder.readinessProbe.initialDelaySeconds`  | Delay before readiness probe is initiated                                                                      | `5`                                                                                                     |
| `forwarder.readinessProbe.periodSeconds`        | How often to perform the probe                                                                                 | `10`                                                                                                    |
| `forwarder.readinessProbe.timeoutSeconds`       | When the probe times out                                                                                       | `5`                                                                                                     |
| `forwarder.readinessProbe.failureThreshold`     | Minimum consecutive failures for the probe to be considered failed after having succeeded.                     | `6`                                                                                                     |
| `forwarder.readinessProbe.successThreshold`     | Minimum consecutive successes for the probe to be considered successful after having failed.                   | `1`                                                                                                     |
| `forwarder.updateStrategy`                      | Update strategy for the forwarder DaemonSet                                                                    | `RollingUpdate`                                                                                         |
| `forwarder.resources`                           | Configure resource requests and limits                                                                         | `nil`                                                                                                   |
| `forwarder.nodeSelector`                        | Node labels for pod assignment                                                                                 | `{}`                                                                                                    |
| `forwarder.tolerations`                         | Tolerations for pod assignment                                                                                 | `[]`                                                                                                    |
| `forwarder.affinity`                            | Affinity for pod assignment                                                                                    | `{}`                                                                                                    |
| `forwarder.podAnnotations`                      | Pod annotations                                                                                                | `{}`                                                                                                    |
| `aggregator.enabled`                            | Enable Fluentd aggregator                                                                                      | `true`                                                                                                  |
| `aggregator.replicaCount`                       | Number of aggregator pods to deploy in the Stateful Set                                                        | `2`                                                                                                     |
| `aggregator.securityContext.enabled`            | Enable security context for aggregator pods                                                                    | `true`                                                                                                  |
| `aggregator.securityContext.fsGroup`            | Group ID for aggregator's containers filesystem                                                                | `1001`                                                                                                  |
| `aggregator.securityContext.runAsUser`          | User ID for aggregator's containers                                                                            | `1001`                                                                                                  |
| `aggregator.configFile`                         | Name of the config file that will be used by Fluentd at launch under the `/opt/bitnami/fluentd/conf` directory | `fluentd.conf`                                                                                          |
| `aggregator.configMap`                          | Name of the config map that contains the Fluentd configuration files                                           | `nil`                                                                                                   |
| `aggregator.port`                               | Kubernetes Service port - Fluentd transport port for the aggregators                                           | `24224`                                                                                                 |
| `aggregator.extraArgs`                          | Extra arguments for the Fluentd command line                                                                   | `nil`                                                                                                   |
| `aggregator.extraEnv`                           | Extra environment variables to pass to the container                                                           | `[]`                                                                                                    |
| `aggregator.containerPorts`                     | Ports the aggregator containers will listen on                                                                 | `Check values.yaml`                                                                                     |
| `aggregator.service.type`                       | Kubernetes service type (`ClusterIP`, `NodePort`, or `LoadBalancer`) for the aggregators                       | `ClusterIP`                                                                                             |
| `aggregator.service.ports`                      | Array containing the aggregator service ports                                                                  | `Check values.yaml file`                                                                                |
| `aggregator.service.loadBalancerIP`             | loadBalancerIP if service type is `LoadBalancer`                                                               | `nil`                                                                                                   |
| `aggregator.service.loadBalancerSourceRanges`   | Addresses that are allowed when service is LoadBalancer                                                        | `[]`                                                                                                    |
| `aggregator.service.clusterIP`                  | Static clusterIP or None for headless services                                                                 | `nil`                                                                                                   |
| `aggregator.service.annotations`                | Annotations for the aggregator service                                                                         | `{}`                                                                                                    |
| `aggregator.persistence.enabled`                | Enable persistence volume for the aggregator                                                                   | `false`                                                                                                 |
| `aggregator.persistence.storageClass`           | Persistent Volume storage class                                                                                | `nil`                                                                                                   |
| `aggregator.persistence.accessMode`             | Persistent Volume access mode                                                                                  | `ReadWriteOnce`                                                                                         |
| `aggregator.persistence.size`                   | Persistent Volume size                                                                                         | `10Gi`                                                                                                  |
| `aggregator.livenessProbe.enabled`              | Enable liveness probes for the aggregator                                                                      | `true`                                                                                                  |
| `aggregator.livenessProbe.initialDelaySeconds`  | Delay before liveness probe is initiated                                                                       | `60`                                                                                                    |
| `aggregator.livenessProbe.periodSeconds`        | How often to perform the probe                                                                                 | `10`                                                                                                    |
| `aggregator.livenessProbe.timeoutSeconds`       | When the probe times out                                                                                       | `5`                                                                                                     |
| `aggregator.livenessProbe.failureThreshold`     | Minimum consecutive failures for the probe to be considered failed after having succeeded.                     | `6`                                                                                                     |
| `aggregator.livenessProbe.successThreshold`     | Minimum consecutive successes for the probe to be considered successful after having failed.                   | `1`                                                                                                     |
| `aggregator.readinessProbe.enabled`             | Enable readiness probes for the aggregator                                                                     | `true`                                                                                                  |
| `aggregator.readinessProbe.initialDelaySeconds` | Delay before readiness probe is initiated                                                                      | `5`                                                                                                     |
| `aggregator.readinessProbe.periodSeconds`       | How often to perform the probe                                                                                 | `10`                                                                                                    |
| `aggregator.readinessProbe.timeoutSeconds`      | When the probe times out                                                                                       | `5`                                                                                                     |
| `aggregator.readinessProbe.failureThreshold`    | Minimum consecutive failures for the probe to be considered failed after having succeeded.                     | `6`                                                                                                     |
| `aggregator.readinessProbe.successThreshold`    | Minimum consecutive successes for the probe to be considered successful after having failed.                   | `1`                                                                                                     |
| `aggregator.updateStrategy`                     | Update strategy for the aggregator DaemonSet                                                                   | `RollingUpdate`                                                                                         |
| `aggregator.resources`                          | Configure resource requests and limits                                                                         | `nil`                                                                                                   |
| `aggregator.nodeSelector`                       | Node labels for pod assignment                                                                                 | `{}`                                                                                                    |
| `aggregator.tolerations`                        | Tolerations for pod assignment                                                                                 | `[]`                                                                                                    |
| `aggregator.affinity`                           | Affinity for pod assignment                                                                                    | `{}`                                                                                                    |
| `aggregator.podAnnotations`                     | Pod annotations                                                                                                | `{}`                                                                                                    |
| `serviceAccount.create`                         | Specify whether a ServiceAccount should be created                                                             | `true`                                                                                                  |
| `serviceAccount.name`                           | The name of the ServiceAccount to create                                                                       | Generated using the `fluentd.fullname` template                                                         |
| `rbac.create`                                   | Specify whether RBAC resources should be created and used                                                      | `true`                                                                                                  |
| `metrics.enabled`                               | Enable the export of Prometheus metrics                                                                        | `nil`                                                                                                   |
| `metrics.service.type`                          | Prometheus metrics service type                                                                                | `ClusterIP`                                                                                             |
| `metrics.service.loadBalancerIP`                | Load Balancer IP if the Prometheus metrics server type is `LoadBalancer`                                       | `nil`                                                                                                   |
| `metrics.service.port`                          | Prometheus metrics service port                                                                                | `24231`                                                                                                 |
| `metrics.service.annotations`                   | Annotations for Prometheus metrics service                                                                     | `{ prometheus.io/scrape: "true", prometheus.io/port: "80", prometheus.io/path: "_prometheus/metrics" }` |
| `metrics.serviceMonitor.enabled`                | if `true`, creates a Prometheus Operator ServiceMonitor (also requires `metrics.enabled` to be `true`)         | `false`                                                                                                 |
| `metrics.serviceMonitor.namespace`              | Namespace in which Prometheus is running                                                                       | `nil`                                                                                                   |
| `metrics.serviceMonitor.interval`               | Interval at which metrics should be scraped.                                                                   | `nil` (Prometheus Operator default value)                                                               |
| `metrics.serviceMonitor.scrapeTimeout`          | Timeout after which the scrape is ended                                                                        | `nil` (Prometheus Operator default value)                                                               |
| `metrics.serviceMonitor.selector`               | Prometheus instance selector labels                                                                            | `nil`                                                                                                   |
| `tls.enabled`                                   | Enable the addition of TLS certificates                                                                        | `false`                                                                                                 |
| `tls.caCertificate`                             | Ca certificate                                                                                                 | Certificate Authority (CA) bundle content                                                               |
| `tls.serverCertificate`                         | Server certificate                                                                                             | Server certificate content                                                                              |
| `tls.serverKey`                                 | Server Key                                                                                                     | Server private key content                                                                              |
| `tls.existingSecret`                            | Existing secret with certificate content                                                                       | `nil`                                                                                                   |
Specify each parameter using the `--set key=value[,key=value]` argument to `helm install`. For example,

```console
$ helm install my-release \
  --set aggregator.port=24444 bitnami/fluentd
```

The above command sets the aggregators to listen on port 24444.

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

```console
$ helm install my-release -f values.yaml bitnami/fluentd
```

> **Tip**: You can use the default [values.yaml](values.yaml)

## Configuration and installation details

### [Rolling VS Immutable tags](https://docs.bitnami.com/containers/how-to/understand-rolling-tags-containers/)

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

### Production configuration and horizontal scaling

This chart includes a `values-production.yaml` file where you can find some parameters oriented to production configuration in comparison to the regular `values.yaml`. You can use this file instead of the default one.

- Number of aggregator nodes:
```diff
- aggregator.replicaCount: 1
+ aggregator.replicaCount: 2
```

- Enable prometheus to access fluentd metrics endpoint:
```diff
- metrics.enabled: false
+ metrics.enabled: true
```

To horizontally scale this chart once it has been deployed, you can upgrade the deployment using a new value for the `aggregator.replicaCount` parameter.

### Forwarding the logs to another service

By default, the aggregators in this chart will send the processed logs to the standard output. However, a common practice is to send them to another service, like Elasticsearch, instead. This can be achieved with this Helm Chart by mounting your own configuration files. For example:

**configmap.yaml**

```yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: elasticsearch-output
data:
  fluentd.conf: |
    # Prometheus Exporter Plugin
    # input plugin that exports metrics
    <source>
      @type prometheus
      port {{ .Values.metrics.service.port }}
    </source>

    # input plugin that collects metrics from MonitorAgent
    <source>
      @type prometheus_monitor
      <labels>
        host ${hostname}
      </labels>
    </source>

    # input plugin that collects metrics for output plugin
    <source>
      @type prometheus_output_monitor
      <labels>
        host ${hostname}
      </labels>
    </source>
    {{- end }}

    # Ignore fluentd own events
    <match fluent.**>
      @type null
    </match>

    # TCP input to receive logs from the forwarders
    <source>
      @type forward
      bind 0.0.0.0
      port {{ .Values.aggregator.port }}
    </source>

    # HTTP input for the liveness and readiness probes
    <source>
      @type http
      bind 0.0.0.0
      port 9880
    </source>

    # Throw the healthcheck to the standard output instead of forwarding it
    <match fluentd.healthcheck>
      @type stdout
    </match>

    # Send the logs to the standard output
    <match **>
      @type elasticsearch
      include_tag_key true
      host "#{ENV['ELASTICSEARCH_HOST']}"
      port "#{ENV['ELASTICSEARCH_PORT']}"
      logstash_format true

      <buffer>
        @type file
        path /opt/bitnami/fluentd/logs/buffers/logs.buffer
        flush_thread_count 2
        flush_interval 5s
      </buffer>
    </match>
```

As an example, using the above configmap, you should specify the required parameters when upgrading or installing the chart:

```console
aggregator.configMap=elasticsearch-output
aggregator.extraEnv[0].name=ELASTICSEARCH_HOST
aggregator.extraEnv[0].value=your-ip-here
aggregator.extraEnv[1].name=ELASTICSEARCH_PORT
aggregator.extraEnv[1].value=your-port-here
```

### Notable changes

## 1.0.0

In this version of the chart the Fluentd forwarder daemon system user will be root by default. This is done to ensure that mounted host paths are readable by the forwarder. For more context, check this [support case](https://github.com/bitnami/charts/issues/1905).

No issues are expected in the upgrade process. However, please ensure that you add extra security measures in your cluster as you will be running root containers. If you want the daemon to be run as a user different from root, you can change the `forwarder.daemonUser` and `forwarder.daemonGroup` values. In this case make sure that the user you choose has sufficient permissions to read log files under `/var/lib/docker/containers` directory.
