Consul CLI uses CONSUL_HTTP_TOKEN, so Nomad should use the same.
Note that consul-template uses CONSUL_TOKEN, which Nomad also uses,
so be careful to preserve any reference to that in the consul-template
context.
Consul provides a feature of Service Definitions where the tags
associated with a service can be modified through the Catalog API,
overriding the value(s) configured in the agent's service configuration.
To enable this feature, the flag enable_tag_override must be configured
in the service definition.
Previously, Nomad did not allow configuring this flag, and thus the default
value of false was used. Now, it is configurable.
Because Nomad itself acts as a state machine around the the service definitions
of the tasks it manages, it's worth describing what happens when this feature
is enabled and why.
Consider the basic case where there is no Nomad, and your service is provided
to consul as a boring JSON file. The ultimate source of truth for the definition
of that service is the file, and is stored in the agent. Later, Consul performs
"anti-entropy" which synchronizes the Catalog (stored only the leaders). Then
with enable_tag_override=true, the tags field is available for "external"
modification through the Catalog API (rather than directly configuring the
service definition file, or using the Agent API). The important observation
is that if the service definition ever changes (i.e. the file is changed &
config reloaded OR the Agent API is used to modify the service), those
"external" tag values are thrown away, and the new service definition is
once again the source of truth.
In the Nomad case, Nomad itself is the source of truth over the Agent in
the same way the JSON file was the source of truth in the example above.
That means any time Nomad sets a new service definition, any externally
configured tags are going to be replaced. When does this happen? Only on
major lifecycle events, for example when a task is modified because of an
updated job spec from the 'nomad job run <existing>' command. Otherwise,
Nomad's periodic re-sync's with Consul will now no longer try to restore
the externally modified tag values (as long as enable_tag_override=true).
Fixes#2057
Nomad jobs may be configured with a TaskGroup which contains a Service
definition that is Consul Connect enabled. These service definitions end
up establishing a Consul Connect Proxy Task (e.g. envoy, by default). In
the case where Consul ACLs are enabled, a Service Identity token is required
for these tasks to run & connect, etc. This changeset enables the Nomad Server
to recieve RPC requests for the derivation of SI tokens on behalf of instances
of Consul Connect using Tasks. Those tokens are then relayed back to the
requesting Client, which then injects the tokens in the secrets directory of
the Task.
When a job is configured with Consul Connect aware tasks (i.e. sidecar),
the Nomad Client should be able to request from Consul (through Nomad Server)
Service Identity tokens specific to those tasks.
Enable any Server to lookup the unique ClusterID. If one has not been
generated, and this node is the leader, generate a UUID and attempt to
apply it through raft.
The value is not yet used anywhere in this changeset, but is a prerequisite
for gh-6701.
This change provides an initial pass at setting up the configuration necessary to
enable use of Connect with Consul ACLs. Operators will be able to pass in a Consul
Token through `-consul-token` or `$CONSUL_TOKEN` in the `job run` and `job revert`
commands (similar to Vault tokens).
These values are not actually used yet in this changeset.
Introduce limits to prevent unauthorized users from exhausting all
ephemeral ports on agents:
* `{https,rpc}_handshake_timeout`
* `{http,rpc}_max_conns_per_client`
The handshake timeout closes connections that have not completed the TLS
handshake by the deadline (5s by default). For RPC connections this
timeout also separately applies to first byte being read so RPC
connections with TLS enabled have `rpc_handshake_time * 2` as their
deadline.
The connection limit per client prevents a single remote TCP peer from
exhausting all ephemeral ports. The default is 100, but can be lowered
to a minimum of 26. Since streaming RPC connections create a new TCP
connection (until MultiplexV2 is used), 20 connections are reserved for
Raft and non-streaming RPCs to prevent connection exhaustion due to
streaming RPCs.
All limits are configurable and may be disabled by setting them to `0`.
This also includes a fix that closes connections that attempt to create
TLS RPC connections recursively. While only users with valid mTLS
certificates could perform such an operation, it was added as a
safeguard to prevent programming errors before they could cause resource
exhaustion.
This commit ensures that Alloc.AllocatedResources is properly populated
when read from persistence stores (namely Raft and client state store).
The alloc struct may have been written previously by an arbitrary old
version that may only populate Alloc.TaskResources.
When parsing a config file which had the consul.timeout param set,
Nomad was reporting an error causing startup to fail. This seems
to be caused by the HCL decoder interpreting the timeout type as
an int rather than a string. This is caused by the struct
TimeoutHCL param having a hcl key of timeout alongside a Timeout
struct param of type time.Duration (int). Ensuring the decoder
ignores the Timeout struct param ensure the decoder runs
correctly.
copy struct values
ensure groupserviceHook implements RunnerPreKillhook
run deregister first
test that shutdown times are delayed
move magic number into variable
Fixes#6853
Canonicalize jobs first before adding any sidecars. This fixes a bug
where sidecar tasks were added without interpolated names and broke
validation. Sidecar tasks must be canonicalized independently.
Also adds a group network to the mock connect job because it wasn't a
valid connect job before!
Noticed that ACL endpoints return 500 status code for user errors. This
is confusing and can lead to false monitoring alerts.
Here, I introduce a concept of RPCCoded errors to be returned by RPC
that signal a code in addition to error message. Codes for now match
HTTP codes to ease reasoning.
```
$ nomad acl bootstrap
Error bootstrapping: Unexpected response code: 500 (ACL bootstrap already done (reset index: 9))
$ nomad acl bootstrap
Error bootstrapping: Unexpected response code: 400 (ACL bootstrap already done (reset index: 9))
```
The existing version constraint uses logic optimized for package
managers, not schedulers, when checking prereleases:
- 1.3.0-beta1 will *not* satisfy ">= 0.6.1"
- 1.7.0-rc1 will *not* satisfy ">= 1.6.0-beta1"
This is due to package managers wishing to favor final releases over
prereleases.
In a scheduler versions more often represent the earliest release all
required features/APIs are available in a system. Whether the constraint
or the version being evaluated are prereleases has no impact on
ordering.
This commit adds a new constraint - `semver` - which will use Semver
v2.0 ordering when evaluating constraints. Given the above examples:
- 1.3.0-beta1 satisfies ">= 0.6.1" using `semver`
- 1.7.0-rc1 satisfies ">= 1.6.0-beta1" using `semver`
Since existing jobspecs may rely on the old behavior, a new constraint
was added and the implicit Consul Connect and Vault constraints were
updated to use it.
* client: improve group service stanza interpolation and check_restart support
Interpolation can now be done on group service stanzas. Note that some task runtime specific information
that was previously available when the service was registered poststart of a task is no longer available.
The check_restart stanza for checks defined on group services will now properly restart the allocation upon
check failures if configured.
This commit introduces support for configuring mount propagation when
mounting volumes with the `volume_mount` stanza on Linux targets.
Similar to Kubernetes, we expose 3 options for configuring mount
propagation:
- private, which is equivalent to `rprivate` on Linux, which does not allow the
container to see any new nested mounts after the chroot was created.
- host-to-task, which is equivalent to `rslave` on Linux, which allows new mounts
that have been created _outside of the container_ to be visible
inside the container after the chroot is created.
- bidirectional, which is equivalent to `rshared` on Linux, which allows both
the container to see new mounts created on the host, but
importantly _allows the container to create mounts that are
visible in other containers an don the host_
private and host-to-task are safe, but bidirectional mounts can be
dangerous, as if the code inside a container creates a mount, and does
not clean it up before tearing down the container, it can cause bad
things to happen inside the kernel.
To add a layer of safety here, we require that the user has ReadWrite
permissions on the volume before allowing bidirectional mounts, as a
defense in depth / validation case, although creating mounts should also require
a priviliged execution environment inside the container.
Fix a bug where a millicious user can access or manipulate an alloc in a
namespace they don't have access to. The allocation endpoints perform
ACL checks against the request namespace, not the allocation namespace,
and performs the allocation lookup independently from namespaces.
Here, we check that the requested can access the alloc namespace
regardless of the declared request namespace.
Ideally, we'd enforce that the declared request namespace matches
the actual allocation namespace. Unfortunately, we haven't documented
alloc endpoints as namespaced functions; we suspect starting to enforce
this will be very disruptive and inappropriate for a nomad point
release. As such, we maintain current behavior that doesn't require
passing the proper namespace in request. A future major release may
start enforcing checking declared namespace.
Without a `LocalServicePort`, Connect services will try to use the
mapped port even when delivering traffic locally. A user can override
this behavior by pinning the port value in the `service` stanza but
this prevents us from using the Consul service name to reach the
service.
This commits configures the Consul proxy with its `LocalServicePort`
and `LocalServiceAddress` fields.
Currently, using a Volume in a job uses the following configuration:
```
volume "alias-name" {
type = "volume-type"
read_only = true
config {
source = "host_volume_name"
}
}
```
This commit migrates to the following:
```
volume "alias-name" {
type = "volume-type"
source = "host_volume_name"
read_only = true
}
```
The original design was based due to being uncertain about the future of storage
plugins, and to allow maxium flexibility.
However, this causes a few issues, namely:
- We frequently need to parse this configuration during submission,
scheduling, and mounting
- It complicates the configuration from and end users perspective
- It complicates the ability to do validation
As we understand the problem space of CSI a little more, it has become
clear that we won't need the `source` to be in config, as it will be
used in the majority of cases:
- Host Volumes: Always need a source
- Preallocated CSI Volumes: Always needs a source from a volume or claim name
- Dynamic Persistent CSI Volumes*: Always needs a source to attach the volumes
to for managing upgrades and to avoid dangling.
- Dynamic Ephemeral CSI Volumes*: Less thought out, but `source` will probably point
to the plugin name, and a `config` block will
allow you to pass meta to the plugin. Or will
point to a pre-configured ephemeral config.
*If implemented
The new design simplifies this by merging the source into the volume
stanza to solve the above issues with usability, performance, and error
handling.
This is an attempt to ease dependency management for external driver
plugins, by avoiding requiring them to compile ugorji/go generated
files. Plugin developers reported some pain with the brittleness of
ugorji/go dependency in particular, specially when using go mod, the
default go mod manager in golang 1.13.
Context
--------
Nomad uses msgpack to persist and serialize internal structs, using
ugorji/go library. As an optimization, we use ugorji/go code generation
to speedup process and aovid the relection-based slow path.
We commit these generated files in repository when we cut and tag the
release to ease reproducability and debugging old releases. Thus,
downstream projects that depend on release tag, indirectly depends on
ugorji/go generated code.
Sadly, the generated code is brittle and specific to the version of
ugorji/go being used. When go mod picks another version of ugorji/go
then nomad (go mod by default uses release according to semver),
downstream projects face compilation errors.
Interestingly, downstream projects don't commonly serialize nomad
internal structs. Drivers and device plugins use grpc instead of
msgpack for the most part. In the few cases where they use msgpag (e.g.
decoding task config), they do without codegen path as they run on
driver specific structs not the nomad internal structs. Also, the
ugorji/go serialization through reflection is generally backward
compatible (mod some ugorji/go regression bugs that get introduced every
now and then :( ).
Proposal
---------
The proposal here is to keep committing ugorji/go codec generated files
for releases but to use a go tag for them.
All nomad development through the makefile, including releasing, CI and
dev flow, has the tag enabled.
Downstream plugin projects, by default, will skip these files and life
proceed as normal for them.
The downside is that nomad developers who use generated code but avoid
using make must start passing additional go tag argument. Though this
is not a blessed configuration.
* connect: add unix socket to proxy grpc for envoy
Fixes#6124
Implement a L4 proxy from a unix socket inside a network namespace to
Consul's gRPC endpoint on the host. This allows Envoy to connect to
Consul's xDS configuration API.
* connect: pointer receiver on structs with mutexes
* connect: warn on all proxy errors
