cmd: add README.md for rg subcommand

cmd/kperf/commands/runnergroup/README.md

@@ -0,0 +1,161 @@
+## runnergroup subcommand
+
+The subcommand is used to manage a set of runners in target kubernetes.
+Before using command, please build container image for kperf first.
+
+```bash
+$ # cd kperf repo
+$ # change repo name to your
+$ export IMAGE_REPO=example.azurecr.io/public
+$ export IMAGE_TAG=v0.0.2
+$ make image-push
+```
+
+After that, build kperf binary.
+
+```bash
+$ # cd kperf repo
+$ make build
+```
+
+> NOTE: `make help` can show more recipes.
+
+### run - deploy a set of runners into kubernetes
+
+Before run `run` command, we should define runner group first.
+Here is an example: there are 10 runners in one group.
+
+```YAML
+# count defines how many runners in the group.
+count: 10 # 10 runners in this group
+# loadProfile defines what the load traffic looks like.
+# All the runners in this group will use the same load profile.
+loadProfile:
+  version: 1
+  description: example profile
+  spec:
+    # rate defines the maximum requests per second (zero is no limit).
+    rate: 100
+    # total defines the total number of requests.
+    total: 10
+    # conns defines total number of individual transports used for traffic.
+    conns: 100
+    # client defines total number of HTTP clients.
+    client: 1000
+    # contentType defines response's content type. (json or protobuf)
+    contentType: json
+    # disableHTTP2 means client will use HTTP/1.1 protocol if it's true.
+    disableHTTP2: false
+    # pick up requests randomly based on defined weight.
+    requests:
+      # staleList means this list request with zero resource version.
+      - staleList:
+          version: v1
+          resource: pods
+          limit: 1000
+        shares: 1000 # Has 50% chance = 1000 / (1000 + 1000)
+      # quorumList means this list request without kube-apiserver cache.
+      - quorumList:
+          version: v1
+          resource: pods
+          limit: 1000
+        shares: 1000
+        shares: 1000 # Has 50% chance = 1000 / (1000 + 1000)
+
+# nodeAffinity defines how to deploy runners into dedicated nodes which have specific labels.
+nodeAffinity:
+  node.kubernetes.io/instance-type:
+    - Standard_D8s_v3
+```
+
+Let's say the local file `/tmp/example-runnergroup-spec.yaml`.
+
+We can run this runner group by the following command:
+
+```bash
+$ # cd kperf repo
+$ # change repo name to your
+$ export IMAGE_REPO=example.azurecr.io/public
+$ export IMAGE_TAG=v0.0.2
+$ export IMAGE_NAME=$IMAGE_REPO/kperf:$IMAGE_TAG
+$
+$ bin/kperf rg run \
+  --runner-image=$IMAGE_NAME \
+  --runnergroup="file:///tmp/example-runnergroup-spec.yaml"
+```
+
+We use URI scheme to load runner group's spec.
+For example, `file://absolute-path`. We also support read spec from configmap, `configmap://name?namespace=ns&specName=dataNameInCM`.
+Please checkout `kperf rg run -h` to see more options.
+
+> NOTE: Currently, we use helm release to deploy a long running sever as controller to
+deploy runners. The namespace is `runnergroups-kperf-io` and we don't allow run
+multiple long running servers right now.
+
+### status - check runnergroup's status
+
+After deploy runner groups successfully, we can use `status` to check.
+
+```bash
+$ # cd kperf repo
+$
+$ bin/kperf rg status
+NAME                   COUNT   SUCCEEDED   FAILED   STATE      START
+runnergroup-server-0   10      10          0        finished   2024-01-30T10:18:36Z
+```
+
+### result - wait for test report
+
+We use `result` to wait for report.
+
+```bash
+$ # cd kperf repo
+$
+$ bin/kperf rg result --wait --timeout=1h
+{
+  "total": 100,
+  "duration": "318.47949ms",
+  "errorStats": {
+    "unknownErrors": [],
+    "responseCodes": {},
+    "http2Errors": {}
+  },
+  "totalReceivedBytes": 89149672,
+  "percentileLatencies": [
+    [
+      0,
+      0.039138658
+    ],
+    [
+      0.5,
+      0.072110663
+    ],
+    [
+      0.9,
+      0.158119337
+    ],
+    [
+      0.95,
+      0.179047998
+    ],
+    [
+      0.99,
+      0.236420101
+    ],
+    [
+      1,
+      0.267788626
+    ]
+  ]
+}
+```
+
+`--wait` is used to block until all the runners finished.
+
+### delete - delete runner groups
+
+```bash
+$ # cd kperf repo
+$
+$ bin/kperf rg delete
+```