Add upgrade method

[johanbrandhorst]

varlink: add Upgrade method to connection

Upgrade can be used to upgrade a connection for sending data. The connection cannot be reused after upgrading.

cmd/varlink-go-interface-generator: Generate Upgrade

Upgrade can be used to get access to the raw underlying connection with the varlink server.

Fixes #18

[coveralls]

Pull Request Test Coverage Report for Build 351

• 63 of 63 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.4%) to 84.258%

---

Totals
Change from base Build 350:	1.4%
Covered Lines:	653
Relevant Lines:	775

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 358

• 63 of 63 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.4%) to 84.258%

---

Totals
Change from base Build 355:	1.4%
Covered Lines:	653
Relevant Lines:	775

---

💛 - Coveralls

[johanbrandhorst]

Thanks for this PR @johanbrandhorst ! this solves my use case just fine. I think this can close the issue #16

Glad to hear it. I ended up not needing this for my own use case in the end, but it seems reasonable to add anyway. Could you share the code you ended up writing for this?

[ffromani]

Thanks for this PR @johanbrandhorst ! this solves my use case just fine. I think this can close the issue #16

Glad to hear it. I ended up not needing this for my own use case in the end, but it seems reasonable to add anyway. Could you share the code you ended up writing for this?

Sure, its' all here: https://github.com/fromanirh/pack8s

At this moment the published code includea a fork of varlink/go with an horrible, horrible hack I added to keep going. On my box I applied this PR on my fork (https://github.com/fromanirh/varlink-go), which I'm going to upload later today.

To be specific, the code I mentioned I'm using to consume the podman API is here: https://github.com/fromanirh/pack8s/tree/master/pkg/varlinkapi

[haraldh]

Hmm, the server needs Write and Read after the connection is upgraded.

[haraldh]

I needed

diff --git a/varlink/call.go b/varlink/call.go
index 50dba0f..db57c06 100644
--- a/varlink/call.go
+++ b/varlink/call.go
@@ -16,7 +16,7 @@ type WriterContext interface {
 // client can be terminated by returning an error from the call instead
 // of sending a reply or error reply.
 type Call struct {
-       Conn      WriterContext
+       Conn      ReadWriterContext
        Request   *[]byte
        In        *serviceCall
        Continues bool
diff --git a/varlink/service.go b/varlink/service.go
index af8aa25..9d35fb5 100644
--- a/varlink/service.go
+++ b/varlink/service.go
@@ -76,7 +76,7 @@ func (s *Service) getInterfaceDescription(ctx context.Context, c Call, name stri
        return c.replyGetInterfaceDescription(ctx, description)
 }

-func (s *Service) HandleMessage(ctx context.Context, conn WriterContext, request []byte) error {
+func (s *Service) HandleMessage(ctx context.Context, conn ReadWriterContext, request []byte) error {
        var in serviceCall

        err := json.Unmarshal(request, &in)

which probably makes a separate WriterContext obsolete

[johanbrandhorst]

I have merged WriterContext into ReadWriterContext. @haraldh is this better?

[haraldh]

could you also rename ReadBytes to something like ReadUntilByte

[johanbrandhorst]

ReadBytes is consistent with the standard library: https://golang.org/pkg/bufio/#Reader.ReadBytes. I would rather not change it. Are you sure?

[haraldh]

Oh.. sorry.. all ok, then

[johanbrandhorst]

Thanks!

[ffromani]

Thanks for merging this PR!

[haraldh]

tagged as release v0.3.0

[haraldh]

updated https://github.com/haraldh/govarlinksendfileexample with contexts