Display Count of Container Images by Name

Track the number of container images in use

This is a query example for the Containers widget in the Docker Overview dashboard of the docker/metrics package.

Query

flowchart LR; %%{init: {"flowchart": {"defaultRenderer": "elk"}} }%% repo{{Events}} 1{{Aggregate}} 2{{Aggregate}} result{{Result Set}} repo --> 1 1 --> 2 2 --> result
logscale
groupBy("container.image.name")
|count(container.image.name)

Introduction

This widget is used to monitor the variety of container images in the environment by counting the occurrences of each unique image name, providing visibility into image distribution and usage patterns.

In this widget, the groupBy() function groups events by image name, and count() calculates the total number of occurrences for each unique container image.

Example incoming data might look like this:

@timestamp#repo#type@id@ingesttimestamp@rawstring@timestamp.nanos@timezone@type_datagen_identifieragent.typeagent.versioncontainer.idcontainer.image.namecontainer.namedocker.container.event.actiondocker.container.event.actor.iddocker.container.event.fromdocker.container.event.statusdocker.container.event.typedocker.diskio.read.bytesdocker.diskio.read.opsdocker.diskio.summary.bytesdocker.diskio.summary.opsdocker.diskio.write.bytesdocker.diskio.write.opsdocker.event.actiondocker.healthcheck.event.end_datedocker.healthcheck.event.exit_codedocker.healthcheck.failingstreakdocker.healthcheck.statusdocker.image.createddocker.image.id.currentdocker.image.id.parentdocker.image.size.regulardocker.image.size.virtualdocker.image.tags[0]docker.info.containers.pauseddocker.info.containers.runningdocker.info.containers.stoppeddocker.info.containers.totaldocker.info.iddocker.info.imagesevent.datasetevent.modulehost.namemetricset.nameservice.type
2026-03-10T06:41:21auto-dashboard-queriesjsongtksp2dMmrYg9WSX5CeYyU5V_2_11_17731248812026-03-10T06:41:21{"docker.image.id.current":"sha256:abcd1234efgh5678","metricset.name":"image","docker.image.size.regular":"133169152","docker.image.created":"2026-03-10T06:41:21.002Z","event.module":"docker","docker.image.tags":["nginx:latest"],"@timestamp":"2026-03-10T06:41:21.002Z","host.name":"docker-host-01","agent.type":"metricbeat","@type":"docker","event.dataset":"docker.image","agent.version":"7.11.1","docker.image.size.virtual":"133169152","docker.image.id.parent":"sha256:parent1234567890ab","service.type":"docker","_datagen_identifier":"bbe9c9c08ebf329bc648a36a3991a240"}0Zdockerbbe9c9c08ebf329bc648a36a3991a240metricbeat7.11.1                   2026-03-10T06:41:21.002Zsha256:abcd1234efgh5678sha256:parent1234567890ab133169152133169152nginx:latest      docker.imagedockerdocker-host-01imagedocker
2026-03-10T06:41:21auto-dashboard-queriesjsongtksp2dMmrYg9WSX5CeYyU5V_2_12_17731248812026-03-10T06:41:22{"@timestamp":"2026-03-10T06:41:21.801Z","event.module":"docker","host.name":"docker-host-02","container.image.name":"nginx:latest","agent.type":"metricbeat","metricset.name":"event","docker.event.action":"stop","docker.container.event.action":"start","_datagen_identifier":"bbe9c9c08ebf329bc648a36a3991a240","service.type":"docker","docker.container.event.type":"container","docker.container.event.from":"redis:6.2-alpine","container.id":"a1b2c3d4e5f6","container.name":"nginx-web","event.dataset":"docker.event","docker.container.event.status":"Up 2 hours","@type":"docker","agent.version":"7.12.0","docker.container.event.actor.id":"b2c3d4e5f6a7"}0Zdockerbbe9c9c08ebf329bc648a36a3991a240metricbeat7.12.0a1b2c3d4e5f6nginx:latestnginx-webstartb2c3d4e5f6a7redis:6.2-alpineUp 2 hourscontainer      stop                docker.eventdockerdocker-host-02eventdocker
2026-03-10T06:41:22auto-dashboard-queriesjsongtksp2dMmrYg9WSX5CeYyU5V_2_13_17731248822026-03-10T06:41:23{"docker.info.containers.paused":"0","docker.info.images":"15","metricset.name":"info","docker.info.containers.running":"5","agent.type":"metricbeat","host.name":"docker-host-03","event.module":"docker","@timestamp":"2026-03-10T06:41:22.581Z","agent.version":"7.13.2","@type":"docker","event.dataset":"docker.info","docker.info.containers.stopped":"2","docker.info.containers.total":"7","_datagen_identifier":"bbe9c9c08ebf329bc648a36a3991a240","service.type":"docker","docker.info.id":"ABCD:EFGH:IJKL:MNOP:QRST:UVWX:YZ12:3456"}0Zdockerbbe9c9c08ebf329bc648a36a3991a240metricbeat7.13.2                         0527ABCD:EFGH:IJKL:MNOP:QRST:UVWX:YZ12:345615docker.infodockerdocker-host-03infodocker
2026-03-10T06:41:23auto-dashboard-queriesjsongtksp2dMmrYg9WSX5CeYyU5V_2_14_17731248832026-03-10T06:41:24{"container.id":"c3d4e5f6a7b8","container.name":"redis-cache","_datagen_identifier":"bbe9c9c08ebf329bc648a36a3991a240","service.type":"docker","docker.healthcheck.failingstreak":"0","@type":"docker","event.dataset":"docker.healthcheck","agent.version":"7.14.0","agent.type":"metricbeat","container.image.name":"postgres:14","event.module":"docker","@timestamp":"2026-03-10T06:41:23.389Z","host.name":"swarm-manager-01","docker.healthcheck.status":"healthy","docker.healthcheck.event.end_date":"2026-03-10T06:41:23.389Z","metricset.name":"healthcheck","docker.healthcheck.event.exit_code":"0"}0Zdockerbbe9c9c08ebf329bc648a36a3991a240metricbeat7.14.0c3d4e5f6a7b8postgres:14redis-cache            2026-03-10T06:41:23.389Z00healthy            docker.healthcheckdockerswarm-manager-01healthcheckdocker
2026-03-10T06:41:24auto-dashboard-queriesjsongtksp2dMmrYg9WSX5CeYyU5V_2_15_17731248842026-03-10T06:41:24{"container.id":"d4e5f6a7b8c9","container.name":"postgres-db","service.type":"docker","_datagen_identifier":"bbe9c9c08ebf329bc648a36a3991a240","docker.diskio.read.ops":"125","docker.diskio.read.bytes":"1048576","docker.diskio.summary.bytes":"3145728","@type":"docker","event.dataset":"docker.diskio","docker.diskio.write.bytes":"2097152","agent.version":"7.15.1","docker.diskio.write.ops":"234","agent.type":"metricbeat","container.image.name":"mongo:5.0","event.module":"docker","@timestamp":"2026-03-10T06:41:24.187Z","host.name":"swarm-worker-01","docker.diskio.summary.ops":"359","metricset.name":"diskio"}0Zdockerbbe9c9c08ebf329bc648a36a3991a240metricbeat7.15.1d4e5f6a7b8c9mongo:5.0postgres-db     104857612531457283592097152234                 docker.diskiodockerswarm-worker-01diskiodocker

Step-by-Step

  1. Starting with the source repository events.

  2. flowchart LR; %%{init: {"flowchart": {"defaultRenderer": "elk"}} }%% repo{{Events}} 1{{Aggregate}} 2{{Aggregate}} result{{Result Set}} repo --> 1 1 --> 2 2 --> result style 1 fill:#ff0000,stroke-width:4px,stroke:#000;
    logscale
    groupBy("container.image.name")

    Groups events by the container.image.name field to prepare for counting unique images.

  3. flowchart LR; %%{init: {"flowchart": {"defaultRenderer": "elk"}} }%% repo{{Events}} 1{{Aggregate}} 2{{Aggregate}} result{{Result Set}} repo --> 1 1 --> 2 2 --> result style 2 fill:#ff0000,stroke-width:4px,stroke:#000;
    logscale
    |count(container.image.name)

    Counts occurrences of each unique container image name, and returns the results in a _count field.

  4. Event Result set.

Summary and Results

The widget is used to monitor the distribution of container images across the environment, helping track image usage and variety.

This widget is useful to maintain an inventory of container images, track image proliferation, and identify commonly used images in the environment.

Sample output from the incoming example data:

_count
14

The output displays the total count of container image occurrences in the _count field, indicating 14 container image instances are present in the environment.