logporter

A simple and lightweight alternative to cAdvisor for extracting basic and custom metrics from Docker containers.

The exporter supports a metric displaying the number of logs over the scrape period. With proper logging configuration and stream separation on the application side, this metric can reflect the actual traffic volume and error rate.

Comparative measurement of CPU and memory usage from cAdvisor and logporter metrics in 3 hours:

Note

On average, CPU consumption is 15-20 times lower and memory consumption is 10 times lower in the basic metrics mode (including IOps and uptime) compared to cAdvisor.

Quick start

Clone the repository and run the pre-configured monitoring stack with a single command:

git clone https://github.com/Lifailon/logporter
cd logporter
docker-compose up -d

The dashboard and Prometheus data source with the added exporter are already connected to Grafana.

Go to Grafana UI: http://localhost:3000 and enter admin:admin.

Manual configuration

• Build the Docker image yourself (optional):

docker build -t lifailon/logporter .

• Run the exporter in a container using a locally built image or one published on Docker Hub:

docker run -d --name logporter \
  -v /var/run/docker.sock:/var/run/docker.sock \
  -p 9333:9333 \
  --restart=always \
  lifailon/logporter:latest

Or use compose to securely use the docker socket through a proxy:

services:
  logporter:
    image: lifailon/logporter:latest
    container_name: logporter
    restart: always
    ports:
      - 9333:9333
    environment:
      - DOCKER_HOST=tcp://docker-proxy:2375

  docker-proxy:
    image: lscr.io/linuxserver/socket-proxy:latest
    container_name: docker-proxy
    restart: always
    environment:
      - CONTAINERS=1
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro

Use environment variables to configure the exporter:

Label	Type	Default	Description
DOCKER_METRICS_PORT	int	9333	The port on which the exporter is listening.
DOCKER_METRICS_HOSTNAME	string	""	A custom hostname that appears in metric tags.
DOCKER_METRICS_CACHE	int	15	Cache time for all collected metrics in seconds.
DOCKER_METRICS_LOG	boolean	false	Collecting the number of messages in logs from all streams.
DOCKER_METRICS_LOG_CACHE	int	15	Cache time for collected logs metrics in seconds.
DOCKER_METRICS_VOLUME	boolean	true	Collecting a list of all volumes and their sizes.
DOCKER_METRICS_VOLUME_CACHE	int	30	Cache time for collected volumes metrics in minutes.
DOCKER_HOST	string	""	Optional: use a docker proxy instead of the docker socket mount for additional security.

Warning

Using custom metrics may increase resource consumption (depending on the number of containers and the logs they contain). The metrics themselves are transmitted instantly thanks to data collection by background workers and caching. Check the duration value in the exporter logs to ensure that it does not exceed the scrape interval.

• Connect the new target to the Prometheus configuration file:

scrape_configs:
  - job_name: logporter
    scrape_interval: 15s
    scrape_timeout: 2s
    static_configs:
      - targets:
        - localhost:9333

• Import the prepared public Grafana dashboard using the id 23848 or from json file.

List of metrics

Name	Data type	Help description
docker_image_size	gauge	The size of the image minus the layer shared by other images
docker_volume_size	gauge	The size of the volumes and the number of containers associated with it in the volumeUsage tag
docker_container_status	gauge	Container status: running (1) or stopped (0)
docker_cpu_usage_total	counter	Total CPU usage (user and kernel) in seconds
docker_cpu_usage_user	counter	User CPU usage in seconds
docker_cpu_usage_kernel	counter	Kernel CPU usage in seconds
docker_memory_total	gauge	Total memory size in bytes
docker_memory_usage	gauge	Usage memory size in bytes
docker_network_received_bytes	counter	Number of bytes received on the network
docker_network_received_packages	counter	Number of packages received on the network
docker_network_transmit_bytes	counter	Number of bytes transmitted on the network
docker_network_transmit_packages	counter	Number of packages transmitted on the network
docker_io_read_bytes	counter	Number of bytes read by the block device
docker_io_write_bytes	counter	Number of bytes write by the block device
docker_process_pids_count	gauge	Number of running processes and threads
docker_logs_stdout_count	counter	Number of messages in logs from standard output
docker_logs_stderr_count	counter	Number of messages in logs from error output
docker_started_time	gauge	Container started time