Update with some explanations on what butido is and does

Signed-off-by: Matthias Beyer <mail@beyermatthias.de>

1 files changed, 72 insertions, 0 deletions

diff --git a/README.md b/README.md
index 32120e1..cf71869 100644
--- a/README.md
+++ b/README.md
@@ -7,3 +7,75 @@ Anyways, it is a tool for building packages for linux distributions in docker
 and it does not make assumptions about the build procedure itself (and thus can
 build .rpm, .deb, or any other package format your scripts can build).
 
+
+## Functionality
+
+Packages are defined in TOML and in hierarchies
+(see [config-rs](https://docs.rs/config/)).
+See the [examples](./examples) for how to define packages.
+
+The "business-logic" of packages are shell scripts which exist in predefined
+"phases".
+These scripts are compiled into one large script (per package) which is then
+run to build the source into a package.
+
+The package definition(s) can hold meta-information and (of course) information
+about a packages dependencies. Both dependencies and meta-information is made
+available in a build.
+
+Everything that is computed before, during or after a build or submit is written
+to a postgres database, including build logs.
+This database can be queried for packages, build information, logs and other
+data.
+
+Successfully built packages are collected in a "staging" store on FS. A staging
+store is created per submit.
+The results can be taken from this "staging" store and be released into a
+"release" store.
+
+
+## Requirements
+
+Building butido is easy, assuming you have a Rust installation:
+
+```bash
+cargo build --release # (remove --release for a debug build)
+```
+
+Running is not so easy:
+
+* Create a git repository
+* Put a `config.toml` file into the repository root, adapt parameters to your
+  needs
+* Write `pkg.toml` files for your packages
+* Run a postgres instance somewhere
+    * configure it to be accessible for butido with user and password
+    * Setup tables (butido cannot do this yet)
+* Run docker instances somewhere, accessible via HTTP or socket
+
+Now you should be ready to try butido. butido takes `--help` in every subcommand
+to explain what it does.
+
+
+### Glossary
+
+| Word        | Explanation                                                                                                      |
++ ----------- + ---------------------------------------------------------------------------------------------------------------- +
+| build / job | The procedure of transforming a set of sources to a package (or, technically, even to multiple packages)         |
+| dependency  | A "package" that is required during the buildtime or during the runtime of another "package"                     |
+| endpoint    | A docker API endpoint butido can talk to                                                                         |
+| jobset      | A list of jobs that can be run in any order or in parallel                                                       |
+| output      | The results of a butido build job                                                                                |
+| package     | A single (archive) file OR the definition of a job                                                               |
+| script      | The script that is run inside a container. Basically the "->" in "source -> package".                            |
+| source      | A file that contains a source code archive                                                                       |
+| submit      | A call to butido for building a single package, which can result in multiple packages (dependencies) being built |
+| tree        | The tree structure that is computed before a packages is built to find out all (transitive) dependencies         |
+
+
+# License
+
+butido was developed for science+computing ag (an Atos company).
+
+License: EPL-2.0
+