$ dok history

Layers of an image with size bars and readable instructions

Synopsis

dok history [OPTIONS] <IMAGE>

Description

The layers of an image in build order, read top-down the way the Dockerfile was written, each with a bar showing its share of the image. Layers over 10% of the total are marked.

Instructions are recovered from the classic builder's /bin/sh -c #(nop) wrapper and from BuildKit's direct form alike, and a multi-line RUN collapses onto one row. -r restores docker's newest-first order.

Arguments

<IMAGE>: Image name, repo:tag or id prefix

Options

-r, --reverse: Newest layer first, the way docker history prints it
--no-trunc: Do not shorten long instructions

Every command also takes the global options: --json, --color, --icons and --theme.

Examples

$ dok history api  # resolves a bare repo to any of its tags

$ dok history api -r  # newest layer first

$ dok history postgres:16-alpine --no-trunc  # keep long instructions whole

Output

JSON output

$ dok history api --json
{
  "count": 9,
  "image": "ghcr.io/demo-shop/api:1.4.2",
  "layers": [
    {
      "created": {
        "age_human": "1mo",
        "age_seconds": 2592000,
        "created": 1787911050
      },
      "fat": true,
      "id": "sha256:9f8e7d6c5b4a",
      "index": 1,
      "instruction": "ADD file:9a2c in /",
      "share": 0.5525,
      "size": {
        "bytes": 145200000,
        "human": "145MB"
      }
    },
    {
      "created": {
        "age_human": "1mo",
        "age_seconds": 2592000,
        "created": 1787911050
      },
      "fat": false,
      "id": "<missing>",
      "index": 2,
      "instruction": "ENV NODE_VERSION=22.9.0",
      "share": 0.0,
      "size": {
        "bytes": 0,
        "human": "0B"
      }
    }
  ],
  "total": {
    "bytes": 262800000,
    "human": "263MB"
  }
}

Longer arrays are cut to their first two elements here.