Service Accounts - Get service account API (elastic#71315)

This PR adds a new API endpoint to retrieve service accounts. Depends on the
request parameters, it returns either all accounts, accounts belong to a
namespace, a specific account, or an empty map if nothing is found.

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/service/GetServiceAccountAction.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.core.security.action.service;
+
+import org.elasticsearch.action.ActionType;
+
+public class GetServiceAccountAction extends ActionType<GetServiceAccountResponse> {
+
+    public static final String NAME = "cluster:admin/xpack/security/service_account/get";
+    public static final GetServiceAccountAction INSTANCE = new GetServiceAccountAction();
+
+    public GetServiceAccountAction() {
+        super(NAME, GetServiceAccountResponse::new);
+    }
+}

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/service/GetServiceAccountRequest.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.core.security.action.service;
+
+import org.elasticsearch.action.ActionRequest;
+import org.elasticsearch.action.ActionRequestValidationException;
+import org.elasticsearch.common.Nullable;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+
+import java.io.IOException;
+import java.util.Objects;
+
+public class GetServiceAccountRequest extends ActionRequest {
+
+    @Nullable
+    private final String namespace;
+    @Nullable
+    private final String serviceName;
+
+    public GetServiceAccountRequest(@Nullable String namespace, @Nullable String serviceName) {
+        this.namespace = namespace;
+        this.serviceName = serviceName;
+    }
+
+    public GetServiceAccountRequest(StreamInput in) throws IOException {
+        super(in);
+        this.namespace = in.readOptionalString();
+        this.serviceName = in.readOptionalString();
+    }
+
+    public String getNamespace() {
+        return namespace;
+    }
+
+    public String getServiceName() {
+        return serviceName;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        GetServiceAccountRequest that = (GetServiceAccountRequest) o;
+        return Objects.equals(namespace, that.namespace) && Objects.equals(serviceName, that.serviceName);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(namespace, serviceName);
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+        out.writeOptionalString(namespace);
+        out.writeOptionalString(serviceName);
+    }
+
+    @Override
+    public ActionRequestValidationException validate() {
+        return null;
+    }
+}

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/service/GetServiceAccountResponse.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.core.security.action.service;
+
+import org.elasticsearch.action.ActionResponse;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.xcontent.ToXContentObject;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Objects;
+
+public class GetServiceAccountResponse extends ActionResponse implements ToXContentObject {
+
+    private final ServiceAccountInfo[] serviceAccountInfos;
+
+    public GetServiceAccountResponse(ServiceAccountInfo[] serviceAccountInfos) {
+        this.serviceAccountInfos = Objects.requireNonNull(serviceAccountInfos);
+    }
+
+    public GetServiceAccountResponse(StreamInput in) throws IOException {
+        super(in);
+        this.serviceAccountInfos = in.readArray(ServiceAccountInfo::new, ServiceAccountInfo[]::new);
+    }
+
+    public ServiceAccountInfo[] getServiceAccountInfos() {
+        return serviceAccountInfos;
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeArray(serviceAccountInfos);
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject();
+        for (ServiceAccountInfo info : serviceAccountInfos) {
+            info.toXContent(builder, params);
+        }
+        builder.endObject();
+        return builder;
+    }
+
+    @Override
+    public String toString() {
+        return "GetServiceAccountResponse{" + "serviceAccountInfos=" + Arrays.toString(serviceAccountInfos) + '}';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        GetServiceAccountResponse that = (GetServiceAccountResponse) o;
+        return Arrays.equals(serviceAccountInfos, that.serviceAccountInfos);
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(serviceAccountInfos);
+    }
+}

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/security/action/service/ServiceAccountInfo.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.core.security.action.service;
+
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.xpack.core.security.authz.RoleDescriptor;
+
+import java.io.IOException;
+import java.util.Objects;
+
+public class ServiceAccountInfo implements Writeable, ToXContent {
+
+    private final String principal;
+    private final RoleDescriptor roleDescriptor;
+
+    public ServiceAccountInfo(String principal, RoleDescriptor roleDescriptor) {
+        this.principal = Objects.requireNonNull(principal, "service account principal cannot be null");
+        this.roleDescriptor = Objects.requireNonNull(roleDescriptor, "service account descriptor cannot be null");
+    }
+
+    public ServiceAccountInfo(StreamInput in) throws IOException {
+        this.principal = in.readString();
+        this.roleDescriptor = new RoleDescriptor(in);
+    }
+
+    public String getPrincipal() {
+        return principal;
+    }
+
+    public RoleDescriptor getRoleDescriptor() {
+        return roleDescriptor;
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeString(principal);
+        roleDescriptor.writeTo(out);
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(principal);
+        builder.field("role_descriptor");
+        roleDescriptor.toXContent(builder, params);
+        builder.endObject();
+        return builder;
+    }
+
+    @Override
+    public String toString() {
+        return "ServiceAccountInfo{" + "principal='" + principal + '\'' + ", roleDescriptor=" + roleDescriptor + '}';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        ServiceAccountInfo that = (ServiceAccountInfo) o;
+        return principal.equals(that.principal) && roleDescriptor.equals(that.roleDescriptor);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(principal, roleDescriptor);
+    }
+}

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/action/service/GetServiceAccountRequestTests.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.core.security.action.service;
+
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.test.AbstractWireSerializingTestCase;
+
+import java.io.IOException;
+
+public class GetServiceAccountRequestTests extends AbstractWireSerializingTestCase<GetServiceAccountRequest> {
+
+    @Override
+    protected Writeable.Reader<GetServiceAccountRequest> instanceReader() {
+        return GetServiceAccountRequest::new;
+    }
+
+    @Override
+    protected GetServiceAccountRequest createTestInstance() {
+        return new GetServiceAccountRequest(randomFrom(randomAlphaOfLengthBetween(3, 8), null),
+            randomFrom(randomAlphaOfLengthBetween(3, 8), null));
+    }
+
+    @Override
+    protected GetServiceAccountRequest mutateInstance(GetServiceAccountRequest instance) throws IOException {
+        if (randomBoolean()) {
+            return new GetServiceAccountRequest(
+                randomValueOtherThan(instance.getNamespace(), () -> randomFrom(randomAlphaOfLengthBetween(3, 8), null)),
+                instance.getServiceName());
+        } else {
+            return new GetServiceAccountRequest(
+                instance.getNamespace(),
+                randomValueOtherThan(instance.getServiceName(), () -> randomFrom(randomAlphaOfLengthBetween(3, 8), null)));
+        }
+    }
+}

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/security/action/service/GetServiceAccountResponseTests.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.core.security.action.service;
+
+import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.common.xcontent.XContentHelper;
+import org.elasticsearch.common.xcontent.XContentType;
+import org.elasticsearch.test.AbstractWireSerializingTestCase;
+import org.elasticsearch.test.XContentTestUtils;
+import org.elasticsearch.xpack.core.security.authz.RoleDescriptor;
+
+import java.io.IOException;
+import java.util.Map;
+
+import static org.hamcrest.Matchers.anEmptyMap;
+import static org.hamcrest.Matchers.equalTo;
+
+public class GetServiceAccountResponseTests extends AbstractWireSerializingTestCase<GetServiceAccountResponse> {
+
+    @Override
+    protected Writeable.Reader<GetServiceAccountResponse> instanceReader() {
+        return GetServiceAccountResponse::new;
+    }
+
+    @Override
+    protected GetServiceAccountResponse createTestInstance() {
+        final String principal = randomPrincipal();
+        return new GetServiceAccountResponse(randomBoolean()
+            ? new ServiceAccountInfo[]{new ServiceAccountInfo(principal, getRoleDescriptorFor(principal))}
+            : new ServiceAccountInfo[0]);
+    }
+
+    @Override
+    protected GetServiceAccountResponse mutateInstance(GetServiceAccountResponse instance) throws IOException {
+        if (instance.getServiceAccountInfos().length == 0) {
+            final String principal = randomPrincipal();
+            return new GetServiceAccountResponse(new ServiceAccountInfo[]{
+                new ServiceAccountInfo(principal, getRoleDescriptorFor(principal))});
+        } else {
+            return new GetServiceAccountResponse(new ServiceAccountInfo[0]);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    public void testToXContent() throws IOException {
+        final GetServiceAccountResponse response = createTestInstance();
+        XContentBuilder builder = XContentFactory.jsonBuilder();
+        response.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        final Map<String, Object> responseMap = XContentHelper.convertToMap(
+            BytesReference.bytes(builder),
+            false, builder.contentType()).v2();
+        final ServiceAccountInfo[] serviceAccountInfos = response.getServiceAccountInfos();
+        if (serviceAccountInfos.length == 0) {
+            assertThat(responseMap, anEmptyMap());
+        } else {
+            assertThat(responseMap.size(), equalTo(serviceAccountInfos.length));
+            for (int i = 0; i < serviceAccountInfos.length - 1; i++) {
+                final String key = serviceAccountInfos[i].getPrincipal();
+                assertRoleDescriptorEquals((Map<String, Object>) responseMap.get(key), serviceAccountInfos[i].getRoleDescriptor());
+            }
+        }
+    }
+
+    private String randomPrincipal() {
+        return randomAlphaOfLengthBetween(3, 8) + "/" + randomAlphaOfLengthBetween(3, 8);
+    }
+
+    private RoleDescriptor getRoleDescriptorFor(String name) {
+        return new RoleDescriptor(name,
+            new String[] { "monitor", "manage_own_api_key" },
+            new RoleDescriptor.IndicesPrivileges[] {
+            RoleDescriptor.IndicesPrivileges.builder()
+                .indices("logs-*", "metrics-*", "traces-*")
+                .privileges("write", "create_index", "auto_configure").build() },
+            null,
+            null,
+            null,
+            null,
+            null);
+    }
+
+    private void assertRoleDescriptorEquals(Map<String, Object> responseFragment, RoleDescriptor roleDescriptor) throws IOException {
+        @SuppressWarnings("unchecked")
+        final Map<String, Object> descriptorMap = (Map<String, Object>) responseFragment.get("role_descriptor");
+        assertThat(RoleDescriptor.parse(roleDescriptor.getName(),
+            XContentTestUtils.convertToXContent(descriptorMap, XContentType.JSON), false, XContentType.JSON),
+            equalTo(roleDescriptor));
+    }
+}

x-pack/plugin/security/qa/operator-privileges-tests/src/javaRestTest/java/org/elasticsearch/xpack/security/operator/Constants.java

@@ -190,6 +190,7 @@ public class Constants {
         "cluster:admin/xpack/security/saml/invalidate",
         "cluster:admin/xpack/security/saml/logout",
         "cluster:admin/xpack/security/saml/prepare",
+        "cluster:admin/xpack/security/service_account/get",
         "cluster:admin/xpack/security/service_account/token/create",
         "cluster:admin/xpack/security/service_account/token/get",
         "cluster:admin/xpack/security/token/create",