io.fabric8.maven.docker.util.DockerFileUtil Maven / Gradle / Ivy
package io.fabric8.maven.docker.util;/*
*
* Copyright 2015 Roland Huss
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.maven.plugin.assembly.interpolation.AssemblyInterpolator;
import org.apache.maven.plugin.assembly.io.DefaultAssemblyReader;
import org.codehaus.plexus.interpolation.fixed.FixedStringSearchInterpolator;
import io.fabric8.maven.docker.assembly.DockerAssemblyConfigurationSource;
/**
* Utility class for dealing with dockerfiles
* @author roland
* @since 21/01/16
*/
public class DockerFileUtil {
private DockerFileUtil() {}
/**
* Extract the base image from a dockerfile. The first line containing a FROM is
* taken.
*
* @param dockerFile file from where to extract the base image
* @param interpolator interpolator for replacing properties
*/
public static String extractBaseImage(File dockerFile, FixedStringSearchInterpolator interpolator) throws IOException {
List fromLines = extractLines(dockerFile, "FROM", interpolator);
if (!fromLines.isEmpty()) {
String[] parts = fromLines.get(0);
if (parts.length > 1) {
return parts[1];
}
}
return null;
}
/**
* Extract all lines containing the given keyword
*
* @param dockerFile dockerfile to examine
* @param keyword keyword to extract the lines for
* @param interpolator interpolator for replacing properties
* @return list of matched lines or an empty list
*/
public static List extractLines(File dockerFile, String keyword, FixedStringSearchInterpolator interpolator) throws IOException {
List ret = new ArrayList<>();
try (BufferedReader reader = new BufferedReader(new FileReader(dockerFile))) {
String line;
while ((line = reader.readLine()) != null) {
String lineInterpolated = interpolator.interpolate(line);
String[] lineParts = lineInterpolated.split("\\s+");
if (lineParts.length > 0 && lineParts[0].equalsIgnoreCase(keyword)) {
ret.add(lineParts);
}
}
}
return ret;
}
/**
* Interpolate a docker file with the given properties and filter
*
* @param dockerFile docker file to interpolate
* @param interpolator interpolator for replacing properties
* @return The interpolated contents of the file.
* @throws IOException
*/
public static String interpolate(File dockerFile, FixedStringSearchInterpolator interpolator) throws IOException {
StringBuilder ret = new StringBuilder();
try (BufferedReader reader = new BufferedReader(new FileReader(dockerFile))) {
String line;
while ((line = reader.readLine()) != null) {
ret.append(interpolator.interpolate(line)).append(System.lineSeparator());
}
}
return ret.toString();
}
/**
* Create an interpolator for the given maven parameters and filter configuration.
*
* @param params The maven parameters.
* @param filter The filter configuration.
* @return An interpolator for replacing maven properties.
*/
public static FixedStringSearchInterpolator createInterpolator(MojoParameters params, String filter) {
String[] delimiters = extractDelimiters(filter);
if (delimiters == null) {
// Don't interpolate anything
return FixedStringSearchInterpolator.create();
}
DockerAssemblyConfigurationSource configSource = new DockerAssemblyConfigurationSource(params, null, null);
// Patterned after org.apache.maven.plugin.assembly.interpolation.AssemblyExpressionEvaluator
return AssemblyInterpolator
.fullInterpolator(params.getProject(),
DefaultAssemblyReader.createProjectInterpolator(params.getProject()), configSource)
.withExpressionMarkers(delimiters[0], delimiters[1]);
}
private static String[] extractDelimiters(String filter) {
if (filter == null ||
filter.equalsIgnoreCase("false") ||
filter.equalsIgnoreCase("none")) {
return null;
}
if (filter.contains("*")) {
Matcher matcher = Pattern.compile("^(?[^*]+)\\*(?.*)$").matcher(filter);
if (matcher.matches()) {
return new String[] { matcher.group("start"), matcher.group("end") };
}
}
return new String[] { filter, filter };
}
}