# Deploying an Agent

The Agent docker image can be configured via environment variables or via volume mounts for the configuration files.

## Connect the Agent to HQ

You can connect the agent to HQ in two ways, all via [provisioning](https://docs.lenses.io/latest/deployment/configuration/agent/automation)

1. Start the Agent docker with the an AGENT\_KEY via environment variables at minimum. You need to create an environment in HQ to get this key
2. Or mount a provisioning file that contains the connection to HQ, **recommended for TLS enabled HQs**

You can still reference environment variables if you mount the file, e.g

```yaml
agentKey:
  value: ${LENSES_HQ_AGENT_KEY
```

### Minimal Start

First deploy HQ and create an environment, then with the AGENT KEY run:

<pre class="language-bash"><code class="lang-bash"><strong>docker run \                                                                          
</strong><strong>  --name "xxx" \
</strong>  --network=lenses \
  --restart=unless-stopped \
  -e PROVISION_AGENT_KEY=YOUR_AGENT_KEY \
  -e PROVISION_HQ_URL=YOUR_LENSES_HQ_URL \
  lensesio/lenses-agent:6.1 
</code></pre>

This will start and connect to HQ but not to Kafka or other services. It will create a provisioning file in **data/provisioning**.

{% hint style="info" %}
Set the docker network accordingly
{% endhint %}

### Start and mount provisioning

{% code title="terminal" %}

```bash
docker run --name lenses-agent \
-v $(pwd)/provisioning.yaml:/mnt/provision-secrets/provisioning.yaml \
-e LENSES_PROVISIONING_PATH=/mnt/provision-secrets \
lensesio/lenses-agent:6.1
```

{% endcode %}

Example provisioning files:

{% tabs %}
{% tab title="TLS Enabled" %}
{% code title="provisioning.yaml" %}

```yaml
lensesHq:
  - name: lenses-hq
    version: 1
    tags: ['hq']
    configuration:
      server:
        value: [LENSES_HQ_URL]
      port:
        value: 10000
      agentKey:
        value: ${LENSES_HQ_AGENT_KEY}
      sslEnabled:
        value: true
      sslTruststore:
        file: "hq-truststore.jks"
      sslTruststorePassword:
        value: ${LENSES_HQ_AGENT_TRUSTSTORE_PWD}
```

{% endcode %}
{% endtab %}

{% tab title="TLS Disabled" %}
{% code title="provisioning.yaml" %}

```yaml
lensesHq:
  - name: lenses-hq
    version: 1
    tags: ['hq']
    configuration:
      server:
        value: [LENSES_HQ_URL]
      port:
        value: 10000
      agentKey:
        value: ${LENSES_HQ_AGENT_KEY}
      sslEnabled:
        value: false
```

{% endcode %}
{% endtab %}
{% endtabs %}

{% hint style="info" %}
**Agent key reference**

Agent key within provisioning.yaml can be referenced as a:

* environment variable shown in example above
* inline string
  {% endhint %}

## Database <a href="#environment-variables" id="environment-variables"></a>

My default the Agent will start with an embedded database, if you wish to use Progress, recommended for production, see [here](https://docs.lenses.io/latest/deployment/configuration/agent/database). Database settings are set in lenses-agent.conf

## Environment Variables <a href="#environment-variables" id="environment-variables"></a>

Environment variables prefixed with **LENSES\_** are transformed into corresponding configuration options. The environment variable name is converted to lowercase and underscores (**\_**) are replaced with dots (**.**). As an example set the option **lenses.port** use the environment variable **LENSES\_PORT**.

Alternatively, the **lenses-agent.conf** can be mounted directly as

* **/mnt/settings/lenses-agent.conf**

***

## Docker volumes <a href="#docker-volumes" id="docker-volumes"></a>

The Docker image exposes four volumes in total, where cache, logs, plugins, and persistent data are stored:

* /data/storage
* /data/plugins
* /data/logs
* /data/kafka-streams-state

### Storage volume <a href="#storage-volume" id="storage-volume"></a>

Resides under **/data/storage** and is used to store persistent data, such as Data Policies. For this data to survive between Docker runs and/or Agent upgrades, the volume must be managed externally (persistent volume).

### Plugins volume <a href="#plugins-volume" id="plugins-volume"></a>

Resides under **/data/plugin**`s` it’s where classes that extend Agent may be added —such as custom Serdes, LDAP filters, UDFs for the Lenses SQL table engine, and custom\_http implementations.

### Logs volume <a href="#logs-volume" id="logs-volume"></a>

Resides under **/data/logs**, logs are stored here. The application also logs to stdout, so the log files aren’t needed for most cases.

### KStreams state volume <a href="#kstreams-state-volume" id="kstreams-state-volume"></a>

Resides under **/data/kafka-streams-state**, used when Lenses SQL is in IN\_PROC configuration. In such a case, Lenses uses this scratch directory to cache Lenses SQL internal state. Whilst this directory can safely be removed, it can be beneficial to keep it around, so the Processors won’t have to rebuild their state during a restart.

***

## Agent TLS and Global JVM Trust Store <a href="#lenses-tls-and-global-jvm-trust-store" id="lenses-tls-and-global-jvm-trust-store"></a>

By default, the the serves connections over plaintext (HTTP). It is possible to use TLS instead. The Docker image offers the ability to provide the content for extra files via secrets mounted as files or as environment variables. Especially for SSL, Docker supports SSL/TLS keys and certificates in Java Keystore (JKS) formats.

This capability is optional, and users can mount such files under custom paths and configure **lenses-agent.conf** manually via environment variables, or **lenses.append.conf**.

There are two ways to use the File/Variable names of the table below.

1. Create a file with the appropriate filename as listed below and mount it unde**r /mnt/settings, /mnt/secrets, or /run/secrets**
2. Set them as environment variables.

All settings except for passwords, can be optionally encoded in base64. The docker will detect such encoding automatically.

| File / Variable Name                        | Description                                                                                                                                                                |
| ------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| FILECONTENT\_JVM\_SSL\_TRUSTSTORE           | The SSL/TLS trust store to use as the global JVM trust store. Add to LENSES\_OPTS the property javax.net.ssl.trustStore                                                    |
| FILECONTENT\_JVM\_SSL\_TRUSTSTORE\_PASSWORD | Τhe trust store password. If set, the startup script will add automatically to LENSES*OPTS the property javax.net.ssl.trustStorePassword (\*\*\_base64 not supported*\*\*) |
| FILECONTENT\_LENSES\_SSL\_KEYSTORE          | The SSL/TLS keystore to use for the TLS listener for the Agent                                                                                                             |

***

## Process UID/GUI <a href="#process-uidgui" id="process-uidgui"></a>

The docker does not require running as root. The default user is set to root for convenience and to verify upon start-up that all the directories and files have the correct permissions. The user drops to **nobody** and group **nogroup** (**65534:65534**) before starting the Agent.

If the image is started without root privileges, the agent will start successfully using the effective uid:gid applied. Ensure any volumes mounted (i.e., for the settings and data) have the correct permission set.