Move ConfigurationContext one level up to enable configurable max ali…

…ases config

This needs to be a property/env since the context is not yet configurable as it has yet to read any YAML
and it might be blocked due to alias limit.

Adding the reading of the property/env to ConfigurationContext
makes sense to avoid YamlUtils to constantly reading the property on every file read
when it attempts to merge all the sources.

plugin/src/main/java/io/jenkins/plugins/casc/ConfigurationAsCode.java

@@ -614,7 +614,8 @@ public void configureWith(YamlSource source) throws ConfiguratorException {
 
     private void configureWith(List<YamlSource> sources) throws ConfiguratorException {
         lastTimeLoaded = System.currentTimeMillis();
-        configureWith( YamlUtils.loadFrom(sources) );
+        ConfigurationContext context = new ConfigurationContext(registry);
+        configureWith(YamlUtils.loadFrom(sources, context), context);
         closeSources(sources);
     }
 
@@ -627,7 +628,8 @@ public Map<Source, String> checkWith(YamlSource source) throws ConfiguratorExcep
 
     private Map<Source, String> checkWith(List<YamlSource> sources) throws ConfiguratorException {
         if (sources.isEmpty()) return Collections.emptyMap();
-        return checkWith( YamlUtils.loadFrom(sources) );
+        ConfigurationContext context = new ConfigurationContext(registry);
+        return checkWith(YamlUtils.loadFrom(sources, context), context);
     }
 
     private void closeSources(List<YamlSource> sources) {
@@ -727,27 +729,28 @@ private static void detectVaultPluginMissing() {
         }
     }
 
-    private void configureWith(Mapping entries) throws ConfiguratorException {
+    private void configureWith(Mapping entries,
+        ConfigurationContext context) throws ConfiguratorException {
         // Initialize secret sources
         SecretSource.all().forEach(SecretSource::init);
 
         // Check input before actually applying changes,
         // so we don't let master in a weird state after some ConfiguratorException has been thrown
         final Mapping clone = entries.clone();
-        checkWith(clone);
+        checkWith(clone, context);
 
         final ObsoleteConfigurationMonitor monitor = ObsoleteConfigurationMonitor.get();
         monitor.reset();
-        ConfigurationContext context = new ConfigurationContext(registry);
+        context.clearListeners();
         context.addListener(monitor::record);
         try (ACLContext acl = ACL.as(ACL.SYSTEM)) {
             invokeWith(entries, (configurator, config) -> configurator.configure(config, context));
         }
     }
 
-    public Map<Source, String> checkWith(Mapping entries) throws ConfiguratorException {
+    public Map<Source, String> checkWith(Mapping entries,
+        ConfigurationContext context) throws ConfiguratorException {
         Map<Source, String> issues = new HashMap<>();
-        ConfigurationContext context = new ConfigurationContext(registry);
         context.addListener( (node,message) -> issues.put(node.getSource(), message) );
         invokeWith(entries, (configurator, config) -> configurator.check(config, context));
         return issues;

plugin/src/main/java/io/jenkins/plugins/casc/ConfigurationContext.java

@@ -2,10 +2,12 @@
 
 import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
+import hudson.Util;
 import io.jenkins.plugins.casc.model.CNode;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.List;
+import org.apache.commons.lang.math.NumberUtils;
 import org.kohsuke.stapler.Stapler;
 
 /**
@@ -14,9 +16,12 @@
 
 public class ConfigurationContext implements ConfiguratorRegistry {
 
+    public static final String CASC_YAML_MAX_ALIASES_ENV = "CASC_YAML_MAX_ALIASES";
+    public static final String CASC_YAML_MAX_ALIASES_PROPERTY = "casc.yaml.max.aliases";
     private Deprecation deprecation = Deprecation.reject;
     private Restriction restriction = Restriction.reject;
     private Unknown unknown = Unknown.reject;
+    private final int yamlMaxAliasesForCollections;
 
     /**
      * the model-introspection model to be applied by configuration-as-code.
@@ -34,12 +39,21 @@ public class ConfigurationContext implements ConfiguratorRegistry {
 
     public ConfigurationContext(ConfiguratorRegistry registry) {
         this.registry = registry;
+        String prop = Util.fixEmptyAndTrim(System.getProperty(
+            CASC_YAML_MAX_ALIASES_PROPERTY,
+            System.getenv(CASC_YAML_MAX_ALIASES_ENV)
+        ));
+        yamlMaxAliasesForCollections = NumberUtils.toInt(prop, 50);
     }
 
     public void addListener(Listener listener) {
         listeners.add(listener);
     }
 
+    public void clearListeners() {
+        listeners.clear();
+    }
+
     public void warning(@NonNull CNode node, @NonNull String message) {
         for (Listener listener : listeners) {
             listener.warning(node, message);
@@ -72,7 +86,9 @@ public void setMode(String mode) {
         this.mode = mode;
     }
 
-
+    public int getYamlMaxAliasesForCollections() {
+        return yamlMaxAliasesForCollections;
+    }
 
     // --- delegate methods for ConfigurationContext
 

plugin/src/main/java/io/jenkins/plugins/casc/yaml/YamlUtils.java

@@ -1,6 +1,7 @@
 package io.jenkins.plugins.casc.yaml;
 
 import io.jenkins.plugins.casc.ConfigurationAsCode;
+import io.jenkins.plugins.casc.ConfigurationContext;
 import io.jenkins.plugins.casc.ConfiguratorException;
 import io.jenkins.plugins.casc.model.Mapping;
 import java.io.IOException;
@@ -27,12 +28,13 @@ public final class YamlUtils {
 
     public static final Logger LOGGER = Logger.getLogger(ConfigurationAsCode.class.getName());
 
-    public static Node merge(List<YamlSource> configs) throws ConfiguratorException {
+    public static Node merge(List<YamlSource> configs,
+        ConfigurationContext context) throws ConfiguratorException {
         Node root = null;
         for (YamlSource source : configs) {
             try (Reader r = source.read()) {
 
-                final Node node = read(source);
+                final Node node = read(source, context);
 
                 if (root == null) {
                     root = node;
@@ -49,9 +51,9 @@ public static Node merge(List<YamlSource> configs) throws ConfiguratorException
         return root;
     }
 
-    public static Node read(YamlSource source) throws IOException {
+    public static Node read(YamlSource source, ConfigurationContext context) throws IOException {
         LoaderOptions loaderOptions = new LoaderOptions();
-        loaderOptions.setMaxAliasesForCollections(100);
+        loaderOptions.setMaxAliasesForCollections(context.getYamlMaxAliasesForCollections());
         Composer composer = new Composer(
             new ParserImpl(new StreamReaderWithSource(source)),
             new Resolver(),
@@ -108,9 +110,10 @@ private static void merge(Node root, Node node, String source) throws Configurat
     /**
      * Load configuration-as-code model from a set of Yaml sources, merging documents
      */
-    public static Mapping loadFrom(List<YamlSource> sources) throws ConfiguratorException {
+    public static Mapping loadFrom(List<YamlSource> sources,
+        ConfigurationContext context) throws ConfiguratorException {
         if (sources.isEmpty()) return Mapping.EMPTY;
-        final Node merged = merge(sources);
+        final Node merged = merge(sources, context);
         if (merged == null) {
             LOGGER.warning("configuration-as-code yaml source returned an empty document.");
             return Mapping.EMPTY;