The current implementation for the task coordinator unblocks tasks by
performing destructive operations over its internal state (like closing
channels and deleting maps from keys).
This presents a problem in situations where we would like to revert the
state of a task, such as when restarting an allocation with tasks that
have already exited.
With this new implementation the task coordinator behaves more like a
finite state machine where task may be blocked/unblocked multiple times
by performing a state transition.
This initial part of the work only refactors the task coordinator and
is functionally equivalent to the previous implementation. Future work
will build upon this to provide bug fixes and enhancements.
The original design for workload identities and ACLs allows for operators to
extend the automatic capabilities of a workload by using a specially-named
policy. This has shown to be potentially unsafe because of naming collisions, so
instead we'll allow operators to explicitly attach a policy to a workload
identity.
This changeset adds workload identity fields to ACL policy objects and threads
that all the way down to the command line. It also a new secondary index to the
ACL policy table on namespace and job so that claim resolution can efficiently
query for related policies.
When a Nomad agent starts and loads jobs that already existed in the
cluster, the default template uid and gid was being set to 0, since this
is the zero value for int. This caused these jobs to fail in
environments where it was not possible to use 0, such as in Windows
clients.
In order to differentiate between an explicit 0 and a template where
these properties were not set we need to use a pointer.
Making the ACL Role listing return object a stub future-proofs the
endpoint. In the event the role object grows, we are not bound by
having to return all fields within the list endpoint or change the
signature of the endpoint to reduce the list return size.
ACL Roles along with policies and global token will be replicated
from the authoritative region to all federated regions. This
involves a new replication loop running on the federated leader.
Policies and roles may be replicated at different times, meaning
the policies and role references may not be present within the
local state upon replication upsert. In order to bypass the RPC
and state check, a new RPC request parameter has been added. This
is used by the replication process; all other callers will trigger
the ACL role policy validation check.
There is a new ACL RPC endpoint to allow the reading of a set of
ACL Roles which is required by the replication process and matches
ACL Policies and Tokens. A bug within the ACL Role listing RPC has
also been fixed which returned incorrect data during blocking
queries where a deletion had occurred.
Since the state store returns a pointer to the shared job structs in
memdb we must always copy it before mutating it and applying the new
version via raft. Otherwise if the rpc fails before the mutated job is
committed to raft (either due to validation, bug, crash, or other exit
condition), the leader server will have an updated copy of the job that
other servers will not have.
Before this change, Client had 2 copies of the config object: config and configCopy. There was no guidance around which to use where (other than configCopy's comment to pass it to alloc runners), both are shared among goroutines and mutated in data racy ways. At least at one point I think the idea was to have `config` be mutable and then grab a lock to overwrite `configCopy`'s pointer atomically. This would have allowed alloc runners to read their config copies in data race safe ways, but this isn't how the current implementation worked.
This change takes the following approach to safely handling configs in the client:
1. `Client.config` is the only copy of the config and all access must go through the `Client.configLock` mutex
2. Since the mutex *only protects the config pointer itself and not fields inside the Config struct:* all config mutation must be done on a *copy* of the config, and then Client's config pointer is overwritten while the mutex is acquired. Alloc runners and other goroutines with the old config pointer will not see config updates.
3. Deep copying is implemented on the Config struct to satisfy the previous approach. The TLS Keyloader is an exception because it has its own internal locking to support mutating in place. An unfortunate complication but one I couldn't find a way to untangle in a timely fashion.
4. To facilitate deep copying I made an *internally backward incompatible API change:* our `helper/funcs` used to turn containers (slices and maps) with 0 elements into nils. This probably saves a few memory allocations but makes it very easy to cause panics. Since my new config handling approach uses more copying, it became very difficult to ensure all code that used containers on configs could handle nils properly. Since this code has caused panics in the past, I fixed it: nil containers are copied as nil, but 0-element containers properly return a new 0-element container. No more "downgrading to nil!"
ACL tokens can now utilize ACL roles in order to provide API
authorization. Each ACL token can be created and linked to an
array of policies as well as an array of ACL role links. The link
can be provided via the role name or ID, but internally, is always
resolved to the ID as this is immutable whereas the name can be
changed by operators.
When resolving an ACL token, the policies linked from an ACL role
are unpacked and combined with the policy array to form the
complete auth set for the token.
The ACL token creation endpoint handles deduplicating ACL role
links as well as ensuring they exist within state.
When reading a token, Nomad will also ensure the ACL role link is
current. This handles ACL roles being deleted from under a token
from a UX standpoint.
Similar to the deployment watcher fix in #14121 - the server code loves these mutable structs so we need to guard access to the struct fields with locks.
Capturing ch := b.capacityChangeCh is sufficient to satisfy the data race detector, but I noticed it was also possible to leak goroutines:
Since the watchCapacity loop is in charge of receiving from capacityChangeCh and exits when stopCh is closed, senders to capacityChangeCh also must exit when stopCh is closed. Otherwise they may block forever if capacityChangeCh is full because it will never be received on again. I did not find evidence of this occurring in my meager smattering of prod goroutine dumps I have laying around, but this isn't surprising as the chan has a buffer of 8096! I would imagine that is sufficient to handle "late" sends and then just get GC'd away when the last reference to the old chan is dropped. This is just additional safety/correctness.
The List RPCs only checked the ACL for the Prefix argument of the request. Add
an ACL filter to the paginator for the List RPC.
Extend test coverage of ACLs in the List RPC and in the `acl` package, and add a
"deny" capability so that operators can deny specific paths or prefixes below an
allowed path.
Move conflict resolution implementation into the state store with a new Apply RPC.
This also makes the RPC for secure variables much more similar to Consul's KV,
which will help us support soft deletes in a post-1.4.0 version of Nomad.
Reimplement quotas in the state store functions.
Co-authored-by: Charlie Voiselle <464492+angrycub@users.noreply.github.com>
This PR changes the use of structs.ConsulMeshGateway to value types
instead of via pointers. This will help in a follow up PR where we
cleanup a lot of custom comparison code with helper functions instead.
New ACL Role RPC endpoints have been created to allow the creation,
update, read, and deletion of ACL roles. All endpoints require a
management token; in the future readers will also be allowed to
view roles associated to their ACL token.
The create endpoint in particular is responsible for deduplicating
ACL policy links and ensuring named policies are found within
state. This is done within the RPC handler so we perform a single
loop through the links for slight efficiency.
This PR changes the behavior of 'nomad job validate' to forward the
request to the nomad leader, rather than responding from any server.
This is because we need the leader when validating Vault tokens, since
the leader is the only server with an active vault client.
This commit includes the new state schema for ACL roles along with
state interaction functions for CRUD actions.
The change also includes snapshot persist and restore
functionality and the addition of FSM messages for Raft updates
which will come via RPC endpoints.
This PR enables setting of the headers block on services registered
into Nomad's service provider. Works just like the existing support
in Consul checks.
* Allow specification of CSI staging and publishing directory path
* Add website documentation for stage_publish_dir
* Replace erroneous reference to csi_plugin.mount_config with csi_plugin.mount_dir
* Avoid requiring CSI plugins to be redeployed after introducing StagePublishDir
Move the secure variables quota enforcement calls into the state store to ensure
quota checks are atomic with quota updates (in the same transaction).
Switch to a machine-size int instead of a uint64 for quota tracking. The
ENT-side quota spec is described as int, and negative values have a meaning as
"not permitted at all". Using the same type for tracking will make it easier to
the math around checks, and uint64 is infeasibly large anyways.
Add secure vars to quota HTTP API and CLI outputs and API docs.
When we delete a namespace, we check to ensure that there are no non-terminal
jobs or CSI volume, which also covers evals, allocs, etc. Secure variables are
also namespaces, so extend this check to them as well.
When we delete a namespace, we check to ensure that there are no non-terminal
jobs, which effectively covers evals, allocs, etc. CSI volumes are also
namespaced, so extend this check to cover CSI volumes.
Workload identities grant implicit access to policies, and operators
will not want to craft separate policies for each invocation of a
periodic or dispatch job. Use the parent job's ID as the JobID claim.
The search RPC used a placeholder policy for searching within the secure
variables context. Now that we have ACL policies built for secure variables, we
can use them for search. Requires a new loose policy for checking if a token has
any secure variables access within a namespace, so that we can filter on
specific paths in the iterator.
Most of our objects use int64 timestamps derived from `UnixNano()` instead of
`time.Time` objects. Switch the keyring metadata to use `UnixNano()` for
consistency across the API.
To discourage accidentally DoS'ing the cluster with secure variables
data, we're providing a very low limit to the maximum size of a given
secure variable. This currently matches the limit for dispatch
payloads.
In future versions, we may increase this limit or make it
configurable, once we have better metrics from real-world operators.
Tasks are automatically granted access to variables on a path that matches their
workload identity, with a well-known prefix. Change the prefix to `nomad/jobs`
to allow for future prefixes like `nomad/volumes` or `nomad/plugins`. Reserve
the prefix by emitting errors during validation.
Two new periodic core jobs have been added which handle removing
expired local and global tokens from state. The local core job is
run on every leader; the global core job is only run on the leader
within the authoritative region.
When applying a raft log to expire ACL tokens, we need to use a
timestamp provided by the leader so that the result is deterministic
across servers. Use leader's timestamp from RPC call
The test for simulating a key rotation across leader elections was
flaky because we weren't waiting for a leader election and was
checking the server configs rather than raft for which server was
currently the leader. Fixing the flake revealed a bug in the test that
we weren't ensuring the new leader was running its own replication, so
it wouldn't pick up the key material from the previous follower.
When secure variables are updated, we were adding the update to the
existing quota tracking without first checking whether it was an
update to an existing variable. In that case we need to add/subtract
only the difference between the new and existing quota usage.
This commit adds basic expiry checking when performing ACL token
resolution. This expiry checking is local to each server and does
not at this time take into account potential time skew on server
hosts.
A new error message has been created so clients whose token has
expired get a clear message, rather than a generic token not
found.
The ACL resolution tests have been refactored into table driven
tests, so additions are easier in the future.
The split between OSS/ENT in ACL checks for the Search RPC has a lot
of repeated code that results in merge conflicts. Move most of the
logic into the shared code so that we can call out to thin functions
for ENT checks.
The ACL token state schema has been updated to utilise two new
indexes which track expiration of tokens that are configured with
an expiration TTL or time. A new state function allows listing
ACL expired tokens which will be used by internal garbage
collection.
The ACL endpoint has been modified so that all validation happens
within a single function call. This is easier to understand and
see at a glance. The ACL token validation now also includes logic
for expiry TTL and times. The ACL endpoint upsert tests have been
condensed into a single, table driven test.
There is a new token canonicalize which provides a single place
for token canonicalization, rather than logic spread in the RPC
handler.
Plan rejections occur when the scheduler work and the leader plan
applier disagree on the feasibility of a plan. This may happen for valid
reasons: since Nomad does parallel scheduling, it is expected that
different workers will have a different state when computing placements.
As the final plan reaches the leader plan applier, it may no longer be
valid due to a concurrent scheduling taking up intended resources. In
these situations the plan applier will notify the worker that the plan
was rejected and that they should refresh their state before trying
again.
In some rare and unexpected circumstances it has been observed that
workers will repeatedly submit the same plan, even if they are always
rejected.
While the root cause is still unknown this mitigation has been put in
place. The plan applier will now track the history of plan rejections
per client and include in the plan result a list of node IDs that should
be set as ineligible if the number of rejections in a given time window
crosses a certain threshold. The window size and threshold value can be
adjusted in the server configuration.
To avoid marking several nodes as ineligible at one, the operation is rate
limited to 5 nodes every 30min, with an initial burst of 10 operations.
This PR adds support for specifying checks in services registered to
the built-in nomad service provider.
Currently only HTTP and TCP checks are supported, though more types
could be added later.
Fixes#13505
This fixes#13505 by treating reserved_ports like we treat a lot of jobspec settings: merging settings from more global stanzas (client.reserved.reserved_ports) "down" into more specific stanzas (client.host_networks[].reserved_ports).
As discussed in #13505 there are other options, and since it's totally broken right now we have some flexibility:
Treat overlapping reserved_ports on addresses as invalid and refuse to start agents. However, I'm not sure there's a cohesive model we want to publish right now since so much 0.9-0.12 compat code still exists! We would have to explain to folks that if their -network-interface and host_network addresses overlapped, they could only specify reserved_ports in one place or the other?! It gets ugly.
Use the global client.reserved.reserved_ports value as the default and treat host_network[].reserverd_ports as overrides. My first suggestion in the issue, but @groggemans made me realize the addresses on the agent's interface (as configured by -network-interface) may overlap with host_networks, so you'd need to remove the global reserved_ports from addresses shared with a shared network?! This seemed really confusing and subtle for users to me.
So I think "merging down" creates the most expressive yet understandable approach. I've played around with it a bit, and it doesn't seem too surprising. The only frustrating part is how difficult it is to observe the available addresses and ports on a node! However that's a job for another PR.
In OSS we can upsert an allocation without worrying about whether that
alloc is in a namespace that actually exists, but in ENT that upsert
will add to the namespace's quotas. Ensure we're doing so in this
secure variables RPC test to fix the test breaking in the ENT repo.
This commit adds configuration parameters to control ACL token
expirations. This includes both limits on the min and max TTL
expiration values, as well as a GC threshold for expired tokens.
* Failing test and TODO for wildcard
* Alias the namespace query parameter for Evals
* eval: fix list when using ACLs and * namespace
Apply the same verification process as in job, allocs and scaling
policy list endpoints to handle the eval list when using an ACL token
with limited namespace support but querying using the `*` wildcard
namespace.
* changelog: add entry for #13530
* ui: set namespace when querying eval
Evals have a unique UUID as ID, but when querying them the Nomad API
still expects a namespace query param, otherwise it assumes `default`.
Co-authored-by: Luiz Aoqui <luiz@hashicorp.com>
When the `Full` flag is passed for key rotation, we kick off a core
job to decrypt and re-encrypt all the secure variables so that they
use the new key.
* SV: CAS
* Implement Check and Set for Delete and Upsert
* Reading the conflict from the state store
* Update endpoint for new error text
* Updated HTTP api tests
* Conflicts to the HTTP api
* SV: structs: Update SV time to UnixNanos
* update mock to UnixNano; refactor
* SV: encrypter: quote KeyID in error
* SV: mock: add mock for namespace w/ SV
We need to track per-namespace storage usage for secure variables even
in Nomad OSS so that a cluster can be seamlessly upgraded from OSS to
ENT without having to re-calculate quota usage.
Provide a hook in the upsert RPC for enforcement of quotas in
ENT. This will be a no-op in Nomad OSS.
Extend the GC job to support periodic key rotation.
Update the GC process to safely support signed workload identity. We
can't GC any key used to sign a workload identity. Finding which key
was used to sign every allocation will be expensive, but there are not
that many keys. This lets us take a conservative approach: find the
oldest live allocation and ensure that we don't GC any key older than
that key.
The blocking query for `Keyring.List` appended the keys for each pass
through the blocking query to the response. This results in mulitple
copies of keys in the response. Overwrite the `reply.Keys` field on
each pass through the blocking query to ensure we only get the
expected page of responses.
Adds a new policy block inside namespaces to control access to secure
variables on the basis of path, with support for globbing.
Splits out VerifyClaim from ResolveClaim.
The ServiceRegistration RPC only needs to be able to verify that a
claim is valid for some allocation in the store; it doesn't care about
implicit policies or capabilities. Split this out to its own method on
the server so that the SecureVariables RPC can reuse it as a separate
step from resolving policies (see next commit).
Support implicit policies based on workload identity
The `Encrypt` method generates an appropriately-sized nonce and uses
that buffer as the prefix for the ciphertext. This keeps the
ciphertext and nonce together for decryption, and reuses the buffer as
much as possible without presenting the temptation to reuse the
cleartext buffer owned by the caller.
We include the key ID as the "additional data" field that's used as an
extra input to the authentication signature, to provide additional
protection that a ciphertext originated with that key.
Refactors the locking for the keyring so that the public methods are
generally (with one commented exception) responsible for taking the
lock and then inner methods are assumed locked.
* Add Path only index for SecureVariables
* Add GetSecureVariablesByPrefix; refactor tests
* Add search for SecureVariables
* Add prefix search for secure variables
This PR splits SecureVariable into SecureVariableDecrypted and
SecureVariableEncrypted in order to use the type system to help
verify that cleartext secret material is not committed to file.
* Make Encrypt function return KeyID
* Split SecureVariable
Co-authored-by: Tim Gross <tgross@hashicorp.com>
In order to support implicit ACL policies for tasks to get their own
secrets, each task would need to have its own ACL token. This would
add extra raft overhead as well as new garbage collection jobs for
cleaning up task-specific ACL tokens. Instead, Nomad will create a
workload Identity Claim for each task.
An Identity Claim is a JSON Web Token (JWT) signed by the server’s
private key and attached to an Allocation at the time a plan is
applied. The encoded JWT can be submitted as the X-Nomad-Token header
to replace ACL token secret IDs for the RPCs that support identity
claims.
Whenever a key is is added to a server’s keyring, it will use the key
as the seed for a Ed25519 public-private private keypair. That keypair
will be used for signing the JWT and for verifying the JWT.
This implementation is a ruthlessly minimal approach to support the
secure variables feature. When a JWT is verified, the allocation ID
will be checked against the Nomad state store, and non-existent or
terminal allocation IDs will cause the validation to be rejected. This
is sufficient to support the secure variables feature at launch
without requiring implementation of a background process to renew
soon-to-expire tokens.
Replication for the secure variables keyring. Because only key
metadata is stored in raft, we need to distribute key material
out-of-band from raft replication. A goroutine runs on each server and
watches for changes to the `RootKeyMeta`. When a new key is received,
attempt to fetch the key from the leader. If the leader doesn't have
the key (which may happen if a key is rotated right before a leader
transition), try to get the key from any peer.
After internal design review, we decided to remove exposing algorithm
choice to the end-user for the initial release. We'll solve nonce
rotation by forcing rotations automatically on key GC (in a core job,
not included in this changeset). Default to AES-256 GCM for the
following criteria:
* faster implementation when hardware acceleration is available
* FIPS compliant
* implementation in pure go
* post-quantum resistance
Also fixed a bug in the decoding from keystore and switched to a
harder-to-misuse encoding method.
The core jobs to garbage collect unused keys and perform full key
rotations will need to be able to query secure variables by key ID for
efficiency. Add an index to the state store and associated query
function and test.
When a server becomes leader, it will check if there are any keys in
the state store, and create one if there is not. The key metadata will
be replicated via raft to all followers, who will then get the key
material via key replication (not implemented in this changeset).
This changeset implements the keystore serialization/deserialization:
* Adds a JSON serialization extension for the `RootKey` struct, along with a metadata stub. When we serialize RootKey to the on-disk keystore, we want to base64 encode the key material but also exclude any frequently-changing fields which are stored in raft.
* Implements methods for loading/saving keys to the keystore.
* Implements methods for restoring the whole keystore from disk.
* Wires it all up with the `Keyring` RPC handlers and fixes up any fallout on tests.
Implement the basic upsert, list, and delete operations for
`RootKeyMeta` needed by the Keyring RPCs.
This changeset also implements two convenience methods
`RootKeyMetaByID` and `GetActiveRootKeyMeta` which are useful for
testing but also will be needed to implement the rest of the RPCs.
Stream snapshot to FSM when restoring from archive
The `RestoreFromArchive` helper decompresses the snapshot archive to a
temporary file before reading it into the FSM. For large snapshots
this performs a lot of disk IO. Stream decompress the snapshot as we
read it, without first writing to a temporary file.
Add bexpr filters to the `RestoreFromArchive` helper.
The operator can pass these as `-filter` arguments to `nomad operator
snapshot state` (and other commands in the future) to include only
desired data when reading the snapshot.
