Even though most of the time these modules will be used by
connectors, there are exceptions (namely, `emqx_rule_engine`).
Besides, they are general enough to land there, more so given
that `emqx_placeholder` is already there.
Treat "${$}" as literal "$". This allows to template express
strings, for example, of the form "${some_var_value}" where
`some_var_value` is interpolated from bindings.
Missing bindings in string templates will be rendered as "undefined",
as before. Rendering still assumes that missing binding with implicit
default (`undefined`) is an error.
This will also restore complete backward compat in `emqx_prometheus`.
This slightly changes semantics: now the attempt to create authenticator
with illegal bindings in templates will fail, instead of treating them
as literals. The runtime behaviour on the other hand should be the same.
Located under `emqx_connector` for now. The APIs of the new modules
are slightly different from the old ones. The new ones are more
explicit in terms of error handling. Also copy the according testsuite
from `emqx_plugin_libs` and enrich it for better coverage.
Co-authored-by: Thales Macedo Garitezi <thalesmg@gmail.com>
Co-authored-by: Stefan Strigler <stefan.strigler@emqx.io>
Co-authored-by: Zaiming (Stone) Shi <zmstone@gmail.com>
Several bridges should be able to share a connector pool defined by a
single connector. The connectors should be possible to enable and
disable similar to how one can disable and enable bridges. There should
also be an API for checking the status of a connector and for
add/edit/delete connectors similar to the current bridge API.
Issues:
https://emqx.atlassian.net/browse/EMQX-10805
Fixes https://emqx.atlassian.net/browse/EMQX-10629
During health checking, we check whether tables in the SQL statement
exist. Such check was done by asking the backend to parse the
statement using a named prepared statements. Concurrent health checks
could then result in the error:
```erlang
{error,{error,error,<<"42P05">>,duplicate_prepared_statement,<<"prepared statement \"get_status\" already exists">>,[{file,<<"prepare.c">>},{line,<<"451">>},{routine,<<"StorePreparedStatement">>},{severity,<<"ERROR">>}]}}
```
This could lead to an inconsistent state in the driver process, which
would crash later when a message from the backend (`READY_FOR_QUERY`, "idle"):
```
2023-07-24T13:05:58.892043+00:00 [error] Generic server <0.2134.0> terminating. Reason: {'module could not be loaded',[{undefined,handle_message,[90,<<"I">>,...
```
Added calls to `epgsql:sync/1` for functions that could return
`{error, sync_required}`.
Also, redundant calls to `parse2` were removed to reduce the number of requests.
Fixes https://emqx.atlassian.net/browse/EMQX-10405
The problem here was that, for async requests, ehttpc responses of the form `{ok, 4__, _,
_}` and similar were being treated as successes.
