open-nomad/client/fingerprint/consul.go

88 lines
2.6 KiB
Go

package fingerprint
import (
"fmt"
"log"
"strconv"
"time"
consul "github.com/hashicorp/consul/api"
client "github.com/hashicorp/nomad/client/config"
"github.com/hashicorp/nomad/nomad/structs"
)
// ConsulFingerprint is used to fingerprint the architecture
type ConsulFingerprint struct {
logger *log.Logger
client *consul.Client
}
// NewConsulFingerprint is used to create an OS fingerprint
func NewConsulFingerprint(logger *log.Logger) Fingerprint {
f := &ConsulFingerprint{logger: logger}
return f
}
func (f *ConsulFingerprint) Fingerprint(config *client.Config, node *structs.Node) (bool, error) {
// Guard against uninitialized Links
if node.Links == nil {
node.Links = map[string]string{}
}
// Only create the client once to avoid creating too many connections to
// Consul.
if f.client == nil {
address := config.ReadDefault("consul.address", "127.0.0.1:8500")
timeout, err := time.ParseDuration(config.ReadDefault("consul.timeout", "10ms"))
if err != nil {
return false, fmt.Errorf("Unable to parse consul.timeout: %s", err)
}
consulConfig := consul.DefaultConfig()
consulConfig.Address = address
consulConfig.HttpClient.Timeout = timeout
f.client, err = consul.NewClient(consulConfig)
if err != nil {
return false, fmt.Errorf("Failed to initialize consul client: %s", err)
}
}
// We'll try to detect consul by making a query to to the agent's self API.
// If we can't hit this URL consul is probably not running on this machine.
info, err := f.client.Agent().Self()
if err != nil {
// Clear any attributes set by a previous fingerprint.
f.clearConsulAttributes(node)
return false, nil
}
node.Attributes["consul.server"] = strconv.FormatBool(info["Config"]["Server"].(bool))
node.Attributes["consul.version"] = info["Config"]["Version"].(string)
node.Attributes["consul.revision"] = info["Config"]["Revision"].(string)
node.Attributes["consul.name"] = info["Config"]["NodeName"].(string)
node.Attributes["consul.datacenter"] = info["Config"]["Datacenter"].(string)
node.Links["consul"] = fmt.Sprintf("%s.%s",
node.Attributes["consul.datacenter"],
node.Attributes["consul.name"])
return true, nil
}
// clearConsulAttributes removes consul attributes and links from the passed
// Node.
func (f *ConsulFingerprint) clearConsulAttributes(n *structs.Node) {
delete(n.Attributes, "consul.server")
delete(n.Attributes, "consul.version")
delete(n.Attributes, "consul.revision")
delete(n.Attributes, "consul.name")
delete(n.Attributes, "consul.datacenter")
delete(n.Links, "consul")
}
func (f *ConsulFingerprint) Periodic() (bool, time.Duration) {
return true, 15 * time.Second
}