O Kubernetes 1.4 foi lançado no início desta semana. Leia o artigo anúncio no blog e REGISTRO DE MUDANÇAS.
Há vários recursos novos nesta versão, mas os principais que me entusiasmam são:
- Instale o Kubernetes usando
kubeadmcomando. Isso é um acréscimo ao mecanismo usual de download do site https://github.com/kubernetes/kubernetes/releases. O comando
kubeadm initeunião do kubeadmOs comandos são muito semelhantes ainicialização do enxame de docasejunção de enxame de docaspara Modo Docker Swarm. - Conjuntos de réplicas federadas
- O ScheduledJob permite executar trabalhos em lote em intervalos regulares.
- Restringir pods a um nó e afinidade e antiafinidade dos pods
- Programação de prioridades de vagens
- Boa aparência Painel de controle do Kubernetes (mais sobre isso mais tarde)
Este blog mostrará:
- Criar um cluster Kubernetes usando o Amazon Web Services
- Criar um serviço Couchbase
- Executar um aplicativo Spring Boot que armazena um documento JSON no Couchbase
Todos os arquivos de descrição de recursos deste blog estão em github.com/arun-gupta/kubernetes-java-sample/tree/master/maven.
Iniciar o cluster do Kubernetes
Baixar binário github.com/kubernetes/kubernetes/releases/download/v1.4.0/kubernetes.tar.gz e extrair Incluir kubernetes/cluster em PATH Iniciar
um cluster Kubernetes de 2 nós:
|
1 |
NUM_NODES=2 NODE_SIZE=m3.medium KUBERNETES_PROVIDER=aws kube-up.sh |
O registro será mostrado como:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 |
... Starting cluster in us-west-2a using provider aws ... calling verify-prereqs ... calling kube-up Starting cluster using os distro: jessie Uploading to Amazon S3 +++ Staging server tars to S3 Storage: kubernetes-staging-0eaf81fbc51209dd47c13b6d8b424149/devel upload: ../../../../../var/folders/81/ttv4n16x7p390cttrm_675y00000gn/T/kubernetes.XXXXXX.bCmvLbtK/s3/bootstrap-script to s3://kubernetes-staging-0eaf81fbc51209dd47c13b6d8b424149/devel/bootstrap-script Uploaded server tars: SERVER_BINARY_TAR_URL: https://s3.amazonaws.com/kubernetes-staging-0eaf81fbc51209dd47c13b6d8b424149/devel/kubernetes-server-linux-amd64.tar.gz SALT_TAR_URL: https://s3.amazonaws.com/kubernetes-staging-0eaf81fbc51209dd47c13b6d8b424149/devel/kubernetes-salt.tar.gz BOOTSTRAP_SCRIPT_URL: https://s3.amazonaws.com/kubernetes-staging-0eaf81fbc51209dd47c13b6d8b424149/devel/bootstrap-script INSTANCEPROFILE arn:aws:iam::598307997273:instance-profile/kubernetes-master 2016-07-29T15:13:35Z AIPAJF3XKLNKOXOTQOCT4 kubernetes-master / ROLES arn:aws:iam::598307997273:role/kubernetes-master 2016-07-29T15:13:33Z / AROAI3Q2KFBD5PCKRXCRM kubernetes-master ASSUMEROLEPOLICYDOCUMENT 2012-10-17 STATEMENT sts:AssumeRole Allow PRINCIPAL ec2.amazonaws.com INSTANCEPROFILE arn:aws:iam::598307997273:instance-profile/kubernetes-minion 2016-07-29T15:13:39Z AIPAIYSH5DJA4UPQIP4BE kubernetes-minion / ROLES arn:aws:iam::598307997273:role/kubernetes-minion 2016-07-29T15:13:37Z / AROAIQ57MPQYSHRPQCT2Q kubernetes-minion ASSUMEROLEPOLICYDOCUMENT 2012-10-17 STATEMENT sts:AssumeRole Allow PRINCIPAL ec2.amazonaws.com Using SSH key with (AWS) fingerprint: SHA256:dX/5wpWuUxYar2NFuGwiZuRiydiZCyx4DGoZ5/jL/j8 Creating vpc. Adding tag to vpc-6b5b4b0f: Name=kubernetes-vpc Adding tag to vpc-6b5b4b0f: KubernetesCluster=kubernetes Using VPC vpc-6b5b4b0f Adding tag to dopt-8fe770eb: Name=kubernetes-dhcp-option-set Adding tag to dopt-8fe770eb: KubernetesCluster=kubernetes Using DHCP option set dopt-8fe770eb Creating subnet. Adding tag to subnet-623a0206: KubernetesCluster=kubernetes Using subnet subnet-623a0206 Creating Internet Gateway. Using Internet Gateway igw-251eab41 Associating route table. Creating route table Adding tag to rtb-d43cedb3: KubernetesCluster=kubernetes Associating route table rtb-d43cedb3 to subnet subnet-623a0206 Adding route to route table rtb-d43cedb3 Using Route Table rtb-d43cedb3 Creating master security group. Creating security group kubernetes-master-kubernetes. Adding tag to sg-d20ca0ab: KubernetesCluster=kubernetes Creating minion security group. Creating security group kubernetes-minion-kubernetes. Adding tag to sg-cd0ca0b4: KubernetesCluster=kubernetes Using master security group: kubernetes-master-kubernetes sg-d20ca0ab Using minion security group: kubernetes-minion-kubernetes sg-cd0ca0b4 Creating master disk: size 20GB, type gp2 Adding tag to vol-99a30b11: Name=kubernetes-master-pd Adding tag to vol-99a30b11: KubernetesCluster=kubernetes Allocated Elastic IP for master: 52.40.9.27 Adding tag to vol-99a30b11: kubernetes.io/master-ip=52.40.9.27 Generating certs for alternate-names: IP:52.40.9.27,IP:172.20.0.9,IP:10.0.0.1,DNS:kubernetes,DNS:kubernetes.default,DNS:kubernetes.default.svc,DNS:kubernetes.default.svc.cluster.local,DNS:kubernetes-master Starting Master Adding tag to i-f95bdae1: Name=kubernetes-master Adding tag to i-f95bdae1: Role=kubernetes-master Adding tag to i-f95bdae1: KubernetesCluster=kubernetes Waiting for master to be ready Attempt 1 to check for master nodeWaiting for instance i-f95bdae1 to be running (currently pending) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be running (currently pending) Sleeping for 3 seconds... [master running] Attaching IP 52.40.9.27 to instance i-f95bdae1 Attaching persistent data volume (vol-99a30b11) to master 2016-09-29T05:14:28.098Z /dev/sdb i-f95bdae1 attaching vol-99a30b11 cluster "aws_kubernetes" set. user "aws_kubernetes" set. context "aws_kubernetes" set. switched to context "aws_kubernetes". user "aws_kubernetes-basic-auth" set. Wrote config for aws_kubernetes to /Users/arungupta/.kube/config Creating minion configuration Creating autoscaling group 0 minions started; waiting 0 minions started; waiting 0 minions started; waiting 0 minions started; waiting 2 minions started; ready Waiting for cluster initialization. This will continually check to see if the API for kubernetes is reachable. This might loop forever if there was some uncaught error during start up. ..............................................................................................................................................................................................................................Kubernetes cluster created. Sanity checking cluster... Attempt 1 to check Docker on node @ 54.70.225.33 ...working Attempt 1 to check Docker on node @ 54.71.36.48 ...working Kubernetes cluster is running. The master is running at: https://52.40.9.27 The user name and password to use is located in /Users/arungupta/.kube/config. ... calling validate-cluster Waiting for 2 ready nodes. 0 ready nodes, 0 registered. Retrying. Waiting for 2 ready nodes. 0 ready nodes, 0 registered. Retrying. Waiting for 2 ready nodes. 0 ready nodes, 0 registered. Retrying. Waiting for 2 ready nodes. 0 ready nodes, 2 registered. Retrying. Waiting for 2 ready nodes. 0 ready nodes, 2 registered. Retrying. Found 2 node(s). NAME STATUS AGE ip-172-20-0-111.us-west-2.compute.internal Ready 39s ip-172-20-0-112.us-west-2.compute.internal Ready 42s Validate output: NAME STATUS MESSAGE ERROR scheduler Healthy ok controller-manager Healthy ok etcd-0 Healthy {"health": "true"} etcd-1 Healthy {"health": "true"} Cluster validation succeeded Done, listing cluster services: Kubernetes master is running at https://52.40.9.27 Elasticsearch is running at https://52.40.9.27/api/v1/proxy/namespaces/kube-system/services/elasticsearch-logging Heapster is running at https://52.40.9.27/api/v1/proxy/namespaces/kube-system/services/heapster Kibana is running at https://52.40.9.27/api/v1/proxy/namespaces/kube-system/services/kibana-logging KubeDNS is running at https://52.40.9.27/api/v1/proxy/namespaces/kube-system/services/kube-dns kubernetes-dashboard is running at https://52.40.9.27/api/v1/proxy/namespaces/kube-system/services/kubernetes-dashboard Grafana is running at https://52.40.9.27/api/v1/proxy/namespaces/kube-system/services/monitoring-grafana InfluxDB is running at https://52.40.9.27/api/v1/proxy/namespaces/kube-system/services/monitoring-influxdb To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'. |
Isso mostra que o cluster do Kubernetes foi iniciado com êxito.
Implantar o serviço Couchbase
Crie o serviço Couchbase e o controlador de replicação:
|
1 2 3 |
kubectl.sh create -f couchbase-service.yml service "couchbase-service" created replicationcontroller "couchbase-rc" created |
O arquivo de configuração está em github.com/arun-gupta/kubernetes-java-sample/blob/master/maven/couchbase-service.yml. Isso cria um serviço Couchbase e
o controlador de replicação de apoio. O nome do serviço é serviço couchbase. Isso será usado posteriormente pelo aplicativo Spring Boot para se comunicar com o banco de dados. Verifique o status dos pods:
|
1 2 3 4 5 |
kubectl.sh get -w pods NAME READY STATUS RESTARTS AGE couchbase-rc-gu9gl 0/1 ContainerCreating 0 6s NAME READY STATUS RESTARTS AGE couchbase-rc-gu9gl 1/1 Running 0 2m |
Observe como o status do pod muda de ContainerCreating para Running. A imagem é baixada e iniciada nesse meio tempo.
Executar o aplicativo Spring Boot
Execute o aplicativo:
|
1 2 |
kubectl.sh create -f bootiful-couchbase.yml pod "bootiful-couchbase" created |
O arquivo de configuração está em github.com/arun-gupta/kubernetes-java-sample/blob/master/maven/bootiful-couchbase.yml. Neste serviço,
COUCHBASE_URI o valor da variável de ambiente é definido como serviço couchbase. Esse é o nome do serviço criado anteriormente. A imagem do Docker usada para esse serviço é arungupta/bootiful-couchbase e é criado usando
fabric8-maven-plugin conforme mostrado em github.com/arun-gupta/kubernetes-java-sample/blob/master/maven/webapp/pom.xml#L57-L68.
Especificamente, o comando para a imagem do Docker é:
|
1 |
java -Dspring.couchbase.bootstrap-hosts=$COUCHBASE_URI -jar /maven/${project.artifactId}.jar |
Isso garante que COUCHBASE_URI está substituindo a variável de ambiente spring.couchbase.bootstrap-hosts conforme definido em application.properties do aplicativo Spring Boot. Obtenha os registros:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 |
kubectl.sh logs -f bootiful-couchbase . ____ _ __ _ _ /\ / ___'_ __ _ _(_)_ __ __ _ ( ( )___ | '_ | '_| | '_ / _` | \/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |___, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v1.4.0.RELEASE) 2016-09-29 05:37:29.227 INFO 5 --- [ main] org.example.webapp.Application : Starting Application v1.0-SNAPSHOT on bootiful-couchbase with PID 5 (/maven/bootiful-couchbase.jar started by root in /) 2016-09-29 05:37:29.259 INFO 5 --- [ main] org.example.webapp.Application : No active profile set, falling back to default profiles: default 2016-09-29 05:37:29.696 INFO 5 --- [ main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@4ccabbaa: startup date [Thu Sep 29 05:37:29 UTC 2016]; root of context hierarchy 2016-09-29 05:37:34.375 INFO 5 --- [ main] c.c.client.core.env.CoreEnvironment : ioPoolSize is less than 3 (1), setting to: 3 2016-09-29 05:37:34.376 INFO 5 --- [ main] c.c.client.core.env.CoreEnvironment : computationPoolSize is less than 3 (1), setting to: 3 2016-09-29 05:37:35.026 INFO 5 --- [ main] com.couchbase.client.core.CouchbaseCore : CouchbaseEnvironment: {sslEnabled=false, sslKeystoreFile='null', sslKeystorePassword='null', queryEnabled=false, queryPort=8093, bootstrapHttpEnabled=true, bootstrapCarrierEnabled=true, bootstrapHttpDirectPort=8091, bootstrapHttpSslPort=18091, bootstrapCarrierDirectPort=11210, bootstrapCarrierSslPort=11207, ioPoolSize=3, computationPoolSize=3, responseBufferSize=16384, requestBufferSize=16384, kvServiceEndpoints=1, viewServiceEndpoints=1, queryServiceEndpoints=1, searchServiceEndpoints=1, ioPool=NioEventLoopGroup, coreScheduler=CoreScheduler, eventBus=DefaultEventBus, packageNameAndVersion=couchbase-java-client/2.2.8 (git: 2.2.8, core: 1.2.9), dcpEnabled=false, retryStrategy=BestEffort, maxRequestLifetime=75000, retryDelay=ExponentialDelay{growBy 1.0 MICROSECONDS, powers of 2; lower=100, upper=100000}, reconnectDelay=ExponentialDelay{growBy 1.0 MILLISECONDS, powers of 2; lower=32, upper=4096}, observeIntervalDelay=ExponentialDelay{growBy 1.0 MICROSECONDS, powers of 2; lower=10, upper=100000}, keepAliveInterval=30000, autoreleaseAfter=2000, bufferPoolingEnabled=true, tcpNodelayEnabled=true, mutationTokensEnabled=false, socketConnectTimeout=1000, dcpConnectionBufferSize=20971520, dcpConnectionBufferAckThreshold=0.2, dcpConnectionName=dcp/core-io, callbacksOnIoPool=false, queryTimeout=7500, viewTimeout=7500, kvTimeout=2500, connectTimeout=5000, disconnectTimeout=25000, dnsSrvEnabled=false} 2016-09-29 05:37:36.063 INFO 5 --- [ cb-io-1-1] com.couchbase.client.core.node.Node : Connected to Node couchbase-service 2016-09-29 05:37:36.256 INFO 5 --- [ cb-io-1-1] com.couchbase.client.core.node.Node : Disconnected from Node couchbase-service 2016-09-29 05:37:37.727 INFO 5 --- [ cb-io-1-2] com.couchbase.client.core.node.Node : Connected to Node couchbase-service 2016-09-29 05:37:38.316 INFO 5 --- [-computations-3] c.c.c.core.config.ConfigurationProvider : Opened bucket books 2016-09-29 05:37:40.655 INFO 5 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup Book{isbn=978-1-4919-1889-0, name=Minecraft Modding with Forge, cost=29.99} 2016-09-29 05:37:41.497 INFO 5 --- [ main] org.example.webapp.Application : Started Application in 14.64 seconds (JVM running for 16.631) 2016-09-29 05:37:41.514 INFO 5 --- [ Thread-5] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@4ccabbaa: startup date [Thu Sep 29 05:37:29 UTC 2016]; root of context hierarchy 2016-09-29 05:37:41.528 INFO 5 --- [ Thread-5] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown 2016-09-29 05:37:41.577 INFO 5 --- [ cb-io-1-2] com.couchbase.client.core.node.Node : Disconnected from Node couchbase-service 2016-09-29 05:37:41.578 INFO 5 --- [ Thread-5] c.c.c.core.config.ConfigurationProvider : Closed bucket books |
A principal instrução de saída a ser observada é
|
1 |
Book{isbn=978-1-4919-1889-0, name=Minecraft Modding with Forge, cost=29.99} |
Isso indica que o documento JSON foi inserido (inserido ou atualizado) no banco de dados do Couchbase.
Painel de controle do Kubernetes
Painel de controle do Kubernetes parece mais abrangente e afirma ter 90% paridade com a CLI. Use Visualização da configuração do kubectl.sh para visualizar as informações de configuração sobre o cluster. O resultado é semelhante:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 |
apiVersion: v1 clusters: - cluster: certificate-authority-data: REDACTED server: https://52.40.9.27 name: aws_kubernetes contexts: - context: cluster: aws_kubernetes user: aws_kubernetes name: aws_kubernetes current-context: aws_kubernetes kind: Config preferences: {} users: - name: aws_kubernetes user: client-certificate-data: REDACTED client-key-data: REDACTED token: 3GuTCLvFnINHed9dWICICidlrSv8C0kg - name: aws_kubernetes-basic-auth user: password: 8pxC121Oj7kN0nCa username: admin |
O clusters.cluster.server mostra a localização do mestre do Kubernetes. O valor da propriedade usuários mostram dois usuários que podem ser usados para acessar o painel. O segundo usa autenticação básica e, portanto, copia a propriedade
nome de usuário e senha valor da propriedade. Em nosso caso, a interface do usuário do painel pode ser acessada em https://52.40.9.27/ui.
Todos os recursos do Kubernetes podem ser facilmente visualizados nesse painel sofisticado.
Encerrar o cluster do Kubernetes
Por fim, desligue o cluster do Kubernetes:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 |
kube-down.sh Bringing down cluster using provider: aws Deleting instances in VPC: vpc-6b5b4b0f Deleting auto-scaling group: kubernetes-minion-group-us-west-2a Deleting auto-scaling launch configuration: kubernetes-minion-group-us-west-2a Deleting auto-scaling group: kubernetes-minion-group-us-west-2a Waiting for instances to be deleted Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... Waiting for instance i-f95bdae1 to be terminated (currently shutting-down) Sleeping for 3 seconds... All instances deleted Releasing Elastic IP: 52.40.9.27 Deleting volume vol-99a30b11 Cleaning up resources in VPC: vpc-6b5b4b0f Cleaning up security group: sg-cd0ca0b4 Cleaning up security group: sg-d20ca0ab Deleting security group: sg-cd0ca0b4 Deleting security group: sg-d20ca0ab Deleting VPC: vpc-6b5b4b0f Done |
https://www.couchbase.com/products/cloud/kubernetes fornecem mais detalhes sobre a execução do Couchbase usando diferentes estruturas de orquestração. Outras referências:
- Fóruns do Couchbase ou StackOverflow
- Siga-nos em @couchbasedev ou @couchbase
- Leia mais sobre Servidor Couchbase
