Fixes and enhancements to native dependencies resolution.

Author: fabiocav

src/WebJobs.Script/Description/DotNet/DependencyHelper.cs

@@ -0,0 +1,108 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the MIT License. See License.txt in the project root for license information.
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using Microsoft.Extensions.DependencyModel;
+using Newtonsoft.Json.Linq;
+
+namespace Microsoft.Azure.WebJobs.Script.Description
+{
+    public static class DependencyHelper
+    {
+        private static readonly Lazy<Dictionary<string, string[]>> _ridGraph = new Lazy<Dictionary<string, string[]>>(BuildRuntimesGraph);
+
+        private static Dictionary<string, string[]> BuildRuntimesGraph()
+        {
+            var ridGraph = new Dictionary<string, string[]>();
+            string runtimesJson = GetRuntimesGraphJson();
+            var runtimes = (JObject)JObject.Parse(runtimesJson)["runtimes"];
+
+            foreach (var runtime in runtimes)
+            {
+                string[] imports = ((JObject)runtime.Value)["#import"]
+                    ?.Values<string>()
+                    .ToArray();
+
+                ridGraph.Add(runtime.Key, imports);
+            }
+
+            return ridGraph;
+        }
+
+        public static IEnumerable<string> GetFallbacks(Dictionary<string, string[]> ridGraph, string rid)
+        {
+            var fallbacks = new HashSet<string>();
+            var queue = new Queue<string>(ridGraph[rid]);
+
+            while (queue.Count > 0)
+            {
+                var currentRid = queue.Dequeue();
+
+                if (fallbacks.Contains(currentRid))
+                {
+                    continue;
+                }
+
+                fallbacks.Add(currentRid);
+
+                foreach (var fallbackRid in ridGraph[currentRid])
+                {
+                    if (!fallbacks.Contains(fallbackRid))
+                    {
+                        queue.Enqueue(fallbackRid);
+                    }
+                }
+            }
+
+            return fallbacks;
+        }
+
+        private static string GetRuntimeAssembliesJson()
+        {
+            return GetResourceFileContents("runtimeassemblies.json");
+        }
+
+        private static string GetRuntimesGraphJson()
+        {
+            return GetResourceFileContents("runtimes.json");
+        }
+
+        private static string GetResourceFileContents(string fileName)
+        {
+            var assembly = typeof(DependencyHelper).Assembly;
+            using (Stream resource = assembly.GetManifestResourceStream($"{assembly.GetName().Name}.{fileName}"))
+            using (var reader = new StreamReader(resource))
+            {
+                return reader.ReadToEnd();
+            }
+        }
+
+        internal static Dictionary<string, ScriptRuntimeAssembly> GetRuntimeAssemblies()
+        {
+            string assembliesJson = GetRuntimeAssembliesJson();
+            JObject assemblies = JObject.Parse(assembliesJson);
+
+            return assemblies["runtimeAssemblies"]
+                .ToObject<ScriptRuntimeAssembly[]>()
+                .ToDictionary(a => a.Name, StringComparer.OrdinalIgnoreCase);
+        }
+
+        /// <summary>
+        /// Gets the default runtime fallback RIDs for a given RID.
+        /// The graph used to build the fallback list is static and
+        /// useful in self-contained scenarios, where this information
+        /// is not available at runtime
+        /// </summary>
+        /// <param name="rid">The runtime identifier to lookup.</param>
+        /// <returns>The runtime fallbacks for the provided identifier.</returns>
+        public static RuntimeFallbacks GetDefaultRuntimeFallbacks(string rid)
+        {
+            IEnumerable<string> fallbacks = GetFallbacks(_ridGraph.Value, rid);
+
+            return new RuntimeFallbacks(rid, fallbacks);
+        }
+    }
+}

src/WebJobs.Script/Description/DotNet/FunctionAssemblyLoadContext.cs

@@ -24,7 +24,7 @@ namespace Microsoft.Azure.WebJobs.Script.Description
     /// </summary>
     public partial class FunctionAssemblyLoadContext : AssemblyLoadContext
     {
-        private static readonly Lazy<Dictionary<string, ScriptRuntimeAssembly>> _runtimeAssemblies = new Lazy<Dictionary<string, ScriptRuntimeAssembly>>(GetRuntimeAssemblies);
+        private static readonly Lazy<Dictionary<string, ScriptRuntimeAssembly>> _runtimeAssemblies = new Lazy<Dictionary<string, ScriptRuntimeAssembly>>(DependencyHelper.GetRuntimeAssemblies);
         private static readonly Lazy<Dictionary<string, ResolutionPolicyEvaluator>> _resolutionPolicyEvaluators = new Lazy<Dictionary<string, ResolutionPolicyEvaluator>>(InitializeLoadPolicyEvaluators);
         private static Lazy<FunctionAssemblyLoadContext> _defaultContext = new Lazy<FunctionAssemblyLoadContext>(() => new FunctionAssemblyLoadContext(ResolveFunctionBaseProbingPath()), true);
 
@@ -201,16 +201,26 @@ private string GetRuntimeAssetPath(string assetFileName, bool isNativeAsset)
             string ridSubFolder = isNativeAsset ? "native" : string.Empty;
             string runtimesPath = Path.Combine(basePath, "runtimes");
 
+            List<string> rids = GetRuntimeFallbacks();
+
+            return rids.Select(r => Path.Combine(runtimesPath, r, ridSubFolder, assetFileName))
+                .Union(_probingPaths)
+                .FirstOrDefault(p => File.Exists(p));
+        }
+
+        private static List<string> GetRuntimeFallbacks()
+        {
             string currentRuntimeIdentifier = GetRuntimeIdentifier();
+
             RuntimeFallbacks fallbacks = DependencyContext.Default
                 .RuntimeGraph
-                .FirstOrDefault(f => string.Equals(f.Runtime, currentRuntimeIdentifier, StringComparison.OrdinalIgnoreCase));
+                .FirstOrDefault(f => string.Equals(f.Runtime, currentRuntimeIdentifier, StringComparison.OrdinalIgnoreCase))
+                ?? DependencyHelper.GetDefaultRuntimeFallbacks(currentRuntimeIdentifier)
+                ?? new RuntimeFallbacks("any");
 
             var rids = new List<string> { fallbacks.Runtime };
             rids.AddRange(fallbacks.Fallbacks);
-
-            return rids.Select(r => Path.Combine(runtimesPath, r, ridSubFolder, assetFileName))
-                .FirstOrDefault(p => File.Exists(p));
+            return rids;
         }
 
         internal string GetUnmanagedLibraryFileName(string unmanagedLibraryName)
@@ -263,25 +273,5 @@ protected static string ResolveFunctionBaseProbingPath()
 
             return Path.Combine(basePath, "bin");
         }
-
-        private static Dictionary<string, ScriptRuntimeAssembly> GetRuntimeAssemblies()
-        {
-            string assembliesJson = GetRuntimeAssembliesJson();
-            JObject assemblies = JObject.Parse(assembliesJson);
-
-            return assemblies["runtimeAssemblies"]
-                .ToObject<ScriptRuntimeAssembly[]>()
-                .ToDictionary(a => a.Name, StringComparer.OrdinalIgnoreCase);
-        }
-
-        private static string GetRuntimeAssembliesJson()
-        {
-            var assembly = typeof(FunctionAssemblyLoadContext).Assembly;
-            using (Stream resource = assembly.GetManifestResourceStream(assembly.GetName().Name + ".runtimeassemblies.json"))
-            using (var reader = new StreamReader(resource))
-            {
-                return reader.ReadToEnd();
-            }
-        }
     }
 }

src/WebJobs.Script/WebJobs.Script.csproj

@@ -12,11 +12,13 @@
   </PropertyGroup>
   <ItemGroup>
     <None Remove="runtimeassemblies.json" />
+    <None Remove="runtimes.json" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="runtimeassemblies.json">
       <CopyToOutputDirectory>Never</CopyToOutputDirectory>
     </EmbeddedResource>
+    <EmbeddedResource Include="runtimes.json" />
   </ItemGroup>
 
   <ItemGroup>