Merge pull request #404 from Paraphraser/20210908-python-old-menu

20210908 Python - old-menu branch - PR 2 of 2

Author: Slyke

.templates/python/Dockerfile

@@ -1,9 +1,48 @@
 FROM python:3
 
-WORKDIR /usr/src/app
+# user+group ID defaults for IOTstack
+ENV IOTSTACK_UID=1000
+ENV IOTSTACK_GID=1000
 
-COPY requirements.txt ./
+# the template folder is named
+ENV TEMPLATE="app"
 
-RUN pip install --no-cache-dir -r requirements.txt
+# where IOTstack template files are stored
+ENV PYTHON_DEFAULTS="/iotstack_defaults/${TEMPLATE}"
 
-CMD [ "python", "./app.py" ]
+# ensure the defaults directory exists
+RUN mkdir -p ${PYTHON_DEFAULTS}
+
+# copy template files to defaults directory in image
+COPY ${TEMPLATE} ${PYTHON_DEFAULTS}
+
+# the requirements file (if it exists) is
+ENV REQUIREMENTS="${PYTHON_DEFAULTS}/requirements.txt"
+
+# set up requirements (if the file exists)
+RUN if [ -e ${REQUIREMENTS} ] ; then pip3 install --no-cache-dir -r ${REQUIREMENTS} ; fi
+
+# the python working directory is 
+ENV PYTHON_WORKDIR="/usr/src/${TEMPLATE}"
+
+# ensure the working directory exists
+RUN mkdir -p ${PYTHON_WORKDIR}
+
+# add an entry-point script
+ENV ENTRY_POINT="docker-entrypoint.sh"
+COPY ${ENTRY_POINT} /${ENTRY_POINT}
+RUN chmod 755 /${ENTRY_POINT}
+
+# unset variables that are not needed
+ENV TEMPLATE=
+ENV REQUIREMENTS=
+ENV ENTRY_POINT=
+
+# set the working directory
+WORKDIR ${PYTHON_WORKDIR}
+
+# away we go
+ENTRYPOINT ["/docker-entrypoint.sh"]
+CMD ["/usr/local/bin/python", "./app.py"]
+
+# EOF

.templates/python/app/app.py

@@ -0,0 +1,8 @@
+import time
+
+print("The world is born. Hello World.", flush=True)
+
+while True:
+
+   time.sleep(10)
+   print("The world is re-born. Hello World.", flush=True)

.templates/python/app/requirements.txt

@@ -0,0 +1,21 @@
+#!/bin/bash
+set -e
+
+# does the working directory exist (something is badly wrong if it does not)
+if [ -d "$PYTHON_WORKDIR" ] ; then
+
+   # are self-healing defaults available?
+   if [ -d "$PYTHON_DEFAULTS" ] ; then
+
+      # yes! replace anything that has gone missing
+      cp -an "$PYTHON_DEFAULTS"/* "$PYTHON_WORKDIR"
+
+   fi
+
+   # set appropriate ownership throughout
+   chown -R "$IOTSTACK_UID:$IOTSTACK_GID" "$PYTHON_WORKDIR"
+
+fi
+
+# start python
+exec "$@"

.templates/python/directoryfix.sh

@@ -2,6 +2,11 @@
     container_name: python
     build: ./services/python/.
     restart: unless-stopped
-    network_mode: host
+    environment:
+      - TZ=Etc/UTC
+      - IOTSTACK_UID=1000
+      - IOTSTACK_GID=1000
+  # ports:
+  #   - "external:internal"
     volumes:
       - ./volumes/python/app:/usr/src/app

.templates/python/docker-entrypoint.sh

@@ -1,51 +1,5 @@
 # Python
-* [Docker hub](https://hub.docker.com/_/python)
 
-## Running python code in docker
+This is "old menu" documentation.
 
-In order to run code in docker the container needs to be build from a Dockerfile. There are 2 key files in the service directory
-
-### services/python/requirements.txt
-
-Normally on your system you would install modules with pip and they would be available system wide. The container that comes off Docker hub is blank and we will have to install them and bake them into the container. Before your first run add the modules that you require to the requirements.txt, each on a new line
-
-```
-flask
-bs4
-```
-**IMPORTANT**: Every time you alter the requirements file you will need to rebuild the container and bake in the new modules
-
-To build the container run `docker-compose build python`. 
-
-### services/python/service.yml
-
-This is the template that gets concatenated into docker-compose.yml and there are a few things to note here
-
-```yml
-  python:
-    container_name: python
-    build: ./services/python/.
-    restart: unless-stopped
-    network_mode: host
-    volumes:
-      - ./volumes/python/app:/usr/src/app
-```
-
-The container runs in host network mode. This is because i have no idea which ports you want to use. The implication of this is you will not be able to connect by name to the other container and therefore if you want to connect to the mqtt service or influx you will need to use `localhost` or `127.0.0.1` because the python container "thinks" from network perspective that it is the Pi
-
-The container is set to restart unless stopped. Therefore if you write an application it will effectively execute in an endless loop. If you only want a run once method then you will need to comment out the "restart" section in the docker-compose.yml file and the service.yml
-
-## Where to put your code
-
-You will need to copy your code to `IOTstack/volumes/python/app`. The container is set to execute `app.py` as the main file.
-
-### writing to the console
-
-If you execute a print statement the text will appear in the console of the container. The output can be accessed by running `docker logs python`
-
-### writing to disk
-Inside the container the working directory is `/usr/src/app` as mapped in the volume command. It would be advised to read or write any data from this directory.
-
-## Image clutter
-
-Doing multiple builds of the python image will create many unused images. These can be cleaned up inside portainer or by running `./scripts/prune-images.sh`
+Please see [New Menu documentation](https://sensorsiot.github.io/IOTstack/Containers/Python/).