Implement runservice maintenance mode and export/import.
When runservice is set in maintenance mode it'll start only the maintenance and
export/import handlers.
Setting maintenance mode will set a key in etcd so all the runservice instances
will detect it and enter in maintenance mode. This is done asyncronously so it
could take some time (future improvements will add some api to show all the
runservice states)
Export is always available and will export the datamanager contents. Currently
only datamanager contents are exported (no logs and workspace archives).
Import is available only during maintenance, given a datamanager export will
import it and reset etcd to this import state.
Use the go sql context functions (ExecContext, QueryContext etc...)
The context is saved inside Tx so the library users should only pass it one time
to the db.Do function.
The cache group fields defines under which cache group the run cache data will
belong. This is needed/useful for some next changes:
* Make cache correctly work for user direct runs. Since the user direct runs all
belong to the same run group (the user id) all the use direct runs will share the
same caches. To distinguish between the different caches we need to use something
in addition to the user id (the local repo uuid generated by the direct run
start command)
* Share the cache between multiple projects
ErrInternal is an internal error that should be provided to the user (http api
will return a 500 with the error message)
It'll be used for any kind of error that are not auth or bad requests (like
errors to communicate to another service)
Don't create an ErrFromRemote wrapping the returned error but
wrap the ErrFromRemote
Also use xerrors Is/As to get the underlying error to return to api clients
while maintaining context for logging
Just a raw replace of "github.com/pkg/errors".
Next steps will improve errors (like remote errors, api errors, not exist errors
etc...) to leverage its functionalities
rename the previous posix storage to posixflat and make it currently not user
selectable (since I'm not sure it's really worth using it).
The new posix storage uses the filesystem without any escaping so it's not a
real flat namespace.
This isn't a real issue since also minio is not a flat namespace and we are so
forced to use it like a hierarchycal filesystem.
Logs and archives can be shared by multiple runs. So removing a run doesn't
imply that we could also remote the logs and archives since they could be
"referenced" by another run.
Store also the runids as specific objects along with the logs and archives so,
we'll remove them only when no runids objects exist.
Also if they are logically part of the runservice the names runserviceExecutor
and runserviceScheduler are long and quite confusing for an external user
Simplify them separating both the code parts and updating the names:
runserviceScheduler -> runservice
runserviceExecutor -> executor
Simone Gotti