Ghostunnel has a notion of "status port", a TCP port (or UNIX socket) that can
be used to expose status and metrics information over HTTPS. The status port
feature can be controlled via the --status
flag. Profiling endpoints on the
status port can be enabled with --enable-pprof
.
The X.509 certificate on the status port will be the same as the certificate used for proxying (either the client or server certificate). This means you can use the status port to inspect/verify the certificate that is being used, which can be useful for orchestration systems.
Example invocation with status port enabled:
ghostunnel client \
--listen localhost:8080 \
--target localhost:8443 \
--keystore test-keys/client-keystore.p12 \
--cacert test-keys/cacert.pem \
--status localhost:6060
Note that we set the status port to "localhost:6060". Ghostunnel will start an internal HTTPS server and listen for connections on the given host/port. You can also specify a UNIX socket instead of a TCP port.
How to check status and read connection metrics:
# Status information (JSON)
curl --cacert test-keys/cacert.pem https://localhost:6060/_status
# Metrics information (JSON)
curl --cacert test-keys/cacert.pem 'https://localhost:6060/_metrics/json'
# Metrics information (Prometheus)
curl --cacert test-keys/cacert.pem 'https://localhost:6060/_metrics/prometheus'
How to use profiling endpoints, if --enable-pprof
is set:
# Human-readable goroutine dump
curl --cacert test-keys/cacert.pem 'https://localhost:6060/debug/pprof/goroutine?debug=1'
# Analyze execution trace using pprof tool
go tool pprof -seconds 5 https+insecure://localhost:6060/debug/pprof/profile
Note that go tool pprof
does not support setting CA certificates at the
moment, hence the use of the https+insecure
scheme in the last example. You
can use the standard https
scheme if your ghostunnel is using a certificate
trusted by your system (c.f. golang/go#20939). For more
information on profiling via pprof, see the runtime/pprof
and
net/http/pprof
docs.