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* create plugin author guide; remove concepts/plugins * style guide; update links * update cni redirect * move host-volume plugin to /plugins/. Add arch host volume content. * Apply Jeff's style guide updates Co-authored-by: Jeff Boruszak <104028618+boruszak@users.noreply.github.com> * Apply suggestions from code review Co-authored-by: Jeff Boruszak <104028618+boruszak@users.noreply.github.com> * Create Base plugin API section, link to BasePlugin interface --------- Co-authored-by: Jeff Boruszak <104028618+boruszak@users.noreply.github.com>
134 lines
4.2 KiB
Plaintext
134 lines
4.2 KiB
Plaintext
---
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layout: docs
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page_title: Raw Fork/Exec task driver
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description: Nomad's Raw Exec task driver lets you execute commands with no resource isolation. Review the Isolated Fork/Exec task driver capabilities, plugin options, client requirements, and client attributes.
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---
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# Configure the Raw Fork/Exec task driver
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Name: `raw_exec`
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The `raw_exec` driver is used to execute a command for a task without any
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isolation. Further, the task is started as the same user as the Nomad process.
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As such, it should be used with extreme care and is disabled by default.
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## Capabilities
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The `raw_exec` driver implements the following [capabilities](/nomad/plugins/author/task-driver#capabilities-capabilities-error).
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| Feature | Implementation |
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| -------------------- | -------------- |
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| `nomad alloc signal` | true |
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| `nomad alloc exec` | true |
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| filesystem isolation | none |
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| network isolation | host, group |
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| volume mounting | none |
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## Client Requirements
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The `raw_exec` driver can run on all supported operating systems. For security
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reasons, it is disabled by default. To enable raw exec, the Nomad client
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configuration must explicitly enable the `raw_exec` driver in the plugin's options:
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```
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plugin "raw_exec" {
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config {
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enabled = true
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}
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}
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```
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Nomad versions before v0.9 use the following client configuration. This configuration is
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also supported in Nomad v0.9.0, but is deprecated in favor of the plugin block:
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```
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client {
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options = {
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"driver.raw_exec.enable" = "1"
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}
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}
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```
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## Plugin Options
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- `enabled` - Specifies whether the driver should be enabled or disabled.
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Defaults to `false`.
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- `denied_host_uids` - (Optional) Specifies a comma-separated list of host uids to
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deny. Ranges can be specified by using a hyphen separating the two inclusive ends.
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If a "user" value is specified in task configuration and that user has a user id in
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the given ranges, the task will error before starting. This will not be checked on Windows
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clients.
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```hcl
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config {
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denied_host_uids = "0,10-15,22"
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}
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```
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- `denied_host_gids` - (Optional) Specifies a comma-separated list of host gids to
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deny. Ranges can be specified by using a hyphen separating the two inclusive ends.
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If a "user" value is specified in task configuration and that user is part of
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any groups with gid's in the specified ranges, the task will error before
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starting. This will not be checked on Windows clients.
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```hcl
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config {
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denied_host_gids = "2,4-8"
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}
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```
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- `denied_envvars` - (Optional) Passes a list of environment variables that
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the driver should scrub from all task environments. Supports globbing with "*"
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wildcard accepted as prefix and/or suffix.
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```hcl
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config {
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denied_envvars = ["AWS_SECRET_KEY", "*_TOKEN"]
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}
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```
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## Client Options
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~> Note: client configuration options will soon be deprecated. Please use
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[plugin options][plugin-options] instead. See the [plugin block][plugin-block] documentation for more information.
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- `driver.raw_exec.enable` - Specifies whether the driver should be enabled or
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disabled. Defaults to `false`.
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## Client Attributes
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The `raw_exec` driver will set the following client attributes:
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- `driver.raw_exec` - This will be set to "1", indicating the driver is available.
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## Resource Isolation
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The `raw_exec` driver provides no filesystem isolation.
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If the launched process creates a new process group, it is possible that
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Nomad will leak processes on shutdown unless the application forwards signals
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properly. Nomad will not leak any processes if cgroups are being used to
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manage the process tree. Cgroups are used on Linux when Nomad is being run with
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appropriate privileges, and the cgroup system is mounted.
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If the cluster is configured with memory oversubscription enabled, a task using
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the `raw_exec` driver can be configured to have no maximum memory limit by
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setting `memory_max = -1`.
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```hcl
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resources {
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cpu = 500
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memory = 128
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memory_max = -1 # no limit
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}
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```
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## Next steps
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[Use the `raw_exec` driver in a job](/nomad/docs/job-declare/task-driver/raw_exec).
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[hardening]: /nomad/docs/deploy/production/requirements#user-permissions
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[service]: /nomad/docs/deploy/production/windows-service
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[plugin-options]: #plugin-options
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[plugin-block]: /nomad/docs/configuration/plugin
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