Rather than installing two separate panic handlers, defer the bookkeeping
separately from recovery, and lift the delegated handler call out to the top
level of the wrapper.
Also: Regularize the server middleware wrappers.
Add writeRPCResponse and writeHTTPResponse helpers, that handle the way RPC
responses are written to HTTP replies. These replace the exported helpers.
Visible effects:
- JSON results are now marshaled without indentation.
- HTTP status codes are now normalized.
- Cache control headers are no longer set.
Details:
- When writing a response to a URL (GET) request, do not marshal the whole
JSON-RPC object into the body, only encode the result or the error object.
This is a user-visible change.
- Do not change the HTTP status code for RPC errors. The RPC error already
reports what went wrong, the HTTP status should only report problems with the
HTTP transaction itself. This is a user-visible change.
- Encode JSON without indentation in POST response bodies. This is mainly cosmetic
but saves quite a bit of response data. Indent is still applied to GET responses to make
life easier for code examples.
- Remove an obsolete TODO about reporting an HTTP error on websocket upgrade.
Nothing needed to change; the upgrader already reports an error.
- Report an HTTP error when starting the server loop fails.
- Improve logging for encoding errors.
- Log less aggressively.
We should not set cache-control headers on RPC responses. HTTP caching
interacts poorly with resources that are expected to change frequently, or
whose rate of change is unpredictable.
More subtly, all calls to the POST endpoint use the same URL, which means a
cacheable response from one call may actually "hide" an uncacheable response
from a subsequent one. This is less of a problem for the GET endpoints, but
that means the behaviour of RPCs varies depending on which HTTP method your
client happens to use. Websocket requests were already marked statically
uncacheable, adding yet a third combination.
To address this:
- Stop setting cache-control headers.
- Update the tests that were checking for those headers.
- Remove the flags to request cache-control.
Apart from affecting the HTTP response headers, this change does not modify the
behaviour of any of the RPC methods.
This continues the push of plumbing contexts through tendermint. I
attempted to find all goroutines in the production code (non-test) and
made sure that these threads would exit when their contexts were
canceled, and I believe this PR does that.
The code in the Tendermint repository makes heavy use of import aliasing.
This is made necessary by our extensive reuse of common base package names, and
by repetition of similar names across different subdirectories.
Unfortunately we have not been very consistent about which packages we alias in
various circumstances, and the aliases we use vary. In the spirit of the advice
in the style guide and https://github.com/golang/go/wiki/CodeReviewComments#imports,
his change makes an effort to clean up and normalize import aliasing.
This change makes no API or behavioral changes. It is a pure cleanup intended
o help make the code more readable to developers (including myself) trying to
understand what is being imported where.
Only unexported names have been modified, and the changes were generated and
applied mechanically with gofmt -r and comby, respecting the lexical and
syntactic rules of Go. Even so, I did not fix every inconsistency. Where the
changes would be too disruptive, I left it alone.
The principles I followed in this cleanup are:
- Remove aliases that restate the package name.
- Remove aliases where the base package name is unambiguous.
- Move overly-terse abbreviations from the import to the usage site.
- Fix lexical issues (remove underscores, remove capitalization).
- Fix import groupings to more closely match the style guide.
- Group blank (side-effecting) imports and ensure they are commented.
- Add aliases to multiple imports with the same base package name.
EDIT: Updated, see [comment below]( https://github.com/tendermint/tendermint/pull/6785#issuecomment-897793175)
This change adds a sketch of the `Debug` mode.
This change adds a `Debug` struct to the node package. This `Debug` struct is intended to be created and started by a command in the `cmd` directory. The `Debug` struct runs the RPC server on the data directories: both the state store and the block store.
This change required a good deal of refactoring. Namely, a new `rpc.go` file was added to the `node` package. This file encapsulates functions for starting RPC servers used by nodes. A potential additional change is to further factor this code into shared code _in_ the `rpc` package.
Minor API tweaks were also made that seemed appropriate such as the mechanism for fetching routes from the `rpc/core` package.
Additional work is required to register the `Debug` service as a command in the `cmd` directory but I am looking for feedback on if this direction seems appropriate before diving much further.
closes: #5908
