quarkusio · yrodiere · Oct 10, 2024
diff --git a/...a/io/quarkus/annotation/processor/documentation/config/discovery/DiscoveryConfigRoot.java b/...a/io/quarkus/annotation/processor/documentation/config/discovery/DiscoveryConfigRoot.java
@@ -1,5 +1,7 @@
 package io.quarkus.annotation.processor.documentation.config.discovery;
 
+import java.util.Map;
+
 import io.quarkus.annotation.processor.documentation.config.model.ConfigPhase;
 import io.quarkus.annotation.processor.documentation.config.model.Extension;
 
@@ -14,16 +16,19 @@ public final class DiscoveryConfigRoot extends DiscoveryRootElement {
     private final String overriddenDocPrefix;
     private final ConfigPhase phase;
     private final String overriddenDocFileName;
+    private final Map<String, String> attributes;
 
     public DiscoveryConfigRoot(Extension extension, String prefix, String overriddenDocPrefix,
             String binaryName, String qualifiedName,
-            ConfigPhase configPhase, String overriddenDocFileName, boolean configMapping) {
+            ConfigPhase configPhase, String overriddenDocFileName, boolean configMapping,
+            Map<String, String> attributes) {
         super(extension, binaryName, qualifiedName, configMapping);
 
         this.prefix = prefix;
         this.overriddenDocPrefix = overriddenDocPrefix;
         this.phase = configPhase;
         this.overriddenDocFileName = overriddenDocFileName;
+        this.attributes = attributes;
     }
 
     public String getPrefix() {
@@ -42,6 +47,10 @@ public String getOverriddenDocFileName() {
         return overriddenDocFileName;
     }
 
+    public Map<String, String> getAttributes() {
+        return attributes;
+    }
+
     public String toString() {
         return toString("");
     }
@@ -53,6 +62,9 @@ public String toString(String prefix) {
         if (overriddenDocFileName != null) {
             sb.append(prefix + "overriddenDocFileName = " + this.overriddenDocFileName + "\n");
         }
+        if (!attributes.isEmpty()) {
+            sb.append(prefix + "attributes = " + this.attributes + "\n");
+        }
         sb.append(super.toString(prefix));
 
         return sb.toString();

diff --git a/...java/io/quarkus/annotation/processor/documentation/config/model/ConfigItemCollection.java b/...java/io/quarkus/annotation/processor/documentation/config/model/ConfigItemCollection.java
@@ -1,6 +1,7 @@
 package io.quarkus.annotation.processor.documentation.config.model;
 
 import java.util.List;
+import java.util.Map;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
@@ -33,6 +34,8 @@ default List<AbstractConfigItem> getNonDeprecatedSections() {
 
     void addItem(AbstractConfigItem item);
 
+    Map<String, String> getAttributes();
+
     boolean hasDurationType();
 
     boolean hasMemorySizeType();

diff --git a/.../src/main/java/io/quarkus/annotation/processor/documentation/config/model/ConfigRoot.java b/.../src/main/java/io/quarkus/annotation/processor/documentation/config/model/ConfigRoot.java
@@ -24,13 +24,18 @@ public class ConfigRoot implements ConfigItemCollection {
     private final String topLevelPrefix;
 
     private final String overriddenDocFileName;
+    private final Map<String, String> attributes = new HashMap<>();
     private final List<AbstractConfigItem> items = new ArrayList<>();
     private final Set<String> qualifiedNames = new HashSet<>();
 
-    public ConfigRoot(Extension extension, String prefix, String overriddenDocPrefix, String overriddenDocFileName) {
+    public ConfigRoot(Extension extension, String prefix, String overriddenDocPrefix, String overriddenDocFileName,
+            Map<String, String> attributes) {
         this.extension = extension;
         this.prefix = prefix;
         this.overriddenDocFileName = overriddenDocFileName;
+        if (attributes != null) {
+            this.attributes.putAll(attributes);
+        }
         this.topLevelPrefix = overriddenDocPrefix != null ? buildTopLevelPrefix(overriddenDocPrefix)
                 : buildTopLevelPrefix(prefix);
     }
@@ -47,6 +52,11 @@ public String getOverriddenDocFileName() {
         return overriddenDocFileName;
     }
 
+    @Override
+    public Map<String, String> getAttributes() {
+        return attributes;
+    }
+
     public void addQualifiedName(String qualifiedName) {
         qualifiedNames.add(qualifiedName);
     }
@@ -92,6 +102,8 @@ public void merge(ConfigRoot other) {
         }
 
         Collections.sort(this.items);
+
+        this.attributes.putAll(other.getAttributes());
     }
 
     private void collectConfigSections(Map<String, ConfigSection> configSections, ConfigItemCollection configItemCollection) {

diff --git a/...c/main/java/io/quarkus/annotation/processor/documentation/config/model/ConfigSection.java b/...c/main/java/io/quarkus/annotation/processor/documentation/config/model/ConfigSection.java
@@ -28,6 +28,11 @@ public List<AbstractConfigItem> getItems() {
         return Collections.unmodifiableList(items);
     }
 
+    @Override
+    public Map<String, String> getAttributes() {
+        return Map.of(); // Sections can't have attributes at the moment.
+    }
+
     @Override
     public int compareTo(AbstractConfigItem o) {
         if (o instanceof ConfigProperty) {

diff --git a/...in/java/io/quarkus/annotation/processor/documentation/config/resolver/ConfigResolver.java b/...in/java/io/quarkus/annotation/processor/documentation/config/resolver/ConfigResolver.java
@@ -71,7 +71,8 @@ public ResolvedModel resolveModel() {
 
         for (DiscoveryConfigRoot discoveryConfigRoot : configCollector.getConfigRoots()) {
             ConfigRoot configRoot = new ConfigRoot(discoveryConfigRoot.getExtension(), discoveryConfigRoot.getPrefix(),
-                    discoveryConfigRoot.getOverriddenDocPrefix(), discoveryConfigRoot.getOverriddenDocFileName());
+                    discoveryConfigRoot.getOverriddenDocPrefix(), discoveryConfigRoot.getOverriddenDocFileName(),
+                    discoveryConfigRoot.getAttributes());
             Map<String, ConfigSection> existingRootConfigSections = new HashMap<>();
 
             configRoot.addQualifiedName(discoveryConfigRoot.getQualifiedName());

diff --git a/...io/quarkus/annotation/processor/documentation/config/scanner/ConfigAnnotationScanner.java b/...io/quarkus/annotation/processor/documentation/config/scanner/ConfigAnnotationScanner.java
@@ -166,7 +166,8 @@ public void scanConfigMappingsWithoutConfigRoot(RoundEnvironment roundEnv, TypeE
                 DiscoveryConfigRoot discoveryConfigRoot = new DiscoveryConfigRoot(config.getExtension(), "dummy", "dummy",
                         utils.element().getBinaryName(configMappingWithoutConfigRoot),
                         configMappingWithoutConfigRoot.getQualifiedName().toString(),
-                        ConfigPhase.BUILD_TIME, null, true);
+                        ConfigPhase.BUILD_TIME, null, true,
+                        Map.of());
                 scanElement(configMappingWithoutConfigRootListeners, discoveryConfigRoot, configMappingWithoutConfigRoot);
             } catch (Exception e) {
                 throw new IllegalStateException(

diff --git a/...a/io/quarkus/annotation/processor/documentation/config/scanner/ConfigMappingListener.java b/...a/io/quarkus/annotation/processor/documentation/config/scanner/ConfigMappingListener.java
@@ -1,5 +1,8 @@
 package io.quarkus.annotation.processor.documentation.config.scanner;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
@@ -41,6 +44,7 @@ public Optional<DiscoveryConfigRoot> onConfigRoot(TypeElement configRoot) {
         AnnotationMirror configMappingAnnotion = null;
         AnnotationMirror configDocPrefixAnnotation = null;
         AnnotationMirror configDocFileNameAnnotation = null;
+        List<AnnotationMirror> configDocAttributeAnnotations = new ArrayList<>();
 
         for (AnnotationMirror annotationMirror : configRoot.getAnnotationMirrors()) {
             String annotationName = utils.element().getQualifiedName(annotationMirror.getAnnotationType());
@@ -61,6 +65,10 @@ public Optional<DiscoveryConfigRoot> onConfigRoot(TypeElement configRoot) {
                 configDocFileNameAnnotation = annotationMirror;
                 continue;
             }
+            if (annotationName.equals(Types.ANNOTATION_CONFIG_DOC_ATTRIBUTE)) {
+                configDocAttributeAnnotations.add(annotationMirror);
+                continue;
+            }
         }
 
         if (configRootAnnotation == null || configMappingAnnotion == null) {
@@ -106,12 +114,30 @@ public Optional<DiscoveryConfigRoot> onConfigRoot(TypeElement configRoot) {
             }
         }
 
+        Map<String, String> configDocAttributes = new HashMap<>();
+        for (AnnotationMirror configDocAttributeAnnotation : configDocAttributeAnnotations) {
+            String attributeName = null;
+            String attributeValue = null;
+            for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : configDocAttributeAnnotation
+                    .getElementValues()
+                    .entrySet()) {
+                if ("name()".equals(entry.getKey().toString())) {
+                    attributeName = entry.getValue().getValue().toString();
+                }
+                if ("value()".equals(entry.getKey().toString())) {
+                    attributeValue = entry.getValue().getValue().toString();
+                }
+            }
+            configDocAttributes.put(attributeName, attributeValue);
+        }
+
         String rootPrefix = ConfigNamingUtil.getRootPrefix(prefix, "", configRoot.getSimpleName().toString(), configPhase);
         String binaryName = utils.element().getBinaryName(configRoot);
 
         DiscoveryConfigRoot discoveryConfigRoot = new DiscoveryConfigRoot(config.getExtension(),
                 rootPrefix, overriddenDocPrefix,
-                binaryName, configRoot.getQualifiedName().toString(), configPhase, overriddenDocFileName, true);
+                binaryName, configRoot.getQualifiedName().toString(), configPhase, overriddenDocFileName, true,
+                configDocAttributes);
         configCollector.addConfigRoot(discoveryConfigRoot);
         return Optional.of(discoveryConfigRoot);
     }

diff --git a/...o/quarkus/annotation/processor/documentation/config/scanner/LegacyConfigRootListener.java b/...o/quarkus/annotation/processor/documentation/config/scanner/LegacyConfigRootListener.java
@@ -1,5 +1,8 @@
 package io.quarkus.annotation.processor.documentation.config.scanner;
 
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
@@ -42,6 +45,7 @@ public Optional<DiscoveryConfigRoot> onConfigRoot(TypeElement configRoot) {
         AnnotationMirror configRootAnnotation = null;
         AnnotationMirror configDocPrefixAnnotation = null;
         AnnotationMirror configDocFileNameAnnotation = null;
+        List<AnnotationMirror> configDocAttributeAnnotations = new ArrayList<>();
 
         for (AnnotationMirror annotationMirror : configRoot.getAnnotationMirrors()) {
             String annotationName = utils.element().getQualifiedName(annotationMirror.getAnnotationType());
@@ -58,6 +62,10 @@ public Optional<DiscoveryConfigRoot> onConfigRoot(TypeElement configRoot) {
                 configDocFileNameAnnotation = annotationMirror;
                 continue;
             }
+            if (annotationName.equals(Types.ANNOTATION_CONFIG_DOC_ATTRIBUTE)) {
+                configDocAttributeAnnotations.add(annotationMirror);
+                continue;
+            }
         }
 
         if (configRootAnnotation == null) {
@@ -103,13 +111,33 @@ public Optional<DiscoveryConfigRoot> onConfigRoot(TypeElement configRoot) {
             }
         }
 
+        Map<String, String> configDocAttributes = new HashMap<>();
+        for (AnnotationMirror configDocAttributeAnnotation : configDocAttributeAnnotations) {
+            String attributeName = null;
+            String attributeValue = null;
+            for (Map.Entry<? extends ExecutableElement, ? extends AnnotationValue> entry : configDocAttributeAnnotation
+                    .getElementValues()
+                    .entrySet()) {
+                if ("name()".equals(entry.getKey().toString())) {
+                    attributeName = entry.getValue().getValue().toString();
+                    break;
+                }
+                if ("value()".equals(entry.getKey().toString())) {
+                    attributeValue = entry.getValue().getValue().toString();
+                    break;
+                }
+            }
+            configDocAttributes.put(attributeName, attributeValue);
+        }
+
         String rootPrefix = ConfigNamingUtil.getRootPrefix(prefix, name, configRoot.getSimpleName().toString(), configPhase);
         String binaryName = utils.element().getBinaryName(configRoot);
 
         DiscoveryConfigRoot discoveryConfigRoot = new DiscoveryConfigRoot(config.getExtension(),
                 rootPrefix, overriddenDocPrefix,
                 binaryName, configRoot.getQualifiedName().toString(),
-                configPhase, overriddenDocFileName, false);
+                configPhase, overriddenDocFileName, false,
+                configDocAttributes);
         configCollector.addConfigRoot(discoveryConfigRoot);
         return Optional.of(discoveryConfigRoot);
     }

diff --git a/...cessor/src/main/java/io/quarkus/annotation/processor/documentation/config/util/Types.java b/...cessor/src/main/java/io/quarkus/annotation/processor/documentation/config/util/Types.java
@@ -32,6 +32,7 @@ private Types() {
     public static final String ANNOTATION_CONFIG_DOC_FILE_NAME = "io.quarkus.runtime.annotations.ConfigDocFilename";
     public static final String ANNOTATION_CONFIG_DOC_PREFIX = "io.quarkus.runtime.annotations.ConfigDocPrefix";
     public static final String ANNOTATION_CONFIG_DOC_ENUM = "io.quarkus.runtime.annotations.ConfigDocEnum";
+    public static final String ANNOTATION_CONFIG_DOC_ATTRIBUTE = "io.quarkus.runtime.annotations.ConfigDocAttribute";
 
     public static final String ANNOTATION_CONFIG_WITH_CONVERTER = "io.smallrye.config.WithConverter";
     public static final String ANNOTATION_CONFIG_WITH_NAME = "io.smallrye.config.WithName";

diff --git a/core/runtime/src/main/java/io/quarkus/runtime/annotations/ConfigDocAttribute.java b/core/runtime/src/main/java/io/quarkus/runtime/annotations/ConfigDocAttribute.java
@@ -0,0 +1,39 @@
+package io.quarkus.runtime.annotations;
+
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * A way to set <a href="https://docs.asciidoctor.org/asciidoc/latest/attributes/attribute-entries/" asciidoc attributes}
+ * (variables) at the start of generated documentation.
+ * <p>
+ * Only taken into account on config roots.
+ * <p>
+ * Each attribute will be rendered as a single line: {@code :name: value}.
+ * <p>
+ * Especially useful for injecting content (e.g. link roots) into documentation
+ * of config groups reused from another extension.
+ * For example a declaration such as {@code @ConfigDocAttribute(name = "myname", value = "myvalue")}
+ * can be referenced in Javadoc that uses {@code @asciidoclet}
+ * with the attribute reference {@code {myname}}.
+ */
+@Retention(RUNTIME)
+@Target(TYPE)
+@Documented
+public @interface ConfigDocAttribute {
+
+    /**
+     * @return The name of the attribute in generated documentation.
+     */
+    String name();
+
+    /**
+     * @return The value of the attribute in generated documentation.
+     */
+    String value();
+
+}
diff --git a/...-maven-plugin/src/main/resources/templates/asciidoc/default/allConfig.qute.adoc b/...-maven-plugin/src/main/resources/templates/asciidoc/default/allConfig.qute.adoc
@@ -9,13 +9,19 @@ h|Type
 h|Default
 
 {#for configRootEntry in extensionConfigRootsEntry.value}
+
 {#if configRootEntry.value.nonDeprecatedItems}
 {#let displayConfigRootDescription=configRootEntry.key.displayConfigRootDescription(extensionConfigRootsEntry.value.size)}
 {#if displayConfigRootDescription}
 h|[.configroot-name]##{configRootEntry.key.description.escapeCellContent}##
 h|Type
 h|Default
 
+{! TODO: Asciidoc only supports defining attributes outside of delimited blocks, so this won't work. !}
+{#for attributeEntry in configRootEntry.value.attributes}
+:{attributeEntry.key}: {attributeEntry.value}
+{/for}
+
 {/if}
 {#for item in configRootEntry.value.items}
 {#if !item.deprecated}

diff --git a/...-plugin/src/main/resources/templates/asciidoc/default/configReference.qute.adoc b/...-plugin/src/main/resources/templates/asciidoc/default/configReference.qute.adoc
@@ -1,3 +1,8 @@
+{! Asciidoc only supports defining attributes outside of delimited blocks !}
+{#for attributeEntry in configItemCollection.attributes}
+:{attributeEntry.key}: {attributeEntry.value}
+{/for}
+
 [.configuration-legend]
 icon:lock[title=Fixed at build time] Configuration property fixed at build time - All other configuration properties are overridable at runtime
 [.configuration-reference{#if searchable}.searchable{/if}, cols="80,.^10,.^10"]