---
layout: default
navsection: installguide
title: Install the cloud dispatcher
...
{% comment %}
Copyright (C) The Arvados Authors. All rights reserved.

SPDX-License-Identifier: CC-BY-SA-3.0
{% endcomment %}

{% include 'notebox_begin_warning' %}
arvados-dispatch-cloud is only relevant for cloud installations. Skip this section if you are installing a on premise cluster that will spool jobs to Slurm.
{% include 'notebox_end' %}

# "Introduction":#introduction
# "Create compute node VM image":#create-image
# "Update config.yml":#update-config
# "Install arvados-dispatch-cloud":#install-packages
# "Start the service":#start-service
# "Restart the API server and controller":#restart-api
# "Confirm working installation":#confirm-working

h2(#introduction). Introduction

The cloud dispatch service is for running containers on cloud VMs. It works with Microsoft Azure and Amazon EC2; future versions will also support Google Compute Engine.

The cloud dispatch service can run on any node that can connect to the Arvados API service, the cloud provider's API, and the SSH service on cloud VMs.  It is not resource-intensive, so you can run it on the API server node.

h2(#create-image). Create compute node VM image and configure resolver

Set up a VM following the steps "to set up a compute node":crunch2-slurm/install-compute-node.html

Compute nodes must be able to resolve the hostnames of the API server and any keepstore servers to your internal IP addresses.  You can do this by running an internal DNS resolver and configuring the compute VMs to use that resolver, or by hardcoding the services in the @/etc/hosts@ file.  For example:

<notextile><pre><code>10.20.30.40     <span class="userinput">ClusterID.example.com</span>
10.20.30.41     <span class="userinput">keep1.ClusterID.example.com</span>
10.20.30.42     <span class="userinput">keep2.ClusterID.example.com</span>
</code></pre></notextile>

Once the VM is fully configured, create a reusable VM image from it and make note of the image id.

h2(#update-config). Update config.yml

h3. Create a private key

Generate an SSH private key with no passphrase. Save it in the cluster configuration file (see @PrivateKey@ in the example below).

<notextile>
<pre><code>~$ <span class="userinput">ssh-keygen -N '' -f ~/.ssh/id_dispatcher</span>
Generating public/private rsa key pair.
Your identification has been saved in /home/user/.ssh/id_dispatcher.
Your public key has been saved in /home/user/.ssh/id_dispatcher.pub.
The key fingerprint is:
[...]
~$ <span class="userinput">cat ~/.ssh/id_dispatcher</span>
-----BEGIN RSA PRIVATE KEY-----
MIIEpQIBAAKCAQEAqXoCzcOBkFQ7w4dvXf9B++1ctgZRqEbgRYL3SstuMV4oawks
ttUuxJycDdsPmeYcHsKo8vsEZpN6iYsX6ZZzhkO5nEayUTU8sBjmg1ZCTo4QqKXr
...
oFyAjVoexx0RBcH6BveTfQtJKbktP1qBO4mXo2dP0cacuZEtlAqW9Eb06Pvaw/D9
foktmqOY8MyctzFgXBpGTxPliGjqo8OkrOyQP2g+FL7v+Km31Xs61P8=
-----END RSA PRIVATE KEY-----
</code></pre>
</notextile>

You can delete the key files after you have copied the private key to your configuration file.

<notextile>
<pre><code>~$ <span class="userinput">rm ~/.ssh/id_dispatcher ~/.ssh/id_dispatcher.pub</span>
</code></pre>
</notextile>

h3. Configure CloudVMs

Add or update the following portions of your cluster configuration file, @config.yml@. Refer to "config.defaults.yml":{{site.baseurl}}/admin/config.html for information about additional configuration options.

<notextile>
<pre><code>    Services:
      DispatchCloud:
        InternalURLs:
          "http://localhost:9006": {}
    Containers:
      CloudVMs:
        # BootProbeCommand is a shell command that succeeds when an instance is ready for service
        BootProbeCommand: "sudo systemctl status docker"

        <b># --- driver-specific configuration goes here --- see Amazon and Azure examples below ---</b>

      DispatchPrivateKey: |
        -----BEGIN RSA PRIVATE KEY-----
        MIIEpQIBAAKCAQEAqXoCzcOBkFQ7w4dvXf9B++1ctgZRqEbgRYL3SstuMV4oawks
        ttUuxJycDdsPmeYcHsKo8vsEZpN6iYsX6ZZzhkO5nEayUTU8sBjmg1ZCTo4QqKXr
        FJ+amZ7oYMDof6QEdwl6KNDfIddL+NfBCLQTVInOAaNss7GRrxLTuTV7HcRaIUUI
        jYg0Ibg8ZZTzQxCvFXXnjseTgmOcTv7CuuGdt91OVdoq8czG/w8TwOhymEb7mQlt
        lXuucwQvYgfoUgcnTgpJr7j+hafp75g2wlPozp8gJ6WQ2yBWcfqL2aw7m7Ll88Nd
        [...]
        oFyAjVoexx0RBcH6BveTfQtJKbktP1qBO4mXo2dP0cacuZEtlAqW9Eb06Pvaw/D9
        foktmqOY8MyctzFgXBpGTxPliGjqo8OkrOyQP2g+FL7v+Km31Xs61P8=
        -----END RSA PRIVATE KEY-----
    InstanceTypes:
      x1md:
        ProviderType: x1.medium
        VCPUs: 8
        RAM: 64GiB
        IncludedScratch: 64GB
        Price: 0.62
      x1lg:
        ProviderType: x1.large
        VCPUs: 16
        RAM: 128GiB
        IncludedScratch: 128GB
        Price: 1.23
</code></pre>
</notextile>

h4. Minimal configuration example for Amazon EC2

<notextile>
<pre><code>    Containers:
      CloudVMs:
        ImageID: ami-01234567890abcdef
        Driver: ec2
        DriverParameters:
          AccessKeyID: XXXXXXXXXXXXXXXXXXXX
          SecretAccessKey: YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY
          SecurityGroupIDs:
          - sg-0123abcd
          SubnetID: subnet-0123abcd
          Region: us-east-1
          EBSVolumeType: gp2
          AdminUsername: arvados
</code></pre>
</notextile>

h4. Minimal configuration example for Azure

<notextile>
<pre><code>    Containers:
      CloudVMs:
        ImageID: "https://zzzzzzzz.blob.core.windows.net/system/Microsoft.Compute/Images/images/zzzzz-compute-osDisk.55555555-5555-5555-5555-555555555555.vhd"
        Driver: azure
        DriverParameters:
          # Credentials.
          SubscriptionID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
          ClientSecret: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
          TenantID: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

          # Data center where VMs will be allocated
          Location: centralus

          # The resource group where the VM and virtual NIC will be
          # created.
          ResourceGroup: zzzzz
          NetworkResourceGroup: yyyyy   # only if different from ResourceGroup
          Network: xxxxx
          Subnet: xxxxx-subnet-private

          # Where to store the VM VHD blobs
          StorageAccount: example
          BlobContainer: vhds

</code></pre>
</notextile>

Get the @SubscriptionID@ and @TenantID@:

<pre>
$ az account list
[
  {
    "cloudName": "AzureCloud",
    "id": "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXX",
    "isDefault": true,
    "name": "Your Subscription",
    "state": "Enabled",
    "tenantId": "YYYYYYYY-YYYY-YYYY-YYYYYYYY",
    "user": {
      "name": "you@example.com",
      "type": "user"
    }
  }
]
</pre>

You will need to create a "service principal" to use as a delegated authority for API access.

<notextile><pre><code>$ az ad app create --display-name "Arvados Dispatch Cloud (<span class="userinput">ClusterID</span>)" --homepage "https://arvados.org" --identifier-uris "https://<span class="userinput">ClusterID.example.com</span>" --end-date 2299-12-31 --password <span class="userinput">Your_Password</span>
$ az ad sp create "<span class="userinput">appId</span>"
(appId is part of the response of the previous command)
$ az role assignment create --assignee "<span class="userinput">objectId</span>" --role Owner --scope /subscriptions/{subscriptionId}/
(objectId is part of the response of the previous command)
</code></pre></notextile>

Now update your @config.yml@ file:

@ClientID@ is the 'appId' value.

@ClientSecret@ is what was provided as <span class="userinput">Your_Password</span>.

h3. Test your configuration

Run the @cloudtest@ tool to verify that your configuration works. This creates a new cloud VM, confirms that it boots correctly and accepts your configured SSH private key, and shuts it down.

<notextile>
<pre><code>~$ <span class="userinput">arvados-server cloudtest && echo "OK!"</span>
</code></pre>
</notextile>

Refer to the "cloudtest tool documentation":../admin/cloudtest.html for more information.

{% assign arvados_component = 'arvados-dispatch-cloud' %}

{% include 'install_packages' %}

{% include 'start_service' %}

{% include 'restart_api' %}

h2(#confirm-working). Confirm working installation

On the dispatch node, start monitoring the arvados-dispatch-cloud logs:

<notextile>
<pre><code>~$ <span class="userinput">sudo journalctl -o cat -fu arvados-dispatch-cloud.service</span>
</code></pre>
</notextile>

"Make sure to install the arvados/jobs image.":install-jobs-image.html

Submit a simple container request:

<notextile>
<pre><code>shell:~$ <span class="userinput">arv container_request create --container-request '{
  "name":            "test",
  "state":           "Committed",
  "priority":        1,
  "container_image": "arvados/jobs:latest",
  "command":         ["echo", "Hello, Crunch!"],
  "output_path":     "/out",
  "mounts": {
    "/out": {
      "kind":        "tmp",
      "capacity":    1000
    }
  },
  "runtime_constraints": {
    "vcpus": 1,
    "ram": 1048576
  }
}'</span>
</code></pre>
</notextile>

This command should return a record with a @container_uuid@ field.  Once @arvados-dispatch-cloud@ polls the API server for new containers to run, you should see it dispatch that same container.

The @arvados-dispatch-cloud@ API a list of queued and running jobs.  For example:

<notextile>
<pre><code>~$ <span class="userinput">curl ...</span>
</code></pre>
</notextile>

When the container finishes, the dispatcher will log it.

After the container finishes, you can get the container record by UUID *from a shell server* to see its results:

<notextile>
<pre><code>shell:~$ <span class="userinput">arv get <b>zzzzz-dz642-hdp2vpu9nq14tx0</b></span>
{
 ...
 "exit_code":0,
 "log":"a01df2f7e5bc1c2ad59c60a837e90dc6+166",
 "output":"d41d8cd98f00b204e9800998ecf8427e+0",
 "state":"Complete",
 ...
}
</code></pre>
</notextile>

You can use standard Keep tools to view the container's output and logs from their corresponding fields.  For example, to see the logs from the collection referenced in the @log@ field:

<notextile>
<pre><code>~$ <span class="userinput">arv keep ls <b>a01df2f7e5bc1c2ad59c60a837e90dc6+166</b></span>
./crunch-run.txt
./stderr.txt
./stdout.txt
~$ <span class="userinput">arv-get <b>a01df2f7e5bc1c2ad59c60a837e90dc6+166</b>/stdout.txt</span>
2016-08-05T13:53:06.201011Z Hello, Crunch!
</code></pre>
</notextile>

If the container does not dispatch successfully, refer to the @arvados-dispatch-cloud@ logs for information about why it failed.