Začetna predloga za Rails razvojno okolje v Dockerju

- Dockerfile na osnovi ruby:4.0.9-slim z razvojnimi orodji in
  klientom PostgreSQL iz repozitorija PGDG
- docker-compose.yml s servisoma app (Rails) in db (PostgreSQL)
- .env.example, .dockerignore in .gitignore
- README z opisom sklada in navodili za nov projekt

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,44 @@
+FROM ruby:4.0.9-slim
+
+# Geme namešča v GEM_HOME slike (/usr/local/bundle), kjer je tudi volume "bundle"
+ENV BUNDLE_JOBS=4 \
+    BUNDLE_RETRY=3
+
+# Glavna različica PostgreSQL; mora se ujemati s strežnikom (nastavi jo docker-compose.yml)
+ARG PG_MAJOR=18
+
+# Uradni repozitorij PostgreSQL (PGDG), da je klient iste različice kot strežnik
+RUN apt-get update -y && apt-get install -y --no-install-recommends \
+  ca-certificates \
+  curl \
+  && install -d /usr/share/postgresql-common/pgdg \
+  && curl -fsSL -o /usr/share/postgresql-common/pgdg/apt.postgresql.org.asc \
+    https://www.postgresql.org/media/keys/ACCC4CF8.asc \
+  && . /etc/os-release \
+  && echo "deb [signed-by=/usr/share/postgresql-common/pgdg/apt.postgresql.org.asc] https://apt.postgresql.org/pub/repos/apt ${VERSION_CODENAME}-pgdg main" \
+    > /etc/apt/sources.list.d/pgdg.list \
+  && apt-get update -y && apt-get install -y --no-install-recommends \
+  build-essential \
+  git \
+  libpq-dev \
+  libyaml-dev \
+  pkg-config \
+  postgresql-client-${PG_MAJOR} \
+  && rm -rf /var/lib/apt/lists/*
+
+# Uporabnik app mora imeti pravico pisanja v mapo z gemi
+RUN useradd -u 1000 -m app \
+  && chown -R app:app /usr/local/bundle
+
+WORKDIR /app
+RUN chown app:app /app
+
+USER app
+
+# Odkomentiraj, ko bo obstajal Gemfile (po rails new)
+#COPY --chown=app:app Gemfile Gemfile.lock ./
+#RUN bundle install
+
+COPY --chown=app:app . .
+
+EXPOSE 3000