In current implementation of Consul, check alias cannot determine
if a service exists or not. Because a service without any check
is semantically considered as passing, so when no healthchecks
are found for an agent, the check was considered as passing.
But this make little sense as the current implementation does not
make any difference between:
* a non-existing service (passing)
* a service without any check (passing as well)
In order to make it work, we have to ensure that when a check did
not find any healthcheck, the service does indeed exists. If it
does not, lets consider the check as failing.
* testing: replace most goe/verify.Values with require.Equal
One difference between these two comparisons is that go/verify considers
nil slices/maps to be equal to empty slices/maps, where as testify/require
does not, and does not appear to provide any way to enable that behaviour.
Because of this difference some expected values were changed from empty
slices to nil slices, and some calls to verify.Values were left.
* Remove github.com/pascaldekloe/goe/verify
Reduce the number of assertion packages we use from 2 to 1
This function now only starts the agent.
Using:
git grep -l 'StartTestAgent(t, true,' | \
xargs sed -i -e 's/StartTestAgent(t, true,/StartTestAgent(t,/g'
Previously the log output included the test name twice and a long date
format. The test output is already grouped by test, so adding the test
name did not add any new information. The date and time are only useful
to understand elapsed time, so using a short format should provide
succident detail.
Also fixed a bug in NewTestAgentWithFields where nil was returned
instead of the test agent.
This test would occasionally fail because we checked for a status of
"critical" initially. This races with the actual healthcheck being run
and declared passing.
We instead use a ttl health check so that we don't rely on timing at all.
This is like a Möbius strip of code due to the fact that low-level components (serf/memberlist) are connected to high-level components (the catalog and mesh-gateways) in a twisty maze of references which make it hard to dive into. With that in mind here's a high level summary of what you'll find in the patch:
There are several distinct chunks of code that are affected:
* new flags and config options for the server
* retry join WAN is slightly different
* retry join code is shared to discover primary mesh gateways from secondary datacenters
* because retry join logic runs in the *agent* and the results of that
operation for primary mesh gateways are needed in the *server* there are
some methods like `RefreshPrimaryGatewayFallbackAddresses` that must occur
at multiple layers of abstraction just to pass the data down to the right
layer.
* new cache type `FederationStateListMeshGatewaysName` for use in `proxycfg/xds` layers
* the function signature for RPC dialing picked up a new required field (the
node name of the destination)
* several new RPCs for manipulating a FederationState object:
`FederationState:{Apply,Get,List,ListMeshGateways}`
* 3 read-only internal APIs for debugging use to invoke those RPCs from curl
* raft and fsm changes to persist these FederationStates
* replication for FederationStates as they are canonically stored in the
Primary and replicated to the Secondaries.
* a special derivative of anti-entropy that runs in secondaries to snapshot
their local mesh gateway `CheckServiceNodes` and sync them into their upstream
FederationState in the primary (this works in conjunction with the
replication to distribute addresses for all mesh gateways in all DCs to all
other DCs)
* a "gateway locator" convenience object to make use of this data to choose
the addresses of gateways to use for any given RPC or gossip operation to a
remote DC. This gets data from the "retry join" logic in the agent and also
directly calls into the FSM.
* RPC (`:8300`) on the server sniffs the first byte of a new connection to
determine if it's actually doing native TLS. If so it checks the ALPN header
for protocol determination (just like how the existing system uses the
type-byte marker).
* 2 new kinds of protocols are exclusively decoded via this native TLS
mechanism: one for ferrying "packet" operations (udp-like) from the gossip
layer and one for "stream" operations (tcp-like). The packet operations
re-use sockets (using length-prefixing) to cut down on TLS re-negotiation
overhead.
* the server instances specially wrap the `memberlist.NetTransport` when running
with gateway federation enabled (in a `wanfed.Transport`). The general gist is
that if it tries to dial a node in the SAME datacenter (deduced by looking
at the suffix of the node name) there is no change. If dialing a DIFFERENT
datacenter it is wrapped up in a TLS+ALPN blob and sent through some mesh
gateways to eventually end up in a server's :8300 port.
* a new flag when launching a mesh gateway via `consul connect envoy` to
indicate that the servers are to be exposed. This sets a special service
meta when registering the gateway into the catalog.
* `proxycfg/xds` notice this metadata blob to activate additional watches for
the FederationState objects as well as the location of all of the consul
servers in that datacenter.
* `xds:` if the extra metadata is in place additional clusters are defined in a
DC to bulk sink all traffic to another DC's gateways. For the current
datacenter we listen on a wildcard name (`server.<dc>.consul`) that load
balances all servers as well as one mini-cluster per node
(`<node>.server.<dc>.consul`)
* the `consul tls cert create` command got a new flag (`-node`) to help create
an additional SAN in certs that can be used with this flavor of federation.
This fixes issue #7318
Between versions 1.5.2 and 1.5.3, a regression has been introduced regarding health
of services. A patch #6144 had been issued for HealthChecks of nodes, but not for healthchecks
of services.
What happened when a reload was:
1. save all healthcheck statuses
2. cleanup everything
3. add new services with healthchecks
In step 3, the state of healthchecks was taken into account locally,
so at step 3, but since we cleaned up at step 2, state was lost.
This PR introduces the snap parameter, so step 3 can use information from step 1
* Use consts for well known tagged adress keys
* Add ipv4 and ipv6 tagged addresses for node lan and wan
* Add ipv4 and ipv6 tagged addresses for service lan and wan
* Use IPv4 and IPv6 address in DNS
Ensure we close the Sentinel Evaluator so as not to leak go routines
Fix a bunch of test logging so that various warnings when starting a test agent go to the ltest logger and not straight to stdout.
Various canned ent meta types always return a valid pointer (no more nils). This allows us to blindly deref + assign in various places.
Update ACL index tracking to ensure oss -> ent upgrades will work as expected.
Update ent meta parsing to include function to disallow wildcarding.
Fixes#6521
Ensure that initial failures to fetch an agent cache entry using the
notify API where the underlying RPC returns a synthetic index of 1
correctly recovers when those RPCs resume working.
The bug in the Cache.notifyBlockingQuery used to incorrectly "fix" the
index for the next query from 0 to 1 for all queries, when it should
have not done so for queries that errored.
Also fixed some things that made debugging difficult:
- config entry read/list endpoints send back QueryMeta headers
- xds event loops don't swallow the cache notification errors
Fixes: #5396
This PR adds a proxy configuration stanza called expose. These flags register
listeners in Connect sidecar proxies to allow requests to specific HTTP paths from outside of the node. This allows services to protect themselves by only
listening on the loopback interface, while still accepting traffic from non
Connect-enabled services.
Under expose there is a boolean checks flag that would automatically expose all
registered HTTP and gRPC check paths.
This stanza also accepts a paths list to expose individual paths. The primary
use case for this functionality would be to expose paths for third parties like
Prometheus or the kubelet.
Listeners for requests to exposed paths are be configured dynamically at run
time. Any time a proxy, or check can be registered, a listener can also be
created.
In this initial implementation requests to these paths are not
authenticated/encrypted.
Also:
* Finished threading replaceExistingChecks setting (from GH-4905)
through service manager.
* Respected the original configSource value that was used to register a
service or a check when restoring persisted data.
* Run several existing tests with and without central config enabled
(not exhaustive yet).
* Switch to ioutil.ReadFile for all types of agent persistence.
This should cut down on test flakiness.
Problems handled:
- If you had enough parallel test cases running, the former circular
approach to handling the port block could hand out the same port to
multiple cases before they each had a chance to bind them, leading to
one of the two tests to fail.
- The freeport library would allocate out of the ephemeral port range.
This has been corrected for Linux (which should cover CI).
- The library now waits until a formerly-in-use port is verified to be
free before putting it back into circulation.
This fixes pathological cases where the write throughput and snapshot size are both so large that more than 10k log entries are written in the time it takes to restore the snapshot from disk. In this case followers that restart can never catch up with leader replication again and enter a loop of constantly downloading a full snapshot and restoring it only to find that snapshot is already out of date and the leader has truncated its logs so a new snapshot is sent etc.
In general if you need to adjust this, you are probably abusing Consul for purposes outside its design envelope and should reconsider your usage to reduce data size and/or write volume.
* Support for maximum size for Output of checks
This PR allows users to limit the size of output produced by checks at the agent
and check level.
When set at the agent level, it will limit the output for all checks monitored
by the agent.
When set at the check level, it can override the agent max for a specific check but
only if it is lower than the agent max.
Default value is 4k, and input must be at least 1.
The observed bug was that a full restart of a consul datacenter (servers
and clients) in conjunction with a restart of a connect-flavored
application with bring-your-own-service-registration logic would very
frequently cause the envoy sidecar service check to never reflect the
aliased service.
Over the course of investigation several bugs and unfortunate
interactions were corrected:
(1)
local.CheckState objects were only shallow copied, but the key piece of
data that gets read and updated is one of the things not copied (the
underlying Check with a Status field). When the stock code was run with
the race detector enabled this highly-relevant-to-the-test-scenario field
was found to be racy.
Changes:
a) update the existing Clone method to include the Check field
b) copy-on-write when those fields need to change rather than
incrementally updating them in place.
This made the observed behavior occur slightly less often.
(2)
If anything about how the runLocal method for node-local alias check
logic was ever flawed, there was no fallback option. Those checks are
purely edge-triggered and failure to properly notice a single edge
transition would leave the alias check incorrect until the next flap of
the aliased check.
The change was to introduce a fallback timer to act as a control loop to
double check the alias check matches the aliased check every minute
(borrowing the duration from the non-local alias check logic body).
This made the observed behavior eventually go away when it did occur.
(3)
Originally I thought there were two main actions involved in the data race:
A. The act of adding the original check (from disk recovery) and its
first health evaluation.
B. The act of the HTTP API requests coming in and resetting the local
state when re-registering the same services and checks.
It took awhile for me to realize that there's a third action at work:
C. The goroutines associated with the original check and the later
checks.
The actual sequence of actions that was causing the bad behavior was
that the API actions result in the original check to be removed and
re-added _without waiting for the original goroutine to terminate_. This
means for brief windows of time during check definition edits there are
two goroutines that can be sending updates for the alias check status.
In extremely unlikely scenarios the original goroutine sees the aliased
check start up in `critical` before being removed but does not get the
notification about the nearly immediate update of that check to
`passing`.
This is interlaced wit the new goroutine coming up, initializing its
base case to `passing` from the current state and then listening for new
notifications of edge triggers.
If the original goroutine "finishes" its update, it then commits one
more write into the local state of `critical` and exits leaving the
alias check no longer reflecting the underlying check.
The correction here is to enforce that the old goroutines must terminate
before spawning the new one for alias checks.
* First conversion
* Use serf 0.8.2 tag and associated updated deps
* * Move freeport and testutil into internal/
* Make internal/ its own module
* Update imports
* Add replace statements so API and normal Consul code are
self-referencing for ease of development
* Adapt to newer goe/values
* Bump to new cleanhttp
* Fix ban nonprintable chars test
* Update lock bad args test
The error message when the duration cannot be parsed changed in Go 1.12
(ae0c435877d3aacb9af5e706c40f9dddde5d3e67). This updates that test.
* Update another test as well
* Bump travis
* Bump circleci
* Bump go-discover and godo to get rid of launchpad dep
* Bump dockerfile go version
* fix tar command
* Bump go-cleanhttp
This PR introduces reloading tls configuration. Consul will now be able to reload the TLS configuration which previously required a restart. It is not yet possible to turn TLS ON or OFF with these changes. Only when TLS is already turned on, the configuration can be reloaded. Most importantly the certificates and CAs.
Prevent race between register and deregister requests by saving them
together in the local state on registration.
Also adds more cleaning in case of failure when registering services
/ checks.
This PR adds two features which will be useful for operators when ACLs are in use.
1. Tokens set in configuration files are now reloadable.
2. If `acl.enable_token_persistence` is set to `true` in the configuration, tokens set via the `v1/agent/token` endpoint are now persisted to disk and loaded when the agent starts (or during configuration reload)
Note that token persistence is opt-in so our users who do not want tokens on the local disk will see no change.
Some other secondary changes:
* Refactored a bunch of places where the replication token is retrieved from the token store. This token isn't just for replicating ACLs and now it is named accordingly.
* Allowed better paths in the `v1/agent/token/` API. Instead of paths like: `v1/agent/token/acl_replication_token` the path can now be just `v1/agent/token/replication`. The old paths remain to be valid.
* Added a couple new API functions to set tokens via the new paths. Deprecated the old ones and pointed to the new names. The names are also generally better and don't imply that what you are setting is for ACLs but rather are setting ACL tokens. There is a minor semantic difference there especially for the replication token as again, its no longer used only for ACL token/policy replication. The new functions will detect 404s and fallback to using the older token paths when talking to pre-1.4.3 agents.
* Docs updated to reflect the API additions and to show using the new endpoints.
* Updated the ACL CLI set-agent-tokens command to use the non-deprecated APIs.
This way we can avoid unnecessary panics which cause other tests not to run.
This doesn't remove all the possibilities for panics causing other tests not to run, it just fixes the TestAgent
Given a query like:
```
{
"Name": "tagged-connect-query",
"Service": {
"Service": "foo",
"Tags": ["tag"],
"Connect": true
}
}
```
And a Consul configuration like:
```
{
"services": [
"name": "foo",
"port": 8080,
"connect": { "sidecar_service": {} },
"tags": ["tag"]
]
}
```
If you executed the query it would always turn up with 0 results. This was because the sidecar service was being created without any tags. You could instead make your config look like:
```
{
"services": [
"name": "foo",
"port": 8080,
"connect": { "sidecar_service": {
"tags": ["tag"]
} },
"tags": ["tag"]
]
}
```
However that is a bit redundant for most cases. This PR ensures that the tags and service meta of the parent service get copied to the sidecar service. If there are any tags or service meta set in the sidecar service definition then this copying does not take place. After the changes, the query will now return the expected results.
A second change was made to prepared queries in this PR which is to allow filtering on ServiceMeta just like we allow for filtering on NodeMeta.
* Add default weights when adding a service with no weights to local state to prevent constant AE re-sync.
This fix was contributed by @42wim in https://github.com/hashicorp/consul/pull/5096 but was merged against the wrong base. This adds it to master and adds a test to cover the behaviour.
* Fix tests that broke due to comparing internal state which now has default weights
Fixes point `#2` of: https://github.com/hashicorp/consul/issues/4903
When registering a service each healthcheck status is saved and restored (https://github.com/hashicorp/consul/blob/master/agent/agent.go#L1914) to avoid unnecessary flaps in health state.
This change extends this feature to single check registration by moving this protection in `AddCheck()` so that both `PUT /v1/agent/service/register` and `PUT /v1/agent/check/register` behave in the same idempotent way.
#### Steps to reproduce
1. Register a check :
```
curl -X PUT \
http://127.0.0.1:8500/v1/agent/check/register \
-H 'Content-Type: application/json' \
-d '{
"Name": "my_check",
"ServiceID": "srv",
"Interval": "10s",
"Args": ["true"]
}'
```
2. The check will initialize and change to `passing`
3. Run the same request again
4. The check status will quickly go from `critical` to `passing` (the delay for this transission is determined by https://github.com/hashicorp/consul/blob/master/agent/checks/check.go#L95)
* Add -enable-local-script-checks options
These options allow for a finer control over when script checks are enabled by
giving the option to only allow them when they are declared from the local
file system.
* Add documentation for the new option
* Nitpick doc wording
* Added new Config for SidecarService in ServiceDefinitions.
* WIP: all the code needed for SidecarService is written... none of it is tested other than config :). Need API updates too.
* Test coverage for the new sidecarServiceFromNodeService method.
* Test API registratrion with SidecarService
* Recursive Key Translation 🤦
* Add tests for nested sidecar defintion arrays to ensure they are translated correctly
* Use dedicated internal state rather than Service Meta for tracking sidecars for deregistration.
Add tests for deregistration.
* API struct for agent register. No other endpoint should be affected yet.
* Additional test cases to cover updates to API registrations
If you provide an invalid HTTP configuration consul will still start again instead of failing. But if you do so the build-in proxy won't be able to start which you might need for connect.
* Implementation of Weights Data structures
Adding this datastructure will allow us to resolve the
issues #1088 and #4198
This new structure defaults to values:
```
{ Passing: 1, Warning: 0 }
```
Which means, use weight of 0 for a Service in Warning State
while use Weight 1 for a Healthy Service.
Thus it remains compatible with previous Consul versions.
* Implemented weights for DNS SRV Records
* DNS properly support agents with weight support while server does not (backwards compatibility)
* Use Warning value of Weights of 1 by default
When using DNS interface with only_passing = false, all nodes
with non-Critical healthcheck used to have a weight value of 1.
While having weight.Warning = 0 as default value, this is probably
a bad idea as it breaks ascending compatibility.
Thus, we put a default value of 1 to be consistent with existing behaviour.
* Added documentation for new weight field in service description
* Better documentation about weights as suggested by @banks
* Return weight = 1 for unknown Check states as suggested by @banks
* Fixed typo (of -> or) in error message as requested by @mkeeler
* Fixed unstable unit test TestRetryJoin
* Fixed unstable tests
* Fixed wrong Fatalf format in `testrpc/wait.go`
* Added notes regarding DNS SRV lookup limitations regarding number of instances
* Documentation fixes and clarification regarding SRV records with weights as requested by @banks
* Rephrase docs
Fixes#4515
This just slightly refactors the logic to only attempt to set the serf wan reconnect timeout when the rest of the serf wan settings are configured - thus avoiding a segfault.
* Fixes TestAgent_IndexChurn
* Fixes TestPreparedQuery_Wrapper
* Increased sleep in agent_test for IndexChurn to 500ms
* Made the comment about joinWAN operation much less of a cliffhanger
Also change how loadProxies works. Now it will load all persisted proxies into a map, then when loading config file proxies will look up the previous proxy token in that map.
Intention de-duplication in previously merged PR actualy failed some tests that were not caught be me or CI. I ran the test files for state changes but they happened not to trigger this case so I made sure they did first and then fixed. That fixed some upstream intention endpoint tests that I'd not run as part of testing the previous fix.
Since commit 9685bdcd0b, service tags are added to the health checks.
Otherwise, when adding a service, tags are not added to its check.
In updateSyncState, we compare the checks of the local agent with the checks of the catalog.
It appears that the service tags are different (missing in one case), and so the check is synchronized.
That increase the ModifyIndex periodically when nothing changes.
Fixed it by adding serviceTags to the check.
Note that the issue appeared in version 0.8.2.
Looks related to #3259.
* Clean up handling of subprocesses and make using a shell optional
* Update docs for subprocess changes
* Fix tests for new subprocess behavior
* More cleanup of subprocesses
* Minor adjustments and cleanup for subprocess logic
* Makes the watch handler reload test use the new path.
* Adds check tests for new args path, and updates existing tests to use new path.
* Adds support for script args in Docker checks.
* Fixes the sanitize unit test.
* Adds panic for unknown watch type, and reverts back to Run().
* Adds shell option back to consul lock command.
* Adds shell option back to consul exec command.
* Adds shell back into consul watch command.
* Refactors signal forwarding and makes Windows-friendly.
* Adds a clarifying comment.
* Changes error wording to a warning.
* Scopes signals to interrupt and kill.
This avoids us trying to send SIGCHILD to the dead process.
* Adds an error for shell=false for consul exec.
* Adds notes about the deprecated script and handler fields.
* De-nests an if statement.
Remove an error in watch reloading that happens when http and https
are both disabled, and use an https address for running watches if
no http addresses are present.
Fixes#3425.
* new config parser for agent
This patch implements a new config parser for the consul agent which
makes the following changes to the previous implementation:
* add HCL support
* all configuration fragments in tests and for default config are
expressed as HCL fragments
* HCL fragments can be provided on the command line so that they
can eventually replace the command line flags.
* HCL/JSON fragments are parsed into a temporary Config structure
which can be merged using reflection (all values are pointers).
The existing merge logic of overwrite for values and append
for slices has been preserved.
* A single builder process generates a typed runtime configuration
for the agent.
The new implementation is more strict and fails in the builder process
if no valid runtime configuration can be generated. Therefore,
additional validations in other parts of the code should be removed.
The builder also pre-computes all required network addresses so that no
address/port magic should be required where the configuration is used
and should therefore be removed.
* Upgrade github.com/hashicorp/hcl to support int64
* improve error messages
* fix directory permission test
* Fix rtt test
* Fix ForceLeave test
* Skip performance test for now until we know what to do
* Update github.com/hashicorp/memberlist to update log prefix
* Make memberlist use the default logger
* improve config error handling
* do not fail on non-existing data-dir
* experiment with non-uniform timeouts to get a handle on stalled leader elections
* Run tests for packages separately to eliminate the spurious port conflicts
* refactor private address detection and unify approach for ipv4 and ipv6.
Fixes#2825
* do not allow unix sockets for DNS
* improve bind and advertise addr error handling
* go through builder using test coverage
* minimal update to the docs
* more coverage tests fixed
* more tests
* fix makefile
* cleanup
* fix port conflicts with external port server 'porter'
* stop test server on error
* do not run api test that change global ENV concurrently with the other tests
* Run remaining api tests concurrently
* no need for retry with the port number service
* monkey patch race condition in go-sockaddr until we understand why that fails
* monkey patch hcl decoder race condidtion until we understand why that fails
* monkey patch spurious errors in strings.EqualFold from here
* add test for hcl decoder race condition. Run with go test -parallel 128
* Increase timeout again
* cleanup
* don't log port allocations by default
* use base command arg parsing to format help output properly
* handle -dc deprecation case in Build
* switch autopilot.max_trailing_logs to int
* remove duplicate test case
* remove unused methods
* remove comments about flag/config value inconsistencies
* switch got and want around since the error message was misleading.
* Removes a stray debug log.
* Removes a stray newline in imports.
* Fixes TestACL_Version8.
* Runs go fmt.
* Adds a default case for unknown address types.
* Reoders and reformats some imports.
* Adds some comments and fixes typos.
* Reorders imports.
* add unix socket support for dns later
* drop all deprecated flags and arguments
* fix wrong field name
* remove stray node-id file
* drop unnecessary patch section in test
* drop duplicate test
* add test for LeaveOnTerm and SkipLeaveOnInt in client mode
* drop "bla" and add clarifying comment for the test
* split up tests to support enterprise/non-enterprise tests
* drop raft multiplier and derive values during build phase
* sanitize runtime config reflectively and add test
* detect invalid config fields
* fix tests with invalid config fields
* use different values for wan sanitiziation test
* drop recursor in favor of recursors
* allow dns_config.udp_answer_limit to be zero
* make sure tests run on machines with multiple ips
* Fix failing tests in a few more places by providing a bind address in the test
* Gets rid of skipped TestAgent_CheckPerformanceSettings and adds case for builder.
* Add porter to server_test.go to make tests there less flaky
* go fmt
When the metadata server is scanning the agents for potential servers
it is parsing the version number which the agent provided when it
joined. This version number has to conform to a certain format, i.e.
'n.n.n'. Without this version number properly set some tests fail with
error messages that disguise the root cause.
The default version number is currently set to 'unknown' in
version/version.go which does not parse and triggers the tests to fail.
The work around is to use a build tag 'consul' which will use the
version number set in version_base.go instead which has the correct
format and is set to the current release version.
In addition, some parts of the code also require the version number to
be of a certain value. Setting it to '0.0.0' for example makes some
tests pass and others fail since they don't pass the semantic check.
When using go build/install/test one has to remember to use '-tags
consul' or tests will fail with non-obvious error messages.
Using build tags makes the build process more complex and error prone
since it prevents the use of the plain go toolchain and - at least in
its current form - introduces subtle build and test issues. We should
try to eliminate build tags for anything else but platform specific
code.
This patch removes all references to specific version numbers in the
code and tests and sets the default version to '9.9.9' which is
syntactically correct and passes the semantic check. This solves the
issue of running go build/install/test without tags for the OSS build.
* Moves magic check and service constants into shared structs package.
* Removes the "consul" service from local state.
Since this service is added by the leader, it doesn't really make sense to
also keep it in local state (which requires special ACLs to configure), and
requires a bunch of special cases in the local state logic. This requires
fewer special cases and makes ACL bootstrapping cleaner.
* Makes coordinate update ACL log message a warning, similar to other AE warnings.
* Adds much more detailed examples for bootstrapping ACLs.
This can hopefully replace https://gist.github.com/slackpad/d89ce0e1cc0802c3c4f2d84932fa3234.
The tests that use the localState of the agent access the internal
variables and call methods which are not guarded by locks creating
data races in tests. While the use of internal variables is somewhat
easy to spot the fact that not all methods are thread-safe is a
surprise.
A proper fix requires the localState struct to be moved into its own
package so that tests in the agent can only access the external
interface.
However, the localState is currently dependent on the agent.Config
which would create a circular dependency. Therefore, the Config
struct needs to be moved first for this to happen.
This patch literally monkey patches the use of the lock around the
cases which have data races and marks them with a
// todo(fs): data race comment.
Hans Hasselberg