Package nl.lexemmens.podman.helper

Class MultiStageBuildOutputHelper

java.lang.Object

nl.lexemmens.podman.helper.MultiStageBuildOutputHelper

public final class MultiStageBuildOutputHelper
extends Object

Utility class that helps to determine the image hashes in case of a multiline Containerfile

Constructor Summary

Constructors

Constructor	Description
MultiStageBuildOutputHelper()

Method Summary

Modifier and Type	Method	Description
void	recordImageHashes(org.apache.maven.plugin.logging.Log log, SingleImageConfiguration image, List<String> processOutput)	Tries to determine the image hashes from the output of a Podman build command when using multistage containerfiles.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MultiStageBuildOutputHelper

public MultiStageBuildOutputHelper()

Method Detail

recordImageHashes

public void recordImageHashes(org.apache.maven.plugin.logging.Log log,
                              SingleImageConfiguration image,
                              List<String> processOutput)

Tries to determine the image hashes from the output of a Podman build command when using multistage containerfiles.

This method uses a lookahead strategy to determine the image hashes. It does not care about individual steps but only looks for stages and image hashes. Image hashes must be either 11 or 64 characters in length in order to be detected.

Identification starts at a line that defines a stage, i.e. FROM [something] AS stageName. From there it will process every next line until it hits the next stage or reaches the last line, whatever comes first. During reading of lines, the last image hash found will be recorded. When a next stage has been found, the last image hash found will be associated with the stage that was being processed.

To be more specific, the following steps are taken by this method, in the order as listed below:

• Read the first line of the output
• Retrieve the current stage from the the line. If the stage is null, then continue with the next line
• If a stage has been found, find the image hash
• Record the image hash for the current stage

This method allows STEP definitions in a Containerfile to produce multiline output.

Parameters:

log - Maven's logger for log output

image - The image configuration

processOutput - The output of a Podman build command