Async api (#128)

* Refactored Transport for better async use

Still a bit rough, but it now builds a big future using combinators. It
still does one `Runtime::block_on()` to keep the existing API, but this
is a first up before making the whole API async.

* Migrate most APIs to be Future-based

I still need to finish a few of the more tricky ones that I've commented
out for now, but most of it compiles and some examples work. In
particular, `Docker::stats()` now properly returns an async stream of
stats.

* Fix events and containerinspect examples

* Fix imageinspect, images, info and top examples

* Fix containercreate, imagedelete and imagepull examples

* Fix more examples

* Add back debug statement in Transport::request

* De-glob imports in examples

* Remove unused imports in examples

* Fix NetworkCreateOptions serialization

* Add back error message extraction in Transport

* Fix Container::create serialization of options

* Add containerdelete example

* Simplify result

* Fix some error handling to remove unwrap()

* Fix Image::export()

* Fix imagebuild example

* Add adapter from Stream of Chunks to AsyncRead

Having an `AsyncRead` is required to be able to use the `FramedRead` and
`Decoder` stuff from tokio_codec. This code is "borrowed" from
https:/github.com/ferristseng/rust-ipfs-api though should probably be
moved to its own crate or to tokio_codec.

* Fix Container::logs()

It now properly demuxes stdout/stderr, and returns a `Stream<Item =
TtyLine>`.

* Fix Container::export()

* Use LineCodec for streaming JSON

Although in my limited testing it seemed to work fine, there is no
guarantee that 1 chunk == 1 piece of valid JSON. However, each JSON
structure seems to be serialized on one line, so use LineCodec to turn
the body into a stream of lines, then deserialize over this.

* Fix serialization of ExecContainerOptions

* Fix Container::exec() (kind of...)

* Simplify deserialisation in Image::delete()

* Small clean-ups

* More clean ups

* Fix rustdoc + remove extraneous "extern crate"

* Fix doc example

* Fix formatting

1 files changed, 24 insertions, 14 deletions

diff --git a/examples/export.rs b/examples/export.rs
index b12e2f8..b8d8eaf 100644
--- a/examples/export.rs
+++ b/examples/export.rs
@@ -1,22 +1,32 @@
 extern crate shiplift;
+extern crate tokio;
 
-use shiplift::Docker;
+use shiplift::{errors::Error, Docker};
 use std::env;
 use std::fs::OpenOptions;
-use std::io::copy;
+use std::io::Write;
+use tokio::prelude::{Future, Stream};
 
 fn main() {
     let docker = Docker::new();
-    if let Some(id) = env::args().nth(1) {
-        let mut export = OpenOptions::new()
-            .write(true)
-            .create(true)
-            .open(format!("{}.tgz", &id))
-            .unwrap();
-        let images = docker.images();
-        let mut exported = images.get(&id).export().unwrap();
-        println!("copying");
-        copy(&mut exported, &mut export).unwrap();
-        println!("copied");
-    }
+    let id = env::args().nth(1).expect("You need to specify an image id");
+
+    let mut export_file = OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open(format!("{}.tar", &id))
+        .unwrap();
+    let images = docker.images();
+    let fut = images
+        .get(&id)
+        .export()
+        .for_each(move |bytes| {
+            export_file
+                .write(&bytes[..])
+                .map(|n| println!("copied {} bytes", n))
+                .map_err(Error::IO)
+        })
+        .map_err(|e| eprintln!("Error: {}", e));
+
+    tokio::run(fut)
 }