Update README.md with CI best practices.

.drone.yml

@@ -0,0 +1,11 @@
+---
+kind: pipeline
+type: docker
+name: default
+
+steps:
+  - name: build
+    image: git.golem.linux.it/golem/gestionale-builder:1
+    commands:
+      - script/build
+

.gitignore

@@ -1,2 +1,2 @@
+build/
 *.pro.user
-build-*

Dockerfile

@@ -0,0 +1,11 @@
+FROM ubuntu:22.04
+
+RUN useradd builder
+
+RUN apt update && apt upgrade -y && apt install -y \
+    git             \
+    make            \
+    cmake           \
+    qtbase5-dev     \
+    g++
+

README.md

@@ -17,15 +17,26 @@ Create `~/.config/it.linux.golem/component.conf` with following content:
     username=golem
     password=guess
 
-## Dependencies
-On Debian/Ubuntu/Mint:
-* qt5-default
-* TODO
+## Build
+Download the build container:
+```
+docker pull git.golem.linux.it/golem/gestionale-build
+```
 
-# Build
-    $ cd $REPOSITORY
-    $ mkdir build-component
-    $ cd build-component
-    $ qmake ../component
-    $ make -j$(nproc)
+Or, if you prefer, you can also build it by yourself:
+```
+script/setup
+```
 
+Then, run all the commands in the build container, simply by preceding them with `docker`.
+Example:
+```
+./docker ls
+```
+
+Every command you'll ever need to build this software should be scripted inside the `script/` directory.
+
+Example: compile everything and produce executable.
+```
+./docker script/build
+```

docker

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+REPODIR=$(realpath $(dirname "$0"))
+
+docker run --rm -ti -u builder \
+    -v "$REPODIR":/workspace   \
+    -v /tmp:/tmp               \
+    -w /workspace              \
+    gestionale-builder         \
+    "$@"
+

script/build

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+REPODIR=$(realpath $(dirname "$0")/..)
+
+BUILDIR="$REPODIR"/build
+
+mkdir -p "$BUILDIR"
+cmake -B "$BUILDIR"
+make -j$(nproc) -C "$BUILDIR"
+

script/setup

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+REPODIR=$(realpath $(dirname "$0")/..)
+
+docker build -t git.golem.linux.it/golem/gestionale-builder:1 "$REPODIR"
+