# Loki Helm Chart

## Prerequisites

Make sure you have Helm [installed](https://helm.sh/docs/using_helm/#installing-helm) and
[deployed](https://helm.sh/docs/using_helm/#installing-tiller) to your cluster. Then add
Loki's chart repository to Helm:

```bash
$ helm repo add loki https://grafana.github.io/loki/charts
```

You can update the chart repository by running:

```bash
$ helm repo update
```

## Deploy Loki and Promtail to your cluster

### Deploy with default config

```bash
$ helm upgrade --install loki loki/loki-stack
```

### Deploy in a custom namespace

```bash
$ helm upgrade --install loki --namespace=loki-stack loki/loki-stack
```

### Deploy with custom config

```bash
$ helm upgrade --install loki loki/loki-stack --set "key1=val1,key2=val2,..."
```

## Deploy Loki only

```bash
$ helm upgrade --install loki loki/loki
```

## Deploy Promtail only

We recommend Promtail to ship your logs to Loki as the configuration is very similar to Prometheus.
This allows you to ensure that labels for metrics and logs are equivalent by re-using the same `scrape_configs` and `relabeling` configuration.
When using Grafana having the same labels will allows you to pivot from Metrics to Logs verify easily by simply switching datasource.

To only install Promtail use the following command:

```bash
$ helm upgrade --install promtail loki/promtail --set "loki.serviceName=loki"
```

If you're not familiar with Prometheus and you don't want to migrate your current agent configs from the start,
 you can use our output plugins specified below.

## Deploy Loki and Fluent Bit to your cluster

```bash
$ helm upgrade --install loki loki/loki-stack \
    --set fluent-bit.enabled=true,promtail.enabled=false
```

## Deploy Fluent Bit only

```bash
$ helm upgrade --install fluent-bit loki/fluent-bit \
    --set "loki.serviceName=loki.svc.cluster.local"
```

## Deploy Loki and Filebeat and logstash to your cluster

```bash
$ helm upgrade --install loki loki/loki-stack \
    --set filebeat.enabled=true,logstash.enabled=true,promtail.enabled=false \
    --set loki.fullnameOverride=loki,logstash.fullnameOverride=logstash-loki
```

## Deploy Grafana to your cluster

To install Grafana on your cluster with helm, use the following command:

```bash
# with Helm 2
$ helm install stable/grafana -n loki-grafana --namespace <YOUR-NAMESPACE>

# with Helm 3
$ helm install loki-grafana stable/grafana -n <YOUR-NAMESPACE>
```

> The chart loki-stack contains a pre-configured Grafana, simply use `--set grafana.enabled=true`

To get the admin password for the Grafana pod, run the following command:

```bash
$ kubectl get secret --namespace <YOUR-NAMESPACE> loki-grafana -o jsonpath="{.data.admin-password}" | base64 --decode ; echo
```

To access the Grafana UI, run the following command:

```bash
$ kubectl port-forward --namespace <YOUR-NAMESPACE> service/loki-grafana 3000:80
```

Navigate to http://localhost:3000 and login with `admin` and the password output above.
Then follow the [instructions for adding the loki datasource](/docs/getting-started/grafana.md), using the URL `http://loki:3100/`.

## Run Loki behind https ingress

If Loki and Promtail are deployed on different clusters you can add an Ingress in front of Loki.
By adding a certificate you create an https endpoint. For extra security enable basic authentication on the Ingress.

In Promtail set the following values to communicate with https and basic auth

```
loki:
  serviceScheme: https
  user: user
  password: pass
```

Sample helm template for ingress:
```
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
    kubernetes.io/ingress.class: {{ .Values.ingress.class }}
    ingress.kubernetes.io/auth-type: "basic"
    ingress.kubernetes.io/auth-secret: {{ .Values.ingress.basic.secret }}
name: loki
spec:
rules:
- host: {{ .Values.ingress.host }}
    http:
    paths:
    - backend:
        serviceName: loki
        servicePort: 3100
tls:
- secretName: {{ .Values.ingress.cert }}
    hosts:
    - {{ .Values.ingress.host }}
```

## Run promtail with syslog support

In order to receive and process syslog message into promtail, the following changes will be necessary:

* Review the [promtail syslog-receiver configuration documentation](/docs/clients/promtail/scraping.md#syslog-receiver)

* Configure the promtail helm chart with the syslog configuration added to the `extraScrapeConfigs` section and associated service definition to listen for syslog messages. For example:

```yaml
extraScrapeConfigs:
  - job_name: syslog
    syslog:
      listen_address: 0.0.0.0:1514
      labels:
        job: "syslog"
  relabel_configs:
    - source_labels: ['__syslog_message_hostname']
      target_label: 'host'
syslogService:
  enabled: true
  type: LoadBalancer
  port: 1514
```

## Run promtail with systemd-journal support

In order to receive and process syslog message into promtail, the following changes will be necessary:

* Review the [promtail systemd-journal configuration documentation](/docs/clients/promtail/scraping.md#journal-scraping-linux-only)

* Configure the promtail helm chart with the systemd-journal configuration added to the `extraScrapeConfigs` section and volume mounts for the promtail pods to access the log files. For example:

```yaml
# Add additional scrape config
extraScrapeConfigs:
  - job_name: journal
    journal:
      path: /var/log/journal
      max_age: 12h
      labels:
        job: systemd-journal
    relabel_configs:
      - source_labels: ['__journal__systemd_unit']
        target_label: 'unit'
      - source_labels: ['__journal__hostname']
        target_label: 'hostname'

# Mount journal directory into promtail pods
extraVolumes:
  - name: journal
    hostPath:
      path: /var/log/journal

extraVolumeMounts:
  - name: journal
    mountPath: /var/log/journal
    readOnly: true
```

## How to contribute

After adding your new feature to the appropriate chart, you can build and deploy it locally to test:

```bash
$ make helm
$ helm upgrade --install loki ./loki-stack-*.tgz
```

After verifying your changes, you need to bump the chart version following [semantic versioning](https://semver.org) rules.
For example, if you update the loki chart, you need to bump the versions as follows:

- Update version loki/Chart.yaml
- Update version loki-stack/Chart.yaml

You can use the `make helm-debug` to test and print out all chart templates. If you want to install helm (tiller) in your cluster use `make helm-install`, to install the current build in your Kubernetes cluster run `make helm-upgrade`.