Repair docker workflow (#85)

* Fixed build error while using the *Docker workflow*

I was faced with this error after running *docker-compose up -d
--build*.

```
Configuring postgresql-libpq-0.9.4.3...
setup: The program 'pg_config' is required but it could not be found.
```

Fixed it by installing the Postgres dev tools like pg_config inside the
Flora dev container

* Fixed the Docker workflow

- Switched the base Docker image from Buster to Bullseye so the latest
  Soufflé version (2.2) can be installed
- Installed Soufflé in the container
- Installed Tmux in the container
- Set up a nice development shell inside the Docker container. The shell
  uses ZSH, Oh-my-ZSH, and a nice welcom message. The environment variables are set
  automatically.

Dockerfile

@@ -1,18 +1,36 @@
 # syntax=docker/dockerfile:1
-FROM haskell:8.10
+FROM gbogard/haskell-bullseye:8.10.7
 
 # generate a working directory
 WORKDIR /flora-server 
 
-# copy the files relevant to build core dependencies
-COPY cabal.project flora.cabal shell.nix environment.sh environment.docker.sh Makefile scripts/start-tmux.sh ./
+# install dependencies (pg_config & yarn)
+RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add -
+RUN curl -fsSL https://deb.nodesource.com/setup_17.x | bash -
+RUN echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list 
+RUN apt update
+RUN apt install -y nodejs yarn libpq-dev mcpp wget zsh tmux
 
-RUN cabal update
-# let nix build the dependencies. This uses nix-shell to cache the setup phase.
-RUN cabal build -j4
+# install soufflé
+RUN wget --content-disposition https://github.com/souffle-lang/souffle/releases/download/2.2/x86_64-ubuntu-2004-souffle-2.2-Linux.deb
+RUN apt install -f -y ./x86_64-ubuntu-2004-souffle-2.2-Linux.deb
 
-# copy asset-relevant dependency files
-COPY assets/package.json assets/yarn.lock assets/
-RUN make assets-deps
+# configure the shell
+RUN sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"
+COPY scripts/shell-welcome.txt /etc/motd
+COPY scripts/.zshrc /root/.zshrc
 
+# build Haskell dependencies
+COPY Makefile cabal.project flora.cabal ./
+RUN cabal build --only-dependencies -j8
+
+# Compile Souffle source files
+COPY cbits ./cbits
+RUN make souffle
+
+# copy and build the assets
+COPY assets ./assets
+RUN make build-assets
+
+RUN echo $PATH > /etc/profile
 CMD [ "/bin/sh", "-c", "sleep 1d"]

Makefile

@@ -62,14 +62,14 @@ style: ## Run the code formatters (stylish-haskell, cabal-fmt, nixfmt)
 nix-shell: ## Enter the Nix shell
 	@nix-shell
 
-docker-build: ## Build the docker image
-	@docker-compose build
-
 docker-start: ## Start the container cluster
-	@docker-compose up -d
+	@docker-compose up -d --build
 
 docker-enter: ## Enter the docker environment
-	docker-compose exec flora-server "nix-shell"
+	docker-compose exec flora-server "zsh"
+
+start-tmux: ## Start a Tmux session with hot code reloading
+	./scripts/start-tmux.sh
 
 soufflé: ## Generate C++ files from the Soufflé Datalog definitions
 	cd cbits ; souffle -g categorise.{cpp,dl}

README.md

@@ -79,15 +79,16 @@ you can also use `db-create` and `db-drop` to create and delete the database in
 
 ### Docker Workflow
 
-A docker-based workflow is provided:
+A docker-based workflow is provided. The idea is to develop from within a container that brings with it all dependencies,
+and communicates with another container for the Postgres database.
 
 ```bash
-# It's gonna take around 13 minutes the first time you build,
-# run "make docker-start" the next times.
-$ docker-compose up -d --build
+# It's gonna take around 13 minutes the first time you build
+$ make docker-start
+# Once the containers are running, you can enter the development environment and start hacking
 $ make docker-enter
-# You'll be in the docker container
-(docker)$ source environment.docker.sh
+# You'll be in the docker container. Environment variables are automatically set 
+# so you should be able to start Flora
 (docker)$ make nix-tmux
 # You'll be in a tmux session, everything should be launched
 # Visit localhost:8084 from your web browser to see if it all works.

docker-compose.yml

@@ -2,7 +2,7 @@ version: "3"
 services:
   flora-server:
     build: .
-    container_name: flora-server
+    container_name: flora-server-dev-env
     ports:
       - "8084:8084"
     volumes:
@@ -14,12 +14,13 @@ services:
   database:
     image: "postgres"
     container_name: database
+    ports:
+      - "5432:5432"
     expose:
       - "5432"
     env_file:
       - database.env
     volumes:
-      - database-data:/flora-server/pgdata/
-
+      - database-data:/var/lib/postgresql/data    
 volumes:
   database-data:

environment.docker.sh → scripts/.zshrc

@@ -1,9 +1,13 @@
-source environment.sh
+export ZSH="$HOME/.oh-my-zsh"
+ZSH_THEME="robbyrussell"
 
-export FLORA_DB_HOST="database"
+plugins=(git)
 
+source $ZSH/oh-my-zsh.sh
+source /flora-server/environment.sh
+export FLORA_DB_HOST="database"
 export FLORA_PG_URI="postgresql://${FLORA_DB_USER}:${FLORA_DB_PASSWORD}@${FLORA_DB_HOST}:${FLORA_DB_PORT}/${FLORA_DB_DATABASE}"
 export FLORA_PG_CONNSTRING="host=${FLORA_DB_HOST} dbname=${FLORA_DB_DATABASE} user=${FLORA_DB_USER} password=${FLORA_DB_PASSWORD}"
-
-
 export FLORA_HTTP_PORT=8084
+
+cat /etc/motd

scripts/start-tmux.sh

@@ -1,5 +1,4 @@
 #!/usr/bin/env bash
-
 set -euxo pipefail
 
 tmux kill-session -t 'flora' || true