Initial provider implementation (#18)

This brings over the initial buildx prototype from pulumi/pulumi-docker
and fixes various build and release issues.

sdk/dotnet/Outputs/CacheFrom.cs

@@ -0,0 +1,75 @@
+// *** WARNING: this file was generated by pulumi. ***
+// *** Do not edit by hand unless you're certain you know what you are doing! ***
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Threading.Tasks;
+using Pulumi.Serialization;
+
+namespace Pulumi.DockerBuild.Outputs
+{
+
+    [OutputType]
+    public sealed class CacheFrom
+    {
+        /// <summary>
+        /// Upload build caches to Azure's blob storage service.
+        /// </summary>
+        public readonly Outputs.CacheFromAzureBlob? Azblob;
+        /// <summary>
+        /// When `true` this entry will be excluded. Defaults to `false`.
+        /// </summary>
+        public readonly bool? Disabled;
+        /// <summary>
+        /// Recommended for use with GitHub Actions workflows.
+        /// 
+        /// An action like `crazy-max/ghaction-github-runtime` is recommended to
+        /// expose appropriate credentials to your GitHub workflow.
+        /// </summary>
+        public readonly Outputs.CacheFromGitHubActions? Gha;
+        /// <summary>
+        /// A simple backend which caches images on your local filesystem.
+        /// </summary>
+        public readonly Outputs.CacheFromLocal? Local;
+        /// <summary>
+        /// A raw string as you would provide it to the Docker CLI (e.g.,
+        /// `type=inline`).
+        /// </summary>
+        public readonly string? Raw;
+        /// <summary>
+        /// Upload build caches to remote registries.
+        /// </summary>
+        public readonly Outputs.CacheFromRegistry? Registry;
+        /// <summary>
+        /// Upload build caches to AWS S3 or an S3-compatible services such as
+        /// MinIO.
+        /// </summary>
+        public readonly Outputs.CacheFromS3? S3;
+
+        [OutputConstructor]
+        private CacheFrom(
+            Outputs.CacheFromAzureBlob? azblob,
+
+            bool? disabled,
+
+            Outputs.CacheFromGitHubActions? gha,
+
+            Outputs.CacheFromLocal? local,
+
+            string? raw,
+
+            Outputs.CacheFromRegistry? registry,
+
+            Outputs.CacheFromS3? s3)
+        {
+            Azblob = azblob;
+            Disabled = disabled;
+            Gha = gha;
+            Local = local;
+            Raw = raw;
+            Registry = registry;
+            S3 = s3;
+        }
+    }
+}