cefadrom/docker-exporter

By cefadrom

•Updated about 2 years ago

Archived

A Prometheus exporter to expose docker metrics that are normally not available through cAdvisor

Image

Monitoring & observability

860

Overview Tags

cefadrom/docker-exporter repository overview

⁠Docker exporter

⁠Description

A small prometheus exporter used to monitor what cAdvisor does not. It currently supports :

Docker images :
- Name
- Tag
- Size
- Virtual size
- Number of containers using it
Docker volumes :
- Name
- Mount point
- Name of docker compose project
- Number of containers using it
Docker networks :
- Name
- Number of containers using it

⁠Usage

⁠Volumes

The exporter needs access to the docker socket to get the data. You can mount it inside the container :

docker run -v /var/run/docker.sock:/var/run/docker.sock cefadrom/docker-exporter

If you want to get the volumes size, you also need to mount the root filesystem inside the container :

docker run -v /var/run/docker.sock:/var/run/docker.sock -v /:/rootfs:ro cefadrom/docker-exporter

If you wish to only get the size of the docker volumes mounted in /var/lib/docker/volumes (default volumes directory), you can mount only this directory :

docker run -v /var/run/docker.sock:/var/run/docker.sock -v /var/lib/docker/volumes:/rootfs/var/lib/docker/volumes:ro cefadrom/docker-exporter

Note: for security reasons, it is recommended to mount data volumes read-only (using :ro).

⁠Docker compose

The recommended way is to use docker compose. Put the exporter config inside the same docker-compose.yml file as your monitoring stack :

services:
    prometheus:
        image: prom/prometheus
        container_name: prometheus
        volumes:
            - ./prometheus.yml:/etc/prometheus/prometheus.yml
        ports:
            - 9090:9090

    docker-exporter:
        image: cefadrom/docker-exporter
        container_name: docker-exporter
        volumes:
            - /var/run/docker.sock:/var/run/docker.sock # To access docker API
            - /:/rootfs:ro # If you want to get volumes size
        ports:
            - 9100:9100

Finally, configure your prometheus.yml file to scrape the exporter. Note that a high scrape interval is recommended as the volume size calculation may be quite ressource intensive, and the data does not change that often.

scrape_configs:
    -   job_name: 'docker-exporter'
        scrape_interval: 10m
        static_configs:
            -   targets: [ 'docker-exporter:9100' ]

⁠Configuration

You can change the exporter server listening port and address, and if fastify logger is enabled. To do so, you can use environment variables :

Environment variable	Default value	Description
`SERVER_PORT`	`9100`	Port on which the exporter will listen
`SERVER_ADDRESS`	`0.0.0.0`	Address on which the exporter will listen
`LOGGER_ENABLED`	`true`	Enable fastify logger

⁠Metrics

Here is a sample of the metrics exposed by the exporter :

# HELP docker_image_size_bytes The size of the image in bytes
# TYPE docker_image_size_bytes gauge
docker_image_size_bytes{id="sha256:efadb309f7ffb875ad073162932b72d0bba5f8da71de54c36055fb843ef31be5",tag="cefadrom/docker-exporter:latest",containers="1"} 217327756
docker_image_size_bytes{id="sha256:3a8d46c63628f568039abf84f17c558cdaf4912d0c54a904e105f93f37f25775",tag="redis:alpine",containers="2"} 37773458

# HELP docker_image_virtual_size_bytes The virtual size of the image in bytes
# TYPE docker_image_virtual_size_bytes gauge
docker_image_virtual_size_bytes{id="sha256:efadb309f7ffb875ad073162932b72d0bba5f8da71de54c36055fb843ef31be5",tag="cefadrom/docker-exporter:latest",containers="1"} 217327756
docker_image_virtual_size_bytes{id="sha256:3a8d46c63628f568039abf84f17c558cdaf4912d0c54a904e105f93f37f25775",tag="redis:alpine",containers="2"} 37773458

# HELP docker_volume_size_bytes The size of the volume in bytes
# TYPE docker_volume_size_bytes gauge
docker_volume_size_bytes{name="portainer_portainer_data",mountpoint="/var/lib/docker/volumes/portainer_portainer_data/_data",compose_project="portainer",containers="1"} 573341
docker_volume_size_bytes{name="dockprom_grafana_data",mountpoint="/var/lib/docker/volumes/dockprom_grafana_data/_data",compose_project="dockprom",containers="1"} 1915362
docker_volume_size_bytes{name="dockprom_prometheus_data",mountpoint="/var/lib/docker/volumes/dockprom_prometheus_data/_data",compose_project="dockprom",containers="1"} 1918972991

# HELP docker_network_container_count The number of containers connected to the network
# TYPE docker_network_container_count gauge
docker_network_container_count{id="39b29ca27bc870e8259451db4c13b76ca88a0d211d3fe102eb5689938f094355",name="host"} 0
docker_network_container_count{id="ea78f0a6ef4949b684c155c5b11addb9cd79b7e2c0f7d43791c699373c5ca921",name="proxy"} 3
docker_network_container_count{id="d199cf3d3d45932efc1140e12922b07e8b31ba2715c1f686d44eff19ad7b69c7",name="bridge"} 0
docker_network_container_count{id="e9dcbdd6749b380fcc8789abbe7fe4eeb985110287d6ad4ef71026640688a914",name="none"} 0

# HELP docker_last_scrape_duration_seconds Duration of the last scrape of metrics from Docker in seconds
# TYPE docker_last_scrape_duration_seconds gauge
docker_last_scrape_duration_seconds 2.755

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Image

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sha256:9948c9cbf…

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10.2 MB

Last updated

about 2 years ago

docker pull cefadrom/docker-exporter