* Update the ACL API docs
* Add a CreateTime to the anon token
Also require acl:read permissions at least to perform rule translation. Don’t want someone DoSing the system with an open endpoint that actually does a bit of work.
* Fix one place where I was referring to id instead of AccessorID
* Add godocs for the API package additions.
* Minor updates: removed some extra commas and updated the acl intro paragraph
* minor tweaks
* Updated the language to be clearer
* Updated the language to be clearer for policy page
* I was also confused by that! Your updates are much clearer.
Co-Authored-By: kaitlincarter-hc <43049322+kaitlincarter-hc@users.noreply.github.com>
* Sounds much better.
Co-Authored-By: kaitlincarter-hc <43049322+kaitlincarter-hc@users.noreply.github.com>
* Updated sidebar layout and deprecated warning
* Add leader token upgrade test and fix various ACL enablement bugs
* Update the leader ACL initialization tests.
* Add a StateStore ACL tests for ACLTokenSet and ACLTokenGetBy* functions
* Advertise the agents acl support status with the agent/self endpoint.
* Make batch token upsert CAS’able to prevent consistency issues with token auto-upgrade
* Finish up the ACL state store token tests
* Finish the ACL state store unit tests
Also rename some things to make them more consistent.
* Do as much ACL replication testing as I can.
This PR is almost a complete rewrite of the ACL system within Consul. It brings the features more in line with other HashiCorp products. Obviously there is quite a bit left to do here but most of it is related docs, testing and finishing the last few commands in the CLI. I will update the PR description and check off the todos as I finish them over the next few days/week.
Description
At a high level this PR is mainly to split ACL tokens from Policies and to split the concepts of Authorization from Identities. A lot of this PR is mostly just to support CRUD operations on ACLTokens and ACLPolicies. These in and of themselves are not particularly interesting. The bigger conceptual changes are in how tokens get resolved, how backwards compatibility is handled and the separation of policy from identity which could lead the way to allowing for alternative identity providers.
On the surface and with a new cluster the ACL system will look very similar to that of Nomads. Both have tokens and policies. Both have local tokens. The ACL management APIs for both are very similar. I even ripped off Nomad's ACL bootstrap resetting procedure. There are a few key differences though.
Nomad requires token and policy replication where Consul only requires policy replication with token replication being opt-in. In Consul local tokens only work with token replication being enabled though.
All policies in Nomad are globally applicable. In Consul all policies are stored and replicated globally but can be scoped to a subset of the datacenters. This allows for more granular access management.
Unlike Nomad, Consul has legacy baggage in the form of the original ACL system. The ramifications of this are:
A server running the new system must still support other clients using the legacy system.
A client running the new system must be able to use the legacy RPCs when the servers in its datacenter are running the legacy system.
The primary ACL DC's servers running in legacy mode needs to be a gate that keeps everything else in the entire multi-DC cluster running in legacy mode.
So not only does this PR implement the new ACL system but has a legacy mode built in for when the cluster isn't ready for new ACLs. Also detecting that new ACLs can be used is automatic and requires no configuration on the part of administrators. This process is detailed more in the "Transitioning from Legacy to New ACL Mode" section below.
* 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
* Support multiple tags for health and catalog api endpoints
Fixes#1781.
Adds a `ServiceTags` field to the ServiceSpecificRequest to support
multiple tags, updates the filter logic in the catalog store, and
propagates these change through to the health and catalog endpoints.
Note: Leaves `ServiceTag` in the struct, since it is being used as
part of the DNS lookup, which in turn uses the health check.
* Update the api package to support multiple tags
Includes additional tests.
* Update new tests to use the `require` library
* Update HealthConnect check after a bad merge
* [Performance On Large clusters] Checks do update services/nodes only when really modified to avoid too many updates on very large clusters
In a large cluster, when having a few thousands of nodes, the anti-entropy
mechanism performs lots of changes (several per seconds) while
there is no real change. This patch wants to improve this in order
to increase Consul scalability when using many blocking requests on
health for instance.
* [Performance for large clusters] Only updates index of service if service is really modified
* [Performance for large clusters] Only updates index of nodes if node is really modified
* Added comments / ensure IsSame() has clear semantics
* Avoid having modified boolean, return nil directly if stutures are Same
* Fixed unstable unit tests TestLeader_ChangeServerID
* Rewrite TestNode_IsSame() for better readability as suggested by @banks
* Rename ServiceNode.IsSame() into IsSameService() + added unit tests
* Do not duplicate TestStructs_ServiceNode_Conversions() and increase test coverage of IsSameService
* Clearer documentation in IsSameService
* Take into account ServiceProxy into ServiceNode.IsSameService()
* Fixed IsSameService() with all new structures
* Refactor Service Definition ProxyDestination.
This includes:
- Refactoring all internal structs used
- Updated tests for both deprecated and new input for:
- Agent Services endpoint response
- Agent Service endpoint response
- Agent Register endpoint
- Unmanaged deprecated field
- Unmanaged new fields
- Managed deprecated upstreams
- Managed new
- Catalog Register
- Unmanaged deprecated field
- Unmanaged new fields
- Managed deprecated upstreams
- Managed new
- Catalog Services endpoint response
- Catalog Node endpoint response
- Catalog Service endpoint response
- Updated API tests for all of the above too (both deprecated and new forms of register)
TODO:
- config package changes for on-disk service definitions
- proxy config endpoint
- built-in proxy support for new fields
* Agent proxy config endpoint updated with upstreams
* Config file changes for upstreams.
* Add upstream opaque config and update all tests to ensure it works everywhere.
* Built in proxy working with new Upstreams config
* Command fixes and deprecations
* Fix key translation, upstream type defaults and a spate of other subtele bugs found with ned to end test scripts...
TODO: tests still failing on one case that needs a fix. I think it's key translation for upstreams nested in Managed proxy struct.
* Fix translated keys in API registration.
≈
* Fixes from docs
- omit some empty undocumented fields in API
- Bring back ServiceProxyDestination in Catalog responses to not break backwards compat - this was removed assuming it was only used internally.
* Documentation updates for Upstreams in service definition
* Fixes for tests broken by many refactors.
* Enable travis on f-connect branch in this branch too.
* Add consistent Deprecation comments to ProxyDestination uses
* Update version number on deprecation notices, and correct upstream datacenter field with explanation in docs
* Fix CA pruning when CA config uses string durations.
The tl;dr here is:
- Configuring LeafCertTTL with a string like "72h" is how we do it by default and should be supported
- Most of our tests managed to escape this by defining them as time.Duration directly
- Out actual default value is a string
- Since this is stored in a map[string]interface{} config, when it is written to Raft it goes through a msgpack encode/decode cycle (even though it's written from server not over RPC).
- msgpack decode leaves the string as a `[]uint8`
- Some of our parsers required string and failed
- So after 1 hour, a default configured server would throw an error about pruning old CAs
- If a new CA was configured that set LeafCertTTL as a time.Duration, things might be OK after that, but if a new CA was just configured from config file, intialization would cause same issue but always fail still so would never prune the old CA.
- Mostly this is just a janky error that got passed tests due to many levels of complicated encoding/decoding.
tl;dr of the tl;dr: Yay for type safety. Map[string]interface{} combined with msgpack always goes wrong but we somehow get bitten every time in a new way :D
We already fixed this once! The main CA config had the same problem so @kyhavlov already wrote the mapstructure DecodeHook that fixes it. It wasn't used in several places it needed to be and one of those is notw in `structs` which caused a dependency cycle so I've moved them.
This adds a whole new test thta explicitly tests the case that broke here. It also adds tests that would have failed in other places before (Consul and Vaul provider parsing functions). I'm not sure if they would ever be affected as it is now as we've not seen things broken with them but it seems better to explicitly test that and support it to not be bitten a third time!
* Typo fix
* Fix bad Uint8 usage
* 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
* Display more information about check being not properly added when it fails
It follows an incident where we add lots of error messages:
[WARN] consul.fsm: EnsureRegistration failed: failed inserting check: Missing service registration
That seems related to Consul failing to restart on respective agents.
Having Node information as well as service information would help diagnose the issue.
* Renamed ensureCheckIfNodeMatches() as requested by @banks
* Allow to rename nodes with IDs, will fix#3974 and #4413
This change allow to rename any well behaving recent agent with an
ID to be renamed safely, ie: without taking the name of another one
with case insensitive comparison.
Deprecated behaviour warning
----------------------------
Due to asceding compatibility, it is still possible however to
"take" the name of another name by not providing any ID.
Note that when not providing any ID, it is possible to have 2 nodes
having similar names with case differences, ie: myNode and mynode
which might lead to DB corruption on Consul server side and
lead to server not properly restarting.
See #3983 and #4399 for Context about this change.
Disabling registration of nodes without IDs as specified in #4414
should probably be the way to go eventually.
* Removed the case-insensitive search when adding a node within the else
block since it breaks the test TestAgentAntiEntropy_Services
While the else case is probably legit, it will be fixed with #4414 in
a later release.
* Added again the test in the else to avoid duplicated names, but
enforce this test only for nodes having IDs.
Thus most tests without any ID will work, and allows us fixing
* Added more tests regarding request with/without IDs.
`TestStateStore_EnsureNode` now test registration and renaming with IDs
`TestStateStore_EnsureNodeDeprecated` tests registration without IDs
and tests removing an ID from a node as well as updated a node
without its ID (deprecated behaviour kept for backwards compatibility)
* Do not allow renaming in case of conflict, including when other node has no ID
* Fixed function GetNodeID that was not working due to wrong type when searching node from its ID
Thus, all tests about renaming were not working properly.
Added the full test cas that allowed me to detect it.
* Better error messages, more tests when nodeID is not a valid UUID in GetNodeID()
* Added separate TestStateStore_GetNodeID to test GetNodeID.
More complete test coverage for GetNodeID
* Added new unit test `TestStateStore_ensureNoNodeWithSimilarNameTxn`
Also fixed comments to be clearer after remarks from @banks
* Fixed error message in unit test to match test case
* Use uuid.ParseUUID to parse Node.ID as requested by @mkeeler
* 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
* Revert "BUGFIX: Unit test relying on WaitForLeader() did not work due to wrong test (#4472)"
This reverts commit cec5d72396.
* Revert "CA initialization while boostrapping and TestLeader_ChangeServerID fix. (#4493)"
This reverts commit 589b589b53.
- Improve resilience of testrpc.WaitForLeader()
- Add additionall retry to CI
- Increase "go test" timeout to 8m
- Add wait for cluster leader to several tests in the agent package
- Add retry to some tests in the api and command packages
* Fix theoretical cache collision bug if/when we use more cache types with same result type
* Generalized fix for blocking query handling when state store methods return zero index
* Refactor test retry to only affect CI
* Undo make file merge
* Add hint to error message returned to end-user requests if Connect is not enabled when they try to request cert
* Explicit error for Roots endpoint if connect is disabled
* Fix tests that were asserting old behaviour
UUID auto-generation here causes trouble in a few cases. The biggest being older
nodes reregistering will fail when the UUIDs are different and the names match
This reverts commit 0f70034082.
This reverts commit d1a8f9cb3f.
This reverts commit cf69ec42a4.
Since DNS is case insensitive and DB as issues when similar names with different
cases are added, check for unicity based on case insensitivity.
Following another big incident we had in our cluster, we also validate
that adding/renaming a not does not conflicts with case insensitive
matches.
We had the following error once:
- one node called: mymachine.MYDC.mydomain was shut off
- another node (different ID) was added with name: mymachine.mydc.mydomain before
72 hours
When restarting the consul server of domain, the consul server restarted failed
to start since it detected an issue in RAFT database because
mymachine.MYDC.mydomain and mymachine.mydc.mydomain had the same names.
Checking at registration time with case insensitivity should definitly fix
those issues and avoid Consul DB corruption.
It will allow the following:
* when connectivity is limited (saturated linnks between DCs), only one
single request to refresh an ACL will be sent to ACL master DC instead
of statcking ACL refresh queries
* when extend-cache is used for ACL, do not wait for result, but refresh
the ACL asynchronously, so no delay is not impacting slave DC
* When extend-cache is not used, keep the existing blocking mechanism,
but only send a single refresh request.
This will fix https://github.com/hashicorp/consul/issues/3524
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.
Uses struct/interface embedding with the embedded structs/interfaces being empty for oss. Also methods on the server/client types are defaulted to do nothing for OSS
Test HTTP/DNS source IP without header/extra EDNS data.
Add WARN log for when prepared query with near=_ip is executed without specifying the source ip
Bugfix for https://github.com/hashicorp/consul/pull/3899
When a node level check is removed (example: maintenance),
some watchers on services might have to recompute their state.
If those nodes are performing blocking queries, they have to be notified.
While their state was updated when node-level state did change or was added
this was not the case when the check was removed. This fixes it.
This patch did give some better results, but break watches on
the services of a node.
It is possible to apply the same optimization for nodes than
to services (one index per instance), but it would complicate
further the patch.
Let's do it in another PR.
This patch improves the watches for services on large cluster:
each service has now its own index, such watches on a specific service
are not modified by changes in the global catalog.
It should improve a lot the performance of tools such as consul-template
or libraries performing watches on very large clusters with many
services/watches.
The lock isn't needed after we clean up the expire bin, and as seen
in #3700 we can get into a deadlock waiting to place the expire index
into the channel while holding this lock.
Fixes#3700
* Relaxes Autopilot promotion logic.
When we defaulted the Raft protocol version to 3 in #3477 we made
the numPeers() routine more strict to only count voters (this is
more conservative and more correct). This had the side effect of
breaking rolling updates because it's at odds with the Autopilot
non-voter promotion logic.
That logic used to wait to only promote to maintain an odd quorum
of servers. During a rolling update (add one new server, wait, and
then kill an old server) the dead server cleanup would still count
the old server as a peer, which is conservative and the right thing
to do, and no longer count the non-voter. This would wait to promote,
so you could get into a stalemate. It is safer to promote early than
remove early, so by promoting as soon as possible we have chosen
that as the solution here.
Fixes#3611
* Gets rid of unnecessary extra not-a-voter check.
This patch removes the porter tool which hands out free ports from a
given range with a library which does the same thing. The challenge for
acquiring free ports in concurrent go test runs is that go packages are
tested concurrently and run in separate processes. There has to be some
inter-process synchronization in preventing processes allocating the
same ports.
freeport allocates blocks of ports from a range expected to be not in
heavy use and implements a system-wide mutex by binding to the first
port of that block for the lifetime of the application. Ports are then
provided sequentially from that block and are tested on localhost before
being returned as available.
* Adds client-side retry for no leader errors.
This paves over the case where the client was connected to the leader
when it loses leadership.
* Adds a configurable server RPC drain time and a fail-fast path for RPCs.
When a server leaves it gets removed from the Raft configuration, so it will
never know who the new leader server ends up being. Without this we'd be
doomed to wait out the RPC hold timeout and then fail. This makes things fail
a little quicker while a sever is draining, and since we added a client retry
AND since the server doing this has already shut down and left the Serf LAN,
clients should retry against some other server.
* Makes the RPC hold timeout configurable.
* Reorders struct members.
* Sets the RPC hold timeout default for test servers.
* Bumps the leave drain time up to 5 seconds.
* Robustifies retries with a simpler client-side RPC hold.
* Reverts untended delete.
* Fixes handling of stop channel and failed barrier attempts.
There were two issues here. First, we needed to not exit when there
was a timeout trying to write the barrier, because Raft might not
step down, so we'd be left as the leader but having run all the step
down actions.
Second, we didn't close over the stopCh correctly, so it was possible
to nil that out and have the leaderLoop never exit. We close over it
properly AND sequence the nil-ing of it AFTER the leaderLoop exits for
good measure, so the code is more robust.
Fixes#3545
* Cleans up based on code review feedback.
* Tweaks comments.
* Renames variables and removes comments.
* Make sure that id and address are set in member created during reaping of catalog nodes that have been removed from serf
* Get address from node table in the state store rather than from service address
* Fix incorrect lookup by checkname instead of node name
* Make sure that serverlookup is called with the right address format, added unit test.
* Address code review comments
* Tweaks style stuff.
* Changes default Raft protocol to 3.
* Changes numPeers() to report only voters.
This should have been there before, but it's more obvious that this
is incorrect now that we default the Raft protocol to 3, which puts
new servers in a read-only state while Autopilot waits for them to
become healthy.
* Fixes TestLeader_RollRaftServer.
* Fixes TestOperator_RaftRemovePeerByAddress.
* Fixes TestServer_*.
Relaxed the check for a given number of voter peers and instead do
a thorough check that all servers see each other in their Raft
configurations.
* Fixes TestACL_*.
These now just check for Raft replication to be set up, and don't
care about the number of voter peers.
* Fixes TestOperator_Raft_ListPeers.
* Fixes TestAutopilot_CleanupDeadServerPeriodic.
* Fixes TestCatalog_ListNodes_ConsistentRead_Fail.
* Fixes TestLeader_ChangeServerID and adjusts the conn pool to throw away
sockets when it sees io.EOF.
* Changes version to 1.0.0 in the options doc.
* Makes metrics test more deterministic with autopilot metrics possible.
* 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
* Added rate limiting for agent RPC calls.
* Initializes the rate limiter based on the config.
* Adds the rate limiter into the snapshot RPC path.
* Adds unit tests for the RPC rate limiter.
* Groups the RPC limit parameters under "limits" in the config.
* Adds some documentation about the RPC limiter.
* Sends a 429 response when the rate limiter kicks in.
* Adds docs for new telemetry.
* Makes snapshot telemetry look like RPC telemetry and cleans up comments.
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.
The error handling of the ACL code relies on the presence of certain
magic error messages. Since the error values are sent via RPC between
older and newer consul agents we cannot just replace the magic values
with typed errors and switch to type checks since this would break
compatibility with older clients.
Therefore, this patch moves all magic ACL error messages into the acl
package and provides default error values and helper functions which
determine the type of error.
* 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.
This isn't racy, it's just a little dirty. The listen will happen and a port
will be selected and injected into the config once the Serf instance is
created, so we don't need the retry loop here.
This fixes TestServer_JoinSeparateLanAndWanAddresses which sets bogus
advertise addresses as part of the test. Port numbers uniquely identify
members since everything is running on localhost.
The sessionTimers map was secured by a lock which wasn't used
properly in the tests. This lead to data races and failing tests
when accessing the length or the members of the map.
This patch adds a separate SessionTimers struct which is safe
for concurrent use and which ecapsulates the behavior of the
sessionTimers map.
When using dynamic ports for the serf clusters then
the actual bind port of the serf WAN cluster needs to
be discovered before the serf LAN cluster is started
since the serf LAN cluster announces the port of the WAN
cluster.
This patch hides the RPC handler overwrite mechanism from the
rest of the code so that it works in all cases and that there
is no cooperation required from the tested code, i.e. we can
drop a.getEndpoint().