This change introduces the Task API: a portable way for tasks to access Nomad's HTTP API. This particular implementation uses a Unix Domain Socket and, unlike the agent's HTTP API, always requires authentication even if ACLs are disabled.
This PR contains the core feature and tests but followup work is required for the following TODO items:
- Docs - might do in a followup since dynamic node metadata / task api / workload id all need to interlink
- Unit tests for auth middleware
- Caching for auth middleware
- Rate limiting on negative lookups for auth middleware
---------
Co-authored-by: Seth Hoenig <shoenig@duck.com>
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!"
Add new namespace ACL requirement for the /v1/jobs/parse endpoint and
return early if HCLv2 parsing fails.
The endpoint now requires the new `parse-job` ACL capability or
`submit-job`.
## Development Environment Changes
* Added stringer to build deps
## New HTTP APIs
* Added scheduler worker config API
* Added scheduler worker info API
## New Internals
* (Scheduler)Worker API refactor—Start(), Stop(), Pause(), Resume()
* Update shutdown to use context
* Add mutex for contended server data
- `workerLock` for the `workers` slice
- `workerConfigLock` for the `Server.Config.NumSchedulers` and
`Server.Config.EnabledSchedulers` values
## Other
* Adding docs for scheduler worker api
* Add changelog message
Co-authored-by: Derek Strickland <1111455+DerekStrickland@users.noreply.github.com>
When a cluster doesn't have a leader, the `nomad operator debug`
command can safely use stale queries to gracefully degrade the
consistency of almost all its queries. The query parameter for these
API calls was not being set by the command.
Some `api` package queries do not include `QueryOptions` because
they target a specific agent, but they can potentially be forwarded to
other agents. If there is no leader, these forwarded queries will
fail. Provide methods to call these APIs with `QueryOptions`.
* debug: refactor nodeclass test
* debug: add case to track down SIGSEGV on client to server Agent.Host RPC
* verify server to avoid panic on AgentHostRequest RPC call, fixes GH-9546
* simplify Agent.Host RPC lookup logic
* command/agent/host: collect host data, multi platform
* nomad/structs/structs: new HostDataRequest/Response
* client/agent_endpoint: add RPC endpoint
* command/agent/agent_endpoint: add Host
* api/agent: add the Host endpoint
* nomad/client_agent_endpoint: add Agent Host with forwarding
* nomad/client_agent_endpoint: use findClientConn
This changes forwardMonitorClient and forwardProfileClient to use
findClientConn, which was cribbed from the common parts of those
funcs.
* command/debug: call agent hosts
* command/agent/host: eliminate calling external programs
Fixes a panic when accessing a.agent.Server() when agent is a client
instead. This pr removes a redundant ACL check since ACLs are validated
at the RPC layer. It also nil checks the agent server and uses Client()
when appropriate.
handle the case where we request a server-id which is this current server
update docs, error on node and server id params
more accurate names for tests
use shared no leader err, formatting
rm bad comment
remove redundant variable
Addresses feedback around monitor implementation
subselect on stopCh to prevent blocking forever.
Set up a separate goroutine to check every 3 seconds for dropped
messages.
rename returned ch to avoid confusion
Adds new package that can be used by client and server RPC endpoints to
facilitate monitoring based off of a logger
clean up old code
small comment about write
rm old comment about minsize
rename to Monitor
Removes connection logic from monitor command
Keep connection logic in endpoints, use a channel to send results from
monitoring
use new multisink logger and interfaces
small test for dropped messages
update go-hclogger and update sink/intercept logger interfaces
Adds nomad monitor command. Like consul monitor, this command allows you
to stream logs from a nomad agent in real time with a a specified log
level
add endpoint tests
Upgrade go-hclog to latest version
The current version of go-hclog pads log prefixes to equal lengths
so info becomes [INFO ] and debug becomes [DEBUG]. This breaks
hashicorp/logutils/level.go Check function. Upgrading to the latest
version removes this padding and fixes log filtering that uses logutils
Check
AgentMonitor is an endpoint to stream logs for a given agent. It allows
callers to pass in a supplied log level, which may be different than the
agents config allowing for temporary debugging with lower log levels.
Pass in logWriter when setting up Agent
Currently when hitting the /v1/agent/self API with ACL Replication
enabled results in the token being returned in the API. This commit
redacts that information, as it should be treated as a shared secret.
