From 52aed4f0f58454b135853521f4cca2e8f52b8e5f Mon Sep 17 00:00:00 2001
From: Rohan Kumar <rohaan@redhat.com>
Date: Tue, 29 Sep 2020 02:00:26 +0530
Subject: [PATCH] Follow up PR for
 https://github.com/fabric8io/docker-maven-plugin/pull/1373

Use regex in order to resolve ARG value
---
 .../fabric8/maven/docker/util/DockerFileUtil.java  | 14 ++++++++++----
 .../maven/docker/util/DockerFileUtilTest.java      |  6 ++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/main/java/io/fabric8/maven/docker/util/DockerFileUtil.java b/src/main/java/io/fabric8/maven/docker/util/DockerFileUtil.java
index 4caf3583f..14836c5ea 100644
--- a/src/main/java/io/fabric8/maven/docker/util/DockerFileUtil.java
+++ b/src/main/java/io/fabric8/maven/docker/util/DockerFileUtil.java
@@ -43,6 +43,8 @@
  */
 public class DockerFileUtil {
 
+    private static final String ARG_PATTERN_REGEX = "\\$(?:\\{(.*)\\}|(.*))";
+
     private DockerFileUtil() {}
 
     /**
@@ -166,10 +168,14 @@ static Map<String, String> extractArgsFromLines(List<String[]> argLines, Map<Str
     }
 
     static String resolveArgValueFromStrContainingArgKey(String argString, Map<String, String> args) {
-        if (argString.startsWith("$") && args.containsKey(argString.substring(1))) {
-            return args.get(argString.substring(1));
-        } else if (argString.startsWith("${") && argString.endsWith("}") && args.containsKey(argString.substring(2, argString.length() - 1))) {
-            return args.get(argString.substring(2, argString.length() - 1));
+        Pattern argPattern = Pattern.compile(ARG_PATTERN_REGEX);
+        Matcher matcher = argPattern.matcher(argString);
+        if (matcher.matches()) {
+            if (matcher.group(1) != null) {
+                return args.get(matcher.group(1));
+            } else if (matcher.group(2) != null) {
+                return args.get(matcher.group(2));
+            }
         }
         return null;
     }
diff --git a/src/test/java/io/fabric8/maven/docker/util/DockerFileUtilTest.java b/src/test/java/io/fabric8/maven/docker/util/DockerFileUtilTest.java
index 10de9e6c9..e8b2cdbce 100644
--- a/src/test/java/io/fabric8/maven/docker/util/DockerFileUtilTest.java
+++ b/src/test/java/io/fabric8/maven/docker/util/DockerFileUtilTest.java
@@ -32,6 +32,7 @@
 import static io.fabric8.maven.docker.util.PathTestUtil.createTmpFile;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
 
 /**
  * @author roland
@@ -133,6 +134,11 @@ public void testMultiStageNamedWithDuplicates() throws Exception {
     public void testResolveArgValueFromStrContainingArgKey() {
         assertEquals("latest", DockerFileUtil.resolveArgValueFromStrContainingArgKey("$VERSION", Collections.singletonMap("VERSION", "latest")));
         assertEquals("test", DockerFileUtil.resolveArgValueFromStrContainingArgKey("${project.scope}", Collections.singletonMap("project.scope", "test")));
+        assertEquals("test", DockerFileUtil.resolveArgValueFromStrContainingArgKey("$ad", Collections.singletonMap("ad", "test")));
+        assertNull(DockerFileUtil.resolveArgValueFromStrContainingArgKey("bla$ad", Collections.singletonMap("ad", "test")));
+        assertNull(DockerFileUtil.resolveArgValueFromStrContainingArgKey("${foo}bar", Collections.singletonMap("foo", "test")));
+        assertNull(DockerFileUtil.resolveArgValueFromStrContainingArgKey("bar${foo}", Collections.singletonMap("foo", "test")));
+        assertNull(DockerFileUtil.resolveArgValueFromStrContainingArgKey("$ad", Collections.emptyMap()));
     }
 
     private File copyToTempDir(String resource) throws IOException {