When Using the snapd REST API, requests sent to the snapd REST API can return both standard HTTP error responses, and a snapd-specific error kind, in the body of the response. These are detailed below.
Status codes
The REST API returns standard HTTP error response status ranges and codes, such as 4xx for client errors and 5xx for server side issues, with descriptions. For example:
| Code | Status | Example description |
|---|---|---|
| 400 | Bad request | Snap is already installed |
| 400 | Bad request | Snap is not installed / unknown action |
| 401 | Unauthorized | Access denied. Login required. |
| 403 | Forbidden | Access denied. Login required. |
| 404 | Not found | Channel not available / snap does not exist |
| 409 | Conflict | Snap snap has change-kind change in progress |
| 500 | Internal server error | many unexpected errors |
Conflict errors (409) may be temporary. They are often returned when a new operation on an entity cannot be initiated because a previous operation is still in progress. This might cause new operations on one or more snaps to see errors with the snap-change-conflict error kind, for example. When a conflicting operation completes, new operations may be retried and should later succeed, assuming the completed operation didn’t break any dependent state for the new operation.
Error kinds
The following error kind values provide extra context on an error response:
app-not-found: the requested app couldn’t be found.assertion-not-found: assertion can not be found.auth-cancelled: authentication was cancelled by the user.bad-query: a bad query was provided.dns-failure: DNS not responding.insufficient-disk-space: returned when disk space awareness is enabled and either an install, remove or refresh operation fails due to insufficient free disk space. The errorvalueis an object that containssnap-names, an array of affected snaps, and achange-kindstring with the failed operation.interfaces-unchanged: the requested interfaces’ operation would have no effect.invalid-auth-data: the authentication data provided failed to validate (e.g. a malformed email address). Thevalueof the error is an object with a key per failed field and a list of the failures on each field.login-required: the requested operation cannot be performed without an authenticated user. This is the kind of any other 401 Unauthorized response.network-timeout: a timeout occurred during the request.option-not-found: the given configuration option does not exist.password-policy: provided password doesn’t meet system policy.snap-already-installed: the requested snap is already installed.snap-architecture-not-available: no snap revision on specified architecture. Value has the same format as forsnap-channel-not-available.snap-change-conflict: the requested operation would conflict with currently ongoing change. This is a temporary error. The errorvalueis an object with optional fieldssnap-name,change-kindof the ongoing change.snap-channel-not-available: no snap revision on specified channel. Thevalueof the error is a rich object with requestedsnap-name,action,channel,architecture, and actually availablereleasesas list of{"architecture":... , "channel": ...}objects.snap-local: cannot perform operation on local snap.snap-needs-classic: the requested snap needs classic confinement to be installed.snap-needs-classic-system: the requested snap can’t be installed on the current non-classic system.snap-needs-devmode: the requested snap needs devmode to be installed.snap-no-update-available: the requested snap does not have an update available.snap-not-a-snap: the given snap or directory does not look like a snap.snap-not-classic: snap not compatible with classic mode.snap-not-found: the requested snap couldn’t be found.snap-not-installed: the requested snap is not installed.snap-revision-not-available: no snap revision available as specified.two-factor-failed: the OTP provided wasn’t recognised.two-factor-required: the client needs to retry thelogincommand including an OTP.unsuccessful: snapctl command was unsuccessful.
Maintenance error kinds
These are used only inside the maintenance field of responses.
daemon-restart: daemon is restarting.system-restart: system is restarting.