101 lines
3 KiB
Go
101 lines
3 KiB
Go
package fingerprint
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import (
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"fmt"
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"log"
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"strconv"
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"time"
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consul "github.com/hashicorp/consul/api"
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client "github.com/hashicorp/nomad/client/config"
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"github.com/hashicorp/nomad/nomad/structs"
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)
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const (
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consulAvailable = "available"
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consulUnavailable = "unavailable"
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)
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// ConsulFingerprint is used to fingerprint for Consul
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type ConsulFingerprint struct {
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logger *log.Logger
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client *consul.Client
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lastState string
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}
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// NewConsulFingerprint is used to create a Consul fingerprint
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func NewConsulFingerprint(logger *log.Logger) Fingerprint {
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return &ConsulFingerprint{logger: logger, lastState: consulUnavailable}
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}
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func (f *ConsulFingerprint) Fingerprint(config *client.Config, node *structs.Node) (bool, error) {
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// Guard against uninitialized Links
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if node.Links == nil {
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node.Links = map[string]string{}
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}
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// Only create the client once to avoid creating too many connections to
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// Consul.
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if f.client == nil {
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consulConfig, err := config.ConsulConfig.ApiConfig()
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if err != nil {
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return false, fmt.Errorf("Failed to initialize the Consul client config: %v", err)
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}
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f.client, err = consul.NewClient(consulConfig)
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if err != nil {
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return false, fmt.Errorf("Failed to initialize consul client: %s", err)
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}
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}
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// We'll try to detect consul by making a query to to the agent's self API.
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// If we can't hit this URL consul is probably not running on this machine.
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info, err := f.client.Agent().Self()
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if err != nil {
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// Clear any attributes set by a previous fingerprint.
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f.clearConsulAttributes(node)
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// Print a message indicating that the Consul Agent is not available
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// anymore
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if f.lastState == consulAvailable {
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f.logger.Printf("[INFO] fingerprint.consul: consul agent is unavailable")
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}
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f.lastState = consulUnavailable
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return false, nil
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}
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node.Attributes["consul.server"] = strconv.FormatBool(info["Config"]["Server"].(bool))
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node.Attributes["consul.version"] = info["Config"]["Version"].(string)
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node.Attributes["consul.revision"] = info["Config"]["Revision"].(string)
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node.Attributes["unique.consul.name"] = info["Config"]["NodeName"].(string)
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node.Attributes["consul.datacenter"] = info["Config"]["Datacenter"].(string)
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node.Links["consul"] = fmt.Sprintf("%s.%s",
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node.Attributes["consul.datacenter"],
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node.Attributes["unique.consul.name"])
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// If the Consul Agent was previously unavailable print a message to
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// indicate the Agent is available now
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if f.lastState == consulUnavailable {
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f.logger.Printf("[INFO] fingerprint.consul: consul agent is available")
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}
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f.lastState = consulAvailable
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return true, nil
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}
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// clearConsulAttributes removes consul attributes and links from the passed
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// Node.
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func (f *ConsulFingerprint) clearConsulAttributes(n *structs.Node) {
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delete(n.Attributes, "consul.server")
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delete(n.Attributes, "consul.version")
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delete(n.Attributes, "consul.revision")
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delete(n.Attributes, "unique.consul.name")
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delete(n.Attributes, "consul.datacenter")
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delete(n.Links, "consul")
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}
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func (f *ConsulFingerprint) Periodic() (bool, time.Duration) {
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return true, 15 * time.Second
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}
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