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
* taskenv: add connect upstream env vars + test
* set taskenv upstreams instead of appending
* Update client/taskenv/env.go
Co-Authored-By: Michael Schurter <mschurter@hashicorp.com>
* adds meta object to service in job spec, sends it to consul
* adds tests for service meta
* fix tests
* adds docs
* better hashing for service meta, use helper for copying meta when registering service
* tried to be DRY, but looks like it would be more work to use the
helper function
Fixes#6041
Unlike all other Consul operations, boostrapping requires Consul be
available. This PR tries Consul 3 times with a backoff to account for
the group services being asynchronously registered with Consul.
Adds a check for differences in `job.Diff` so that task group networks
and services, including new Consul connect stanzas, show up in the job
plan outputs.
* nomad: add admission controller framework
* nomad: add admission controller framework and Consul Connect hooks
* run admission controllers before checking permissions
* client: add default node meta for connect configurables
* nomad: remove validateJob func since it has been moved to admission controller
* nomad: use new TaskKind type
* client: use consts for connect sidecar image and log level
* Apply suggestions from code review
Co-Authored-By: Michael Schurter <mschurter@hashicorp.com>
* nomad: add job register test with connect sidecar
* Update nomad/job_endpoint_hooks.go
Co-Authored-By: Michael Schurter <mschurter@hashicorp.com>
* jobspec: breakup parse.go into smaller files
* add sidecar_task parsing to jobspec and api
* jobspec: combine service parsing logic for task and group service stanzas
* api: use slice of ConsulUpstream values instead of pointers
