[YUNIKORN-2965] Move statedump and stack REST to debug endpoint

docs/api/cluster.md

@@ -67,3 +67,198 @@ As an example, here is a response from a cluster with 1 resource manager.
 ### Error response
 
 **Code** : `500 Internal Server Error`
+
+## Metrics
+
+Endpoint to retrieve metrics from the Prometheus server.
+The metrics are dumped with help messages and type information.
+
+**URL** : `/ws/v1/metrics`
+
+**Method** : `GET`
+
+**Auth required** : NO
+
+### Success response
+
+**Code** : `200 OK`
+
+**Content examples**
+
+```text
+# HELP go_gc_duration_seconds A summary of the pause duration of garbage collection cycles.
+# TYPE go_gc_duration_seconds summary
+go_gc_duration_seconds{quantile="0"} 2.567e-05
+go_gc_duration_seconds{quantile="0.25"} 3.5727e-05
+go_gc_duration_seconds{quantile="0.5"} 4.5144e-05
+go_gc_duration_seconds{quantile="0.75"} 6.0024e-05
+go_gc_duration_seconds{quantile="1"} 0.00022528
+go_gc_duration_seconds_sum 0.021561648
+go_gc_duration_seconds_count 436
+# HELP go_goroutines Number of goroutines that currently exist.
+# TYPE go_goroutines gauge
+go_goroutines 82
+# HELP go_info Information about the Go environment.
+# TYPE go_info gauge
+go_info{version="go1.12.17"} 1
+# HELP go_memstats_alloc_bytes Number of bytes allocated and still in use.
+# TYPE go_memstats_alloc_bytes gauge
+go_memstats_alloc_bytes 9.6866248e+07
+
+...
+
+# HELP yunikorn_scheduler_vcore_nodes_usage Nodes resource usage, by resource name.
+# TYPE yunikorn_scheduler_vcore_nodes_usage gauge
+yunikorn_scheduler_vcore_nodes_usage{range="(10%, 20%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="(20%,30%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="(30%,40%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="(40%,50%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="(50%,60%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="(60%,70%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="(70%,80%]"} 1
+yunikorn_scheduler_vcore_nodes_usage{range="(80%,90%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="(90%,100%]"} 0
+yunikorn_scheduler_vcore_nodes_usage{range="[0,10%]"} 0
+```
+
+## Configuration
+
+Endpoint to retrieve the current scheduler configuration
+
+**URL** : `/ws/v1/config`
+
+**Method** : `GET`
+
+**Auth required** : NO
+
+### Success response
+
+**Code** : `200 OK`
+
+**Content example (with `Accept: application/json` header)**
+
+```json
+{
+    "Partitions": [
+        {
+            "Name": "default",
+            "Queues": [
+                {
+                    "Name": "root",
+                    "Parent": true,
+                    "Resources": {},
+                    "SubmitACL": "*",
+                    "ChildTemplate": {
+                        "Resources": {}
+                    }
+                }
+            ],
+            "PlacementRules": [
+                {
+                    "Name": "tag",
+                    "Create": true,
+                    "Filter": {
+                        "Type": ""
+                    },
+                    "Value": "namespace"
+                }
+            ],
+            "Preemption": {
+                "Enabled": false
+            },
+            "NodeSortPolicy": {
+                "Type": ""
+            }
+        }
+    ],
+    "Checksum": "FD5D3726DF0F02416E02F3919D78F61B15D14425A34142D93B24C137ED056946",
+    "Extra": {
+        "event.trackingEnabled": "false",
+        "log.core.scheduler.level": "info",
+        "log.core.security.level": "info",
+        "log.level": "debug"
+    }
+}
+```
+
+**Content example (without `Accept: application/json` header)**
+
+```yaml
+partitions:
+    - name: default
+      queues:
+          - name: root
+            parent: true
+            submitacl: "*"
+      placementrules:
+          - name: tag
+            create: true
+            value: namespace
+checksum: FD5D3726DF0F02416E02F3919D78F61B15D14425A34142D93B24C137ED056946
+extra:
+    event.trackingEnabled: "false"
+    log.core.scheduler.level: info
+    log.core.security.level: info
+    log.level: debug
+
+```
+
+## Configuration validation
+
+**URL** : `/ws/v1/validate-conf`
+
+**Method** : `POST`
+
+**Auth required** : NO
+
+### Success response
+
+Regardless whether the configuration is allowed or not if the server was able to process the request, it will yield a 200 HTTP status code.
+
+**Code** : `200 OK`
+
+#### Allowed configuration
+
+Sending the following simple configuration yields an accept
+
+```yaml
+partitions:
+  - name: default
+    queues:
+      - name: root
+        queues:
+          - name: test
+```
+
+Reponse
+
+```json
+{
+    "allowed": true,
+    "reason": ""
+}
+```
+
+#### Disallowed configuration
+
+The following configuration is not allowed due to the "wrong_text" field put into the yaml file.
+
+```yaml
+partitions:
+  - name: default
+    queues:
+      - name: root
+        queues:
+          - name: test
+  - wrong_text
+```
+
+Reponse
+
+```json
+{
+    "allowed": false,
+    "reason": "yaml: unmarshal errors:\n  line 7: cannot unmarshal !!str `wrong_text` into configs.PartitionConfig"
+}
+```
+