The plural `serverAddresses` field in gRPC config has been deprecated for a bit now. We've removed the last usages of it in our staging/prod environments and can clear out the related code. Moving forward we only support a singular `serverAddress` and rely on DNS to direct to multiple instances of a given server.
We'd like to start using the DNS load balancer in the latest version of gRPC. That means putting all IPs for a service under a single hostname (or using a SRV record, but we're not taking that path). This change adds an sd-test-srv to act as our service discovery DNS service. It returns both Boulder IP addresses for any A lookup ending in ".boulder". This change also sets up the Docker DNS for our boulder container to defer to sd-test-srv when it doesn't know an answer.
sd-test-srv doesn't know how to resolve public Internet names like `github.com`. Resolving public names is required for the `godep-restore` test phase, so this change breaks out a copy of the boulder container that is used only for `godep-restore`.
This change implements a shim of a DNS resolver for gRPC, so that we can switch to DNS-based load balancing with the currently vendored gRPC, then when we upgrade to the latest gRPC we won't need a simultaneous config update.
Also, this change introduces a check at the end of the integration test that each backend received at least one RPC, ensuring that we are not sending all load to a single backend.
This PR updates the Boulder gRPC clientInterceptor to update a Prometheus gauge stat for each in-flight RPC it dispatches, sliced by service and method.
A unit test is included that uses a custom ChillerServer that lets the test block up a bunch of RPCs, check the in-flight gauge value is increased, unblock the RPCs, and recheck that the in-flight gauge is reduced. To check the gauge value for a specific set of labels a new test-tools.go function GaugeValueWithLabels is added.
Updates #3635
We may see RPCs that are dispatched by a client but do not arrive at the server for some time afterwards. To have insight into potential request latency at this layer we want to publish the time delta between when a client sent an RPC and when the server received it.
This PR updates the gRPC client interceptor to add the current time to the gRPC request metadata context when it dispatches an RPC. The server side interceptor is updated to pull the client request time out of the gRPC request metadata. Using this timestamp it can calculate the latency and publish it as an observation on a Prometheus histogram.
Accomplishing the above required wiring a clock through to each of the client interceptors. This caused a small diff across each of the gRPC aware boulder commands.
A small unit test is included in this PR that checks that a latency stat is published to the histogram after an RPC to a test ChillerServer is made. It's difficult to do more in-depth testing because using fake clocks makes the latency 0 and using real clocks requires finding a way to queue/delay requests inside of the gRPC mechanisms not exposed to Boulder.
Updates https://github.com/letsencrypt/boulder/issues/3635 - Still TODO: Explicitly logging latency in the VA, tracking outstanding RPCs as a gauge.
The go-grpc-prometheus package by default registers its metrics with Prometheus' global registry. In #3167, when we stopped using the global registry, we accidentally lost our gRPC metrics. This change adds them back.
Specifically, it adds two convenience functions, one for clients and one for servers, that makes the necessary metrics object and registers it. We run these in the main function of each server.
I considered adding these as part of StatsAndLogging, but the corresponding ClientMetrics and ServerMetrics objects (defined by go-grpc-prometheus) need to be subsequently made available during construction of the gRPC clients and servers. We could add them as fields on Scope, but this seemed like a little too much tight coupling.
Also, update go-grpc-prometheus to get the necessary methods.
```
$ go test github.com/grpc-ecosystem/go-grpc-prometheus/...
ok github.com/grpc-ecosystem/go-grpc-prometheus 0.069s
? github.com/grpc-ecosystem/go-grpc-prometheus/examples/testproto [no test files]
```
Previously our gRPC client code called the wrong function, enabling server-side instead of client-side histograms.
Also, add a timing stat for the generate / store combination in OCSP Updater.
Previously, a given binary would have three TLS config fields (CA cert, cert,
key) for its gRPC server, plus each of its configured gRPC clients. In typical
use, we expect all three of those to be the same across both servers and clients
within a given binary.
This change reuses the TLSConfig type already defined for use with AMQP, adds a
Load() convenience function that turns it into a *tls.Config, and configures it
for use with all of the binaries. This should make configuration easier and more
robust, since it more closely matches usage.
This change preserves temporary backwards-compatibility for the
ocsp-updater->publisher RPCs, since those are the only instances of gRPC
currently enabled in production.
There's an off-the-shelf package that provides most of the stats we care about
for gRPC using interceptors. This change vendors go-grpc-prometheus and its
dependencies, and calls out to the interceptors provided by that package from
our own interceptors.
This will allow us to get metrics like latency histograms by call, status codes
by call, and so on.
Fixes#2390.
This change vendors go-grpc-prometheus and its dependencies. Per contributing guidelines, I've run the tests on these dependencies, and they pass:
go test github.com/davecgh/go-spew/spew github.com/grpc-ecosystem/go-grpc-prometheus github.com/grpc-ecosystem/go-grpc-prometheus/examples/testproto github.com/pmezard/go-difflib/difflib github.com/stretchr/testify/assert github.com/stretchr/testify/require github.com/stretchr/testify/suite
ok github.com/davecgh/go-spew/spew 0.022s
ok github.com/grpc-ecosystem/go-grpc-prometheus 0.120s
? github.com/grpc-ecosystem/go-grpc-prometheus/examples/testproto [no test files]
ok github.com/pmezard/go-difflib/difflib 0.042s
ok github.com/stretchr/testify/assert 0.021s
ok github.com/stretchr/testify/require 0.017s
ok github.com/stretchr/testify/suite 0.012s
Previously we had custom code in each gRPC wrapper to implement timeouts. Moving
the timeout code into the client interceptor allows us to simplify things and
reduce code duplication.
As described in #2282, our gRPC code uses mutual TLS to authenticate both clients and servers. However, currently our gRPC servers will accept any client certificate signed by the internal CA we use to authenticate connections. Instead, we would like each server to have a list of which clients it will accept. This will improve security by preventing the compromise of one client private key being used to access endpoints unrelated to its intended scope/purpose.
This PR implements support for gRPC servers to specify a list of accepted client names. A `serverTransportCredentials` implementing `ServerHandshake` uses a `verifyClient` function to enforce that the connecting peer presents a client certificate with a SAN entry that matches an entry on the list of accepted client names
The `NewServer` function from `grpc/server.go` is updated to instantiate the `serverTransportCredentials` used by `grpc.NewServer`, specifying an accepted names list populated from the `cmd.GRPCServerConfig.ClientNames` config field.
The pre-existing client and server certificates in `test/grpc-creds/` are replaced by versions that contain SAN entries as well as subject common names. A DNS and an IP SAN entry are added to allow testing both methods of specifying allowed SANs. The `generate.sh` script is converted to use @jsha's `minica` tool (OpenSSL CLI is blech!).
An example client whitelist is added to each of the existing gRPC endpoints in config-next/ to allow the SAN of the test RPC client certificate.
Resolves#2282
Daniel McCarney
Roland Bracewell Shoemaker
Jacob Hoffman-Andrews