Este blog faz parte de uma série de blogs com várias partes que mostra como executar seus aplicativos no Kubernetes. Ele usará o Couchbaseum banco de dados de documentos distribuídos NoSQL de código aberto, como o contêiner do Docker.
A primeira parte (Couchbase no Kubernetes) explicou como iniciar o cluster do Kubernetes usando o Vagrant. A segunda parte (Kubernetes na Amazon) explicou como executar essa configuração no Amazon Web Services.
Esta terceira parte mostrará:
- Como configurar e iniciar o cluster do Kubernetes no Google Cloud
- Execute o contêiner do Docker no cluster do Kubernetes
- Expor o pod no Kubernetes como serviço
- Desligar o cluster
Aqui está uma visão geral rápida:
Vamos entrar em detalhes!
Primeiros passos com o Google Compute Engine fornecem instruções detalhadas sobre como configurar o Kubernetes no Google Cloud.
Download e configuração do Google Cloud SDK
É necessário um pouco de configuração se você nunca acessou o Google Cloud em sua máquina. Isso foi um pouco complicado e pode ser simplificado.
- Criar uma conta faturável em Google Cloud
- Instalar SDK do Google Cloud
- Configurar credenciais: gcloud auth login
- Crie um novo projeto do Google Cloud e dê um nome a ele
couchbase-em-kubernetes - Defina o projeto:
gcloud config set project couchbase-on-kubernetes - Definir zona padrão:
gcloud config set compute/zone us-central1-a - Criar uma instância:
gcloud compute instances create example-instance --machine-type n1-standard-1 --image debian-8 - SSH na instância:
gcloud compute ssh exemplo-instância - Excluir a instância:
gcloud compute instances delete example-instance
Configurar o cluster do Kubernetes no Google Cloud
O cluster do Kubernetes pode ser criado no Google Cloud como:
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set KUBERNETES_PROVIDER=gce ./cluster/kube-up.sh |
Certifique-se de que PROVEDOR DE KUBERNETES é definido como gce ou não definir nada. Por padrão, isso provisiona um cluster Kubernetes de 4 nós com um mestre. Isso significa que são criadas 5 máquinas virtuais.
Se você baixou o Kubernetes de github.com/kubernetes/kubernetes/releasestodos os valores podem ser alterados em cluster/aws/config-default.sh.
Iniciar o Kubernetes no Google Cloud mostra o seguinte registro. O SDK do Google Cloud estava se comportando de forma um pouco estranha, mas adotar os padrões parece funcionar:
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./kubernetes/cluster/kube-up.sh ... Starting cluster using provider: gce ... calling verify-prereqs You have specified individual components to update. If you are trying to install new components, use: $ gcloud components install alpha Do you want to run install instead (y/N)? Your current Cloud SDK version is: 99.0.0 Installing components from version: 99.0.0 ┌──────────────────────────────────────────────┐ │ These components will be installed. │ ├───────────────────────┬────────────┬─────────┤ │ Name │ Version │ Size │ ├───────────────────────┼────────────┼─────────┤ │ gcloud Alpha Commands │ 2016.01.12 │ < 1 MiB │ └───────────────────────┴────────────┴─────────┘ For the latest full release notes, please visit: https://cloud.google.com/sdk/release_notes Do you want to continue (Y/n)? ╔════════════════════════════════════════════════════════════╗ ╠═ Creating update staging area ═╣ ╠════════════════════════════════════════════════════════════╣ ╠═ Installing: gcloud Alpha Commands ═╣ ╠════════════════════════════════════════════════════════════╣ ╠═ Creating backup and activating new installation ═╣ ╚════════════════════════════════════════════════════════════╝ Performing post processing steps...done. Update done! You have specified individual components to update. If you are trying to install new components, use: $ gcloud components install beta Do you want to run install instead (y/N)? Your current Cloud SDK version is: 99.0.0 Installing components from version: 99.0.0 ┌─────────────────────────────────────────────┐ │ These components will be installed. │ ├──────────────────────┬────────────┬─────────┤ │ Name │ Version │ Size │ ├──────────────────────┼────────────┼─────────┤ │ gcloud Beta Commands │ 2016.01.12 │ < 1 MiB │ └──────────────────────┴────────────┴─────────┘ For the latest full release notes, please visit: https://cloud.google.com/sdk/release_notes Do you want to continue (Y/n)? ╔════════════════════════════════════════════════════════════╗ ╠═ Creating update staging area ═╣ ╠════════════════════════════════════════════════════════════╣ ╠═ Installing: gcloud Beta Commands ═╣ ╠════════════════════════════════════════════════════════════╣ ╠═ Creating backup and activating new installation ═╣ ╚════════════════════════════════════════════════════════════╝ Performing post processing steps...done. Update done! All components are up to date. ... calling kube-up Your active configuration is: [default] Project: couchbase-on-kubernetes Zone: us-central1-b Creating gs://kubernetes-staging-9479406781 Creating gs://kubernetes-staging-9479406781/... +++ Staging server tars to Google Storage: gs://kubernetes-staging-9479406781/devel +++ kubernetes-server-linux-amd64.tar.gz uploaded (sha1 = 1ff42f7c31837851d919a66fc07f34b9dbdacf28) +++ kubernetes-salt.tar.gz uploaded (sha1 = f307380ad6af7dabcf881b132146fa775c18dca8) Looking for already existing resources Starting master and configuring firewalls Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/zones/us-central1-b/disks/kubernetes-master-pd]. NAME ZONE SIZE_GB TYPE STATUS kubernetes-master-pd us-central1-b 20 pd-ssd READY Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/regions/us-central1/addresses/kubernetes-master-ip]. Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/firewalls/default-default-ssh]. Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/firewalls/kubernetes-master-https]. NAME NETWORK SRC_RANGES RULES SRC_TAGS TARGET_TAGS default-default-ssh default 0.0.0.0/0 tcp:22 NAME NETWORK SRC_RANGES RULES SRC_TAGS TARGET_TAGS kubernetes-master-https default 0.0.0.0/0 tcp:443 kubernetes-master +++ Logging using Fluentd to gcp ./kubernetes/cluster/../cluster/../cluster/gce/util.sh: line 434: @: unbound variable ./kubernetes/cluster/../cluster/../cluster/gce/util.sh: line 434: @: unbound variable ./kubernetes/cluster/../cluster/../cluster/gce/util.sh: line 434: @: unbound variable ./kubernetes/cluster/../cluster/../cluster/gce/util.sh: line 434: @: unbound variable Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/firewalls/default-default-internal]. NAME NETWORK SRC_RANGES RULES SRC_TAGS TARGET_TAGS default-default-internal default 10.0.0.0/8 tcp:1-65535,udp:1-65535,icmp Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/firewalls/kubernetes-minion-all]. NAME NETWORK SRC_RANGES RULES SRC_TAGS TARGET_TAGS kubernetes-minion-all default 10.244.0.0/16 tcp,udp,icmp,esp,ah,sctp kubernetes-minion Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/zones/us-central1-b/instances/kubernetes-master]. NAME ZONE MACHINE_TYPE PREEMPTIBLE INTERNAL_IP EXTERNAL_IP STATUS kubernetes-master us-central1-b n1-standard-1 10.128.0.2 104.197.213.249 RUNNING Creating minions. ./kubernetes/cluster/../cluster/../cluster/gce/util.sh: line 434: @: unbound variable ./kubernetes/cluster/../cluster/../cluster/gce/util.sh: line 434: @: unbound variable Attempt 1 to create kubernetes-minion-template WARNING: You have selected a disk size of under [200GB]. This may result in poor I/O performance. For more information, see: https://developers.google.com/compute/docs/disks/persistent-disks#pdperformance. Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/instanceTemplates/kubernetes-minion-template]. NAME MACHINE_TYPE PREEMPTIBLE CREATION_TIMESTAMP kubernetes-minion-template n1-standard-1 2016-03-03T14:01:14.322-08:00 Created [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/zones/us-central1-b/instanceGroupManagers/kubernetes-minion-group]. NAME ZONE BASE_INSTANCE_NAME SIZE TARGET_SIZE INSTANCE_TEMPLATE AUTOSCALED kubernetes-minion-group us-central1-b kubernetes-minion 4 kubernetes-minion-template Waiting for group to become stable, current operations: creating: 4 Waiting for group to become stable, current operations: creating: 4 Waiting for group to become stable, current operations: creating: 4 Waiting for group to become stable, current operations: creating: 4 Waiting for group to become stable, current operations: creating: 4 Waiting for group to become stable, current operations: creating: 4 Waiting for group to become stable, current operations: creating: 3 Group is stable MINION_NAMES=kubernetes-minion-1hmm kubernetes-minion-3x1d kubernetes-minion-h1ov kubernetes-minion-nshn Using master: kubernetes-master (external IP: 104.197.213.249) 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. cluster "couchbase-on-kubernetes_kubernetes" set. user "couchbase-on-kubernetes_kubernetes" set. context "couchbase-on-kubernetes_kubernetes" set. switched to context "couchbase-on-kubernetes_kubernetes". user "couchbase-on-kubernetes_kubernetes-basic-auth" set. Wrote config for couchbase-on-kubernetes_kubernetes to /Users/arungupta/.kube/config Kubernetes cluster is running. The master is running at: https://104.197.213.249 The user name and password to use is located in /Users/arungupta/.kube/config. ... calling validate-cluster Waiting for 4 ready nodes. 0 ready nodes, 0 registered. Retrying. Waiting for 4 ready nodes. 0 ready nodes, 2 registered. Retrying. Waiting for 4 ready nodes. 0 ready nodes, 3 registered. Retrying. Waiting for 4 ready nodes. 0 ready nodes, 4 registered. Retrying. Waiting for 4 ready nodes. 3 ready nodes, 4 registered. Retrying. Waiting for 4 ready nodes. 3 ready nodes, 4 registered. Retrying. Found 4 node(s). NAME LABELS STATUS AGE kubernetes-minion-1hmm kubernetes.io/hostname=kubernetes-minion-1hmm Ready 1m kubernetes-minion-3x1d kubernetes.io/hostname=kubernetes-minion-3x1d Ready 52s kubernetes-minion-h1ov kubernetes.io/hostname=kubernetes-minion-h1ov Ready 1m kubernetes-minion-nshn kubernetes.io/hostname=kubernetes-minion-nshn Ready 1m Validate output: NAME STATUS MESSAGE ERROR controller-manager Healthy ok nil scheduler Healthy ok nil etcd-0 Healthy {"health": "true"} nil etcd-1 Healthy {"health": "true"} nil Cluster validation succeeded Done, listing cluster services: Kubernetes master is running at https://104.197.213.249 GLBCDefaultBackend is running at https://104.197.213.249/api/v1/proxy/namespaces/kube-system/services/default-http-backend Heapster is running at https://104.197.213.249/api/v1/proxy/namespaces/kube-system/services/heapster KubeDNS is running at https://104.197.213.249/api/v1/proxy/namespaces/kube-system/services/kube-dns KubeUI is running at https://104.197.213.249/api/v1/proxy/namespaces/kube-system/services/kube-ui Grafana is running at https://104.197.213.249/api/v1/proxy/namespaces/kube-system/services/monitoring-grafana InfluxDB is running at https://104.197.213.249/api/v1/proxy/namespaces/kube-system/services/monitoring-influxdb |
Há algumas variáveis não vinculadas e uma mensagem de AVISO, mas isso não parece prejudicar o script. O Google Cloud Console mostra: 
Cinco instâncias são criadas conforme mostrado - uma para o nó mestre e quatro para os nós de trabalho.
Executar o contêiner do Docker no cluster do Kubernetes no Google Cloud
Agora que o cluster está em funcionamento, obtenha uma lista de todos os nós:
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./kubernetes/cluster/kubectl.sh get no NAME LABELS STATUS AGE kubernetes-minion-1hmm kubernetes.io/hostname=kubernetes-minion-1hmm Ready 47m kubernetes-minion-3x1d kubernetes.io/hostname=kubernetes-minion-3x1d Ready 46m kubernetes-minion-h1ov kubernetes.io/hostname=kubernetes-minion-h1ov Ready 47m kubernetes-minion-nshn kubernetes.io/hostname=kubernetes-minion-nshn Ready 47m |
Ele mostra quatro nós de trabalho. Crie um pod do Couchbase:
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./kubernetes/cluster/kubectl.sh run couchbase --image=arungupta/couchbase replicationcontroller "couchbase" created |
Observe como o nome da imagem pode ser especificado na CLI. Esse comando cria um controlador de replicação com um único pod. O pod usa arungupta/couchbase Imagem do Docker que fornece um servidor Couchbase pré-configurado. Qualquer imagem do Docker pode ser especificada aqui.
Obtenha todos os recursos do RC:
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./kubernetes/cluster/kubectl.sh get rc CONTROLLER CONTAINER(S) IMAGE(S) SELECTOR REPLICAS AGE couchbase couchbase arungupta/couchbase run=couchbase 1 48s |
Isso mostra o controlador de replicação que foi criado para você.
Obtenha todos os Pods:
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./kubernetes/cluster/kubectl.sh get po NAME READY STATUS RESTARTS AGE couchbase-s8v9r 1/1 Running 0 1m |
A saída mostra o pod que é criado como parte do controlador de replicação.
Obtenha mais detalhes sobre o Pod:
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./kubernetes/cluster/kubectl.sh describe po couchbase-s8v9r Name: couchbase-s8v9r Namespace: default Image(s): arungupta/couchbase Node: kubernetes-minion-3x1d/10.128.0.3 Start Time: Thu, 03 Mar 2016 14:53:36 -0800 Labels: run=couchbase Status: Running Reason: Message: IP: 10.244.3.3 Replication Controllers: couchbase (1/1 replicas created) Containers: couchbase: Container ID: docker://601ee2e4c822814c3969a241e37c97bf4d0d209f952f24707ab308192d289098 Image: arungupta/couchbase Image ID: docker://298618e67e495c2535abd17b60241565e456a4c9ee96c923ecf844a9dbcccced QoS Tier: cpu: Burstable Requests: cpu: 100m State: Running Started: Thu, 03 Mar 2016 14:54:46 -0800 Ready: True Restart Count: 0 Environment Variables: Conditions: Type Status Ready True Volumes: default-token-frsd7: Type: Secret (a secret that should populate this volume) SecretName: default-token-frsd7 Events: FirstSeen LastSeen Count From SubobjectPath Reason Message ───────── ──────── ───── ──── ───────────── ────── ─────── 1m 1m 1 {kubelet kubernetes-minion-3x1d} implicitly required container POD Pulled Container image "gcr.io/google_containers/pause:0.8.0" already present on machine 1m 1m 1 {scheduler } Scheduled Successfully assigned couchbase-s8v9r to kubernetes-minion-3x1d 1m 1m 1 {kubelet kubernetes-minion-3x1d} implicitly required container POD Created Created with docker id c1de9da87f1e 1m 1m 1 {kubelet kubernetes-minion-3x1d} spec.containers{couchbase} Pulling Pulling image "arungupta/couchbase" 1m 1m 1 {kubelet kubernetes-minion-3x1d} implicitly required container POD Started Started with docker id c1de9da87f1e 29s 29s 1 {kubelet kubernetes-minion-3x1d} spec.containers{couchbase} Pulled Successfully pulled image "arungupta/couchbase" 29s 29s 1 {kubelet kubernetes-minion-3x1d} spec.containers{couchbase} Created Created with docker id 601ee2e4c822 29s 29s 1 {kubelet kubernetes-minion-3x1d} spec.containers{couchbase} Started Started with docker id 601ee2e4c822 |
Expor o pod no Kubernetes como serviço
Agora que nosso pod está em execução, como posso acessar o servidor Couchbase? Você precisa expô-lo fora do cluster do Kubernetes. O kubectl expose pega um pod, serviço ou controlador de replicação e o expõe como um serviço do Kubernetes.
Vamos expor o controlador de replicação criado anteriormente e expô-lo:
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./kubernetes/cluster/kubectl.sh expose rc couchbase --target-port=8091 --port=8091 --type=LoadBalancer service "couchbase" exposed |
Obtenha mais detalhes sobre o Service:
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./kubernetes/cluster/kubectl.sh describe svc couchbase Name: couchbase Namespace: default Labels: run=couchbase Selector: run=couchbase Type: LoadBalancer IP: 10.0.37.150 LoadBalancer Ingress: 104.197.118.35 Port: 8091/TCP NodePort: 30808/TCP Endpoints: 10.244.3.3:8091 Session Affinity: None Events: FirstSeen LastSeen Count From SubobjectPath Reason Message ───────── ──────── ───── ──── ───────────── ────── ─────── 2m 2m 1 {service-controller } CreatingLoadBalancer Creating load balancer 1m 1m 1 {service-controller } CreatedLoadBalancer Created load balancer |
O Ingresso do balanceador de carga O atributo fornece o endereço IP do balanceador de carga que agora está acessível publicamente. Aguarde 3 minutos para que o balanceador de carga se estabilize. Acesse-o usando a porta 8091 e a página de login do Console da Web do Couchbase será exibida: 
Digite as credenciais como "Administrator" e "password" para ver o console da Web: 
Assim, você acabou de acessar seu pod fora do cluster do Kubernetes.
Encerrar o cluster do Kubernetes
Por fim, desligue o cluster usando cluster/kube-down.sh roteiro.
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./kubernetes/cluster/kube-down.sh Bringing down cluster using provider: gce You have specified individual components to update. If you are trying to install new components, use: $ gcloud components install alpha Do you want to run install instead (y/N)? All components are up to date. You have specified individual components to update. If you are trying to install new components, use: $ gcloud components install beta Do you want to run install instead (y/N)? All components are up to date. All components are up to date. Your active configuration is: [default] Project: couchbase-on-kubernetes Zone: us-central1-b Bringing down cluster Deleted [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/zones/us-central1-b/instanceGroupManagers/kubernetes-minion-group]. Deleted [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/instanceTemplates/kubernetes-minion-template]. Updated [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/zones/us-central1-b/instances/kubernetes-master]. Deleted [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/zones/us-central1-b/instances/kubernetes-master]. Deleted [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/firewalls/kubernetes-master-https]. Deleted [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/firewalls/kubernetes-minion-all]. Deleting routes kubernetes-ad3beb92-e18b-11e5-8e71-42010a800002 Deleted [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/global/routes/kubernetes-ad3beb92-e18b-11e5-8e71-42010a800002]. Deleted [https://www.googleapis.com/compute/v1/projects/couchbase-on-kubernetes/regions/us-central1/addresses/kubernetes-master-ip]. property "clusters.couchbase-on-kubernetes_kubernetes" unset. property "users.couchbase-on-kubernetes_kubernetes" unset. property "users.couchbase-on-kubernetes_kubernetes-basic-auth" unset. property "contexts.couchbase-on-kubernetes_kubernetes" unset. property "current-context" unset. Cleared config for couchbase-on-kubernetes_kubernetes from /Users/arungupta/.kube/config Done |
Aproveite!
