* client: accommodate Consul 1.14.0 gRPC and agent self changes.
Consul 1.14.0 changed the way in which gRPC listeners are
configured, particularly when using TLS. Prior to the change, a
single listener was responsible for handling plain-text and
encrypted gRPC requests. In 1.14.0 and beyond, separate listeners
will be used for each, defaulting to 8502 and 8503 for plain-text
and TLS respectively.
The change means that Nomad’s Consul Connect integration would not
work when integrated with Consul clusters using TLS and running
1.14.0 or greater.
The Nomad Consul fingerprinter identifies the gRPC port Consul has
exposed using the "DebugConfig.GRPCPort" value from Consul’s
“/v1/agent/self” endpoint. In Consul 1.14.0 and greater, this only
represents the plain-text gRPC port which is likely to be disbaled
in clusters running TLS. In order to fix this issue, Nomad now
takes into account the Consul version and configured scheme to
optionally use “DebugConfig.GRPCTLSPort” value from Consul’s agent
self return.
The “consul_grcp_socket” allocrunner hook has also been updated so
that the fingerprinted gRPC port attribute is passed in. This
provides a better fallback method, when the operator does not
configure the “consul.grpc_address” option.
* docs: modify Consul Connect entries to detail 1.14.0 changes.
* changelog: add entry for #15309
* fixup: tidy tests and clean version match from review feedback.
* fixup: use strings tolower func.
After Deployments were added in Nomad 0.6.0, the `AllocUpdateRequestType` raft
log entry was no longer in use. Mark this as deprecated, remove the associated
dead code, and remove references to the metrics it emits from the docs. We'll
leave the entry itself just in case we encounter old raft logs that we need to
be able to safely load.
During unusual outage recovery scenarios on large clusters, a backlog of
millions of evaluations can appear. In these cases, the `eval delete` command can
put excessive load on the cluster by listing large sets of evals to extract the
IDs and then sending larges batches of IDs. Although the command's batch size
was carefully tuned, we still need to be JSON deserialize, re-serialize to
MessagePack, send the log entries through raft, and get the FSM applied.
To improve performance of this recovery case, move the batching process into the
RPC handler and the state store. The design here is a little weird, so let's
look a the failed options first:
* A naive solution here would be to just send the filter as the raft request and
let the FSM apply delete the whole set in a single operation. Benchmarking with
1M evals on a 3 node cluster demonstrated this can block the FSM apply for
several minutes, which puts the cluster at risk if there's a leadership
failover (the barrier write can't be made while this apply is in-flight).
* A less naive but still bad solution would be to have the RPC handler filter
and paginate, and then hand a list of IDs to the existing raft log
entry. Benchmarks showed this blocked the FSM apply for 20-30s at a time and
took roughly an hour to complete.
Instead, we're filtering and paginating in the RPC handler to find a page token,
and then passing both the filter and page token in the raft log. The FSM apply
recreates the paginator using the filter and page token to get roughly the same
page of evaluations, which it then deletes. The pagination process is fairly
cheap (only abut 5% of the total FSM apply time), so counter-intuitively this
rework ends up being much faster. A benchmark of 1M evaluations showed this
blocked the FSM apply for 20-30ms at a time (typical for normal operations) and
completes in less than 4 minutes.
Note that, as with the existing design, this delete is not consistent: a new
evaluation inserted "behind" the cursor of the pagination will fail to be
deleted.
The exec driver and other drivers derived from the shared executor check the
path of the command before handing off to libcontainer to ensure that the
command doesn't escape the sandbox. But we don't check any host volume mounts,
which should be safe to use as a source for executables if we're letting the
user mount them to the container in the first place.
Check the mount config to verify the executable lives in the mount's host path,
but then return an absolute path within the mount's task path so that we can hand
that off to libcontainer to run.
Includes a good bit of refactoring here because the anchoring of the final task
path has different code paths for inside the task dir vs inside a mount. But
I've fleshed out the test coverage of this a good bit to ensure we haven't
created any regressions in the process.
This PR updates template and meta docs pages to give examples of accessing
meta values in templates. To do so one must use the environment variable form
of the meta key name, which isn't obvious and wasn't yet documented.
* Fix s3 URLs so that they work
Unfortunately, s3 urls prefixed with https:// do NOT work with the underlying go-getter library. As such, this fixes the examples so that they are working examples that won't cause problems for people reading the docs.
See discussion in https://github.com/hashicorp/nomad/issues/1113 circa 2016.
* Use s3:// protocol schema for artifact examples
Per the discussion in https://github.com/hashicorp/nomad/pull/15123,
we're going to use the explicit s3 protocol in the examples since that
is the likeliest to work in all scenarios
When replication of a single key fails, the replication loop breaks early and
therefore keys that fall later in the sorting order will never get
replicated. This is particularly a problem for clusters impacted by the bug that
caused #14981 and that were later upgraded; the keys that were never replicated
can now never be replicated, and so we need to handle them safely.
Included in the replication fix:
* Refactor the replication loop so that each key replicated in a function call
that returns an error, to make the workflow more clear and reduce nesting. Log
the error and continue.
* Improve stability of keyring replication tests. We no longer block leadership
on initializing the keyring, so there's a race condition in the keyring tests
where we can test for the existence of the root key before the keyring has
been initialize. Change this to an "eventually" test.
But these fixes aren't enough to fix#14981 because they'll end up seeing an
error once a second complaining about the missing key, so we also need to fix
keyring GC so the keys can be removed from the state store. Now we'll store the
key ID used to sign a workload identity in the Allocation, and we'll index the
Allocation table on that so we can track whether any live Allocation was signed
with a particular key ID.
The existing docs on required capabilities are a little sparse and have been the
subject of a lots of questions. Expand on this information and provide a pointer
to the ongoing design discussion around rootless Nomad.
The client ACL cache was not accounting for tokens which included
ACL role links. This change modifies the behaviour to resolve role
links to policies. It will also now store ACL roles within the
cache for quick lookup. The cache TTL is configurable in the same
manner as policies or tokens.
Another small fix is included that takes into account the ACL
token expiry time. This was not included, which meant tokens with
expiry could be used past the expiry time, until they were GC'd.
This PR removes the assertion around when the 'task' field of
a check may be set. Starting in Nomad 1.4 we automatically set
the task field on all checks in support of the NSD checks feature.
This is causing validation problems elsewhere, e.g. when a group
service using the Consul provider sets 'task' it will fail
validation that worked previously.
The assertion of leaving 'task' unset was only about making sure
job submitters weren't expecting some behavior, but in practice
is causing bugs now that we need the task field for more than it
was originally added for.
We can simply update the docs, noting when the task field set by
job submitters actually has value.
* docs: clarify nomad vars vs vault
I think we should make the difference in root key management between
Nomad and Vault clear in the concept docs. I didn't see anywhere else in
the docs we compared it.
I also s/secrets/variables everywhere except the first sentence since
the feature is intended to be more generic than secrets. Right now it's
more of a compliment to Consul's kv than Vault due to root key handling
and featureset.
* Update website/content/docs/concepts/variables.mdx
Co-authored-by: Tim Gross <tgross@hashicorp.com>
This is probably undocumented for a reason, but the `enabled` toggle in the
`periodic` stanza is very useful so I figured I try adding it to the docs.
The feature has been secretly avaliable since #9142 and was called out in that
PR as being a dubious addition, only added to avoid regressions.
The use case for disabling a periodic job in this way is to prevent it from
running without modifying the schedule. Ideally Nomad would make it more clear
that this was the case, and allow you to force a run of the job, but even with
those rough edges I think users would benefit from knowing about this toggle.
This changeset adds new architecture internals documents to the contributing
guide. These are intentionally here and not on the public-facing website because
the material is not required for operators and includes a lot of diagrams that
we can cheaply maintain with mermaid syntax but would involve art assets to have
up on the main site that would become quickly out of date as code changes happen
and be extremely expensive to maintain. However, these should be suitable to use
as points of conversation with expert end users.
Included:
* A description of Evaluation triggers and expected counts, with examples.
* A description of Evaluation states and implicit states. This is taken from an
internal document in our team wiki.
* A description of how writing the State Store works. This is taken from a
diagram I put together a few months ago for internal education purposes.
* A description of Evaluation lifecycle, from registration to running
Allocations. This is mostly lifted from @lgfa29's amazing mega-diagram, but
broken into digestible chunks and without multi-region deployments, which I'd
like to cover in a future doc.
Also includes adding Deployments to our public-facing glossary.
Co-authored-by: Luiz Aoqui <luiz@hashicorp.com>
Co-authored-by: Michael Schurter <mschurter@hashicorp.com>
Co-authored-by: Seth Hoenig <shoenig@duck.com>
This reverts PR #12416 and commit 6668ce022a.
While the driver options are well and truly deprecated, this documentation also
covers features like `fingerprint.denylist` that are not available any other
way. Let's revert this until #12420 is ready.
* cleanup: fixup linter warnings in schedular/feasible.go
* core: numeric operands comparisons in constraints
This PR changes constraint comparisons to be numeric rather than
lexical if both operands are integers or floats.
Inspiration #4856Closes#4729Closes#14719
* fix: always parse as int64
* docs: write a lot of words about heartbeats
Alternative to #14670
* Apply suggestions from code review
Co-authored-by: Tim Gross <tgross@hashicorp.com>
* use descriptive title for link
* rework example of high failover ttl
Co-authored-by: Tim Gross <tgross@hashicorp.com>
* fingerprint: add node attr for reserverable cores
Add an attribute for the number of reservable CPU cores as they may
differ from the existing `cpu.numcores` due to client configuration or
OS support.
Hopefully clarifies some confusion in #14676
* add changelog
* num_reservable_cores -> reservablecores
Extension of #14673
Once Vault is initially fingerprinted, extend the period since changes
should be infrequent and the fingerprint is relatively expensive since
it is contacting a central Vault server.
Also move the period timer reset *after* the fingerprint. This is
similar to #9435 where the idea is to ensure the retry period starts
*after* the operation is attempted. 15s will be the *minimum* time
between fingerprints now instead of the *maximum* time between
fingerprints.
In the case of Vault fingerprinting, the original behavior might cause
the following:
1. Timer is reset to 15s
2. Fingerprint takes 16s
3. Timer has already elapsed so we immediately Fingerprint again
Even if fingerprinting Vault only takes a few seconds, that may very
well be due to excessive load and backing off our fingerprints is
desirable. The new bevahior ensures we always wait at least 15s between
fingerprint attempts and should allow some natural jittering based on
server load and network latency.
Clients periodically fingerprint Vault and Consul to ensure the server has
updated attributes in the client's fingerprint. If the client can't reach
Vault/Consul, the fingerprinter clears the attributes and requires a node
update. Although this seems like correct behavior so that we can detect
intentional removal of Vault/Consul access, it has two serious failure modes:
(1) If a local Consul agent is restarted to pick up configuration changes and the
client happens to fingerprint at that moment, the client will update its
fingerprint and result in evaluations for all its jobs and all the system jobs
in the cluster.
(2) If a client loses Vault connectivity, the same thing happens. But the
consequences are much worse in the Vault case because Vault is not run as a
local agent, so Vault connectivity failures are highly correlated across the
entire cluster. A 15 second Vault outage will cause a new `node-update`
evalution for every system job on the cluster times the number of nodes, plus
one `node-update` evaluation for every non-system job on each node. On large
clusters of 1000s of nodes, we've seen this create a large backlog of evaluations.
This changeset updates the fingerprinting behavior to keep the last fingerprint
if Consul or Vault queries fail. This prevents a storm of evaluations at the
cost of requiring a client restart if Consul or Vault is intentionally removed
from the client.
In Nomad 1.2.6 we shipped `eval list`, which accepts a `-json` flag, and
deprecated the usage of `eval status` without an evaluation ID with an upgrade
note that it would be removed in Nomad 1.4.0. This changeset completes that
work.
* scheduler: stopped-yet-running allocs are still running
* scheduler: test new stopped-but-running logic
* test: assert nonoverlapping alloc behavior
Also add a simpler Wait test helper to improve line numbers and save few
lines of code.
* docs: tried my best to describe #10446
it's not concise... feedback welcome
* scheduler: fix test that allowed overlapping allocs
* devices: only free devices when ClientStatus is terminal
* test: output nicer failure message if err==nil
Co-authored-by: Mahmood Ali <mahmood@hashicorp.com>
Co-authored-by: Michael Schurter <mschurter@hashicorp.com>
* Fixing heading order, adding text for links
* Apply suggestions from code review
Co-authored-by: Tim Gross <tgross@hashicorp.com>
* Applying more suggestions from code review
Co-authored-by: Tim Gross <tgross@hashicorp.com>
