When calling a method and the user hasn't provided any method call
parameters on the command line we expect them on stdin instead. This
might be confusing for people using varlinkctl for the first time, since
omitting the parameters will just throw you at a blinking cursor.
Let's be a bit more helpful, and show a friendly message when we are
connected to a TTY (i.e. run interactively).
For putting together "varlinkctl call" command lines it's useful to
quickly enumerate all methods implemented by a service. Hence, let's add
a new "list-methods" which uses the introspection data of a service to
quickly list methods.
This is implemented as a special flavour of the "introspect" logic,
and just suppresses all output except for the method names.
let's make it easier to use the introspection functionality of
"varlinkctl": if no interface name is shown, display the introspection
data of all available interfaces. Moreover, allow that multiple
interfaces can be listed, in which case we enumerate them all.
This relieves the user from having to list interfaces first in order to
find the ones which to introspect.
This is preparation for making our Varlink API a public API. Since our
Varlink API is built on top of our JSON API we need to make that public
first (it's a nice API, but JSON APIs there are already enough, this is
purely about the Varlink angle).
I made most of the json.h APIs public, and just placed them in
sd-json.h. Sometimes I wasn't so sure however, since the underlying data
structures would have to be made public too. If in doubt I didn#t risk
it, and moved the relevant API to src/libsystemd/sd-json/json-util.h
instead (without any sd_* symbol prefixes).
This is mostly a giant search/replace patch.
In varlink.c we generally do not make failing callback functions fatal,
since that should be up to the app. Hence, in case of varlinkctl (where
we want failures to be fatal), make sure to propagate the error back
explicitly.
Before this change a failing call to "varlinkctl --more call …" would result in
a zero exit code. With this it will correctly exit with a non-zero exit
code.
For the other verbs turning off JSON mode makes sense, but for "call"
not so much, after all the contents of a method call reply is JSON we
couldn't really show any other way.
Hence, when JSON output was not configured otherwise in "call", default
to the same as -j.
It exposes the varlink_collect() call we internally provide: it collects
all responses of a method call that is issued with the "more" method
call flag. It then returns the result as a single JSON array.
As it turns out we do this in a similar way at various times (and
sometimes incorrectly), hence add a common implementation to share the
code and fix the incorrect behaviour.
The parameter returns the flags field of the reply message. This is only
relevant in very few cases, hence drop it from the call, but keep it in
a more generic varlink_call_full() call for those who need it.
Do something similar for varlink_callb().
varlink_dispatch() is a simple wrapper around json_dispatch() that
returns clean, standards-compliant InvalidParameter error back to
clients, if the specified JSON cannot be parsed properly.
For this json_dispatch() is extended to return the offending field's
name. Because it already has quite a few parameters, I then renamed
json_dispatch() to json_dispatch_full() and made json_dispatch() a
wrapper around it that passes the new argument as NULL. While doing so I
figured we should also get rid of the bad= argument in the short
wrapper, since it's only used in the OCI code.
To simplify the OCI code this adds a second wrapper oci_dispatch()
around json_dispatch_full(), that fills in bad= the way we want.
Net result: instead of one json_dispatch() call there are now:
1. json_dispatch_full() for the fully feature mother of all dispathers.
2. json_dispatch() for the simpler version that you want to use most of
the time.
3. varlink_dispatch() that generates nice Varlink errors
4. oci_dispatch() that does the OCI specific error handling
And that's all there is.
Yu Watanabe
Lennart Poettering
Luca Boccassi
Mike Yuan