iptables and Cortex Integration

Input and output integration overview

The iptables plugin for Telegraf collects metrics on packet and byte counts for specified iptables rules, providing insights into firewall activity and performance.

This plugin enables Telegraf to send metrics to Cortex using the Prometheus remote write protocol, allowing seamless ingestion into Cortex’s scalable, multi-tenant time series storage.

Integration details

iptables

The iptables plugin gathers packets and bytes counters for rules within a set of table and chain from the Linux iptables firewall. The plugin monitors rules identified by associated comments, as rules without comments are ignored. This approach ensures a unique identification for the monitored rules, which is particularly important since the rule number can change dynamically as rules are modified. To use this plugin effectively, users must name their rules with unique comments. The plugin also requires elevated permissions (CAP_NET_ADMIN and CAP_NET_RAW) to run, which can be configured either by running Telegraf as root (discouraged), using systemd capabilities, or by configuring sudo appropriately. Additionally, defining multiple instances of the plugin might lead to conflicts; thus, using locking mechanisms in the configuration is recommended to avoid errors during concurrent accesses.

Cortex

With Telegraf’s HTTP output plugin and the prometheusremotewrite data format you can send metrics directly to Cortex, a horizontally scalable, long-term storage backend for Prometheus. Cortex supports multi-tenancy and accepts remote write requests using the Prometheus protobuf format. By using Telegraf as the collection agent and Remote Write as the transport mechanism, organizations can extend observability into sources not natively supported by Prometheus—such as Windows hosts, SNMP-enabled devices, or custom application metrics—while leveraging Cortex’s high-availability and long-retention capabilities.

Configuration

iptables

[[inputs.iptables]]
  ## iptables require root access on most systems.
  ## Setting 'use_sudo' to true will make use of sudo to run iptables.
  ## Users must configure sudo to allow telegraf user to run iptables with
  ## no password.
  ## iptables can be restricted to only list command "iptables -nvL".
  use_sudo = false
  ## Setting 'use_lock' to true runs iptables with the "-w" option.
  ## Adjust your sudo settings appropriately if using this option
  ## ("iptables -w 5 -nvl")
  use_lock = false
  ## Define an alternate executable, such as "ip6tables". Default is "iptables".
  # binary = "ip6tables"
  ## defines the table to monitor:
  table = "filter"
  ## defines the chains to monitor.
  ## NOTE: iptables rules without a comment will not be monitored.
  ## Read the plugin documentation for more information.
  chains = [ "INPUT" ]

Cortex

[[outputs.http]]
  ## Cortex Remote Write endpoint
  url = "http://cortex.example.com/api/v1/push"

  ## Use POST to send data
  method = "POST"

  ## Send metrics using Prometheus remote write format
  data_format = "prometheusremotewrite"

  ## Optional HTTP headers for authentication
  # [outputs.http.headers]
  #   X-Scope-OrgID = "your-tenant-id"
  #   Authorization = "Bearer YOUR_API_TOKEN"

  ## Optional TLS configuration
  # tls_ca = "/path/to/ca.pem"
  # tls_cert = "/path/to/cert.pem"
  # tls_key = "/path/to/key.pem"
  # insecure_skip_verify = false

  ## Request timeout
  timeout = "10s"

Input and output integration examples

iptables

1. Monitoring Firewall Performance: Monitor the performance and efficiency of your firewall rules in real time. By tracking packet and byte counters, network administrators can identify which rules are most active and may require optimization. This enables proactive management of firewall configurations to enhance security and performance, especially in environments where dynamic adjustments are frequently made.

2. Understanding Traffic Patterns: Analyze incoming and outgoing traffic patterns based on specific rules. By leveraging the metrics gathered by this plugin, system admins can gain insights into which services are receiving the most traffic, effectively identifying popular services and potential security threats from unusual traffic spikes.

3. Automated Alerting on Traffic Anomalies: Integrate the iptables plugin with an alerting system to notify administrators of unusual activity detected by the firewall. By setting thresholds on the collected metrics, such as sudden increases in packets dropped or unexpected protocol use, teams can automate responses to potential security incidents, enabling swift remediation of threats to the network.

4. Comparative Analysis of Firewall Rules: Conduct comparative analyses of different firewall rules over time. By collecting historical packet and byte metrics, organizations can evaluate the effectiveness of various rules, making data-driven decisions on which rules to modify, reinforce, or remove altogether, thus streamlining their firewall configurations.

Cortex

1. Unified Multi-Tenant Monitoring: Use Telegraf to collect metrics from different teams or environments and push them to Cortex with separate X-Scope-OrgID headers. This enables isolated data ingestion and querying per tenant, ideal for managed services and platform teams.

2. Extending Prometheus Coverage to Edge Devices: Deploy Telegraf on edge or IoT devices to collect system metrics and send them to a centralized Cortex cluster. This approach ensures consistent observability even for environments without local Prometheus scrapers.

3. Global Service Observability with Federated Tenants: Aggregate metrics from global infrastructure by configuring Telegraf agents to push data into regional Cortex clusters, each tagged with tenant identifiers. Cortex handles deduplication and centralized access across regions.

4. Custom App Telemetry Pipeline: Collect app-specific telemetry via Telegraf’s exec or http input plugins and forward it to Cortex. This allows DevOps teams to monitor app-specific KPIs in a scalable, query-efficient format while keeping metrics logically grouped by tenant or service.

Feedback

Thank you for being part of our community! If you have any general feedback or found any bugs on these pages, we welcome and encourage your input. Please submit your feedback in the InfluxDB community Slack.