How to troubleshoot Anbox Cloud

This section covers some of the most commonly encountered problems and gives instructions for resolving them.

Initial setup

You might encounter the following issues while setting up your system.

Juju hook installation failure

Applies to: Anbox Cloud

Several Juju units of my deployment show hook: installation failure. Why?

You used the wrong Ubuntu Advantage token. Most likely, you used the Ubuntu Advantage for Infrastructure token that every user gets for free limited personal use.

To deploy Anbox Cloud, you need a commercial subscription for Ubuntu Advantage for Applications. Using a different token will result in a failed deployment. This failure is currently not recoverable.

Socket permission error for amc

Applies to: Anbox Cloud

I receive the following socket permission error when trying to use the amc command:

Post http://unix/1.0/images: dial unix /var/snap/ams/common/server/unix.socket: connect: permission denied

What is wrong?

Most likely, you are trying to run the amc command as a user that is not part of the ams group. The socket has its ownership set to root:ams, so that only root or users that are part of the ams group are allowed to use the Unix domain socket.

By default, Anbox Cloud automatically adds the ubuntu user to the ams group during the installation. You can manually add further users to the ams group with the following command:

sudo gpasswd -a <user_name> ams

To apply the change, you might need to log out and back in.

Debugging container failures

The following issues should help you determining why your container failed.

More information about failures

Applies to: Anbox Cloud, Anbox Cloud Appliance

A container failed to start. Where can I find more information why it failed to start?

If a container fails to start, its status is set to error. AMS automatically fetches several log files from the container and makes them available for further inspection. From the log files, you can find out what went wrong. The reason is not always straightforward, because several things play into the container startup, for example, the application that the container is hosting or any installed addons.

See How to view the container logs for instructions on how to access the container log files.

Published application version not found

Applies to: Anbox Cloud, Anbox Cloud Appliance

When launching a container for an application, I get an error about the “published application version not found”. Why?

If you launch a container by only specifying the application ID and the application has no published version yet, you must explicitly specify the version that you want to launch or publish a version of the application. See How to launch application containers and How to publish application versions for more information.

Creating applications

You might encounter the following issues when creating an application.

Application manifest

Applies to: Anbox Cloud, Anbox Cloud Appliance

Is there an automatic way to create a manifest for an application?

No. The application manifest describes necessary metadata on top of the APK, which AMS needs. You can simplify the manifest to only contain the name field, but you will lose a lot of control about how your application is being executed.

No such file or directory

Applies to: Anbox Cloud, Anbox Cloud Appliance

When creating an application, I get an error that there is “no such file or directory”. Why?

Due to Snap strict confinement, the folder or tarball file must be located in the home directory. There is no workaround for this requirement. The same requirement applies to addon creation.

LXD cluster

The following issues might occur if you use clustering.

AMS hook failed: “lxd-relation-changed”

Applies to: Anbox Cloud

I see an error message like the following in the output of juju debug-log --include ams:

unit-ams-0: 13:30:51 INFO unit.ams/0.juju-log Error adding LXD node lxd5 to AMS: 1 - Flag --timeout has been deprecated, Using the timeout argument has no longer an effect as cancelling cluster operations is not supported
Error: Get "": Unable to connect to:
unit-ams-0: 13:30:51 ERROR unit.ams/0.juju-log Hook error:
Traceback (most recent call last):
  File "/var/lib/juju/agents/unit-ams-0/.venv/lib/python3.8/site-packages/charms/reactive/", line 74, in main
  File "/var/lib/juju/agents/unit-ams-0/.venv/lib/python3.8/site-packages/charms/reactive/", line 390, in dispatch
  File "/var/lib/juju/agents/unit-ams-0/.venv/lib/python3.8/site-packages/charms/reactive/", line 359, in _invoke
  File "/var/lib/juju/agents/unit-ams-0/.venv/lib/python3.8/site-packages/charms/reactive/", line 181, in invoke
 File "/var/lib/juju/agents/unit-ams-0/charm/reactive/", line 356, in endpoint_lxd_changed
  File "/var/lib/juju/agents/unit-ams-0/charm/reactive/", line 333, in process_cluster_changes
    update_lxd_nodes_in_service(nodes, use_node_state=True)
  File "/var/lib/juju/agents/unit-ams-0/charm/reactive/", line 966, in update_lxd_nodes_in_service
    if add_lxd_node_to_service(n) and use_node_state:
  File "/var/lib/juju/agents/unit-ams-0/charm/reactive/", line 1061, in add_lxd_node_to_service
    raise ex
  File "/var/lib/juju/agents/unit-ams-0/charm/reactive/", line 1050, in add_lxd_node_to_service
    check_output(cmd, stderr=STDOUT)
  File "/usr/lib/python3.8/", line 415, in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
  File "/usr/lib/python3.8/", line 516, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['amc', 'node', 'add', 'lxd5', '', '--storage-device', 'dir', '--network-bridge-mtu', '1500', '--timeout', '5m']' returned non-zero exit status 1.

What is the problem, and how can I fix it?

This error indicates a faulty LXD node. Most likely, something went wrong when AMS tried adding a new LXD node to the cluster, either because the LXD node was not available on the network or it joining the cluster failed for unknown reasons.

The easiest way to make the AMS unit work again is to remove the faulty LXD node (lxd/5 in this example) by running the following command:

juju remove-unit --force lxd/5

Note: Add --destroy-storage to the command if you allocated dedicated storage for LXD.

After the LXD unit is successfully removed, resolve the failed hook of the AMS unit. For that, first disable
automatic retries to prevent Juju from re-running the failed hook:

juju model-config automatically-retry-hooks=false

Wait for any pending hook execution to finish. Check juju status to monitor the status.

Once the model has settled, resolve the failed hook by running the following command:

juju resolve ams/0 --no-retry

Check the juju status output. The status of the ams/0 unit should switch back to active.

To verify that the LXD cluster is still correctly in place, compare the output of juju ssh ams/0 -- amc node ls
and juju ssh lxd/0 -- lxc cluster ls. Both commands should list the same LXD nodes.

Finally, enable automatic retries again:

juju model-config automatically-retry-hooks=true