open-nomad/website/source/docs/drivers/raw_exec.html.md

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docs	Drivers: Raw Exec	docs-drivers-raw-exec	The Raw Exec task driver simply fork/execs and provides no isolation.

Raw Fork/Exec Driver

Name: raw_exec

The raw_exec driver is used to execute a command for a task without any isolation. Further, the task is started as the same user as the Nomad process. As such, it should be used with extreme care and is disabled by default.

Task Configuration

The raw_exec driver supports the following configuration in the job spec:

• command - The command to execute. Must be provided. If executing a binary that exists on the host, the path must be absolute. If executing a binary that is downloaded from an artifact, the path can be relative from the allocations's root directory.

• args - (Optional) A list of arguments to the optional command. References to environment variables or any interpretable Nomad variables will be interpreted before launching the task. For example:

      args = ["${nomad.datacenter}", "${MY_ENV}", "${meta.foo}"]
  

Examples

To run a binary present on the Node:

  task "example" {
    driver = "raw_exec"

    config {
      # When running a binary that exists on the host, the path must be absolute
      command = "/bin/sleep"
      args = ["1"]
    }
  }

To execute a binary downloaded from an artifact:

  task "example" {
    driver = "raw_exec"

    config {
      command = "binary.bin"
    }

    artifact {
      source = "https://dl.dropboxusercontent.com/u/1234/binary.bin"
      options {
        checksum = "sha256:abd123445ds4555555555"
      }
    }
  }

Client Requirements

The raw_exec driver can run on all supported operating systems. It is however disabled by default. In order to be enabled, the Nomad client configuration must explicitly enable the raw_exec driver in the client's options field:

    client {
        options = {
            "driver.raw_exec.enable" = "1"
        }
    }

Client Attributes

The raw_exec driver will set the following client attributes:

• driver.raw_exec - This will be set to "1", indicating the driver is available.

Here is an example of using these properties in a job file:

job "docs" {
  # Only run this job where raw-exec is enabled. (Note: this constraint is
  # applied automatically if you specify a task that uses the raw-exec driver).
  constraint {
    attribute = "${driver.raw_exec}"
    value     = "1"
  }
}

Resource Isolation

The raw_exec driver provides no isolation.