plugins: Add Custom hypervisor minimal changes (apache#7692)

Design document: https://cwiki.apache.org/confluence/display/CLOUDSTACK/%5BDRAFT%5D+Minimal+changes+to+allow+new+dynamic+hypervisor+type%3A+Custom+Hypervisor

This PR introduces the minimal changes to add a new hypervisor type (internally named Custom in the codebase, and configurable display name), allowing to write an external hypervisor plugin as a Custom Hypervisor to CloudStack

The custom hypervisor name is set by the setting: 'hypervisor.custom.display.name'. The new hypervisor type does not affect the behaviour of any CloudStack operation, it simply introduces a new hypervisor type into the system.

CloudStack does not have any means to dynamically add new hypervisor types. The hypervisor types are internally preset by an enum defined within the CloudStack codebase and unless a new version supports a new hypervisor it is not possible to add a host of a hypervisor that is not in part of the enum. It is possible to implement minimal changes in CloudStack to support a new hypervisor plugin that may be developed privately

This PR is an initial work on allowing new dynamic hypervisor types (adds a new element to the HypervisorType enum, but allows variable display name for the hypervisor)

Replace the HypervisorType from a fixed enum to an extensible registry mechanism, registered from the hypervisor plugin

- The new hypervisor type is internally named 'Custom' to the CloudStack services (management server and agent services, database records).
- A new global setting ‘hypervisor.custom.display.name’ allows administrators to set the display name of the hypervisor type. The display name will be shown in the CloudStack UI and API.
   - In case the ‘hypervisor.list’ setting contains the display name of the new hypervisor type, the setting value is automatically updated after the ‘hypervisor.custom.display.name’ setting is updated.
- The new Custom hypervisor type supports:
   - Direct downloads (the ability to download templates into primary storage from the hypervisor hosts without using secondary storage)
   - Local storage (use hypervisor hosts local storage as primary storage)
   - Template format: RAW format (the templates to be registered on the new hypervisor type must be in RAW format)
- The UI is also extended to display the new hypervisor type and the supported features listed above.
- The above are the minimal changes for CloudStack to support the new hypervisor type, which can be tested by integrating the plugin codebase with this feature.

This PR allows the cloud administrators to test custom hypervisor plugins implementations in CloudStack and easily integrate it into CloudStack as a new hypervisor type ("Custom"), reducing the implementation to only the hypervisor supported specific storage/networking and the hypervisor resource to communicate with the management server.

- CloudStack admin should be able to create a zone for the new custom hypervisor and add clusters, hosts into the zone with normal operations
- CloudStack users should be able to execute normal VMs/volumes/network/storage operations on VMs/volumes running on the custom hypervisor hosts

(cherry picked from commit 8b5ba13)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: nvazquez

api/src/main/java/com/cloud/hypervisor/Hypervisor.java

@@ -27,7 +27,7 @@ public class Hypervisor {
     static Map<String, HypervisorType> hypervisorTypeMap;
     static Map<HypervisorType, ImageFormat> supportedImageFormatMap;
 
-    public static enum HypervisorType {
+    public enum HypervisorType {
         None, //for storage hosts
         XenServer,
         KVM,
@@ -40,6 +40,7 @@ public static enum HypervisorType {
         Ovm,
         Ovm3,
         LXC,
+        Custom,
 
         Any; /*If you don't care about the hypervisor type*/
 
@@ -57,6 +58,7 @@ public static enum HypervisorType {
             hypervisorTypeMap.put("lxc", HypervisorType.LXC);
             hypervisorTypeMap.put("any", HypervisorType.Any);
             hypervisorTypeMap.put("ovm3", HypervisorType.Ovm3);
+            hypervisorTypeMap.put("custom", HypervisorType.Custom);
 
             supportedImageFormatMap = new HashMap<>();
             supportedImageFormatMap.put(HypervisorType.XenServer, ImageFormat.VHD);
@@ -68,7 +70,19 @@ public static enum HypervisorType {
 
         public static HypervisorType getType(String hypervisor) {
             return hypervisor == null ? HypervisorType.None :
-                    hypervisorTypeMap.getOrDefault(hypervisor.toLowerCase(Locale.ROOT), HypervisorType.None);
+                    (hypervisor.toLowerCase(Locale.ROOT).equalsIgnoreCase(
+                            HypervisorGuru.HypervisorCustomDisplayName.value()) ? Custom :
+                            hypervisorTypeMap.getOrDefault(hypervisor.toLowerCase(Locale.ROOT), HypervisorType.None));
+        }
+
+        /**
+         * Returns the display name of a hypervisor type in case the custom hypervisor is used,
+         * using the 'hypervisor.custom.display.name' setting. Otherwise, returns hypervisor name
+         */
+        public String getHypervisorDisplayName() {
+            return !Hypervisor.HypervisorType.Custom.equals(this) ?
+                    this.toString() :
+                    HypervisorGuru.HypervisorCustomDisplayName.value();
         }
 
         /**

api/src/main/java/com/cloud/hypervisor/HypervisorGuru.java

@@ -20,6 +20,7 @@
 import java.util.Map;
 
 import org.apache.cloudstack.backup.Backup;
+import org.apache.cloudstack.framework.config.ConfigKey;
 
 import com.cloud.agent.api.Command;
 import com.cloud.agent.api.to.NicTO;
@@ -35,6 +36,10 @@
 
 public interface HypervisorGuru extends Adapter {
 
+    ConfigKey<String> HypervisorCustomDisplayName = new ConfigKey<>(String.class,
+            "hypervisor.custom.display.name", ConfigKey.CATEGORY_ADVANCED, "Custom",
+            "Display name for custom hypervisor", true, ConfigKey.Scope.Global, null);
+
     HypervisorType getHypervisorType();
 
     /**

api/src/main/java/org/apache/cloudstack/api/command/user/template/RegisterTemplateCmd.java

@@ -23,6 +23,7 @@
 import java.util.List;
 import java.util.Map;
 
+import com.cloud.hypervisor.HypervisorGuru;
 import org.apache.cloudstack.api.APICommand;
 import org.apache.cloudstack.api.ApiCommandResourceType;
 import org.apache.cloudstack.api.ApiConstants;
@@ -342,9 +343,11 @@ protected void validateParameters() {
             throw new ServerApiException(ApiErrorCode.PARAM_ERROR,
                     "Parameter zoneids cannot combine all zones (-1) option with other zones");
 
-        if (isDirectDownload() && !getHypervisor().equalsIgnoreCase(Hypervisor.HypervisorType.KVM.toString())) {
-            throw new ServerApiException(ApiErrorCode.PARAM_ERROR,
-                    "Parameter directdownload is only allowed for KVM templates");
+        String customHypervisor = HypervisorGuru.HypervisorCustomDisplayName.value();
+        if (isDirectDownload() && !(getHypervisor().equalsIgnoreCase(Hypervisor.HypervisorType.KVM.toString())
+                || getHypervisor().equalsIgnoreCase(customHypervisor))) {
+            throw new ServerApiException(ApiErrorCode.PARAM_ERROR, String.format("Parameter directdownload " +
+                    "is only allowed for KVM or %s templates", customHypervisor));
         }
 
         if (!isDeployAsIs() && osTypeId == null) {

api/src/main/java/org/apache/cloudstack/api/response/HostForMigrationResponse.java

@@ -24,7 +24,6 @@
 
 import com.cloud.host.Host;
 import com.cloud.host.Status;
-import com.cloud.hypervisor.Hypervisor.HypervisorType;
 import com.cloud.serializer.Param;
 import com.google.gson.annotations.SerializedName;
 
@@ -84,7 +83,7 @@ public class HostForMigrationResponse extends BaseResponse {
 
     @SerializedName(ApiConstants.HYPERVISOR)
     @Param(description = "the host hypervisor")
-    private HypervisorType hypervisor;
+    private String hypervisor;
 
     @SerializedName("cpunumber")
     @Param(description = "the CPU number of the host")
@@ -295,7 +294,7 @@ public void setVersion(String version) {
         this.version = version;
     }
 
-    public void setHypervisor(HypervisorType hypervisor) {
+    public void setHypervisor(String hypervisor) {
         this.hypervisor = hypervisor;
     }
 

api/src/main/java/org/apache/cloudstack/api/response/HostResponse.java

@@ -29,7 +29,6 @@
 
 import com.cloud.host.Host;
 import com.cloud.host.Status;
-import com.cloud.hypervisor.Hypervisor.HypervisorType;
 import com.cloud.serializer.Param;
 import com.google.gson.annotations.SerializedName;
 
@@ -89,7 +88,7 @@ public class HostResponse extends BaseResponseWithAnnotations {
 
     @SerializedName(ApiConstants.HYPERVISOR)
     @Param(description = "the host hypervisor")
-    private HypervisorType hypervisor;
+    private String hypervisor;
 
     @SerializedName("cpusockets")
     @Param(description = "the number of CPU sockets on the host")
@@ -335,7 +334,7 @@ public void setVersion(String version) {
         this.version = version;
     }
 
-    public void setHypervisor(HypervisorType hypervisor) {
+    public void setHypervisor(String hypervisor) {
         this.hypervisor = hypervisor;
     }
 
@@ -602,7 +601,7 @@ public String getVersion() {
         return version;
     }
 
-    public HypervisorType getHypervisor() {
+    public String getHypervisor() {
         return hypervisor;
     }
 

api/src/main/java/org/apache/cloudstack/api/response/HypervisorCapabilitiesResponse.java

@@ -20,7 +20,6 @@
 import org.apache.cloudstack.api.BaseResponse;
 import org.apache.cloudstack.api.EntityReference;
 
-import com.cloud.hypervisor.Hypervisor.HypervisorType;
 import com.cloud.hypervisor.HypervisorCapabilities;
 import com.cloud.serializer.Param;
 import com.google.gson.annotations.SerializedName;
@@ -37,7 +36,7 @@ public class HypervisorCapabilitiesResponse extends BaseResponse {
 
     @SerializedName(ApiConstants.HYPERVISOR)
     @Param(description = "the hypervisor type")
-    private HypervisorType hypervisor;
+    private String hypervisor;
 
     @SerializedName(ApiConstants.MAX_GUESTS_LIMIT)
     @Param(description = "the maximum number of guest vms recommended for this hypervisor")
@@ -83,11 +82,11 @@ public void setHypervisorVersion(String hypervisorVersion) {
         this.hypervisorVersion = hypervisorVersion;
     }
 
-    public HypervisorType getHypervisor() {
+    public String getHypervisor() {
         return hypervisor;
     }
 
-    public void setHypervisor(HypervisorType hypervisor) {
+    public void setHypervisor(String hypervisor) {
         this.hypervisor = hypervisor;
     }
 

api/src/main/java/org/apache/cloudstack/api/response/VMSnapshotResponse.java

@@ -25,7 +25,6 @@
 import org.apache.cloudstack.api.BaseResponseWithTagInformation;
 import org.apache.cloudstack.api.EntityReference;
 
-import com.cloud.hypervisor.Hypervisor;
 import com.cloud.serializer.Param;
 import com.cloud.vm.snapshot.VMSnapshot;
 import com.google.gson.annotations.SerializedName;
@@ -111,7 +110,7 @@ public class VMSnapshotResponse extends BaseResponseWithTagInformation implement
 
     @SerializedName(ApiConstants.HYPERVISOR)
     @Param(description = "the type of hypervisor on which snapshot is stored")
-    private Hypervisor.HypervisorType hypervisor;
+    private String hypervisor;
 
     public VMSnapshotResponse() {
         tags = new LinkedHashSet<ResourceTagResponse>();
@@ -266,11 +265,11 @@ public void setTags(Set<ResourceTagResponse> tags) {
         this.tags = tags;
     }
 
-    public Hypervisor.HypervisorType getHypervisor() {
+    public String getHypervisor() {
         return hypervisor;
     }
 
-    public void setHypervisor(Hypervisor.HypervisorType hypervisor) {
+    public void setHypervisor(String hypervisor) {
         this.hypervisor = hypervisor;
     }
 }

engine/schema/src/main/java/com/cloud/storage/GuestOSHypervisorVO.java

@@ -26,6 +26,7 @@
 import javax.persistence.Id;
 import javax.persistence.Table;
 
+import com.cloud.hypervisor.Hypervisor;
 import com.cloud.utils.db.GenericDao;
 
 @Entity
@@ -72,7 +73,7 @@ public String getHypervisorVersion() {
 
     @Override
     public String getHypervisorType() {
-        return hypervisorType;
+        return Hypervisor.HypervisorType.getType(hypervisorType).toString();
     }
 
     @Override

engine/storage/integration-test/src/test/resources/component.xml

@@ -121,6 +121,11 @@
     <property name="name" value="KVM Agent"/>
   </bean>
 
+  <bean id="CustomServerDiscoverer"
+        class="com.cloud.hypervisor.discoverer.CustomServerDiscoverer">
+    <property name="name" value="CustomHW Agent" />
+  </bean>
+
   <bean id="BareMetalDiscoverer" class="com.cloud.baremetal.BareMetalDiscoverer">
     <property name="name" value="Bare Metal Agent"/>
   </bean>

plugins/network-elements/dns-notifier/src/main/resources/components-example.xml

@@ -111,6 +111,7 @@ under the License.
             <adapter name="XCP Agent" class="com.cloud.hypervisor.xenserver.discoverer.XcpServerDiscoverer"/>
             <adapter name="SecondaryStorage" class="com.cloud.storage.secondary.SecondaryStorageDiscoverer"/>
             <adapter name="KVM Agent" class="com.cloud.hypervisor.kvm.discoverer.KvmServerDiscoverer"/>
+            <adapter name="CustomHW Agent" class="com.cloud.hypervisor.discoverer.CustomServerDiscoverer"/>
             <adapter name="Bare Metal Agent" class="com.cloud.baremetal.BareMetalDiscoverer"/>
 			<adapter name="Ovm Discover" class="com.cloud.ovm.hypervisor.OvmDiscoverer" />
         </adapters>