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| layout | page_title | sidebar_current | description |
|---|---|---|---|
| guides | LXC | guides-external-lxc | Guide for using LXC external task driver plugin. |
LXC
The lxc driver provides an interface for using LXC for running application
containers. This guide walks through the steps involved in configuring a Nomad client agent to be able to run lxc jobs. You can download the external LXC driver here.
~> Note: This guide is compatible with Nomad 0.9 and above. If you are using an older version of Nomad, see the LXC driver documentation.
Reference Material
Installation Instructions
Step 1: Install the lxc and lxc-templates Packages
Before deploying an LXC workload, you will need to install the lxc and lxc-templates packages which will provide the runtime and templates to start your container. Run the following command:
sudo apt install -y lxc lxc-templates
Step 2: Download and Install the LXC Driver
External drivers must be placed in the plugin_dir directory which
defaults to data_dir/plugins. Make a directory called plugins in data_dir (which is /opt/nomad/data in the example below) and download/place the LXC driver in it. The following sequence of commands illustrate this process:
$ sudo mkdir -p /opt/nomad/data/plugins
$ curl -O https://releases.hashicorp.com/nomad-driver-lxc/0.1.0-rc2/nomad-driver-lxc_0.1.0-rc2_linux_amd64.zip
$ unzip nomad-driver-lxc_0.1.0-rc2_linux_amd64.zip
Archive: nomad-driver-lxc_0.1.0-rc2_linux_amd64.zip
inflating: nomad-driver-lxc
$ sudo mv nomad-driver-lxc /opt/nomad/data/plugins
You can now delete the original zip file:
$ rm ./nomad-driver-lxc*.zip
Step 3: Verify the LXC Driver Status
After completing the previous steps, you do not need to explicitly enable the LXC driver in the client configuration, as it is enabled by default.
Restart the Nomad client service:
$ sudo systemctl restart nomad
After a few seconds, run the nomad node status command to verify the client
node is ready:
$ nomad node status
ID DC Name Class Drain Eligibility Status
81c22a0c dc1 ip-172-31-5-174 <none> false eligible ready
You can now run the nomad node status command against the specific node ID to
see which drivers are initialized on the client. In our case, the client node ID
is 81c22a0c (your client node ID will be different). You should see lxc
appear in the Driver Status section as show below:
$ nomad node status 81c22a0c
ID = 81c22a0c
Name = ip-172-31-5-174
Class = <none>
DC = dc1
Drain = false
Eligibility = eligible
Status = ready
Uptime = 2h13m30s
Driver Status = docker,exec,java,lxc,mock_driver,raw_exec,rkt
...
Step 4: Register the Nomad Job
You can run this LXC example job to register a Nomad job that deploys an LXC workload.
$ nomad run lxc.nomad
==> Monitoring evaluation "d8be10f4"
Evaluation triggered by job "example-lxc"
Allocation "4248c82e" created: node "81c22a0c", group "example"
Allocation "4248c82e" status changed: "pending" -> "running" (Tasks are running)
Evaluation status changed: "pending" -> "complete"
==> Evaluation "d8be10f4" finished with status "complete"
Step 5: Check the Status of the Job
Run the following command to check the status of the jobs in your cluster:
$ nomad status
ID Type Priority Status Submit Date
example-lxc service 50 running 2019-01-28T22:05:36Z
As shown above, our job is successfully running. You can see detailed information about our specific job with the following command:
$ nomad status example-lxc
ID = example-lxc
Name = example-lxc
Submit Date = 2019-01-28T22:05:36Z
Type = service
Priority = 50
Datacenters = dc1
Status = running
Periodic = false
Parameterized = false
Summary
Task Group Queued Starting Running Failed Complete Lost
example 0 0 1 0 0 0
Allocations
ID Node ID Task Group Version Desired Status Created Modified
4248c82e 81c22a0c example 0 run running 6m58s ago 6m47s ago
More Configuration Options
The LXC driver is enabled by default in the client configuration. In order to
provide additional options to the LXC plugin, add plugin
options volumes_enabled and lxc_path for the lxc
driver in the client's configuration file like in the following example:
plugin "nomad-driver-lxc" {
config {
enabled = true
volumes_enabled = true
lxc_path = "/var/lib/lxc"
}
}