How to use Podman and Quadlet to start Harvest pollers

[cgrinds]

Summary

The goal is to create Podman quadlets for each Harvest poller without Prometheus and Grafana containers.

1. Install Harvest and generate harvest-compose.yml per normal
2. Use podlet to generate Quadlet files from harvest-compose.yml
3. Make a few edits to quadlet files and move to /etc/containers/systemd/
4. systemctl daemon-reload
5. systemctl start poller-sar, systemctl start poller-u2, ...
5. Reboot machine and verify pollers all correctly restart

Generate harvest-compose

Installed Harvest and generate harvest-compose.yml

# cat harvest-compose.yml
services:

  u2:
    image: ghcr.io/netapp/harvest:latest
    container_name: poller-u2
      #restart: unless-stopped
    ports:
      - "12990:12990"
    command: '--poller u2 --promPort 12990 --config /opt/harvest.yml'
    volumes:
      - ./cert:/opt/harvest/cert
      - ./harvest.yml:/opt/harvest.yml
      - ./conf:/opt/harvest/conf
    networks:
      - backend

  sar:
    image: ghcr.io/netapp/harvest:latest
    container_name: poller-sar
      #restart: unless-stopped
    ports:
      - "12991:12991"
    command: '--poller sar --promPort 12991 --config /opt/harvest.yml'
    volumes:
      - ./cert:/opt/harvest/cert
      - ./harvest.yml:/opt/harvest.yml
      - ./conf:/opt/harvest/conf
    networks:
      - backend

Podlet

Install podlet or compare the example harvest-compose.yml above with the generated quadlets below.

# podlet compose harvest-compose.yml

# u2.container
[Container]
ContainerName=poller-u2
Exec=--poller u2 --promPort 12990 --config /opt/harvest.yml
Image=ghcr.io/netapp/harvest:latest
Network=backend
PublishPort=12990:12990
Volume=./cert:/opt/harvest/cert
Volume=./harvest.yml:/opt/harvest.yml
Volume=./conf:/opt/harvest/conf

---

# sar.container
[Container]
ContainerName=poller-sar
Exec=--poller sar --promPort 12991 --config /opt/harvest.yml
Image=ghcr.io/netapp/harvest:latest
Network=backend
PublishPort=12991:12991
Volume=./cert:/opt/harvest/cert
Volume=./harvest.yml:/opt/harvest.yml
Volume=./conf:/opt/harvest/conf

Edit quadlets

Podlet create two Yaml documents, one for each poller.
We are going to make the following adjustments to the podlet output and copy/paste the final output into /etc/containers/systemd/poller-u2.container and /etc/containers/systemd/poller-sar.container

The edits are:

1. Remove the Network=backend line that was included for Prometheus.
2. Change all Volume paths to fully qualified paths. (e.g. change ./cert to /opt/harvest/cert if you installed Harvest at /opt/harvest)
3. Because we want to restart the pollers when the machine reboots add the following section

[Install]
# Start by default on boot
WantedBy=multi-user.target default.target

[Service]
Restart=always

Here is the final output for the sar service.

# sar.container
[Container]
ContainerName=poller-sar
Exec=--poller sar --promPort 12991 --config /opt/harvest.yml
Image=ghcr.io/netapp/harvest:latest
PublishPort=12991:12991
Volume=/opt/harvest/cert:/opt/harvest/cert
Volume=/opt/harvest/harvest.yml:/opt/harvest.yml
Volume=/opt/harvest/conf:/opt/harvest/conf

[Install]
# Start by default on boot
WantedBy=multi-user.target default.target

[Service]
Restart=always

Copy that service file to /etc/containers/systemd/poller-sar.container

Versions

RHEL 9.4

podman version
Client:       Podman Engine
Version:      4.9.4-rhel
API Version:  4.9.4-rhel
Go Version:   go1.21.11 (Red Hat 1.21.11-1.el9_4)
Built:        Fri Jun 21 07:36:53 2024
OS/Arch:      linux/amd64

Harvest 24.11

podlet 0.3.0

Reference

• https://docs.podman.io/en/latest/markdown/podman-systemd.unit.5.html
• https://www.redhat.com/en/blog/multi-container-application-podman-quadlet