update installation.txt
Add building with docker section
@@ -270,6 +270,25 @@ Then just build using cargo and the appropriate target::
$ cargo build --target x86_64-unknown-linux-musl
+Build from source using Docker
+==============================
+
+Clone vagga repository
+
+ $ git clone https://github.com/tailhook/vagga && cd vagga
+
+Describe vagga version
+
+ $ git describe
+
+Result would be something like `v0.8.1-19-g372bded`
+
+Compile vagga with dockerized rust:
+
+ $ docker run --rm --user "$(id -u)":"$(id -g)" -e VAGGA_VERSION=v0.8.1-19-g372bded -v "$PWD":/usr/src/myapp -w /usr/src/myapp rust cargo build --release
+
+Compiled binary move to `/usr/local/bin`
+
OS X / Windows
==============
