job "[[ .instance ]]-exporters" {

[[- $c := merge .monitoring.exporters . ]]
[[ template "common/job_start" $c ]]

  # Run exporters. Use a separated job so exporters can run in a distinct node_pool
  group "exporters" {
    
    count = [[ $c.count ]]

    network {
      mode = "bridge"
      port "ping" {}
      port "blackbox" {}
      port "consul" {}
      port "cluster" {}
    }

    service {
      name = "ping-exporter[[ .consul.suffix ]]"
      port = "ping"
      meta {
        alloc        = "${NOMAD_ALLOC_INDEX}"
        metrics-port = "${NOMAD_HOST_PORT_ping}"
      }
    }

    service {
      name = "blackbox-exporter[[ .consul.suffix ]]"
      port = "blackbox"
      meta {
        alloc = "${NOMAD_ALLOC_INDEX}"
      }
    }

    service {
      name = "consul-exporter[[ .consul.suffix ]]"
      port = "ping"
      meta {
        alloc        = "${NOMAD_ALLOC_INDEX}"
        metrics-port = "${NOMAD_HOST_PORT_consul}"
      }
    }

    service {
      name = "cluster-exporter[[ .consul.suffix ]]"
      port = "cluster"
      meta {
        alloc = "${NOMAD_ALLOC_INDEX}"
      }
    }

[[- if gt (len $c.ping.probes) 0 ]]
[[- $e := merge $c.ping $c ]]
    # Ping exporter will collect ICMP ping stats and expose them
    # Note : we could do it with blackbox, but as pings require privileges, it's better to grant it
    # to a smaller, more focused container. This one only handle icmp pings check, and only from the configuration file
    task "ping-exporter" {
      driver = "[[ $e.nomad.driver ]]"

      config {
        image           = "[[ $e.image ]]"
        readonly_rootfs = true
        pids_limit      = 30
        # Pings require privileges
        privileged      = true
        userns_mode     = "host"
        command         = "ping_exporter"
        args            = [
          "--web.listen-address=127.0.0.1:9427",
          "--config.path=/local/config.yml"
        ]
      }

[[ template "common/file_env" $e ]]

      template {
        data        = <<_EOT
[[ template "monitoring/ping_exporter/config.yml" $e ]]
_EOT
        destination = "local/config.yml"
      }

[[ template "common/resources" $e ]]
    }
[[- end ]]

[[- if or (gt (len $c.blackbox.tcp_probes) 0) (gt (len $c.blackbox.http_probes) 0) ]]
[[- $e := merge $c.blackbox $c ]]
    # Blackbox exporter will probe http/tcp targets and expose them
    # for prometheus
    task "blackbox-exporter" {
      driver = "[[ $e.nomad.driver ]]"

      config {
        image           = "[[ $e.image ]]"
        readonly_rootfs = true
        pids_limit      = 30
      }

[[ template "common/file_env" $e ]]
[[ template "common/resources" $e ]]

    }
[[- end ]]

    # Export consul services status to prometheus
    task "consul-exporter" {
[[- $e := merge $c.consul $c ]]
      driver = "[[ $e.nomad.driver ]]"

      config {
        image           = "[[ $e.image ]]"
        readonly_rootfs = true
        pids_limit      = 30
        command         = "/local/consul-exporter"
      }

[[ template "common/file_env" $e ]]
[[ template "common/vault.policies" $e ]]

      template {
        data = <<_EOT
[[ template "monitoring/consul-exporter/start.sh" $e ]]
_EOT
        destination = "local/consul-exporter"
        perms       = 755
      }

      template {
        data = <<_EOT
CONSUL_HTTP_TOKEN={{ with secret "consul/creds/consul-exporter[[ .consul.suffix ]]" }}{{ .Data.token }}{{ end }}
_EOT
        destination = "secrets/.consul.env"
        uid         = 100000
        gid         = 100000
        perms       = 400
        env         = true
      }

[[ template "common/resources" $e ]]
    }

    # The cluster metrics exposes prometheus metrics from the various nodes of the cluster
    # Nomad, Consul and Vault
    # It also exposes the other exporters metrics with mTLS
    task "cluster-metrics-proxy" {
[[- $e := merge $c.cluster $c ]]
      driver = "[[ $e.nomad.driver ]]"
      user   = 8685

      logs {
        disabled = true
      }

      lifecycle {
        hook    = "poststart"
        sidecar = true
      }

      config {
        image           = "[[ $e.image ]]"
        readonly_rootfs = true
        pids_limit      = 30
        # Mount the config in nginx conf dir
        volumes = [
          "secrets/metrics.conf:/etc/nginx/conf.d/default.conf"
        ]
[[ template "common/tmpfs" "/tmp" ]]
      }

[[ template "common/vault.policies" $e ]]

      # This is the main nginx configuration, which will proxypass requests to the real metrics endpoints
      template {
        data =<<_EOT
[[ template "monitoring/cluster-exporter/nginx.conf" $e ]]
_EOT
        destination   = "secrets/metrics.conf"
        perms         = "0440"
        uid           = 108685
        gid           = 100000
        change_mode   = "signal"
        change_signal = "SIGHUP"
      }

      # Get certificate to add mTLS to metrics endpoints
      template {
        data =<<_EOT
{{- with pkiCert "[[ .prometheus.vault_pki ]]/issue/metrics" (printf "ip_sans=%s" (env "NOMAD_HOST_IP_cluster")) }}
{{ .Cert }}
{{ .Key }}
{{- end }}
_EOT
        destination   = "secrets/metrics.bundle.pem"
        change_mode   = "signal"
        change_signal = "SIGHUP"
      }

      # Get the CA for the monitoring PKI
      template {
        data        =<<_EOT
{{ with secret "[[ .vault.root ]]pki/monitoring/cert/ca_chain" }}{{ .Data.ca_chain }}{{ end }}
_EOT
        destination = "local/monitoring.ca.pem"
      }

      # Get a Nomad client certificate
      template {
        data = <<_EOT
{{- with pkiCert "pki/nomad/issue/cluster-exporter[[ .consul.suffix ]]" "common_name=metrics-proxy.nomad.[[ .consul.domain ]]" "ttl=24h" }}
{{ .Data.Cert }}
{{ .Data.Key }}
{{- end }}
_EOT
        destination   = "secrets/nomad_client_bundle.pem"
        perms         = "0400"
        uid           = 108685
        gid           = 100000
        change_mode   = "signal"
        change_signal = "SIGHUP"
      }

      # The CA chain for Nomad
      template {
        data        = <<_EOT
{{ with secret "pki/nomad/cert/ca_chain" }}{{ .Data.ca_chain }}{{ end }}
_EOT
        destination = "local/nomad_ca.crt"
      }

      # Same for Consul
      template {
        data = <<_EOT
{{- with pkiCert "pki/consul/issue/cluster-exporter[[ .consul.suffix ]]" "common_name=metrics-proxy.consul.[[ .consul.domain ]]" "ttl=24h" }}
{{ .Data.Cert }}
{{ .Data.Key }}
{{- end }}
_EOT
        destination   = "secrets/consul_client_bundle.pem"
        perms         = "0400"
        uid           = 108685
        gid           = 100000
        change_mode   = "signal"
        change_signal = "SIGHUP"
      }
      template {
        data        = <<_EOT
{{ with secret "pki/consul/cert/ca_chain" }}{{ .Data.ca_chain }}{{ end }}
_EOT
        destination = "local/consul_ca.crt"
      }

[[ template "common/resources" $e ]]
    }
  }
}