Na Movile, temos diversas aplicações rodando em nossa infraestrutura distribuídas em datacenters e provedores de cloud, como AWS, Google e Azure. Com isso, sempre nos preocupamos em disponibilizar o deploy dessas aplicações, da melhor maneira, possibilitando: fácil gerenciamento, rastreabilidade e atualização. Atualmente construímos pacotes RPM dessas aplicações a cada release e nossa automação com o Chef se encarrega de fazer o deploy nos servidores. Assim, o objetivo deste artigo é demonstrar com um exemplo bem simples como estamos fazendo o deploy de aplicações “conteinerizadas”, orquestrado pelo Kubernetes.
Kubernetes
Atualmente estamos migrando algumas aplicações para contêineres e escolhemos o Kubernetes para orquestração devido às principais características:
- Self-healing
Se ocorrer alguma falha, como um crash na aplicação, o contêiner é recriado de maneira instantânea ao invés de ficar parado, com problema, esperando uma ação manual.
- Auto-scaling
É possível realizar o auto-scaling de maneira extremamente simples definindo o número de réplicas de seu pod.
- Gerenciamento de DNS
Para cada pod é criado sua entrada de DNS e, se desenvolvido seu devido manifesto, também cria um nome que pode responder para vários pods (DNS round-robin).
- Load Balancer
É possível criar load balancers externos e internos para publicar os Front-ends.
- Rolling Update e Rollback
Atualização de suas aplicações controladas e graduais assim como a facilidade de reversão caso algo dê errado!
Exemplo de aplicação em Kubernetes
Para facilitar o entendimento, irei demonstrar uma configuração extremamente simples de deploy em Kubernetes:
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<span style="font-weight: 400;">$ cat exemplo-deploy.yaml</span> <span style="font-weight: 400;">apiVersion: apps/v1beta1</span> <span style="font-weight: 400;">kind: Deployment</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> name: exemplo-deploy</span> <span style="font-weight: 400;"> namespace: default</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;">app: exemplo-deploy</span> <span style="font-weight: 400;">spec:</span> <span style="font-weight: 400;"> template:</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">labels:</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">app: exemplo-deploy</span> <span style="font-weight: 400;">spec:</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">containers:</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">- name: exemplo-deploy</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">image: nginx:latest</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">ports:</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">- containerPort: 80</span> <span style="font-weight: 400;">$ cat exemplo-service.yaml</span> <span style="font-weight: 400;">apiVersion: v1</span> <span style="font-weight: 400;">kind: Service</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> name: exemplo-service</span> <span style="font-weight: 400;"> namespace: default</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;">app: exemplo</span> <span style="font-weight: 400;">spec:</span> <span style="font-weight: 400;"> ports:</span> <span style="font-weight: 400;"> - protocol: TCP</span> <span style="font-weight: 400;">port: 80</span> <span style="font-weight: 400;">targetPort: 80</span> <span style="font-weight: 400;"> selector:</span> <span style="font-weight: 400;">app: exemplo-deploy</span> <span style="font-weight: 400;"> type: LoadBalancer</span> <span style="font-weight: 400;">$ kubectl apply -f exemplo-service.yaml</span> <span style="font-weight: 400;">service "exemplo-service" created</span> <span style="font-weight: 400;">$ kubectl apply -f exemplo-deploy.yaml</span> <span style="font-weight: 400;">deployment "exemplo-deploy" created</span> <span style="font-weight: 400;">$ kubectl get svc</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;"> TYPE </span> <span style="font-weight: 400;">CLUSTER-IP </span> <span style="font-weight: 400;">EXTERNAL-IP </span> <span style="font-weight: 400;">PORT(S) </span> <span style="font-weight: 400;">AGE</span> <span style="font-weight: 400;">exemplo-service </span> <span style="font-weight: 400;">LoadBalancer 10.55.246.1</span> <span style="font-weight: 400;">104.154.94.121 80:30650/TCP </span> <span style="font-weight: 400;">57s</span> <span style="font-weight: 400;">kubernetes ClusterIP </span> <span style="font-weight: 400;">10.55.240.1</span> <span style="font-weight: 400;"><none> </span> <span style="font-weight: 400;">443/TCP </span> <span style="font-weight: 400;">55d</span> <span style="font-weight: 400;">$ kubectl get pods</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">READY </span> <span style="font-weight: 400;">STATUS RESTARTS AGE</span> <span style="font-weight: 400;">exemplo-deploy-7f56cfb95f-jn55s </span> <span style="font-weight: 400;">1/1 Running 0 1m</span> <span style="font-weight: 400;">$ curl -I http://104.154.94.121</span> <span style="font-weight: 400;">HTTP/1.1 200 OK</span> <span style="font-weight: 400;">Server: nginx/1.15.0</span> <span style="font-weight: 400;">Date: Wed, 13 Jun 2018 21:51:33 GMT</span> <span style="font-weight: 400;">Content-Type: text/html</span> <span style="font-weight: 400;">Content-Length: 612</span> <span style="font-weight: 400;">Last-Modified: Tue, 05 Jun 2018 12:00:18 GMT</span> <span style="font-weight: 400;">Connection: keep-alive</span> <span style="font-weight: 400;">ETag: "5b167b52-264"</span> <span style="font-weight: 400;">Accept-Ranges: bytes</span> <span style="font-weight: 400;">$</span> |
Como visto no exemplo acima, fizemos o deploy do nginx pelo Kubernetes expondo sua porta publicamente pelo load balancer.
Quando temos uma aplicação somente, é fácil de controlar seus arquivos YAML, mas e quando temos diversas aplicações onde a grande maioria é semelhante, muitas vezes, só mudando de nome e porta? E se eu quiser alterar a versão ou alterar o valor de um campo? Por causa dessas e outras perguntas,tive a necessidade de encontrar algo que facilitasse o templating desses arquivos YAML e encontrei o Helm.
Helm
O Helm é um gerenciador de aplicações Kubernetes que te ajuda a criar, versionar, compartilhar e publicar seus artefatos. Você consegue desenvolver templates dos seus arquivos YAML e durante a instalação de cada aplicação personalizar por parâmetros as variáveis com facilidade. O Helm é mantido pela comunidade e gigantes como Google e Microsoft.
Componentes
O Helm tem dois principais componentes:
- Helm Client
É o CLI onde gerenciamos repositórios, desenvolvemos localmente os charts e interagimos com o Tiller server. Escrito em Go, utiliza o protocolo gRPC para interagir com o servidor Tiller.
- Tiller Server
É o servidor que interage com a API do Kubernetes através dos comandos executados pelo Helm Client. Também é escrito em Go.
Instalação
A instalação é bem simples mas exige atenção na pós-instalação, pois em alguns casos é necessário criar uma role para garantir o acesso do Tiller no cluster Kubernetes:
- Instalação do Client:
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<span style="font-weight: 400;">$ curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get > get_helm.sh</span> <span style="font-weight: 400;">$ chmod 700 get_helm.sh</span> <span style="font-weight: 400;">$ ./get_helm.sh</span> |
- Criar o ServiceAccount e ClusterRoleBinding:
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<span style="font-weight: 400;">$ cat rbac-config.yaml</span> <span style="font-weight: 400;">apiVersion: v1</span> <span style="font-weight: 400;">kind: ServiceAccount</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> name: tiller</span> <span style="font-weight: 400;"> namespace: kube-system</span> <span style="font-weight: 400;">---</span> <span style="font-weight: 400;">apiVersion: rbac.authorization.k8s.io/v1beta1</span> <span style="font-weight: 400;">kind: ClusterRoleBinding</span> <span style="font-weight: 400;"> metadata:</span> <span style="font-weight: 400;">name: tiller</span> <span style="font-weight: 400;">roleRef:</span> <span style="font-weight: 400;"> apiGroup: rbac.authorization.k8s.io</span> <span style="font-weight: 400;"> kind: ClusterRole</span> <span style="font-weight: 400;"> name: cluster-admin</span> <span style="font-weight: 400;">subjects:</span> <span style="font-weight: 400;"> - kind: ServiceAccount</span> <span style="font-weight: 400;">name: tiller</span> <span style="font-weight: 400;">namespace: kube-system</span> <span style="font-weight: 400;">$ kubectl create -f rbac-config.yaml</span> |
- Inicializar o Tiller no cluster e atualizar o repositório:
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<span style="font-weight: 400;">$ helm init --service-account tiller</span> <span style="font-weight: 400;">$ helm repo update</span> |
Pronto! Agora você pode procurar e instalar pacotes do repositório público e criar os seus próprios!
Charts
O Helm utiliza um formato de empacotamento chamado “charts“. Um chart é uma coleção de arquivos que descrevem os recursos que serão aplicados no Kubernetes (os YAMLs).
- Estrutura do Chart
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<span style="font-weight: 400;">exemplo/</span> <span style="font-weight: 400;">Chart.yaml </span> <span style="font-weight: 400;"># A YAML file containing information about the chart</span> <span style="font-weight: 400;">LICENSE </span> <span style="font-weight: 400;"># OPTIONAL: A plain text file containing the license for the chart</span> <span style="font-weight: 400;">README.md </span> <span style="font-weight: 400;"># OPTIONAL: A human-readable README file</span> <span style="font-weight: 400;">requirements.yaml # OPTIONAL: A YAML file listing dependencies for the chart</span> <span style="font-weight: 400;">values.yaml </span> <span style="font-weight: 400;"># The default configuration values for this chart</span> <span style="font-weight: 400;">charts/ </span> <span style="font-weight: 400;"># A directory containing any charts upon which this chart depends.</span> <span style="font-weight: 400;">templates/ # A directory of templates that, when combined with values,</span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;"> # will generate valid Kubernetes manifest files.</span> <span style="font-weight: 400;">templates/NOTES.txt # OPTIONAL: A plain text file containing short usage notes</span> |
- Criando nosso chart
Agora vamos ao que interessa! Vamos transformar nossa aplicação “exemplo” em um chart! Primeiro vamos iniciá-lo:
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<span style="font-weight: 400;">$ helm create exemplo</span> <span style="font-weight: 400;">Creating exemplo</span> <span style="font-weight: 400;">$</span> |
Será criado um diretório chamado “exemplo” já com alguns arquivos de apoio, recomendo fortemente verificar esses arquivos para entender melhor sua estrutura.
No nosso caso, vamos apagar tudo da pasta templates e começar do zero!
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<span style="font-weight: 400;">$ rm -rf exemplo/templates/*</span> |
Agora vamos mover nosso exemplo-deploy.yaml e exemplo-service.yaml para a pasta exemplo/templates e alterar onde queremos colocar as diretivas de template:
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<span style="font-weight: 400;">$ cat exemplo/templates/exemplo-deploy.yaml</span> <span style="font-weight: 400;">apiVersion: apps/v1beta1</span> <span style="font-weight: 400;">kind: Deployment</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> name: {{ .Release.Name }}-deploy</span> <span style="font-weight: 400;"> namespace: {{ .Release.Namespace }}</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;"> app: {{ .Release.Name }}-deploy</span> <span style="font-weight: 400;">spec:</span> <span style="font-weight: 400;"> template:</span> <span style="font-weight: 400;"> metadata:</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;"> app: {{ .Release.Name }}-deploy</span> <span style="font-weight: 400;"> spec:</span> <span style="font-weight: 400;"> containers:</span> <span style="font-weight: 400;"> - name: exemplo-deploy</span> <span style="font-weight: 400;"> image: nginx:{{ .Values.deployment.version }}</span> <span style="font-weight: 400;"> ports:</span> <span style="font-weight: 400;"> - containerPort: 80</span> <span style="font-weight: 400;">$ cat exemplo/templates/exemplo-service.yaml</span> <span style="font-weight: 400;">apiVersion: v1</span> <span style="font-weight: 400;">kind: Service</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> name: {{ .Release.Name }}-service</span> <span style="font-weight: 400;"> namespace: {{ .Release.Namespace }}</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;"> app: {{ .Release.Name }}</span> <span style="font-weight: 400;">spec:</span> <span style="font-weight: 400;"> ports:</span> <span style="font-weight: 400;"> - protocol: TCP</span> <span style="font-weight: 400;"> port: {{ .Values.service.port }}</span> <span style="font-weight: 400;"> targetPort: 80</span> <span style="font-weight: 400;"> selector:</span> <span style="font-weight: 400;"> app: {{ .Release.Name }}-deploy</span> <span style="font-weight: 400;"> type: LoadBalancer</span> |
E o exemplo/values.yaml irá conter alguns valores padrão que poderão ser alterados pelo usuário na instalação do chart:
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<span style="font-weight: 400;">$ cat exemplo/values.yaml</span> <span style="font-weight: 400;">deployment:</span> <span style="font-weight: 400;"> version: latest </span> <span style="font-weight: 400;">service:</span> <span style="font-weight: 400;"> port: 80</span> <span style="font-weight: 400;">$</span> |
Vamos testar o chart no modo dry-run e debug para verificar se tudo está conforme esperamos:
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<span style="font-weight: 400;">$ helm install --dry-run --debug exemplo/</span> <span style="font-weight: 400;">[debug] Created tunnel using local port: '38007'</span> <span style="font-weight: 400;">[debug] SERVER: "127.0.0.1:38007"</span> <span style="font-weight: 400;">[debug] Original chart version: ""</span> <span style="font-weight: 400;">[debug] CHART PATH: /home/ip_fix/exemplo</span> <span style="font-weight: 400;">NAME: fair-salamander</span> <span style="font-weight: 400;">REVISION: 1</span> <span style="font-weight: 400;">RELEASED: Sun Jun 17 20:25:10 2018</span> <span style="font-weight: 400;">CHART: exemplo-0.1.0</span> <span style="font-weight: 400;">USER-SUPPLIED VALUES:</span> <span style="font-weight: 400;">{}</span> <span style="font-weight: 400;">COMPUTED VALUES:</span> <span style="font-weight: 400;">deployment:</span> <span style="font-weight: 400;"> version: latest</span> <span style="font-weight: 400;">service:</span> <span style="font-weight: 400;"> port: 80</span> <span style="font-weight: 400;">HOOKS:</span> <span style="font-weight: 400;">MANIFEST:</span> <span style="font-weight: 400;">---</span> <span style="font-weight: 400;"># Source: exemplo/templates/exemplo-service.yaml</span> <span style="font-weight: 400;">apiVersion: v1</span> <span style="font-weight: 400;">kind: Service</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> name: fair-salamander-service</span> <span style="font-weight: 400;"> namespace: default</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;"> app: fair-salamander</span> <span style="font-weight: 400;">spec:</span> <span style="font-weight: 400;"> ports:</span> <span style="font-weight: 400;"> - protocol: TCP</span> <span style="font-weight: 400;"> port: 80</span> <span style="font-weight: 400;"> targetPort: 80</span> <span style="font-weight: 400;"> selector:</span> <span style="font-weight: 400;"> app: fair-salamander-deploy</span> <span style="font-weight: 400;"> type: LoadBalancer</span> <span style="font-weight: 400;">---</span> <span style="font-weight: 400;"># Source: exemplo/templates/exemplo-deploy.yaml</span> <span style="font-weight: 400;">apiVersion: apps/v1beta1</span> <span style="font-weight: 400;">kind: Deployment</span> <span style="font-weight: 400;">metadata:</span> <span style="font-weight: 400;"> name: fair-salamander-deploy</span> <span style="font-weight: 400;"> namespace: default</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;"> app: fair-salamander-deploy</span> <span style="font-weight: 400;">spec:</span> <span style="font-weight: 400;"> template:</span> <span style="font-weight: 400;"> metadata:</span> <span style="font-weight: 400;"> labels:</span> <span style="font-weight: 400;"> app: fair-salamander-deploy</span> <span style="font-weight: 400;"> spec:</span> <span style="font-weight: 400;"> containers:</span> <span style="font-weight: 400;"> - name: exemplo-deploy</span> <span style="font-weight: 400;"> image: nginx:latest</span> <span style="font-weight: 400;"> ports:</span> <span style="font-weight: 400;"> - containerPort: 80</span> <span style="font-weight: 400;">$</span> |
Como podem ver, simulei a instalação para ver o template renderizado sem ser instalado de fato, sem passar parâmetros adicionais para ver os valores padrão. Ele gerou automaticamente o Release Name (fair-salamander).
- Instalando e testando o Chart
Agora vamos ver o resultado final da instalação do que seriam duas aplicações iguais, mas com parâmetros diferentes na instalação, sem a necessidade de retrabalho.
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<span style="font-weight: 400;">$ helm install exemplo/ --name exemplo01 --namespace exemplo01 --set deployment.version=1.15.0,service.port=8080</span> <span style="font-weight: 400;">NAME: exemplo01</span> <span style="font-weight: 400;">LAST DEPLOYED: Sun Jun 17 20:40:50 2018</span> <span style="font-weight: 400;">NAMESPACE: exemplo01</span> <span style="font-weight: 400;">STATUS: DEPLOYED</span> <span style="font-weight: 400;">RESOURCES:</span> <span style="font-weight: 400;">==> v1/Service</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">TYPE </span> <span style="font-weight: 400;">CLUSTER-IP</span> <span style="font-weight: 400;">EXTERNAL-IP PORT(S) </span> <span style="font-weight: 400;">AGE</span> <span style="font-weight: 400;">exemplo01-service LoadBalancer 10.55.250.66 <pending></span> <span style="font-weight: 400;">8080:30097/TCP 2s</span> <span style="font-weight: 400;">==> v1beta1/Deployment</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">DESIRED CURRENT UP-TO-DATE AVAILABLE AGE</span> <span style="font-weight: 400;">exemplo01-deploy 1 1 </span> <span style="font-weight: 400;">1 </span> <span style="font-weight: 400;"> 0 2s</span> <span style="font-weight: 400;">==> v1/Pod(related)</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">READY STATUS </span> <span style="font-weight: 400;">RESTARTS AGE</span> <span style="font-weight: 400;">exemplo01-deploy-55b74c5c58-dl9qj 0/1 ContainerCreating 0 </span> <span style="font-weight: 400;">2s</span> <span style="font-weight: 400;">$ helm install exemplo/ --name exemplo02 --namespace exemplo02 --set deployment.version=1.14.0,service.port=8081</span> <span style="font-weight: 400;">NAME: exemplo02</span> <span style="font-weight: 400;">LAST DEPLOYED: Sun Jun 17 20:41:25 2018</span> <span style="font-weight: 400;">NAMESPACE: exemplo02</span> <span style="font-weight: 400;">STATUS: DEPLOYED</span> <span style="font-weight: 400;">RESOURCES:</span> <span style="font-weight: 400;">==> v1/Service</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">TYPE </span> <span style="font-weight: 400;">CLUSTER-IP EXTERNAL-IP PORT(S) </span> <span style="font-weight: 400;">AGE</span> <span style="font-weight: 400;">exemplo02-service LoadBalancer 10.55.255.9 <pending></span> <span style="font-weight: 400;">8081:31590/TCP 0s</span> <span style="font-weight: 400;">==> v1beta1/Deployment</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">DESIRED CURRENT UP-TO-DATE AVAILABLE AGE</span> <span style="font-weight: 400;">exemplo02-deploy 1 1 </span> <span style="font-weight: 400;">1 </span> <span style="font-weight: 400;">0 </span> <span style="font-weight: 400;">0s</span> <span style="font-weight: 400;">==> v1/Pod(related)</span> <span style="font-weight: 400;">NAME READY STATUS </span> <span style="font-weight: 400;">RESTARTS AGE</span> <span style="font-weight: 400;">exemplo02-deploy-768c96479b-hn7zn 0/1 ContainerCreating 0 </span> <span style="font-weight: 400;">0s</span> <span style="font-weight: 400;">$ helm list</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">REVISION UPDATED </span> <span style="font-weight: 400;"> STATUS CHART </span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">NAMESPACE</span> <span style="font-weight: 400;">exemplo01 </span> <span style="font-weight: 400;">1 </span> <span style="font-weight: 400;"> Sun Jun 17 20:40:50 2018 DEPLOYED exemplo-0.1.0 </span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">exemplo01</span> <span style="font-weight: 400;">exemplo02 </span> <span style="font-weight: 400;">1 </span> <span style="font-weight: 400;"> Sun Jun 17 20:41:25 2018 DEPLOYED exemplo-0.1.0 </span> <span style="font-weight: 400;"> </span> <span style="font-weight: 400;">exemplo02</span> |
Ambos pacotes instalados com sucesso! Vamos conferir se realmente funcionou?
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<span style="font-weight: 400;">$ kubectl get pods -n exemplo01</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">READY </span> <span style="font-weight: 400;">STATUS RESTARTS AGE</span> <span style="font-weight: 400;">exemplo01-deploy-55b74c5c58-wtzpr 1/1 Running 0 </span> <span style="font-weight: 400;">21s</span> <span style="font-weight: 400;">$ kubectl get svc -n exemplo01</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">TYPE </span> <span style="font-weight: 400;"> CLUSTER-IP </span> <span style="font-weight: 400;">EXTERNAL-IP </span> <span style="font-weight: 400;">PORT(S) </span> <span style="font-weight: 400;">AGE</span> <span style="font-weight: 400;">exemplo01-service LoadBalancer 10.55.250.197 35.225.126.33 8080:31764/TCP 33s</span> <span style="font-weight: 400;">$ curl -I http://35.225.126.33:8080</span> <span style="font-weight: 400;">HTTP/1.1 200 OK</span> <span style="font-weight: 400;">Server: nginx/1.15.0</span> <span style="font-weight: 400;">Date: Sun, 17 Jun 2018 23:55:46 GMT</span> <span style="font-weight: 400;">Content-Type: text/html</span> <span style="font-weight: 400;">Content-Length: 612</span> <span style="font-weight: 400;">Last-Modified: Tue, 05 Jun 2018 12:00:18 GMT</span> <span style="font-weight: 400;">Connection: keep-alive</span> <span style="font-weight: 400;">ETag: "5b167b52-264"</span> <span style="font-weight: 400;">Accept-Ranges: bytes</span> <span style="font-weight: 400;">$ kubectl get pods -n exemplo02</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">READY </span> <span style="font-weight: 400;">STATUS RESTARTS AGE</span> <span style="font-weight: 400;">exemplo02-deploy-768c96479b-dll24 1/1 Running 0 </span> <span style="font-weight: 400;">1m</span> <span style="font-weight: 400;">$ kubectl get svc -n exemplo02</span> <span style="font-weight: 400;">NAME </span> <span style="font-weight: 400;">TYPE </span> <span style="font-weight: 400;">CLUSTER-IP</span> <span style="font-weight: 400;">EXTERNAL-IP </span> <span style="font-weight: 400;">PORT(S) </span> <span style="font-weight: 400;">AGE</span> <span style="font-weight: 400;">exemplo02-service LoadBalancer 10.55.255.7 35.193.109.201 8081:31513/TCP 1m</span> <span style="font-weight: 400;">$ curl -I http://35.193.109.201:8081</span> <span style="font-weight: 400;">HTTP/1.1 200 OK</span> <span style="font-weight: 400;">Server: nginx/1.14.0</span> <span style="font-weight: 400;">Date: Sun, 17 Jun 2018 23:56:29 GMT</span> <span style="font-weight: 400;">Content-Type: text/html</span> <span style="font-weight: 400;">Content-Length: 612</span> <span style="font-weight: 400;">Last-Modified: Tue, 17 Apr 2018 13:46:53 GMT</span> <span style="font-weight: 400;">Connection: keep-alive</span> <span style="font-weight: 400;">ETag: "5ad5facd-264"</span> <span style="font-weight: 400;">Accept-Ranges: bytes</span> <span style="font-weight: 400;">$</span> |
Conclusão
O Helm é uma ferramenta muito flexível na construção de nossos pacotes para Kubernetes. Há muito o que ser explorado como assinatura de charts, criação e sincronização dos pacotes para um repositório privado e até testes para validação! Espero que este simples artigo desperte o seu interesse e traga novas ideias para serem aplicadas com o Helm.
* https://kubernetes.io/
* https://helm.sh/
* https://medium.com/@abhaydiwan/kubernetes-introduction-and-twelve-key-features-cdfe8a1f2d21
Everson “IP_FIX” Tavares tem mais de 14 anos de experiência na área de TI, principalmente em ambientes Linux e Cloud Computing, também já tendo atuado com redes e segurança da informação. Atualmente focado em cloud computing e automação, participo diretamente de projetos de aplicações que necessitam de integração contínua, agilidade, disponibilidade, qualidade, estabilidade com escalabilidade e elasticidade utilizando a metodologia devops.
Bom artigo Everson, parabéns!
Tenho uma dúvida, estou na luta de fazer o helm funcionar usando o rolling update sendo que minha imagem docker sempre usa a versão latest.
Coloquei como imagepullpolicy: always, tentei deixar o force no upgrade mas, ele não recria os pods, só consegui forçando com a flag –recreate-pods,. mas ai ele recria todosao mesmo tempo, consegue me ajudar?