This PR brings semver capabilities in our RPC layer to
ensure that we can upgrade the servers in rolling fashion
while keeping I/O in progress. This is only a framework change
the functionality remains the same as such and we do not
have any special API changes for now. But in future when
we bring in API changes we will be able to upgrade servers
without a downtime.
Additional change in this PR is to not abort when serverVersions
mismatch in a distributed cluster, instead wait for the quorum
treat the situation as if the server is down. This allows
for administrator to properly upgrade all the servers in the cluster.
Fixes#5393
This change introduces following simplified steps to follow
during config migration.
```
// Steps to move from version N to version N+1
// 1. Add new struct serverConfigVN+1 in config-versions.go
// 2. Set configCurrentVersion to "N+1"
// 3. Set serverConfigCurrent to serverConfigVN+1
// 4. Add new migration function (ex. func migrateVNToVN+1()) in config-migrate.go
// 5. Call migrateVNToVN+1() from migrateConfig() in config-migrate.go
// 6. Make changes in config-current_test.go for any test change
```
This is an improvement upon existing implementation
by avoiding transfer of access and secret keys over
the network. This change only exchanges JWT tokens
generated by an rpc client. Even if the JWT can be
traced over the network on a non-TLS connection, this
change makes sure that we never really expose the
secret key over the network.
Since go1.8 os.RemoveAll and os.MkdirAll both support long
path names i.e UNC path on windows. The code we are carrying
was directly borrowed from `pkg/os` package and doesn't need
to be in our repo anymore. As a side affect this also
addresses our codecoverage issue.
Refer #4658
This is a consolidation effort, avoiding usage
of naked strings in codebase. Whenever possible
use constants which can be repurposed elsewhere.
This also fixes `goconst ./...` reported issues.
* Rename GenericArgs to AuthRPCArgs
* Rename GenericReply to AuthRPCReply
* Remove authConfig.loginMethod and add authConfig.ServiceName
* Rename loginServer to AuthRPCServer
* Rename RPCLoginArgs to LoginRPCArgs
* Rename RPCLoginReply to LoginRPCReply
* Version and RequestTime are added to LoginRPCArgs and verified by
server side, not client side.
* Fix data race in lockMaintainence loop.
