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Export Teleport Audit Events to Splunk

Teleport's Event Handler plugin receives audit logs from the Teleport Auth Service and forwards them to your log management solution, letting you perform historical analysis, detect unusual behavior, and form a better understanding of how users interact with your Teleport cluster.

In this guide, we will show you how to configure the Teleport Event Handler plugin to send your Teleport audit logs to Splunk. In this setup, the Teleport Event Handler plugin forwards audit logs from Teleport to Splunk's Universal Forwarder, which stores them in Splunk Cloud Platform or Splunk Enterprise for visualization and alerting.

Prerequisites​

  • A running Teleport cluster version 15.4.22 or above. If you want to get started with Teleport, sign up for a free trial or set up a demo environment.

  • The tctl admin tool and tsh client tool.

    On Teleport Enterprise, you must use the Enterprise version of tctl, which you can download from your Teleport account workspace. Otherwise, visit Installation for instructions on downloading tctl and tsh for Teleport Community Edition.

Recommended: Configure Machine ID to provide short-lived Teleport credentials to the plugin. Before following this guide, follow a Machine ID deployment guide to run the tbot binary on your infrastructure.

  • Splunk Cloud Platform or Splunk Enterprise v9.0.1 or above.

  • A Linux host where you will run the Teleport Event Handler plugin and Splunk Universal Forwarder. The Universal Forwarder must be installed on the host.

    Running the Teleport Event Handler and Universal Forwarder on separate hosts

    If you run the Teleport Event Handler and Universal Forwarder on the same host, there is no need to open a port on the host for ingesting logs. However, if you run the Universal Forwarder on a separate host from the Teleport Event Handler, you will need to open a port on the Universal Forwarder host to traffic from the Teleport Event Handler. This guide assumes that the Universal Forwarder is listening on port 9061.

  • On Splunk Enterprise, port 8088 should be open to traffic from the host running the Teleport Event Handler and Universal Forwarder.

  • To check that you can connect to your Teleport cluster, sign in with tsh login, then verify that you can run tctl commands using your current credentials. tctl is supported on macOS and Linux machines.

    For example:

    $ tsh login --proxy=teleport.example.com --user=email@example.com
    $ tctl status
    # Cluster  teleport.example.com
    # Version  15.4.22
    # CA pin   sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678

    If you can connect to the cluster and run the tctl status command, you can use your current credentials to run subsequent tctl commands from your workstation. If you host your own Teleport cluster, you can also run tctl commands on the computer that hosts the Teleport Auth Service for full permissions.

Step 1/4. Set up the Teleport Event Handler plugin​

The Event Handler plugin is a binary that runs independently of your Teleport cluster. It authenticates to your Teleport cluster and your Splunk Universal Forwarder using mutual TLS. In this section, you will install the Teleport Event Handler plugin on the Linux host where you are running your Universal Forwarder and generate credentials that the plugin will use for authentication.

Install the Teleport Event Handler plugin​

Follow the instructions for your environment to install the Teleport Event Handler plugin on your Universal Forwarder host:

$ curl -L -O https://get.gravitational.com/teleport-event-handler-v15.4.22-linux-amd64-bin.tar.gz
$ tar -zxvf teleport-event-handler-v15.4.22-linux-amd64-bin.tar.gz
$ sudo ./teleport-event-handler/install

We currently only build the Event Handler plugin for amd64 machines. For ARM architecture, you can build from source.

Generate a starter config file​

Generate a configuration file with placeholder values for the Teleport Event Handler plugin. Later in this guide, we will edit the configuration file for your environment.

Run the configure command to generate a sample configuration. Replace mytenant.teleport.sh with the DNS name of your Teleport Enterprise Cloud tenant:

$ teleport-event-handler configure . mytenant.teleport.sh:443

You'll see the following output:

Teleport event handler 15.4.22

[1] mTLS Fluentd certificates generated and saved to ca.crt, ca.key, server.crt, server.key, client.crt, client.key
[2] Generated sample teleport-event-handler role and user file teleport-event-handler-role.yaml
[3] Generated sample fluentd configuration file fluent.conf
[4] Generated plugin configuration file teleport-event-handler.toml

The plugin generates several setup files:

$ ls -l
# -rw------- 1 bob bob     1038 Jul  1 11:14 ca.crt
# -rw------- 1 bob bob     1679 Jul  1 11:14 ca.key
# -rw------- 1 bob bob     1042 Jul  1 11:14 client.crt
# -rw------- 1 bob bob     1679 Jul  1 11:14 client.key
# -rw------- 1 bob bob      541 Jul  1 11:14 fluent.conf
# -rw------- 1 bob bob     1078 Jul  1 11:14 server.crt
# -rw------- 1 bob bob     1766 Jul  1 11:14 server.key
# -rw------- 1 bob bob      260 Jul  1 11:14 teleport-event-handler-role.yaml
# -rw------- 1 bob bob      343 Jul  1 11:14 teleport-event-handler.toml
File(s)Purpose
ca.crt and ca.keySelf-signed CA certificate and private key for Fluentd
server.crt and server.keyFluentd server certificate and key
client.crt and client.keyFluentd client certificate and key, all signed by the generated CA
teleport-event-handler-role.yamluser and role resource definitions for Teleport's event handler
fluent.confFluentd plugin configuration
Running the Event Handler separately from the log forwarder

This guide assumes that you are running the Event Handler on the same host or Kubernetes pod as your log forwarder. If you are not, you will need to instruct the Event Handler to generate mTLS certificates for subjects besides localhost. To do this, use the --cn and --dns-names flags of the teleport-event-handler configure command.

For example, if your log forwarder is addressable at forwarder.example.com and the Event Handler at handler.example.com, you would run the following configure command:

$ teleport-event-handler configure --cn=handler.example.com --dns-names=forwarder.example.com

The command generates client and server certificates with the subjects set to the value of --cn.

The --dns-names flag accepts a comma-separated list of DNS names. It will append subject alternative names (SANs) to the server certificate (the one you will provide to your log forwarder) for each DNS name in the list. The Event Handler looks up each DNS name before appending it as an SAN and exits with an error if the lookup fails.

We'll re-purpose the files generated for Fluentd in our Universal Forwarder configuration.

Define RBAC resources​

The teleport-event-handler configure command generated a file called teleport-event-handler-role.yaml. This file defines a teleport-event-handler role and a user with read-only access to the event API:

kind: role
metadata:
  name: teleport-event-handler
spec:
  allow:
    rules:
      - resources: ['event', 'session']
        verbs: ['list','read']
version: v5
---
kind: user
metadata:
  name: teleport-event-handler
spec:
  roles: ['teleport-event-handler']
version: v2

Move this file to your workstation (or recreate it by pasting the snippet above) and use tctl on your workstation to create the role and the user:

$ tctl create -f teleport-event-handler-role.yaml
# user "teleport-event-handler" has been created
# role 'teleport-event-handler' has been created

Enable issuing of credentials for the Event Handler role​

With the role created, you now need to allow the Machine ID bot to produce credentials for this role.

This can be done with tctl, replacing my-bot with the name of your bot:

$ tctl bots update my-bot --add-roles teleport-event-handler

Export the plugin identity​

Give the plugin access to a Teleport identity file. We recommend using Machine ID for this in order to produce short-lived identity files that are less dangerous if exfiltrated, though in demo deployments, you can generate longer-lived identity files with tctl:

Configure tbot with an output that will produce the credentials needed by the plugin. As the plugin will be accessing the Teleport API, the correct output type to use is identity.

For this guide, the directory destination will be used. This will write these credentials to a specified directory on disk. Ensure that this directory can be written to by the Linux user that tbot runs as, and that it can be read by the Linux user that the plugin will run as.

Modify your tbot configuration to add an identity output.

If running tbot on a Linux server, use the directory output to write identity files to the /opt/machine-id directory:

outputs:
- type: identity
  destination:
    type: directory
    # For this guide, /opt/machine-id is used as the destination directory.
    # You may wish to customize this. Multiple outputs cannot share the same
    # destination.
    path: /opt/machine-id

If running tbot on Kubernetes, write the identity file to Kubernetes secret instead:

outputs:
  - type: identity
    destination:
      type: kubernetes_secret
      name: teleport-event-handler-identity

If operating tbot as a background service, restart it. If running tbot in one-shot mode, execute it now.

You should now see an identity file under /opt/machine-id or a Kubernetes secret named teleport-event-handler-identity. This contains the private key and signed certificates needed by the plugin to authenticate with the Teleport Auth Service.

Step 2/4. Configure the Universal Forwarder​

In this step, you will configure the Universal Forwarder to receive audit logs from the Teleport Event Handler plugin and forward them to Splunk. The Event Handler sends audit logs as HTTP POST requests with the content type application/json.

We will assume that you assigned $SPLUNK_HOME to /opt/splunkforwarder when installing the Universal Forwarder.

Finding your $SPLUNK_HOME

To find your $SPLUNK_HOME, run the following command to see the location of your Universal Forwarder service definition, which the init system systemd uses to run the Universal Forwarder:

$ sudo systemctl status SplunkForwarder.service
● SplunkForwarder.service - Systemd service file for Splunk, generated by 'splunk enable boot-start'
     Loaded: loaded (/lib/systemd/system/SplunkForwarder.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2022-10-07 15:57:37 UTC; 2h 18min ago
   Main PID: 1772 (splunkd)
      Tasks: 53 (limit: 2309)
     Memory: 70.8M (limit: 1.8G)
     CGroup: /system.slice/SplunkForwarder.service
             ├─1772 splunkd --under-systemd --systemd-delegate=yes -p 8089 _internal_launch_under_systemd
             └─1810 [splunkd pid=1772] splunkd --under-systemd --systemd-delegate=yes -p 8089 _internal_launch_under_systemd [process-runner]

View the file at the path shown in the Loaded: field. Your $SPLUNK_HOME will include the filepath segments in ExecStart before /bin. In this case, $SPLUNK_HOME is /opt/splunkforwarder/:

ExecStart=/opt/splunkforwarder/bin/splunk _internal_launch_under_systemd

Create an index for your audit logs​

Create an index for your Teleport audit logs by visiting the home page of the Splunk UI and navigating to Settings > Indexes. Click New Index. Name your index teleport-audit-logs and assign the Index Data Type field to "Events".

Creating an Index

The values of the remaining fields, Max raw data size and Searchable retention (days) depend on your organization's resources and practices for log management.

Click Save

Create a token for the Universal Forwarder​

The Universal Forwarder authenticates client traffic using a token. To generate a token, visit the home page of the Splunk UI. Navigate to Settings > Data inputs In the Local inputs table, find the HTTP Event Collector row and click Add new

Enter a name you can use to recognize the token later so you can manage it, e.g., Teleport Audit Events. Click Next.

Create a Token

In the Input Settings view (above), next to the Source type field, click Select. In the Select Source Type dropdown menu, click Structured, then _json. Splunk will index incoming logs as JSON, which is the format the Event Handler uses to send logs to the Universal Forwarder.

In the Index section, select the teleport-audit-logs index you created earlier. Click Review then view the summary and click Submit. Copy the Token Value field and keep it somewhere safe so you can use it later in this guide.

Prepare a certificate file for the Universal Forwarder​

The Universal Forwarder signs TLS certificates using a file that contains both an X.509-format certificate and an RSA private key. To prepare this, run the following commands on the Universal Forwarder host, where server.crt and server.key are two of the files you generated earlier with the teleport-event-handler configure the command:

$ cp server.crt server.pem
$ cat server.key >> server.pem

Allow the Universal Forwarder to access the certificate file:

$ sudo chown splunk:splunk server.pem

Configure the HTTP Event Collector​

On your Universal Forwarder host, create a file at /opt/splunkforwarder/etc/system/local/inputs.conf with the following content:

[http]
port = 9061
disabled = false
serverCert = server.pem
sslPassword =
requireClientCert = true

[http://audit]
token =
index = teleport-audit-logs
allowQueryStringAuth = true

This configuration enables the HTTP input, which will listen on port 9061 and receive logs from the Teleport Event Handler Plugin, assigning them to the teleport-audit-logs index.

Assign serverCert to the path to the server.pem file you generated earlier.

To assign sslPassword, run the following command in the directory that contains fluent.conf:

$ cat fluent.conf | grep passphrase
private_key_passphrase "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"

Copy the passphrase and paste it as the value of sslPassword.

The token field in the [http://audit] section enables the Universal Forwarder to collect logs from HTTP clients that present a token. Assign token to the token you generated earlier.

allowQueryStringAuth enables the Teleport Event Handler to include the token in a query string, rather than the Authorization HTTP header (the default). This is necessary because the Teleport Event Handler does not currently support custom HTTP headers.

Configure TLS​

To configure secure communications between the Universal Forwarder and the Teleport Event Handler, create a file called /opt/splunkforwarder/etc/system/local/server.conf with the following content (if this file already exists, add the following field in the [sslConfig] section):

[sslConfig]
sslRootCAPath =

Assign sslRootCAPath to the path of the ca.crt file you generated earlier.

Ensure that the Universal Forwarder can read the CA certificate:

$ sudo chmod +r ca.crt

Configure an output​

Instruct the Universal Forwarder to send the logs it collects to Splunk.

Create a file at the path /opt/splunkforwarder/etc/system/local/outputs.conf with the following content:

[tcpout]
sslVerifyServerCert = true

[httpout]
httpEventCollectorToken =
uri =

Fill in httpEventCollectorToken with the token you generated earlier.

Assign uri to the following, replacing MYHOST with the hostname of your Splunk instance and 8088 with the port you are using for your Splunk HTTP Event Collector.

https://MYHOST:8088

The format of the URL to use will depend on your Splunk deployment. See the list of acceptable URL formats in the Splunk documentation.

Note that you must only include the scheme, host, and port of the URL. The Universal Forwarder will append the correct URL path of the Splunk ingestion API when forwarding logs.

Finally, restart the Universal Forwarder:

$ sudo systemctl restart SplunkForwarder

Step 3/4. Run the Teleport Event Handler plugin​

Now that you have configured your Universal Forwarder to receive logs via HTTP and forward them to Splunk, you will ensure that the Teleport Event Handler plugin is configured to authenticate to the Universal Forwarder and your Teleport cluster, then run the Teleport Event Handler.

Configure the Teleport Event Handler​

In this section, you will configure the Teleport Event Handler for your environment.

Earlier, we generated a file called teleport-event-handler.toml to configure the Fluentd event handler. This file includes setting similar to the following:

storage = "./storage"
timeout = "10s"
batch = 20
namespace = "default"
# The window size configures the duration of the time window for the event handler
# to request events from Teleport. By default, this is set to 24 hours.
# Reduce the window size if the events backend cannot manage the event volume 
# for the default window size.
# The window size should be specified as a duration string, parsed by Go's time.ParseDuration.
window-size = "24h"

[forward.fluentd]
ca = "/home/bob/event-handler/ca.crt"
cert = "/home/bob/event-handler/client.crt"
key = "/home/bob/event-handler/client.key"
url = "https://fluentd.example.com:8888/test.log"
session-url = "https://fluentd.example.com:8888/session"

[teleport]
addr = "example.teleport.com:443"
identity = "identity"

Modify the configuration to replace fluentd.example.com with the domain name of your Fluentd deployment.

Update the configuration file as follows.

Change forward.fluentd.url to the following:

url = "https://localhost:9061/services/collector/raw?token=MYTOKEN"

Ensure the URL includes the scheme, host and port of your Universal Forwarder's HTTP input, plus the URL path that the Universal Forwarder uses for raw data (/services/collector/raw).

Replace MYTOKEN with the token you generated earlier for the Splunk Universal Forwarder. If you are running the Universal Forwarder and Event Handler on separate hosts, replace localhost with your Universal Forwarder's IP address or domain name.

Change forward.fluentd.session-url to the same value as forward.fluentd.url, but with the query parameter key &noop= appended to the end:

session-url = "https://localhost:9061/services/collector/raw?token=MYTOKEN&noop="

For audit logs related to Teleport sessions, the Teleport Event Handler appends routing information to the URL that our HTTP input configuration does not use. Adding the noop query parameter causes the Teleport Event Handler to append the routing information as the parameter's value so the Universal Forwarder can discard it.

Next, edit the teleport section of the configuration as follows:

addr: Include the hostname and HTTPS port of your Teleport Proxy Service or Teleport Enterprise Cloud account (e.g., teleport.example.com:443 or mytenant.teleport.sh:443).

identity: Fill this in with the path to the identity file you exported earlier.

client_key, client_crt, root_cas: Comment these out, since we are not using them in this configuration.

If you are providing credentials to the Event Handler using a tbot binary that runs on a Linux server, make sure the value of identity in the Event Handler configuration is the same as the path of the identity file you configured tbot to generate, /opt/machine-id/identity.

Ensure that the Teleport Event Handler can read the identity file:

$ chmod +r auth.pem

Start the Teleport Event Handler​

Start the Teleport Teleport Event Handler by following the instructions below.

Copy the teleport-event-handler.toml file to /etc on your Linux server. Update the settings within the toml file to match your environment. Make sure to use absolute paths on settings such as identity and storage. Files and directories in use should only be accessible to the system user executing the teleport-event-handler service such as /var/lib/teleport-event-handler.

Next, create a systemd service definition at the path /usr/lib/systemd/system/teleport-event-handler.service with the following content:

[Unit]
Description=Teleport Event Handler
After=network.target

[Service]
Type=simple
Restart=always
ExecStart=/usr/local/bin/teleport-event-handler start --config=/etc/teleport-event-handler.toml --teleport-refresh-enabled=true
ExecReload=/bin/kill -HUP $MAINPID
PIDFile=/run/teleport-event-handler.pid

[Install]
WantedBy=multi-user.target

If you are not using Machine ID to provide short-lived credentials to the Event Handler, you can remove the --teleport-refresh-enabled true flag.

Enable and start the plugin:

$ sudo systemctl enable teleport-event-handler
$ sudo systemctl start teleport-event-handler
Choose when to start exporting events

You can configure when you would like the Teleport Event Handler to begin exporting events when you run the start command. This example will start exporting from May 5th, 2021:

$ teleport-event-handler start --config /etc/teleport-event-handler.toml --start-time "2021-05-05T00:00:00Z"

You can only determine the start time once, when first running the Teleport Event Handler. If you want to change the time frame later, remove the plugin state directory that you specified in the storage field of the handler's configuration file.

Once the Teleport Event Handler starts, you will see notifications about scanned and forwarded events:

$ sudo journalctl -u teleport-event-handler
DEBU   Event sent id:f19cf375-4da6-4338-bfdc-e38334c60fd1 index:0 ts:2022-09-21
18:51:04.849 +0000 UTC type:cert.create event-handler/app.go:140
...

Step 4/4. Visualize your audit logs in Splunk​

Since our setup forwards audit logs to Splunk in the structured JSON format, Splunk automatically indexes them, so fields will be available immediately for use in visualizations. You can use these fields to create dashboards that track the way users are interacting with your Teleport cluster.

For example, from the Splunk UI home page, navigate to Search & Reporting > Dashboards > Create New Dashboard. Enter "Teleport Audit Log Types" for the title of your dashboard and click Classic Dashboards. Click Create then, in the Edit Dashboard view, click Add Panel.

In the Add Panel sidebar, click New > Column Chart. For the Search String field, enter the following:

index="teleport-audit-logs" | timechart count by event

Once you click Add to Dashboard you will see a count of Teleport event types over time, which gives you a general sense of how users are interacting with Teleport:

Event Types over Time

Troubleshooting connection issues​

If the Teleport Event Handler is displaying error logs while connecting to your Teleport Cluster, ensure that:

  • The certificate the Teleport Event Handler is using to connect to your Teleport cluster is not past its expiration date. This is the value of the --ttl flag in the tctl auth sign command, which is 12 hours by default.
  • Ensure that in your Teleport Event Handler configuration file (teleport-event-handler.toml), you have provided the correct host and port for the Teleport Proxy Service.

Next steps​

Now that you are exporting your audit logs to Splunk, consult our audit log reference so you can plan visualizations and alerts.

In this guide, we made use of impersonation to supply credentials to the Teleport Event Handler to communicate with your Teleport cluster. To learn more about impersonation, read our guide.

While this guide uses the tctl auth sign command to issue credentials for the Teleport Event Handler, production clusters should use Machine ID for safer, more reliable renewals. Read our guide to getting started with Machine ID.