This adds a websocket endpoint for handling `nomad exec`.
The endpoint is a websocket interface, as we require a bi-directional
streaming (to handle both input and output), which is not very appropriate for
plain HTTP 1.0. Using websocket makes implementing the web ui a bit simpler. I
considered using golang http hijack capability to treat http request as a plain
connection, but the web interface would be too complicated potentially.
Furthermore, the API endpoint operates against the raw core nomad exec streaming
datastructures, defined in protobuf, with json serializer. Our APIs use json
interfaces in general, and protobuf generates json friendly golang structs.
Reusing the structs here simplify interface and reduce conversion overhead.
This command will be used to send a signal to either a single task within an
allocation, or all of the tasks if <task-name> is omitted. If the sent signal
terminates the allocation, it will be treated as if the allocation has crashed,
rather than as if it was operator-terminated.
Signal validation is currently handled by the driver itself and nomad
does not attempt to restrict or validate them.
This adds a `nomad alloc stop` command that can be used to stop and
force migrate an allocation to a different node.
This is built on top of the AllocUpdateDesiredTransitionRequest and
explicitly limits the scope of access to that transition to expose it
under the alloc-lifecycle ACL.
The API returns the follow up eval that can be used as part of
monitoring in the CLI or parsed and used in an external tool.
This adds a `nomad alloc restart` command and api that allows a job operator
with the alloc-lifecycle acl to perform an in-place restart of a Nomad
allocation, or a given subtask.
This fixes a bug with JSON agent configuration parsing where the AST
for the plugin stanza had unnecessary flattening originating from hcl parsing
library. The workaround fixes the AST by popping off the flattened element and wrapping
it in a list. The workaround comes from similar code in terraform.
There were no existing test cases for json parsing so I added a few.
The driver manager is modeled after the device manager and is started by the client.
It's responsible for handling driver lifecycle and reattachment state, as well as
processing the incomming fingerprint and task events from each driver. The mananger
exposes a method for registering event handlers for task events that is used by the
task runner to update the server when a task has been updated with an event.
Since driver fingerprinting has been implemented by the driver manager, it is no
longer needed in the fingerprint mananger and has been removed.
