Table: dockerfile_instruction - Query Docker Dockerfile Instructions using SQL

Dockerfile Instructions are the commands that are used in a Dockerfile to build a Docker image. These instructions specify what to include in the Docker image and how it should behave when it is run. They are the building blocks of Docker images, specifying everything from the base image to use, to the commands to run, to the metadata to include.

Table Usage Guide

The dockerfile_instruction table provides insights into the instructions used within Dockerfiles in Docker. As a DevOps engineer, explore instruction-specific details through this table, including the instruction type, arguments, and associated metadata. Utilize it to uncover information about instructions, such as what base images are used, the commands that are run, and the metadata that is included.

Examples

List instructions in a specific Dockerfile

Explore the sequence of instructions within a specific Dockerfile to better understand the build process and dependencies. This could be beneficial in assessing the complexity of the build, identifying potential areas for optimization, or troubleshooting issues. Set the path column to query a specific Dockerfile. A full path must be provided.

select
  *
from
  dockerfile_instruction
where
  path = '/full/path/to/Dockerfile'
order by
  start_line;

select
  *
from
  dockerfile_instruction
where
  path = '/full/path/to/Dockerfile'
order by
  start_line;

List all Dockerfiles matched in the paths config

Explore all Dockerfile instructions sorted by their respective paths and starting lines. This can help you understand the structure and organization of your Dockerfiles, making it easier to manage and troubleshoot your Docker environment.

The paths config parameter sets directories (including wildcards) to search for Dockerfiles. To match, either the filename is Dockerfile (e.g. Dockerfile, Dockerfile.example), or the extension is .dockerfile (e.g. nginx.dockerfile).

select
  *
from
  dockerfile_instruction
order by
  path,
  start_line;

select
  *
from
  dockerfile_instruction
order by
  path,
  start_line;

List base images

Explore the foundational elements of your Docker environment by identifying the base images used in your Dockerfiles. This can aid in understanding dependencies, ensuring consistency, and managing potential security vulnerabilities across your projects.

select
  path,
  start_line,
  data ->> 'image' as image,
  data ->> 'tag' as tag
from
  dockerfile_instruction as cmd
where
  cmd.cmd = 'from'
order by
  path,
  start_line,
  image,
  tag;

select
  path,
  start_line,
  json_extract(data, '$.image') as image,
  json_extract(data, '$.tag') as tag
from
  dockerfile_instruction as cmd
where
  cmd.cmd = 'from'
order by
  path,
  start_line,
  image,
  tag;

Find all exposed ports

Identify instances where certain ports are exposed in your Dockerfile instructions. This can help you manage and secure your network traffic by understanding which ports are open.

select
  path,
  start_line,
  (p ->> 'port') :: int as port,
  p ->> 'protocol' as protocol
from
  dockerfile_instruction as cmd,
  jsonb_array_elements(data) as p
where
  cmd.cmd = 'expose'
order by
  path,
  start_line,
  port,
  protocol;

select
  path,
  start_line,
  cast(json_extract(p.value, '$.port') as integer) as port,
  json_extract(p.value, '$.protocol') as protocol
from
  dockerfile_instruction as cmd,
  json_each(cmd.data) as p
where
  cmd.cmd = 'expose'
order by
  path,
  start_line,
  port,
  protocol;

Schema for dockerfile_instruction

Name	Type	Operators	Description
_ctx	jsonb		Steampipe context in JSON form, e.g. connection_name.
args	jsonb		Array of arguments passed to the command.
data	jsonb		Command data, parsed into a convenient format for each command type.
end_line	bigint		Last line number of this cmd in the file.
flags	jsonb		Flags passed to the command.
instruction	text		Command name in lowercase form, e.g. from, env, run, etc.
path	text	=	Full path of the file.
prev_comment	jsonb		Comment above the command in the Dockerfile.
source	text		Full original source code of the cmd.
stage	text		Stage name in the Dockerfile, defaults to the stage number.
stage_number	bigint		Stage number in the Dockerfile, starting at zero.
start_line	bigint		First line number of this cmd in the file.
sub_instruction	text		Sub command name in lowercase form, e.g. set to 'run' for 'onbuild run ...'.

Export

This table is available as a standalone Exporter CLI. Steampipe exporters are stand-alone binaries that allow you to extract data using Steampipe plugins without a database.

You can download the tarball for your platform from the Releases page, but it is simplest to install them with the steampipe_export_installer.sh script:

/bin/sh -c "$(curl -fsSL https://steampipe.io/install/export.sh)" -- docker

You can pass the configuration to the command with the --config argument:

steampipe_export_docker --config '<your_config>' dockerfile_instruction