allow usage of Mustache placeholders in additional build command file (#359)

Author: ddsharpe

imagetool/src/main/java/com/oracle/weblogic/imagetool/cli/menu/CommonOptions.java

@@ -76,8 +76,8 @@ private void handleAdditionalBuildCommands() throws IOException {
                 throw new FileNotFoundException(Utils.getMessage("IMG-0030", additionalBuildCommandsPath));
             }
 
-            AdditionalBuildCommands additionalBuildCommands = AdditionalBuildCommands.load(additionalBuildCommandsPath);
-            dockerfileOptions.setAdditionalBuildCommands(additionalBuildCommands.getContents());
+            AdditionalBuildCommands additionalBuildCommands = new AdditionalBuildCommands(additionalBuildCommandsPath);
+            dockerfileOptions.setAdditionalBuildCommands(additionalBuildCommands.getContents(dockerfileOptions));
         }
 
         if (additionalBuildFiles != null) {

imagetool/src/main/java/com/oracle/weblogic/imagetool/util/AdditionalBuildCommands.java

@@ -5,16 +5,22 @@
 
 import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.Callable;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
+import com.github.mustachejava.DefaultMustacheFactory;
+import com.github.mustachejava.Mustache;
+import com.github.mustachejava.MustacheFactory;
 import com.oracle.weblogic.imagetool.logging.LoggingFacade;
 import com.oracle.weblogic.imagetool.logging.LoggingFactory;
 
@@ -30,10 +36,16 @@ public class AdditionalBuildCommands {
     public static final String AFTER_WDT = "after-wdt-command";
     public static final String FINAL_BLD = "final-build-commands";
 
-    private List<NamedPattern> sections;
-    private Map<String, List<String>> contents;
+    private final List<NamedPattern> sections;
+    private final Map<String, List<String>> contents;
 
-    private AdditionalBuildCommands() {
+    /**
+     * Load the contents of the additional build commands file into this object.
+     * Existing data in this instance are replaced.
+     * @param file Path to the additional build commands file that should be loaded.
+     * @throws IOException if an issue occurs locating or opening the file provided
+     */
+    public AdditionalBuildCommands(Path file) throws IOException {
         sections = new ArrayList<>();
         sections.add(getPattern(PACKAGES));
         sections.add(getPattern(BEFORE_JDK));
@@ -43,6 +55,8 @@ private AdditionalBuildCommands() {
         sections.add(getPattern(BEFORE_WDT));
         sections.add(getPattern(AFTER_WDT));
         sections.add(getPattern(FINAL_BLD));
+        contents = new HashMap<>();
+        load(file);
     }
 
     private static NamedPattern getPattern(String key) {
@@ -61,8 +75,38 @@ public int size() {
         return contents.size();
     }
 
-    public Map<String,List<String>> getContents() {
-        return contents;
+    /**
+     * Get the contents of the file provided on the command line as additional build commands.
+     * The file is parsed into a map based on the sections in the file. The returned map
+     * will have one entry per section found in the provided file (such as "final-build-commands").
+     * The Callable list value for each entry is for late resolution of the contents.  If the user
+     * provides mustache placeholders in the file, those placeholders will get resolved when the call
+     * method is invoked and not when getContents is returned.  This allows getContents to be called
+     * before DockerfileOptions is completely populated.
+     *
+     * @param options The backing file that will be used to resolve any mustache placeholders in the file
+     * @return a map by section name of the additional build file contents
+     */
+    public Map<String, Callable<List<String>>> getContents(DockerfileOptions options) {
+        Map<String, Callable<List<String>>> callableResult = new HashMap<>();
+        for (Map.Entry<String, List<String>> entry: contents.entrySet()) {
+            // implements the "call" method so that the contents are resolved at the time they are retrieved
+            Callable<List<String>> value = () -> {
+                List<String> resolvedLines = new ArrayList<>();
+                MustacheFactory mf = new DefaultMustacheFactory();
+                // Parse each line in the file contents using mustache and the provided "options"
+                for (String line: entry.getValue()) {
+                    StringWriter writer = new StringWriter();
+                    Mustache mustache = mf.compile(new StringReader(line), "x");
+                    mustache.execute(writer, options);
+                    writer.flush();
+                    resolvedLines.add(writer.toString());
+                }
+                return resolvedLines;
+            };
+            callableResult.put(entry.getKey(), value);
+        }
+        return callableResult;
     }
 
     /**
@@ -80,26 +124,23 @@ public List<String> getSection(String name) {
      * @param file Path to the additional build commands file that should be loaded.
      * @throws IOException if an issue occurs locating or opening the file provided
      */
-    public static AdditionalBuildCommands load(Path file) throws IOException {
+    private void load(Path file) throws IOException {
         logger.entering(file);
-        AdditionalBuildCommands result = new AdditionalBuildCommands();
-        result.contents = new HashMap<>();
-
         try (BufferedReader reader = Files.newBufferedReader(file)) {
             List<String> buffer = new ArrayList<>();
             String currentSection = null;
             String line;
             while ((line = reader.readLine()) != null) {
                 logger.finest(line);
-                String sectionStart = result.checkForSectionHeader(line);
+                String sectionStart = checkForSectionHeader(line);
                 //skip any lines that come before the first section header
                 if (currentSection != null && sectionStart == null) {
                     //collect lines inside current section
                     buffer.add(line);
                 } else if (currentSection != null) {
                     //while in a section, found next section start (save last section, and start new section)
                     logger.fine("IMG-0015", buffer.size(), currentSection);
-                    result.contents.put(currentSection, buffer);
+                    contents.put(currentSection, buffer);
                     buffer = new ArrayList<>();
                     currentSection = sectionStart;
                 } else if (sectionStart != null) {
@@ -111,15 +152,14 @@ public static AdditionalBuildCommands load(Path file) throws IOException {
             if (currentSection != null && !buffer.isEmpty()) {
                 //finished reading file, store the remaining lines that were read for the section
                 logger.fine("IMG-0015", buffer.size(), currentSection);
-                result.contents.put(currentSection, buffer);
+                contents.put(currentSection, buffer);
             }
         } catch (IOException ioe) {
             logger.severe("IMG-0013", file.getFileName());
             throw ioe;
         }
 
         logger.exiting();
-        return result;
     }
 
     private String checkForSectionHeader(String line) {

imagetool/src/main/java/com/oracle/weblogic/imagetool/util/DockerfileOptions.java

@@ -11,19 +11,24 @@
 import java.util.List;
 import java.util.Map;
 import java.util.StringJoiner;
+import java.util.concurrent.Callable;
 import java.util.stream.Collectors;
 
 import com.oracle.weblogic.imagetool.aru.AruPatch;
 import com.oracle.weblogic.imagetool.cli.menu.PackageManagerType;
 import com.oracle.weblogic.imagetool.installer.MiddlewareInstall;
 import com.oracle.weblogic.imagetool.installer.MiddlewareInstallPackage;
+import com.oracle.weblogic.imagetool.logging.LoggingFacade;
+import com.oracle.weblogic.imagetool.logging.LoggingFactory;
 import com.oracle.weblogic.imagetool.wdt.WdtOperation;
 
 /**
  * Provides the data used by the Dockerfile templates (in mustache).
  */
 public class DockerfileOptions {
 
+    private static final LoggingFacade logger = LoggingFactory.getLogger(DockerfileOptions.class);
+
     private static final String DEFAULT_JAVA_HOME = "/u01/jdk";
     private static final String DEFAULT_ORACLE_HOME = "/u01/oracle";
     private static final String DEFAULT_DOMAIN_HOME = "/u01/domains/base_domain";
@@ -79,7 +84,7 @@ public class DockerfileOptions {
     private String wdtBase;
 
     // Additional Build Commands
-    private Map<String, List<String>> additionalBuildCommands;
+    private Map<String, Callable<List<String>>> additionalBuildCommands;
 
     /**
      * Options to be used with the Mustache template.
@@ -897,16 +902,21 @@ public String wlsdeploy_properties() {
      *
      * @param commands Additional build commands grouped by section.
      */
-    public DockerfileOptions setAdditionalBuildCommands(Map<String, List<String>> commands) {
+    public DockerfileOptions setAdditionalBuildCommands(Map<String, Callable<List<String>>> commands) {
         additionalBuildCommands = commands;
         return this;
     }
 
     private List<String> getAdditionalCommandsForSection(String sectionName) {
-        if (additionalBuildCommands == null) {
+        if (additionalBuildCommands == null || !additionalBuildCommands.containsKey(sectionName)) {
+            return Collections.emptyList();
+        }
+        try {
+            return additionalBuildCommands.get(sectionName).call();
+        } catch (Exception e) {
+            logger.severe("IMG-0114", sectionName, e.getLocalizedMessage());
             return Collections.emptyList();
         }
-        return additionalBuildCommands.get(sectionName);
     }
 
     @SuppressWarnings("unused")

imagetool/src/main/resources/ImageTool.properties

@@ -112,3 +112,4 @@ IMG-0110=Retries exhausted, unable to obtain patch information from Oracle
 IMG-0111=The directory specified with WLSIMG_BLDDIR must exist prior to running this tool: {0}
 IMG-0112=The value specified with WLSIMG_BLDDIR must be a directory: {0}
 IMG-0113=The directory specified with WLSIMG_BLDDIR must be writable: {0}
+IMG-0114=Unable to parse section {0} of additionalBuildCommands: {1}

imagetool/src/test/java/com/oracle/weblogic/imagetool/util/AdditionalBuildCommandsTest.java

@@ -6,6 +6,9 @@
 import java.io.IOException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 
 import org.junit.jupiter.api.Tag;
 import org.junit.jupiter.api.Test;
@@ -23,15 +26,15 @@ private static Path getPath(String filename) {
     @Test
     void loadSingleSectionFile() throws IOException {
         String filename = "one-section.txt";
-        AdditionalBuildCommands cmds = AdditionalBuildCommands.load(getPath(filename));
+        AdditionalBuildCommands cmds = new AdditionalBuildCommands(getPath(filename));
 
         assertEquals(1, cmds.size(), "File did not have expected number of sections: " + filename);
     }
 
     @Test
     void loadTwoSectionFile() throws IOException {
         String filename = "two-sections.txt";
-        AdditionalBuildCommands cmds = AdditionalBuildCommands.load(getPath(filename));
+        AdditionalBuildCommands cmds = new AdditionalBuildCommands(getPath(filename));
         assertEquals(2, cmds.size(), "File did not have expected number of sections: " + filename);
         assertEquals(3, cmds.getSection(AdditionalBuildCommands.AFTER_FMW).size(),
             "Wrong number of lines in AFTER_FMW section of " + filename);
@@ -40,8 +43,24 @@ void loadTwoSectionFile() throws IOException {
     }
 
     @Test
-    void loadBadSectionFile() throws IOException {
-        String filename = "bad-section.txt";
-        assertThrows(IllegalArgumentException.class, () -> AdditionalBuildCommands.load(getPath(filename)));
+    void loadBadSectionFile() {
+        Path file = getPath("bad-section.txt");
+        assertThrows(IllegalArgumentException.class, () -> new AdditionalBuildCommands(file));
+    }
+
+    @Test
+    void resolveMustachePlaceHolders() throws Exception {
+        AdditionalBuildCommands cmds = new AdditionalBuildCommands(getPath("two-mustache.txt"));
+        DockerfileOptions options = new DockerfileOptions("123");
+        // default Oracle Home and Java Home are expected, /u01/oracle, /u01/jdk.
+        options.setAdditionalBuildCommands(cmds.getContents(options));
+
+        List<String> expected = Arrays.asList(
+            "echo This is the Oracle Home: /u01/oracle",
+            "echo This is the Java Home: /u01/jdk");
+        assertEquals(expected, options.finalBuildCommands());
+
+        // If a section is requested that is NOT in the file, the getter should return an empty list.
+        assertEquals(Collections.emptyList(), options.beforeFmwInstall());
     }
 }

imagetool/src/test/resources/additionalBuildCommands/two-mustache.txt

@@ -0,0 +1,6 @@
+// Copyright 2022, Oracle Corporation and/or its affiliates.  All rights reserved.
+// Licensed under the Universal Permissive License v 1.0 as shown at http://oss.oracle.com/licenses/upl.
+
+[final-build-commands]
+echo This is the Oracle Home: {{{oracle_home}}}
+echo This is the Java Home: {{{java_home}}}