Add documentation on everything

Dockerfile

@@ -2,48 +2,71 @@ FROM rstudio/plumber:latest
 
 ENV TZ "Africa/Nairobi"
 
+# install base libraries we need
 RUN apt-get -y update -qq && apt-get -y --no-install-recommends install \
-	tini \
-	libmariadb-dev \
-	libmysqlclient21 \
-	openjdk-8-jdk-headless \
-	cron \
-	curl \
-	&& rm -rf /var/lib/apt/lists/* \
-	&& rm -rf /etc/cron.*/*
+    tini \
+    libmariadb-dev \
+    libmysqlclient21 \
+    openjdk-8-jdk-headless \
+    cron \
+    curl \
+    && rm -rf /var/lib/apt/lists/* \
+    && rm -rf /etc/cron.*/*
 
+# install the R packages we need
+# for these, the latest version should always be usable
 RUN install2.r --error --skipinstalled \
-	tidyverse \
-	pool \
-	clock \
-	config \
-	uuid \
-	readr \
-	RMariaDB \
-	DBI \
-	&& rm -rf /tmp/downloaded_packages
+    tidyverse \
+    pool \
+    clock \
+    config \
+    uuid \
+    readr \
+    RMariaDB \
+    DBI \
+    && rm -rf /tmp/downloaded_packages
 
+# The model always needs to run on the exact version of h2o used to train it
 RUN Rscript -e "remotes::install_version('h2o', '3.42.0.2')"
 
+# Add the prediction model to the app
 COPY IIT-Prediction/model/V7 /app/model
+# Add the production extraction query to the app
 COPY SQL/iit_prod_data_extract.sql /app/iit_prod_data_extract.sql
+
+# The next scripts are used for cron jobs
+# this script triggers the predictions to run by hitting the API endpoint
 COPY docker-resources/run_predictions.sh /app/run_predictions.sh
 RUN chmod 0744 /app/run_predictions.sh
+# this script runs a small number of stored procedures we depend on to update
+# various tables used in the predictions
 COPY docker-resources/run_daily_stored_procedures.sh /app/run_daily_stored_procedures.sh
 RUN chmod 0744 /app/run_daily_stored_procedures.sh
+
+# this is a Docker entrypoint script
+# it ensures the cron daemon is started and then runs the API
 COPY docker-resources/docker-entrypoint.sh /docker-entrypoint.sh
 RUN chmod 0744 /docker-entrypoint.sh
 
+# here we actually setup the cron jobs, using our source crontab
+# cron is _very_ picky, so it may not be best to mess with this
 COPY docker-resources/crontab /etc/cron.d/iit-crontab
 RUN chmod 0644 /etc/cron.d/iit-crontab
 RUN crontab -u root /etc/cron.d/iit-crontab
-RUN touch /var/log/cron.log
 
+# now we also need to add the R code used here
+# this R code actually runs the stored procedures for run_daily_stored_procedures.sh
+# this is done in R so we can re-use the database settings for the API
 COPY docker-resources/dailyStoredProcedures.R /app/dailyStoredProcedures.R
+# plumber.R is the main app
 COPY docker-resources/plumber.R /app/plumber.R
 
+# EXPOSE is just documentation; by default, the API is run on port 8000
+# In production, this port is not exposed, as we hit the API from inside the container
 EXPOSE 8000
 
+# setup the entrypoint
 ENTRYPOINT ["tini", "--", "/docker-entrypoint.sh"]
 
+# this may not be necessary, but its left in to match the parent container defaults
 CMD ["/app/plumber.R"]