security: run Docker container as non-root user

Running containers as a non-root user is a long standing security practice.
The changes ensure that the sourcebot user is created and has the correct
level of permissions to run all its dependencies (postgres, redis and node).

Please note that as a side effect, existing mounted volumes would need to
have their ownership reviewed or it may not be able to access the files.
This is specially the case for previous versions that would create said
files as 0:0.

To fix that, users can run chown -R 1500:1500 /path/.sourcebot. The chmod
may also need to be a bit more strict in such cases, so changing that is
advised: chown -R 0750 /path/.sourcebot.

Signed-off-by: Paulo Gomes <pjbgf@linux.com>

Author: pjbgf

Dockerfile

@@ -225,12 +225,26 @@ RUN mkdir -p /run/postgresql && \
     chown -R postgres:postgres /run/postgresql && \
     chmod 775 /run/postgresql
 
+# To run as non-root, the user must be part of postgres, redis and node groups
+RUN addgroup -g 1500 sourcebot && \
+    adduser -D -u 1500 -h /app -S sourcebot && \
+    adduser sourcebot postgres && \
+    adduser sourcebot redis && \
+    adduser sourcebot node && \
+    chown -R sourcebot /data && \
+    chown -R sourcebot /app && \
+    mkdir /var/log/sourcebot && \
+    chown sourcebot /var/log/sourcebot
+
 COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
 COPY prefix-output.sh ./prefix-output.sh
 RUN chmod +x ./prefix-output.sh
 COPY entrypoint.sh ./entrypoint.sh
 RUN chmod +x ./entrypoint.sh
 
+
+USER sourcebot
+
 EXPOSE 3000
 ENV PORT=3000
 ENV HOSTNAME="0.0.0.0"

entrypoint.sh

@@ -77,19 +77,20 @@ fi
 
 # Check if DATA_CACHE_DIR exists, if not create it
 if [ ! -d "$DATA_CACHE_DIR" ]; then
-    mkdir -p "$DATA_CACHE_DIR"
+    mkdir -m 0750 -p "$DATA_CACHE_DIR"
 fi
 
 # Check if DATABASE_DATA_DIR exists, if not initialize it
 if [ "$DATABASE_EMBEDDED" = "true" ] && [ ! -d "$DATABASE_DATA_DIR" ]; then
-    echo -e "\e[34m[Info] Initializing database at $DATABASE_DATA_DIR...\e[0m"
-    mkdir -p $DATABASE_DATA_DIR && chown -R postgres:postgres "$DATABASE_DATA_DIR"
-    su postgres -c "initdb -D $DATABASE_DATA_DIR"
+    echo -e "\e[34m[Info] Initializing database at $DATABASE_D\ATA_DIR...\e[0m"
+    mkdir -m 0750 -p $DATABASE_DATA_DIR
+
+    initdb -D "$DATABASE_DATA_DIR"
 fi
 
 # Create the redis data directory if it doesn't exist
 if [ "$REDIS_EMBEDDED" = "true" ] && [ ! -d "$REDIS_DATA_DIR" ]; then
-    mkdir -p $REDIS_DATA_DIR
+    mkdir -m 0750 -p $REDIS_DATA_DIR
 fi
 
 if [ -z "$SOURCEBOT_ENCRYPTION_KEY" ]; then
@@ -180,13 +181,25 @@ echo "{\"version\": \"$NEXT_PUBLIC_SOURCEBOT_VERSION\", \"install_id\": \"$SOURC
 
 # Start the database and wait for it to be ready before starting any other service
 if [ "$DATABASE_EMBEDDED" = "true" ]; then
-    su postgres -c "postgres -D $DATABASE_DATA_DIR" &
-    until pg_isready -h localhost -p 5432 -U postgres; do
+    postgres -D "$DATABASE_DATA_DIR" &
+    until pg_isready -h localhost -p 5432 -d sourcebot -U postgres; do
         echo -e "\e[34m[Info] Waiting for the database to be ready...\e[0m"
         sleep 1
+
+        # As postgres runs in the background, we must check if it is still
+        # running, otherwise the "until" loop will be running indefinitely.
+        if ! pgrep -x "postgres" > /dev/null; then
+            echo "postgres failed to run"
+            exit 1
+        break
+    fi
     done
 
-    # Check if the database already exists, and create it if it dne
+    # Running as non-root we need to ensure the postgres account is created.
+    psql -U postgres -tc "SELECT 1 FROM pg_roles WHERE rolname='postgres'" | grep -q 1 \
+        || createuser postgres -s
+
+    # Check if the database already exists, and create it if it doesn't
     EXISTING_DB=$(psql -U postgres -tAc "SELECT 1 FROM pg_database WHERE datname = 'sourcebot'")
 
     if [ "$EXISTING_DB" = "1" ]; then
@@ -205,4 +218,4 @@ DATABASE_URL="$DATABASE_URL" yarn workspace @sourcebot/db prisma:migrate:prod
 mkdir -p /var/log/sourcebot
 
 # Run supervisord
-exec supervisord -c /etc/supervisor/conf.d/supervisord.conf
+exec supervisord -c /etc/supervisor/conf.d/supervisord.conf