feat(core): Initial GET on CLI (re. #72)

ToDo.md

@@ -25,7 +25,8 @@
 1. `MarkdownGenerator.java` add Mermaid (like in `demo-model-docgen.md`)
 1. `MarkdownGenerator.java` https://github.com/google/closure-templates/issues/1300 ?
 
-1. Enforce https://www.conventionalcommits.org like git commit messages
+1. https://github.com/enola-dev/enola/issues/102 :
+   Enforce https://www.conventionalcommits.org like git commit messages
    starting with feat/model/fix/build/docs/clean/format/refactor: and core/k8s/tools:
    using https://github.com/jorisroovers/gitlint
 
@@ -82,11 +83,18 @@
 
 1. [Run `mkdocs build` instead of in `build.bash` as a `sh_test` in Bazel with `docs/**` + `mkdocs.yaml` as (only) `srcs`](https://github.com/enola-dev/enola/compare/main...vorburger:enola:mkdocs_build_test) - fix weird problems
 
-1. Proto design: Is this a real requirement, or can we forget about this: _"Note that IDs are not "unique", and 2 different IDs may refer to the same underlying object; for example: `k8s:pod?name=echoserver-6dfb6c7764-45gvk&...` and `k8s:pod?uid=561f1bec-f768-4c5b-b96e-37306d7f2f8a&...`"_
+1. Proto design: Is this a real requirement, or can we forget about this: _"Note that IDs are not "unique", and 2
+   different IDs may refer to the same underlying object; for example: `k8s:pod?name=echoserver-6dfb6c7764-45gvk&...`
+   and `k8s:pod?uid=561f1bec-f768-4c5b-b96e-37306d7f2f8a&...`"_
 
-1. Proto design: Should `EntityKind` have a _"param_parent, to allow grouping common ones, just during declaration in textproto, but inlined for use."_ or shall we forget about that?
+1. Proto design: Should `EntityKind` have a _"param_parent, to allow grouping common ones, just during declaration in
+   textproto, but inlined for use."_ or shall we forget about that?
 
-1. Proto design: Should we permit RPC clients to _"specify the ID in either (oneof)string text or "broken down" parts form. This is simply for dev convenience in UX such as CLI or Web UIs, and to avoid the proliferation of incompatible parsers. The implementation validates the text, and rejects e.g. "demo:foo?bad=a=b" or "demo:foo?bad=a&bad=b". The string text oneof form is NOT "decoded" like un-escaped (incl. un-quoted) at all, simply "split" ... ? There was `IDsTest.java` and `IDs.java` code related to this which I removed on 2023-03-19:_
+1. Proto design: Should we permit RPC clients to _"specify the ID in either (oneof)string text or "broken down" parts
+   form. This is simply for dev convenience in UX such as CLI or Web UIs, and to avoid the proliferation of incompatible
+   parsers. The implementation validates the text, and rejects e.g. "demo:foo?bad=a=b" or "demo:foo?bad=a&bad=b". The
+   string text oneof form is NOT "decoded" like un-escaped (incl. un-quoted) at all, simply "split" ... ? There
+   was `IDsTest.java` and `IDs.java` code related to this which I removed on 2023-03-19:_
 
        message ID {
            oneof oneof {

cli/BUILD.bazel

@@ -22,6 +22,8 @@ java_binary(
     main_class = "dev.enola.cli.Enola",
     deps = [
         "//common/common",
+        "//core/lib:core_proto_java_library",
+        "//core/lib:lib_java",
         "//core/impl",
         "@maven//:com_google_guava_guava",
         "@maven//:info_picocli_picocli",

cli/src/main/java/dev/enola/cli/Enola.java

@@ -35,7 +35,8 @@
         subcommands = {
             HelpCommand.class, // TODO , Version.class
             AutoComplete.GenerateCompletion.class,
-            DocGen.class
+            DocGen.class,
+            Get.class
         })
 public class Enola {
 

cli/src/main/java/dev/enola/cli/Get.java

@@ -0,0 +1,58 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2023 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.cli;
+
+import dev.enola.core.EnolaServiceRegistry;
+import dev.enola.core.IDs;
+import dev.enola.core.meta.EntityKindRepository;
+import dev.enola.core.proto.GetEntityRequest;
+import dev.enola.core.proto.ID;
+
+import picocli.CommandLine;
+import picocli.CommandLine.Model.CommandSpec;
+import picocli.CommandLine.Parameters;
+import picocli.CommandLine.Spec;
+
+@CommandLine.Command(name = "get", description = "Get Entity")
+public class Get extends CommandWithModel {
+
+    // TODO @Parameters(index = "0..*") List<String> ids;
+    // TODO ID instead of String, with https://picocli.info/#_strongly_typed_everything
+    @Parameters(index = "0", paramLabel = "id", description = "ID of Entity")
+    String idString;
+
+    @Spec CommandSpec spec;
+
+    @Override
+    protected void run(EntityKindRepository ekr) throws Exception {
+        // TODO Move this from CLI to Core?
+        EnolaServiceRegistry service = new EnolaServiceRegistry();
+        // TODO registry.register(...);
+
+        ID id = IDs.parse(idString); // TODO replace with ITypeConverter
+        // TODO Validate id; here it must have ns+name+path!
+
+        var request = GetEntityRequest.newBuilder().setId(id).build();
+        var response = service.getEntity(request);
+        var entity = response.getEntity();
+
+        // TODO Allow formatting it as JSON or YAML, via Resource!
+        // TODO What else do we do with the Entity?!
+        spec.commandLine().getOut().println(entity);
+    }
+}

cli/src/test/java/dev/enola/cli/EnolaTest.java

@@ -73,4 +73,17 @@ public void testDocGen() throws IOException {
             Truth.assertThat(r.charSource().read()).endsWith(MarkdownDocGenerator.FOOTER);
         }
     }
+
+    @Test
+    public void testGet() {
+        var exec =
+                cli(
+                        "-v",
+                        "get",
+                        "--model",
+                        "classpath:cli-test-model.textproto",
+                        "test:first/helo");
+        assertThat(exec).err().isEmpty();
+        assertThat(exec).hasExitCode(0).out().isEmpty();
+    }
 }

common/common/src/main/java/dev/enola/common/io/resource/EmptyResource.java

@@ -24,6 +24,7 @@
 import java.net.URI;
 
 class EmptyResource implements ReadableResource {
+    // TODO Perhaps rename this to VoidResource with void:/ URI?
 
     static final EmptyResource INSTANCE = new EmptyResource();
 

core/impl/src/main/java/dev/enola/core/EnolaServiceRegistry.java

@@ -0,0 +1,53 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2023 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.core;
+
+import dev.enola.core.proto.GetEntityRequest;
+import dev.enola.core.proto.GetEntityResponse;
+import dev.enola.core.proto.ID;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class EnolaServiceRegistry implements EnolaService {
+
+    private final Map<ID, EnolaService> registry;
+
+    public EnolaServiceRegistry() {
+        registry = new HashMap<>();
+    }
+
+    public void register(ID id, EnolaService service) {
+        var lookup = IDs.withoutPath(id);
+        var existing = registry.get(lookup);
+        if (existing != null) {
+            throw new IllegalArgumentException("Service already registered for: " + lookup);
+        }
+        registry.put(lookup, service);
+    }
+
+    @Override
+    public GetEntityResponse getEntity(GetEntityRequest r) {
+        var lookup = IDs.withoutPath(r.getId());
+        var delegate = registry.get(lookup);
+        if (delegate == null) {
+            throw new IllegalArgumentException("No Connector registered for: " + lookup);
+        }
+        return delegate.getEntity(r);
+    }
+}

core/impl/src/main/java/dev/enola/core/docgen/MarkdownDocGenerator.java

@@ -71,7 +71,7 @@ public void render(EntityKindRepository kinds, Appendable md) throws IOException
     }
 
     private void render(EntityKind ek, Appendable md) throws IOException {
-        ID idWithoutPathArguments = ID.newBuilder(ek.getId()).clearPaths().build();
+        ID idWithoutPathArguments = IDs.withoutPath(ek.getId());
         String fqn = IDs.toPath(idWithoutPathArguments);
         List<String> pathArguments =
                 ek.getId().getPathsList().stream().collect(Collectors.toList());

core/impl/src/main/java/dev/enola/core/docgen/MermaidGenerator.java

@@ -36,7 +36,7 @@ static void renderMermaid(EntityKindRepository kinds, Appendable md) throws IOEx
     }
 
     private static void renderMermaidEntity(EntityKind ek, Appendable md) throws IOException {
-        ID idWithoutPathArguments = ID.newBuilder(ek.getId()).clearPaths().build();
+        ID idWithoutPathArguments = IDs.withoutPath(ek.getId());
         String fqn = IDs.toPath(idWithoutPathArguments);
         String name = StringUtil.capitalize(idWithoutPathArguments.getEntity());
         List<String> pathArguments =

core/lib/BUILD.bazel

@@ -59,6 +59,7 @@ java_proto_library(
         "util_proto",
     ],
     visibility = [
+        "//cli:__subpackages__",
         "//connectors:__subpackages__",
         "//core:__subpackages__",
     ],
@@ -98,6 +99,7 @@ java_library(
     # TODO Required for https://github.com/google/closure-templates/issues/1300 or not?
     # resources = glob(["src/main/java/**/*.proto"]),
     visibility = [
+        "//cli:__subpackages__",
         "//connectors:__subpackages__",
         "//core:__subpackages__",
     ],

core/lib/src/main/java/dev/enola/core/IDs.java

@@ -38,14 +38,13 @@
  */
 public final class IDs {
 
-    private IDs() {}
-
     private static final String URI_SCHEME = "enola";
+    private static final Splitter SLASH_SPLITTER =
+            Splitter.on('/').omitEmptyStrings().trimResults();
 
     // private static final Joiner AMPERSAND_JOINER = Joiner.on('&').skipNulls();
 
-    private static final Splitter SLASH_SPLITTER =
-            Splitter.on('/').omitEmptyStrings().trimResults();
+    private IDs() {}
 
     public static ID parse(String s) {
         if (s.startsWith(URI_SCHEME)) {
@@ -196,4 +195,10 @@ public static String toQueryURI(ID id) {
             return sb.toString();
         }
     */
+
+    public static ID withoutPath(ID id) {
+        if (id == null) return null;
+        if (id.getPathsCount() == 0) return id;
+        return ID.newBuilder(id).clearPaths().build();
+    }
 }

core/lib/src/main/java/dev/enola/core/enola_core.proto

@@ -100,22 +100,25 @@ message GetEntityRequest {
 
   // Request to inline Entity#link, by the same string key as used there.
   // (Conceptually inspired by e.g. GraphQL architecture.)
-  repeated string inline_links = 2;
+  // TODO repeated string inline_links = 2;
 }
 message GetEntityResponse {
   Entity entity = 1;
 
-  repeated InlineLinkData data = 2;
-  message InlineLinkData {
-    oneof oneof {
-      google.protobuf.Any protos = 1;
-      string json = 2;
-    }
-  }
+  /*
+    TODO Think this through & implement it...
+
+    repeated InlineLinkData data = 2;
+    message InlineLinkData {
+      oneof oneof {
+        google.protobuf.Any protos = 1;
+        string json = 2;
+      }
+    } */
 }
 
-// TODO Later have an RPC for a time series XRequest, and XResponse with
-// repeated Entity?
+// TODO rpc watch(), for a time series WatchRequest/Response with repeated
+// Entity?
 //   google.protobuf.Timestamp ts = 2;
 //   google.protobuf.Timestamp start = 2;
 //   google.protobuf.Timestamp end = 3;

core/lib/src/main/java/dev/enola/core/meta/enola_meta.proto

@@ -26,14 +26,14 @@ option java_string_check_utf8 = true;
 option java_package = "dev.enola.core.meta.proto";
 option java_multiple_files = true;
 
-message MetaModelPackage {
-  // Scheme, as-in ID.parts.scheme; in lower case and without any spaces.
-  // TODO Enable this, with validation that entities don't have it, and
-  // "complete" it on read string package = 1;
-
-  // List of entities kinds of this model.
-  repeated EntityKind entities = 2;
-}
+// message MetaModelPackage {
+// Scheme, as-in ID.parts.scheme; in lower case and without any spaces.
+// TODO Enable this, with validation that entities don't have it, and
+// "complete" it on read string package = 1;
+
+// List of entities kinds of this model.
+// repeated EntityKind entities = 2;
+// }
 
 message EntityKinds {
   repeated EntityKind kinds = 1;

core/lib/src/test/java/dev/enola/core/IDsTest.java

@@ -19,6 +19,8 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static dev.enola.core.IDs.withoutPath;
+
 import static org.junit.Assert.assertThrows;
 
 import dev.enola.core.proto.ID;
@@ -99,4 +101,16 @@ public void testParseBad() {
     private void badEnolaID(String id) {
         assertThrows(IllegalArgumentException.class, () -> IDs.parse(id));
     }
+
+    @Test
+    public void testWithoutPath() {
+        assertThat(withoutPath(null)).isNull();
+        assertThat(withoutPath(ID.getDefaultInstance())).isEqualTo(ID.getDefaultInstance());
+
+        var id1 = ID.newBuilder().setNs("foo").setEntity("bar").build();
+        assertThat(withoutPath(id1)).isSameInstanceAs(id1);
+
+        var id2 = ID.newBuilder(id1).addPaths("name").addPaths("uuid").build();
+        assertThat(withoutPath(id2)).isEqualTo(id1);
+    }
 }