docker refresh and doco

Expand dockerfile with docker-compose
doco DOCKER.md

add venv doco to README.md

add gitignore to exclude python venv

Signed-off-by: Nic Boet <[email protected]>

.gitignore

@@ -0,0 +1,3 @@
+venv*
+.cache/*
+*.zone

DOCKER.md

@@ -0,0 +1,49 @@
+# Docker
+
+Dockerfile and docker-compose.yml provide alternative for installations and development
+
+Some tweaking is expected to suit a production deployment
+
+## Build
+
+```shell
+docker-compose build
+```
+
+## AdBlock Zone
+
+The example container writes the generated rpz-adblocker.zone file under /bind-adblock
+
+Docker-compose file has an options for using either a volume (i.e containerized bind9 integration) or host mount point (i.e. bind9 running on the docker host os) for that path.
+
+## Deploy
+
+```shell
+docker-compose up -d
+```
+
+## Running Considerations
+
+### Cron
+
+The current image runs the python script at startup and then exits.
+There is no cron scheduler provided at this time.
+
+### On Demand
+
+Once deployed, issuing a run will start the container again, run the update script, then exit after writing the zone file.
+
+```shell
+docker run bind-adblock_updater
+```
+
+### Bind9 Zone reloads
+
+You might wish to combine bind-adblock and bind9 into the same container in which a cron service controls executing this python script and in turn can trigger named to reload the zone. 
+
+An aggressive workaround is start the adblock updater container then fully restart the bind9 container.
+
+```shell
+docker-compose up updater >/dev/null 2>&1 && docker-compose restart bind9 >/dev/null 2>&1
+```
+

Dockerfile

@@ -1,14 +1,19 @@
 FROM python:latest
 
-ENV SRC="."
+WORKDIR /root
 
-VOLUME /bind-adblock
+COPY blocklist.txt .
+COPY config.yml .
+COPY update-zonefile.py .
+COPY requirements.txt .
 
-COPY ${SRC}/blocklist.txt ./
-COPY ${SRC}/config.yml ./
-COPY ${SRC}/update-zonefile.py ./
-COPY ${SRC}/requirements.txt ./
+ENV VIRTUAL_ENV=/opt/venv
+RUN python3 -m venv $VIRTUAL_ENV
+ENV PATH="$VIRTUAL_ENV/bin:$PATH"
 
-RUN pip install -r requirements.txt
+RUN pip install --upgrade pip && \
+    pip install -r requirements.txt
+
+RUN mkdir /bind-adblock
 
 CMD ["python3", "./update-zonefile.py", "--no-bind", "/bind-adblock/rpz-adblocker.zone", "rpz.adblocker"]

README.md

@@ -27,6 +27,9 @@ See [requirements.txt](requirements.txt)
 
 To install
 ```
+python3 -m venv venv
+source venv/bin/activate
+pip install --upgrade pip
 pip install -r requirements.txt
 ```
 

docker-compose.yml

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+---
+version: "3"
+
+services:
+  updater:
+    container_name: adblock
+    build:
+      context: .
+    volumes:
+      - 'bind9-zones:/bind-adblock'
+      # - '/var/bind:/bind-adblock'
+
+volumes:
+  bind9-zones: