Install yarn

Author: Chuxel

containers/ruby-2-rails-5/.devcontainer/Dockerfile

@@ -34,6 +34,13 @@ RUN apt-get update \
     #
     # Install nodejs
     && apt-get install -y nodejs \
+    # 
+    # Install yarn
+    && apt-get install -y curl apt-transport-https lsb-release \
+    && curl -sS https://dl.yarnpkg.com/$(lsb_release -is | tr '[:upper:]' '[:lower:]')/pubkey.gpg | apt-key add - 2>/dev/null \
+    && echo "deb https://dl.yarnpkg.com/$(lsb_release -is | tr '[:upper:]' '[:lower:]')/ stable main" | tee /etc/apt/sources.list.d/yarn.list \
+    && apt-get update \
+    && apt-get -y install --no-install-recommends yarn \
     #
     # Install debug tools
     && gem install \