Adds nomad exec support in our API, by hitting the websocket endpoint.
We introduce API structs that correspond to the drivers streaming exec structs.
For creating the websocket connection, we reuse the transport setting from api
http client.
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.
Currently when operators need to log onto a machine where an alloc
is running they will need to perform both an alloc/job status
call and then a call to discover the node name from the node list.
This updates both the job status and alloc status output to include
the node name within the information to make operator use easier.
Closes#2359
Cloess #1180
* Divest api/ package of deps elsewhere in the nomad repo.
This will allow making api/ a module without then pulling in the
external repo, leading to a package name conflict.
This required some migration of tests to an apitests/ folder (can be
moved anywhere as it has no deps on it). It also required some
duplication of code, notably some test helpers from api/ -> apitests/
and part (but not all) of testutil/ -> api/testutil/.
Once there's more separation and an e.g. sdk/ folder those can be
removed in favor of a dep on the sdk/ folder, provided the sdk/ folder
doesn't depend on api/ or /.
* Also remove consul dep from api/ package
* Fix stupid linters
* Some restructuring
Add some tests to ensure that api/structs values are in sync.
Given that vendoring libraries prune tests by default, test dependencies
aren't leaked to clients of the package - so it should be safe to add
such dependency without affecting api clients.
Given that the values will rarely change, specially considering that any
changes would be backward incompatible change. As such, it's simpler to
keep syncing manually in the rare occasion and avoid the syncing code
overhead.
Embed pointer conversion functions in the API package to avoid
unnecessary package dependency. `helper` package imports more
dependencies relevant for internal use (e.g. `hcl`).
nomad/structs is an internal package and imports many libraries (e.g.
raft, codec) that are not relevant to api clients, and may cause
unnecessary dependency pain (e.g. `github.com/ugorji/go/codec`
version is very old now).
Here, we add a code generator that imports the relevant constants from
`nomad/structs`.
I considered using this approach for other structs, but didn't find a
quick viable way to reduce duplication. `nomad/structs` use values as
struct fields (e.g. `string`), while `api` uses value pointer (e.g.
`*string`) instead. Also, sometimes, `api` structs contain deprecated
fields or additional documentation, so simple copy-paste doesn't work.
For these reasons, I opt to keep the status quo.
Track current memory usage, `memory.usage_in_bytes`, in addition to
`memory.max_memory_usage_in_bytes` and friends. This number is closer
what Docker reports.
Related to https://github.com/hashicorp/nomad/issues/5165 .
The whole approach to monitoring drains has ordering issues and lacks
state to output useful error messages.
AFAICT to get the tests passing reliably I needed to change the behavior
of monitoring.
Parts of these tests are skipped in CI, and they should be rewritten as
e2e tests.
IOPS have been modelled as a resource since Nomad 0.1 but has never
actually been detected and there is no plan in the short term to add
detection. This is because IOPS is a bit simplistic of a unit to define
the performance requirements from the underlying storage system. In its
current state it adds unnecessary confusion and can be removed without
impacting any users. This PR leaves IOPS defined at the jobspec parsing
level and in the api/ resources since these are the two public uses of
the field. These should be considered deprecated and only exist to allow
users to stop using them during the Nomad 0.9.x release. In the future,
there should be no expectation that the field will exist.
This change makes few compromises:
* Looks up the devices associated with tasks at look up time. Given
that `nomad alloc status` is called rarely generally (compared to stats
telemetry and general job reporting), it seems fine. However, the
lookup overhead grows bounded by number of `tasks x total-host-devices`,
which can be significant.
* `client.Client` performs the task devices->statistics lookup. It
passes self to alloc/task runners so they can look up the device statistics
allocated to them.
* Currently alloc/task runners are responsible for constructing the
entire RPC response for stats
* The alternatives for making task runners device statistics aware
don't seem appealing (e.g. having task runners contain reference to hostStats)
* On the alloc aggregation resource usage, I did a naive merging of task device statistics.
* Personally, I question the value of such aggregation, compared to
costs of struct duplication and bloating the response - but opted to be
consistent in the API.
* With naive concatination, device instances from a single device group used by separate tasks in the alloc, would be aggregated in two separate device group statistics.
Closing the frames chan is the only race-free way to signal to receivers
that all frames have been sent and no errors have occurred.
If EOF is sent on error chan receivers may not receive the last frame
(or frames since the chan is buffered) before receiving the error.
Closing frames is the idiomatic way of signaling there is no more data
to be read from a chan.
This change updates the console log message when performing a node
drain and particulary when a node has marked all allocs for
migration. Previously it logged 'drain complete' which was a little
confusing to operators as the node is not drained at this point.
Closes#4183
The parse endpoint accepts a hcl jobspec body within a json object
and returns the parsed json object for the job. This allows users to
register jobs with the nomad json api without specifically needing
a nomad binary to parse their hcl encoded jobspec file.
Before the drain CLI would block until the node was marked as completing
drain operations. While technically correct, it could lead operators (or
more likely: scripts) to shutdown drained nodes before all of its
allocations had *actually* terminated.
This change makes the CLI block until all allocations have terminated
(unless ignoring system jobs).
This PR allows marking a node as eligible for scheduling while toggling
drain. By default the `nomad node drain -disable` commmand will mark it
as eligible but the drainer will maintain in-eligibility.
