From 9feac719e5657b75fdb75234d364f4a1ff92ba7c Mon Sep 17 00:00:00 2001
From: Silvio Giebl <gieblsilvio@outlook.com>
Date: Fri, 13 Dec 2024 13:16:51 +0100
Subject: [PATCH] Handle logging output of DockerLayerTask

---
 .../oci/internal/string/LineOutputStream.kt   | 86 +++++++++++++++++++
 .../gradle/oci/layer/DockerLayerTask.kt       | 13 +++
 2 files changed, 99 insertions(+)
 create mode 100644 src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/string/LineOutputStream.kt

diff --git a/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/string/LineOutputStream.kt b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/string/LineOutputStream.kt
new file mode 100644
index 00000000..bd12a2d8
--- /dev/null
+++ b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/internal/string/LineOutputStream.kt
@@ -0,0 +1,86 @@
+package io.github.sgtsilvio.gradle.oci.internal.string
+
+import java.io.OutputStream
+
+private const val CR = '\r'.code.toByte()
+private const val LF = '\n'.code.toByte()
+
+/**
+ * Interprets an output stream as UTF-8 lines.
+ * Supports LF, CR LF and CR line endings.
+ */
+internal class LineOutputStream(private val consumer: (String) -> Unit) : OutputStream() {
+
+    private val buffer = ByteStringBuilder()
+    private var lastCR = false
+
+    override fun write(b: Int) = write(byteArrayOf(b.toByte()))
+
+    override fun write(b: ByteArray, off: Int, len: Int) {
+        val end = off + len
+        if ((len < 0) || (off < 0) || (off > b.size) || (end < 0) || (end > b.size)) {
+            throw IndexOutOfBoundsException()
+        }
+        var start = off
+        var i = off
+        while (i < end) {
+            when (b[i]) {
+                LF -> {
+                    if (!lastCR) {
+                        consumer(buffer.toString(b, start, i))
+                    }
+                    start = i + 1
+                    lastCR = false
+                }
+                CR -> {
+                    consumer(buffer.toString(b, start, i))
+                    start = i + 1
+                    lastCR = true
+                }
+                else -> {
+                    lastCR = false
+                }
+            }
+            i++
+        }
+        buffer.append(b, start, end)
+    }
+
+    override fun close() {
+        if (buffer.size > 0) {
+            consumer(buffer.toString())
+        }
+    }
+}
+
+private class ByteStringBuilder {
+
+    private var buffer = ByteArray(0)
+    var size = 0
+        private set
+
+    fun append(b: ByteArray, fromIndex: Int, toIndex: Int) {
+        val additionalSize = toIndex - fromIndex
+        if (additionalSize == 0) {
+            return
+        }
+        val currentSize = size
+        val newSize = currentSize + additionalSize
+        if (newSize > buffer.size) {
+            buffer = buffer.copyOf(newSize)
+        }
+        System.arraycopy(b, fromIndex, buffer, currentSize, additionalSize)
+        size = newSize
+    }
+
+    fun toString(b: ByteArray, fromIndex: Int, toIndex: Int): String {
+        return if (size == 0) {
+            String(b, fromIndex, toIndex - fromIndex)
+        } else {
+            append(b, fromIndex, toIndex)
+            toString()
+        }
+    }
+
+    override fun toString() = String(buffer, 0, size).also { size = 0 }
+}
diff --git a/src/main/kotlin/io/github/sgtsilvio/gradle/oci/layer/DockerLayerTask.kt b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/layer/DockerLayerTask.kt
index f57c0f41..b480e73f 100644
--- a/src/main/kotlin/io/github/sgtsilvio/gradle/oci/layer/DockerLayerTask.kt
+++ b/src/main/kotlin/io/github/sgtsilvio/gradle/oci/layer/DockerLayerTask.kt
@@ -1,6 +1,7 @@
 package io.github.sgtsilvio.gradle.oci.layer
 
 import io.github.sgtsilvio.gradle.oci.internal.copyspec.DEFAULT_MODIFICATION_TIME
+import io.github.sgtsilvio.gradle.oci.internal.string.LineOutputStream
 import io.github.sgtsilvio.gradle.oci.platform.Platform
 import org.apache.commons.compress.archivers.tar.TarArchiveInputStream
 import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream
@@ -50,14 +51,18 @@ abstract class DockerLayerTask @Inject constructor(private val execOperations: E
         execOperations.exec {
             commandLine("docker", "build", "-", "--platform", platformArgument, "-t", imageReference, "--no-cache")
             standardInput = ByteArrayInputStream(assembleDockerfile().toByteArray())
+            errorOutput = createErrorStream()
         }
         val temporaryDirectory = temporaryDir
         val savedImageTarFile = temporaryDirectory.resolve("image.tar")
         execOperations.exec {
             commandLine("docker", "save", imageReference, "-o", savedImageTarFile)
+            errorOutput = createErrorStream()
         }
         execOperations.exec {
             commandLine("docker", "rmi", imageReference)
+            standardOutput = LineOutputStream { logger.info(it) }
+            errorOutput = createErrorStream()
         }
         val manifest = TarArchiveInputStream(FileInputStream(savedImageTarFile)).use { savedImageTarInputStream ->
             if (!savedImageTarInputStream.findEntry("manifest.json")) {
@@ -113,6 +118,14 @@ abstract class DockerLayerTask @Inject constructor(private val execOperations: E
         return if (variant.isEmpty()) s else "$s/$variant"
     }
 
+    private fun createErrorStream() = LineOutputStream { line ->
+        if (line.startsWith("ERROR")) {
+            logger.error(line)
+        } else {
+            logger.info(line)
+        }
+    }
+
     private fun TarArchiveInputStream.findEntry(path: String): Boolean {
         while (nextEntry != null) {
             if (currentEntry.name == path) {