knot knot

MariaDB

The following example runs a MariaDB server within a space. Storage is provided by a volume configured with the hostpath CSI driver.

MariaDB is initialized with the root password set to the user’s Service Password as defined in their user profile.

The job assumes Docker is being used for container management. If Podman is being used, change the driver to podman and update the image to registry-1.docker.io/paularlott/knot-mariadb:11.04 to enable spaces to be created using Podman.

Nomad Cluster

Nomad Job

job "${{.user.username}}-${{.space.name}}" {
  datacenters = ["dc1"]

  update {
    max_parallel     = 1
    min_healthy_time = "30s"
    healthy_deadline = "1m"
    auto_revert      = false
  }

  group "mariadb" {
    count = 1

    volume "data_volume" {
      type            = "csi"
      source          = "mariadb_${{.space.id}}"
      read_only       = false
      attachment_mode = "file-system"
      access_mode     = "single-node-writer"
    }

    task "mariadb" {
      env {
        # Define environment variables for agent
        KNOT_SERVER           = "${{.server.url}}"
        KNOT_AGENT_ENDPOINT   = "${{.server.agent_endpoint}}"
        KNOT_SPACEID          = "${{.space.id}}"
        KNOT_TCP_PORT         = "3306"
        KNOT_USER             = "mysql"
        MARIADB_ROOT_PASSWORD = "${{.user.service_password}}"
      }

      driver = "docker"
      config {
        image = "paularlott/knot-mariadb:11.04"

        hostname = "${{ .space.name }}"

        mount {
          type   = "bind"
          source = "local/custom.cnf"
          target = "/etc/mysql/conf.d/custom.cnf"
        }
      }

      volume_mount {
        volume      = "data_volume"
        destination = "/var/lib/mysql"
      }

      resources {
        cpu = 300
        memory = 1024
      }

      template {
        data = <<EOF
[mysqld]
port=3306
default_storage_engine   = InnoDB
innodb_file_per_table    = 1
innodb_lock_wait_timeout = 120
table_definition_cache   = 3000

innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size         = 8M
innodb_log_file_size           = 512M

key_buffer_size    = 16M
max_allowed_packet = 256M
thread_stack       = 192K
thread_cache_size  = 8

myisam-recover  = BACKUP
max_connections = 100

query_cache_size        = 512M
query_cache_limit       = 8M
join_buffer_size        = 256K
table_cache             = 5000
open_files_limit        = 15000
innodb_buffer_pool_size = 8000M
character-set-server    = utf8mb4
collation-server        = utf8mb4_general_ci
init-connect            = 'SET NAMES utf8mb4'
group_concat_max_len    = 10240

[mysql]
default-character-set = utf8mb4

[mysqldump]
max_allowed_packet = 256M
EOF

        destination   = "local/custom.cnf"
        change_mode   = "noop"
      }
    }
  }
}

Volume Definition

volumes:
  - id: "mariadb_${{.space.id}}"
    name: "mariadb_${{.space.id}}"
    plugin_id: "hostpath"
    capacity_min: 10G
    capacity_max: 10G
    mount_options:
      fs_type: "xfs"
      mount_flags:
        - rw
        - noatime
    capabilities:
      - access_mode: "single-node-writer"
        attachment_mode: "file-system"

Connecting to MariaDB

The space exports the MariaDB port 3306 via the TCP proxy, allowing it to be connected to using port forwarding. For example:

knot forward port 127.0.0.1:3306 <space> 3306

Where <space> is the name of the space.

Once the above command is running, any desktop MySQL/MariaDB client should be able to connect to port 3306 on localhost. knot will handle forwarding the data to the MariaDB server running within the space.