Squad represents a group of game servers (GameServer), they have the same resource configuration,
and the Carrier controller maintains the specified number of copies of the group of GameServer.
It controls the update and scaling of this group of GameServer.
Create a Squad
Create a Squad with 2 replicas:
cat <<EOF | kubectl apply -f -
apiVersion: carrier.ocgi.dev/v1alpha1
kind: Squad
metadata:
name: squad-example
namespace: default
spec:
replicas: 2
strategy:
rollingUpdate:
maxSurge: 1
maxUnavailable: 1
type: RollingUpdate
template:
metadata:
labels:
foo: bar
spec:
ports:
- container: server
containerPort: 7654
name: default
protocol: TCP
template:
spec:
containers:
- image: ocgi/simple-tcp:0.1
name: server
EOF
- Fetch the Squad status
# kubectl get sqd
NAME SCHEDULING DESIRED CURRENT UP-TO-DATE READY AGE
squad-example MostAllocated 2 2 2 2 4s
Each field of GameServer represents:
- NAME describes the name of the Squad in the cluster
- SCHEDULING scheduling strategy. The default is
MostAllocated, supportMostAllocated,LeastAllocated- MostAllocated: Applicable to dynamic clusters, InterPodAffinity will be injected to make Pod dispatch to one machine as much as possible to ensure the packing rate, and at the same time, the GameServer that has the least impact when shrinking;
- LeastAllocated: Native scheduling strategy, scheduling to nodes with less resource usage, more GameServers will be affected when the cluster is scaled.
- DESIRED The number of replicas expected, consistent with the description of
.spec.replicas - CURRENT current number of copies
- UP-TO-DATE shows the number of copies that have been updated in order to reach the desired status
- READY The number of copies that are ready
- AGE shows the running time of the application
View GameServer and Pod information:
# kubectl get gs
NAME STATE ADDRESS PORT PORTRANGE NODE AGE
squad-example-75ddb545d9-cqgph Running 172.16.5.9 172.16.212.247 21s
squad-example-75ddb545d9-nzvkx Running 172.16.5.8 172.16.212.247 21s
# kubectl get pods
NAME READY STATUS RESTARTS AGE
squad-example-75ddb545d9-cqgph 2/2 Running 0 42s
squad-example-75ddb545d9-nzvkx 2/2 Running 0 42s
- Access the GameServer
# telnet 172.16.5.8 7654
Trying 172.16.5.8...
Connected to 172.16.5.8.
Escape character is '^]'.
VERSION
Version: 0.1
Scale the Squad
- Scale up
Scale up the number of replicas of squad-example from 2 to 4:
# kubectl scale sqd squad-example --replicas=4
squad.carrier.ocgi.dev/squad-example scaled
# kubectl get gs
NAME STATE ADDRESS PORT PORTRANGE NODE AGE
squad-example-75ddb545d9-66k6p Running 172.16.5.1 172.16.212.247 8s
squad-example-75ddb545d9-cqgph Running 172.16.5.9 172.16.212.247 90m
squad-example-75ddb545d9-fm228 Running 172.16.5.0 172.16.212.247 8s
squad-example-75ddb545d9-nzvkx Running 172.16.5.8 172.16.212.247 90m
# kubectl get pods
NAME READY STATUS RESTARTS AGE
squad-example-75ddb545d9-66k6p 2/2 Running 0 16s
squad-example-75ddb545d9-cqgph 2/2 Running 0 90m
squad-example-75ddb545d9-fm228 2/2 Running 0 16s
squad-example-75ddb545d9-nzvkx 2/2 Running 0 90m
- Scale down
Scale down the number of replicas of squad-example from 4 to 3:
# kubectl scale sqd squad-example --replicas=3
squad.carrier.ocgi.dev/squad-example scaled
# kubectl get gs
NAME STATE ADDRESS PORT PORTRANGE NODE AGE
squad-example-75ddb545d9-66k6p Running 172.16.5.1 172.16.212.247 2m22s
squad-example-75ddb545d9-fm228 Running 172.16.5.0 172.16.212.247 2m22s
squad-example-75ddb545d9-nzvkx Running 172.16.5.8 172.16.212.247 92m
# kubectl get pods
NAME READY STATUS RESTARTS AGE
squad-example-75ddb545d9-66k6p 2/2 Running 0 2m37s
squad-example-75ddb545d9-fm228 2/2 Running 0 2m37s
squad-example-75ddb545d9-nzvkx 2/2 Running 0 92m
Update the Squad
Update the squad-example image to ocgi/simple-tcp:0.2:
# kubectl patch squad squad-example --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/template/spec/containers/0/image", "value":"ocgi/simple-tcp:0.2"}]'
# kubectl get gs
NAME STATE ADDRESS PORT PORTRANGE NODE AGE
squad-example-5df4fb94c6-75565 Running 172.16.5.4 172.16.212.247 34s
squad-example-5df4fb94c6-lzb92 Running 172.16.5.2 172.16.212.247 43s
squad-example-5df4fb94c6-sjv9f Running 172.16.5.3 172.16.212.247 43s
# telnet 172.16.5.2 7654
Trying 172.16.5.2...
Connected to 172.16.5.2.
Escape character is '^]'.
VERSION
Version: 0.2
As we can see, the image of squad-example has been updated to ocgi/simple-tcp:0.2.
Rollback update
Sometimes after we complete the update, we find that there is a BUG or unstable online, and we want to roll back to the previous version, then we can achieve it through the Squad rollback function. A certain number of versions (10 by default) are saved in Squad so that the specified version can be rolled back at any time.
For example, we found a BUG after updating to ocgi/simple-tcp:0.2, and hope to roll back to the previous version ocgi/simple-tcp:0.1, we can execute it.
The revision is set to 0, which means to roll back to the latest version.
# kubectl patch squad squad-example --type='json' -p='[{"op": "add", "path": "/spec/rollbackTo", "value": {"revision": 0}}]'
Check the squad-example image:
# kubectl get sqd squad-example -o jsonpath="{..image}"
ocgi/simple-tcp:0.1
# kubectl get gs
NAME STATE ADDRESS PORT PORTRANGE NODE AGE
squad-example-75ddb545d9-6n7jh Running 172.16.5.6 172.16.212.247 24s
squad-example-75ddb545d9-l4dpc Running 172.16.5.7 172.16.212.247 19s
squad-example-75ddb545d9-lflnv Running 172.16.5.5 172.16.212.247 24s
# telnet 172.16.5.5 7654
Trying 172.16.5.5...
Connected to 172.16.5.5.
Escape character is '^]'.
VERSION
Version: 0.1
As we can see, the image has been rollbacked to ocgi/simple-tcp:0.1.
Reference
For more information, please refer to the Squad introduction.