Updated container-README.md with better instructions, spelling

container-README.md

@@ -1,56 +1,95 @@
-# prezto docker container
+# Prezto Docker Container
 
 This branch contains a Dockerfile and a Makefile that hopefully may
 prove helpful for prezto development.
 
-The idea is to have a totally independendn and isolated environemnet
-in which to quickly make changes to either prezto-core or any plugin
-that may bein development, enabling automated testing and even
-continuous integration.
+The idea is to have a totally independent and isolated environemnet
+in which to test changes to either prezto-core or any plugin that you
+may be working on, **without disrupting your environment**, thus enabling
+automated testing and even continuous integration.
+
+This is a proof of concept, it may not be even a good idea to have
+this on the main prezto repository. on the other hand, the container
+image should depend on the code, so if the team finds this to be a
+useful tool, there are choices to be made in that respect. My
+intention is to introduce this as a helpful tool for development and
+for new users to try prezto easely
+
+Here is a screencast showing what the container can do so far
 
 [![asciicast](https://asciinema.org/a/277054.svg)](https://asciinema.org/a/277054)
 
-The container is a basic install of alpine linux, so the image
-download is reasonably small
+The container is a basic install of [alpine linux][1] so the download
+is reasonably small at around 200M, since  debian based images can
+weigh in around 1.5G.
 
-On the container we have a few utilities and additionalsoftware that
-prezto has core support for, and you can  check it out in a snap by doing:
+On the container we have a few utilities and additional software that
+prezto has core support for, (tmux, make, etc) and you can try it i
+easily by running:
 
 ```bash
     docker pull hlecuanda/prezto-dev:latest
 ```
-once you have the image, create a container from it with:
+
+once you have the image, create a container from it:
+
+```bash
+    docker run -it --rm -h prezto hlecuanda/prezto-dev:latest
+```
+
+That will create an interactive (`--it`) ephemeral container (`--rm`)
+whose hostname is prezto (`-h prezto`) based on the aforementioned
+imag. you should be sitting at the plain sorin prompt in a brand new
+prezto instance.
+
+A development and testing workflow can be achieved by mounting a
+project's directory on to the image's filesystem:
 
 ```bash
-docker run -it --rm -h prezto hlecuanda/prezto-dev:latest
+    cd /path/to/project/root
+    docker run -it --rm -h prezto \
+            -v $(pwd):/home/prezto/.zprezto/modules/${:-$(pwd):t} \
+            hlecuanda/prezto-dev:latest
 ```
 
-That will set you on a prompt within the container with a
-vanilla install of prezto.
+This will mount the current directory on the container's filesystem,
+you can develop on your own machine and environnment, and test your
+changes running on the container, your actual source will already be
+in-place on prezto's directory hierarchy, as if it was just cloned
+recursively (v.gr for modules with extenral dependencies)
 
-A development and testing workflow can be achieved by mounting the stuff
-you're working on to the image's filesystem:
+Keep in mind that the containers created in this fashion are ephemeral,
+so anything you write on the contain'ers filesystem will be lost,
+unless you remove the `--rm` option like so:
 
 ```bash
-docker run -it --rm -h prezto \
-        -v /local/path:/home/prezto \
-        -v /local/path/zdotdir:/home/preztoa \
-        -v /local/module-dev-src:/home/prezto/.zprezto/modules/yourmodulea \
-        hlecuanda/prezto-dev:latest
+    cd /path/to/project/root
+    docker run -it -h prezto --name prezto \
+            -v $(pwd):/home/prezto/.zprezto/modules/${:-$(pwd):t} \
+            hlecuanda/prezto-dev:latest
 ```
+This will create a container named prezto, (`--name prezto`) with it's
+hostname set to prezto also (`-h prezto`) that will retain changes
+made to it's filesystem. When you detach, the container willi stop and
+you can spinit up again using:
 
-the third volume mapping is particularly interesting. you can
-develop on your own machine and environnment, and when spinning up the
-container, your actual source is already in-plase as if installed on a
-vanilla prezto instance
+```bash
+    docker start -ai prezto
+```
 
-keep in mind that the container are ephemeral, unless you remove the
-`--rm` option which will create new containers each time you run the
-command, but the changes to the filesystemwill persist on a container
-file that you can later spin up again to re-use.
+Containers started this way will remember the volume mounts they were
+created with, so the project directory we previously mounted with
+`-v` on the `docker run` command, will be ready on the image.
 
 I have found epehermeral containers to be most useful since you get an
 untainted, pristine environment for testing every time you spin up the
 container.
 
-hope this turns out to be useful. 
+Since the docker commands can be a bit verbose, the included Makefile
+automates some of the frequent steps in the workflow, although it can
+be replaced by shell functions  quite easily;
+
+<script src="https://gist.github.com/hlecuanda/78a6a39877c9753230a11c2d8832f4b6.js"></script>
+
+hope this turns out to be useful.
+[1]:https://alpinelinux.org