DEV Community

loading...
Cover image for Getting Started with Hashicorp Nomad

Getting Started with Hashicorp Nomad

Clivern
Horsin' around (⊙.☉)7
Updated on ・5 min read

Basic Setup (Not Recommended):

  • Download nomad binary & make it executable:
$ wget https://releases.hashicorp.com/nomad/1.0.5/nomad_1.0.5_linux_amd64.zip
$ unzip nomad_1.0.5_linux_amd64.zip
$ mv nomad /usr/local/bin/
Enter fullscreen mode Exit fullscreen mode
  • Create configs directory & data directory:
$ sudo mkdir --parents /opt/nomad
$ sudo mkdir --parents /opt/data/redis
$ sudo mkdir --parents /etc/nomad.d
$ sudo chmod 700 /etc/nomad.d
$ sudo chmod 700 /opt/data

$ sudo touch /etc/nomad.d/nomad.hcl
$ sudo touch /etc/nomad.d/server.hcl
$ sudo touch /etc/nomad.d/client.hcl
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the /etc/nomad.d/nomad.hcl configuration file
datacenter = "dc1"
data_dir = "/opt/nomad"
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the /etc/nomad.d/client.hcl configuration file
client {
  enabled = true

  host_volume "redis_data" {
    path      = "/opt/data/redis"
    read_only = false
  }
}

plugin "docker" {
  config {
    volumes {
      enabled      = true
      selinuxlabel = "z"
    }
  }
}
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the /etc/nomad.d/server.hcl configuration file
acl {
  enabled = true
}
server {
  enabled = true
  bootstrap_expect = 1
}
Enter fullscreen mode Exit fullscreen mode
  • Create a nomad service file
$ sudo touch /etc/systemd/system/nomad.service
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the nomad service file /etc/systemd/system/nomad.service
[Unit]
Description=Nomad
Documentation=https://nomadproject.io/docs/

[Service]
ExecStart=/usr/local/bin/nomad agent -config /etc/nomad.d
Restart=on-failure
RestartSec=2

[Install]
WantedBy=multi-user.target
Enter fullscreen mode Exit fullscreen mode
  • Start nomad
sudo systemctl enable nomad
sudo systemctl start nomad
sudo systemctl status nomad
Enter fullscreen mode Exit fullscreen mode
  • Genertal ACL secrets
$ nomad acl bootstrap
Accessor ID  = a8b724ef-b5eb-21c0-1a68-b0d3616e1e62
Secret ID    = 07fe0ee6-59bc-8ea0-aeeb-9b4e9edcb555
Name         = Bootstrap Token
Type         = management
Global       = true
Policies     = n/a
Create Time  = 2021-05-10 21:05:21.498072284 +0000 UTC
Create Index = 10
Modify Index = 10

$ export NOMAD_TOKEN=07fe0ee6-59bc-8ea0-aeeb-9b4e9edcb555
Enter fullscreen mode Exit fullscreen mode
  • Create your first job to deploy a stateless container from the server ui http://127.0.0.1:4646/ui
job "api" {
  datacenters = ["dc1"]

  group "example" {
    task "server" {
      driver = "docker"

      config {
        image = "hashicorp/http-echo:0.2.1"

        args = [
          "-listen",
          ":5678",
          "-text",
          "hello world",
        ]
      }

      resources {
        network {
          mbits = 10

          port "http" {
            static = "5678"
          }
        }
      }
    }
  }
}
Enter fullscreen mode Exit fullscreen mode
  • And another one for stateful container
job "cache" {
  datacenters = ["dc1"]

  group "redis" {

    volume "redis_data" {
      type      = "host"
      read_only = false
      source    = "redis_data"
    }

    task "server" {
      driver = "docker"

      volume_mount {
        volume      = "redis_data"
        destination = "/data"
        read_only   = false
      }

      config {
        image = "redis:4-alpine"

        labels = {
          "sh.hippo.service" = "redis"
          "sh.hippo.service_type" = "cache"
        }

        port_map {
          http = 6379
        }

        command = "redis-server"

        args = [
          "--requirepass",
          "mystery",
        ]
      }

      env = {
        HEALTHY_FOR    = -1,
      }

      resources {
        cpu    = 100
        memory = 256

        network {
          mbits = 10

          port "http" {
            static = "6379"
          }
        }
      }
    }
  }
}
Enter fullscreen mode Exit fullscreen mode

Multi Nodes Setup (Recommended):

To fully understand how nomad cluster should look like, please check this guide!

Assuming we have two servers, one for the nomad server (Leader) and another for the client. Both servers are in DC1. The leader server has public IP $SERVER_PUBLIC_IP and private IP $SERVER_PRIVATE_IP.

First we run the leader or the nomad server by following the next steps:

  • Download nomad binary & make it executable:
$ wget https://releases.hashicorp.com/nomad/1.0.5/nomad_1.0.5_linux_amd64.zip
$ unzip nomad_1.0.5_linux_amd64.zip
$ mv nomad /usr/local/bin/
Enter fullscreen mode Exit fullscreen mode
  • Create configs directory & data directory:
$ sudo mkdir --parents /opt/nomad
$ sudo mkdir --parents /opt/data/redis
$ sudo mkdir --parents /etc/nomad.d
$ sudo chmod 700 /etc/nomad.d
$ sudo chmod 700 /opt/data

$ sudo touch /etc/nomad.d/nomad.hcl
$ sudo touch /etc/nomad.d/server.hcl
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the /etc/nomad.d/nomad.hcl configuration file
datacenter = "dc1"
data_dir = "/opt/nomad"
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the /etc/nomad.d/server.hcl configuration file
acl {
  enabled = true
}

server {
  enabled = true
  bootstrap_expect = 1
}

bind_addr = "$SERVER_PUBLIC_IP"

addresses {
  http = "$SERVER_PUBLIC_IP"
  rpc  = "$SERVER_PRIVATE_IP"
  serf = "$SERVER_PRIVATE_IP"
}

advertise {
  http = "$SERVER_PUBLIC_IP:4646"
  rpc  = "$SERVER_PRIVATE_IP:4647"
  serf = "$SERVER_PRIVATE_IP:4648"
}
Enter fullscreen mode Exit fullscreen mode
  • Create a nomad service file
$ sudo touch /etc/systemd/system/nomad.service
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the nomad service file /etc/systemd/system/nomad.service
[Unit]
Description=Nomad
Documentation=https://nomadproject.io/docs/

[Service]
ExecStart=/usr/local/bin/nomad agent -config /etc/nomad.d
Restart=on-failure
RestartSec=2

[Install]
WantedBy=multi-user.target
Enter fullscreen mode Exit fullscreen mode
  • Start nomad
sudo systemctl enable nomad
sudo systemctl start nomad
sudo systemctl status nomad
Enter fullscreen mode Exit fullscreen mode
  • Genertal ACL secrets
$ nomad acl bootstrap -address=http://$SERVER_PUBLIC_IP:4646
Accessor ID  = a8b724ef-b5eb-21c0-1a68-b0d3616e1e62
Secret ID    = 07fe0ee6-59bc-8ea0-aeeb-9b4e9edcb555
Name         = Bootstrap Token
Type         = management
Global       = true
Policies     = n/a
Create Time  = 2021-05-10 21:05:21.498072284 +0000 UTC
Create Index = 10
Modify Index = 10

$ export NOMAD_TOKEN=07fe0ee6-59bc-8ea0-aeeb-9b4e9edcb555
Enter fullscreen mode Exit fullscreen mode

Then we run the client by following the next steps:

  • Download nomad binary & make it executable:
$ wget https://releases.hashicorp.com/nomad/1.0.5/nomad_1.0.5_linux_amd64.zip
$ unzip nomad_1.0.5_linux_amd64.zip
$ mv nomad /usr/local/bin/
Enter fullscreen mode Exit fullscreen mode
  • Create configs directory & data directory:
$ sudo mkdir --parents /opt/nomad
$ sudo mkdir --parents /opt/data/redis
$ sudo mkdir --parents /etc/nomad.d
$ sudo chmod 700 /etc/nomad.d
$ sudo chmod 700 /opt/data

$ sudo touch /etc/nomad.d/nomad.hcl
$ sudo touch /etc/nomad.d/client.hcl
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the /etc/nomad.d/nomad.hcl configuration file
datacenter = "dc1"
data_dir = "/opt/nomad"
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the /etc/nomad.d/client.hcl configuration file
client {
  enabled = true

  servers = ["$SERVER_PRIVATE_IP:4647"]

  host_volume "redis_data" {
    path      = "/opt/data/redis"
    read_only = false
  }
}

plugin "docker" {
  config {
    volumes {
      enabled      = true
      selinuxlabel = "z"
    }
  }
}
Enter fullscreen mode Exit fullscreen mode
  • Create a nomad service file
$ sudo touch /etc/systemd/system/nomad.service
Enter fullscreen mode Exit fullscreen mode
  • Add this configuration to the nomad service file /etc/systemd/system/nomad.service
[Unit]
Description=Nomad
Documentation=https://nomadproject.io/docs/

[Service]
ExecStart=/usr/local/bin/nomad agent -config /etc/nomad.d
Restart=on-failure
RestartSec=2

[Install]
WantedBy=multi-user.target
Enter fullscreen mode Exit fullscreen mode
  • Start nomad
sudo systemctl enable nomad
sudo systemctl start nomad
sudo systemctl status nomad
Enter fullscreen mode Exit fullscreen mode

CNI Plugins in Nomad

Nomad uses CNI plugins when bridge networking is used. To install CNI plugins:

$ curl -L -o cni-plugins.tgz https://github.com/containernetworking/plugins/releases/download/v0.8.0/cni-plugins-linux-amd64-v0.8.0.tgz
$ mkdir -p /opt/cni/bin
$ tar -C /opt/cni/bin -xzf cni-plugins.tgz
Enter fullscreen mode Exit fullscreen mode
job "clivern" {
  datacenters = ["dc1"]

  group "services" {

    network {

      port "toad0_srv" {
        static = 8080
      }

      port "toad1_srv" {
        static = 8081
      }
    }

    task "toad0" {
      driver = "docker"

      config {
        image = "clivern/toad:release-0.2.4"

        labels = {
          "com.clivern.service" = "toad"
          "com.clivern.service_type" = "web"
        }

        ports = ["toad0_srv"]

        command = "./toad"

        args = [
          "--port",
          "${NOMAD_PORT_toad0_srv}",
        ]
      }

      env = {
        IS_STATEFUL    = "false",
        TOAD0_ADDR     = "${NOMAD_HOST_ADDR_toad0_srv}",
        TOAD1_ADDR     = "${NOMAD_HOST_ADDR_toad1_srv}",
      }

      resources {
        network {
          mbits = 10
        }
      }
    }

    task "toad1" {
      driver = "docker"

      config {
        image = "clivern/toad:release-0.2.3"

        labels = {
          "com.clivern.service" = "toad"
          "com.clivern.service_type" = "web"
        }

        ports = ["toad1_srv"]

        command = "./toad"

        args = [
          "--port",
          "${NOMAD_PORT_toad1_srv}",
        ]
      }

      env = {
        IS_STATEFUL    = "false",
        TOAD0_ADDR     = "${NOMAD_HOST_ADDR_toad0_srv}",
        TOAD1_ADDR     = "${NOMAD_HOST_ADDR_toad1_srv}",
      }

      resources {
        network {
          mbits = 10
        }
      }
    }
  }
}
Enter fullscreen mode Exit fullscreen mode

References:

Discussion (0)