- [X] Have you signed the [CLA](http://www.ubuntu.com/legal/contributors/)? ----- ### Overview The provided name for a LXD executor object is converted to comply with [LXD naming conventions](https://linuxcontainers.org/lxd/docs/master/instances/) for instances. ### Problem LXC has a 63 character limit on instance names. [This snapcraft commit](https://github.com/snapcore/snapcraft/commit/21cb1ab9ae26cf3322356c190eb555ed05f2d498) adds 18-20 characters to the image name. This is blocking snaps with long names from upgrading to core22. Charmcraft has the [same issue](https://github.com/canonical/charmcraft/issues/629). #### Snapcraft naming convention ``` snapcraft-<project-name>-on-<build-on>-for-<build-for>-<project-path-inode> └ 10 ┘└ 2 - 41 ┘└ 8-11 ┘└ 9-12 ┘└ 10 ┘ ``` Min size: 10 + 2 + 8 + 9 + 10 = 39 Max size: 10 + 41 + 11 + 12 + 10 = 84 #### Charmcraft naming convention ``` charmcraft-<project-name>-<project-path-inode>-<bases-index>-<build-on-index>-<build-for> └ 11 ┘└ 2 - ∞ ┘└ 10 ┘└ 2 ┘└ 2 ┘└ 7 ┘ ``` Min size: 11 + 2 + 10 + 2 + 2 + 7 = 34 Max size: unbound ### Solution `craft-providers` is responsible for complying with each provider’s specific requirements. For LXD, `craft-providers` will: 1. truncate the first 40 characters name 2. remove forbidden characters 3. append a hash of the name ``` <truncated-name>-<hash-of-name> └ 1 - 40 ┘1└ 20 ┘ ``` Min size: 1 + 1 + 20 = 22 Max size: 40 + 1 + 20 = 61 Note: This is an internal change. Applications using `craft-providers` should continue to choose their own unique names for instances. The only restriction is that the name must contain at least one alphanumeric character. LP: #[1981205](https://bugs.launchpad.net/snapcraft/+bug/1981205) (CRAFT-1235)