cloudfoundry-incubator/stratos

package terminal

import (
    "fmt"
    "io/ioutil"

    "github.com/cloudfoundry-incubator/stratos/src/jetstream/plugins/kubernetes/api"
    "github.com/cloudfoundry-incubator/stratos/src/jetstream/repository/interfaces"
    "github.com/cloudfoundry-incubator/stratos/src/jetstream/repository/interfaces/config"

    log "github.com/sirupsen/logrus"
)

const (
    serviceAccountTokenFile = "/var/run/secrets/kubernetes.io/serviceaccount/token"
    serviceHostEnvVar       = "KUBERNETES_SERVICE_HOST"
    servicePortEnvVar       = "KUBERNETES_SERVICE_PORT"
    // For dev - read token from env var
    serviceTokenEnvVar = "KUBE_TERMINAL_SERVICE_ACCOUNT_TOKEN"

    stratosRoleLabel         = "stratos-role"
    stratosKubeTerminalRole  = "kube-terminal"
    stratosSessionAnnotation = "stratos-session"

    consoleContainerName = "kube-terminal"
)

// KubeTerminal supports spawning pods to provide a CLI environment to the user
type KubeTerminal struct {
    PortalProxy interfaces.PortalProxy
    Namespace   string `configName:"STRATOS_KUBERNETES_NAMESPACE"`
    Image       string `configName:"STRATOS_KUBERNETES_TERMINAL_IMAGE"`
    Token       []byte
    APIServer   string
    Kube        api.Kubernetes
}

// NewKubeTerminal checks that the environment is set up to support the Kube Terminal
func NewKubeTerminal(p interfaces.PortalProxy) *KubeTerminal {
    // Only enabled in tech preview
    if !p.GetConfig().EnableTechPreview {
        log.Info("Kube Terminal not enabled - requires tech preview")
        return nil
    }

    kt := &KubeTerminal{
        PortalProxy: p,
    }
    if err := config.Load(kt, p.Env().Lookup); err != nil {
        log.Warnf("Unable to load Kube Terminal configuration. %v", err)
        return nil
    }

    // Check that we have everything we need
    if len(kt.Image) == 0 || len(kt.Namespace) == 0 {
        log.Warn("Kube Terminal configuration is not complete")
        return nil
    }

    // Read the Kubernetes API Endpoint
    host, hostFound := p.Env().Lookup(serviceHostEnvVar)
    port, portFound := p.Env().Lookup(servicePortEnvVar)
    if !hostFound || !portFound {
        log.Warn("Kubernetes API Server configuration not found (host and/or port env vars not set)")
        return nil
    }
    kt.APIServer = fmt.Sprintf("https://%s:%s", host, port)

    // Read the Service Account Token
    token, err := ioutil.ReadFile(serviceAccountTokenFile)
    if err != nil {
        // Check env var
        tkn, found := p.Env().Lookup(serviceTokenEnvVar)
        if !found {
            log.Warnf("Unable to load Service Account token. %v", err)
            return nil
        }
        token = []byte(tkn)
    }

    kt.Token = token

    log.Debug("Kubernetes Terminal configured")
    return kt
}