FTC provides automatic monitoring for foreman hosts, similar to how Nagios exported resources work but with 25% less pain.

• Foreman >= 1.23
• A telegraf instance running in Kubernetes, deployed by the influxdata/telegraf Helm chart

./ftc --help

./ftc \
  --foreman-username=admin \
  --foreman-password=hunter2 \
  --foreman-url=https://foreman.dev.lsst.io:443 \
  --k8s-credentials=config \
  --k8s-namespace=telegraf-hosts \
  --k8s-configmap=telegraf-hosts \
  --k8s-configmap-key=ping.conf \
  --k8s-deployment=telegraf-hosts \
  --k8s-volume=config

Configuration can be passed to ftc through environment variables or CLI options. If an option is specified via both an environment and CLI option the CLI option will take precedence.

Additional options can be supplied to formatters. Additional options are specified as a JSON string.

• exclude_fqdns: A list of regular expressions of FQDNs to ignore. This is generally used to ignore interfaces used for PXE booting and are shut down during normal operation.
• servers (dns_forward only): A list of DNS servers to perform DNS queries against.

Ftc is in charge of scraping and modifying host information from Foreman and shoving it into Kubernetes so telegraf can monitor hosts. It provides this functionality with the following algorithm.

1. Enumerate the Foreman API for all hosts and host interfaces
2. Generate a telegraf config file suitable to be written into /etc/telegraf/telegraf.d/<input>.conf
3. Compare the generated config file against a Kubernetes configmap holding the Telegraf config file. If they don't match the config file is updated within the configmap.
4. Check and potentially modify the Telegraf deployment so that it mounts the generated config file within /etc/telegraf/telegraf.d/<input>.conf; by default it'll be mounted in the wrong location (/etc/telegraf/<input>.conf).
5. Restart the deployment if the configmap or Deployment has changed to ensure that the new files are loaded. This works around Kubernetes issue #50345

FTC will automatically monitor Foreman host interfaces with the following properties:

1. The interface is managed by Foreman
2. The interface has an IP address/MAC address (on the assumption that interfaces without either an IP address or MAC address is a virtual or unused interface)
3. The interface has been assigned an FQDN

Application development is performed by building and then running docker containers. Helper commands are provided with rake.

To build a container:

bundle exec rake docker:build

To run the application:

cat > .env <<-EOD
FOREMAN_USERNAME=admin
FOREMAN_PASSWORD=hunter2
FOREMAN_URL=https://foreman.ls.lsst.org:443
SSL_CA_FILE=/local/ca.crt

K8S_CREDENTIALS=config
K8S_CONTEXT=ruka
K8S_NAMESPACE=it-telegraf-hosts
K8S_CONFIGMAP=telegraf-ping
K8S_CONFIGMAP_KEY=ping.conf
K8S_DEPLOYMENT=telegraf-ping
K8S_VOLUME=config

FORMATTER_NAME=ping
FORMATTER_OPTIONS={"exclude_fqdns": [".*-pxe\."]}
EOD

bundle exec rake docker:run # Uses environment settings from `.env`

To release an image:

git tag x.y.z # use your version here
bundle exec rake docker:build docker:release
git push --tags