Allow running multiple instances.

Address #3

.env-distr

@@ -20,3 +20,7 @@ WEBCAM_INPUT=input_raspicam.so -fps 5
 
 # USB Webcam in 16:9 example
 # WEBCAM_INPUT=input_uvc.so -d /dev/video0 -r 640x360 -fps 5
+
+# Listen to the following ports:
+# HTTP_PORT=80
+# HTTPS_PORT=443

.env-extra-distr

@@ -0,0 +1,23 @@
+# Sample file for driving an extra printer
+#
+# Copy this file to .env-<printer name> -- e.g. .env.extra
+# To start an additional instance run:
+#   docker-compose --project-name extra --env-file .env-extra up -d
+# or use the convenience script:
+#   docker-compose-multi.sh extra up -d
+
+# Architecture -- same as in your main .env file
+OP_MACHINE_NAME=raspberrypi3
+
+# Webcam configuration
+# Ensure you use only one Raspberry Pi Camera for all instances.
+# Supported configurations:
+#   - One Raspberry Pi Camera, One USB Camera
+#   - Two USB cameras
+# If you do not have a camera, set "WEBCAM_START=false"
+WEBCAM_START=false
+WEBCAM_INPUT=input_uvc.so -d /dev/video0 -r 640x480 -fps 5
+
+# Listen to the following ports -- Must be different for every instances!
+HTTP_PORT=8080
+HTTPS_PORT=8443

README.md

@@ -17,6 +17,7 @@
   - [Updates](#updates)
 - [First run](#first-run)
 - [Note about persistence](#note-about-persistence)
+- [Multiple printers](#multiple-printers)
 
 <!-- TOC END -->
 # Introduction
@@ -234,3 +235,64 @@ docker-compose up -d
 ```
 
 By doing this, you will loose any change made to the code, in particular if you installed plugins you will have to re-install them (but their configuration will be preserved).
+
+# Multiple printers
+
+Although driving multiple printers from the same Raspberry Pi is possible, it might lead to performance issues. 
+This setup is nevertheless easy to achieve with the _plain Docker_ setup.  
+It is a good solution if:
+
+- You have a powerful Raspberry Pi
+- You have multiple printers but use only one at a time
+
+You can run any number of instances of this _container stack_ by using a different _project name_ and a different `.env` file.  
+The `docker-compose-multi.sh` convenience script is provided to simplify operations.
+
+Assuming you already have a running instance, to add a new one simply copy the `.env-extra-distr` sample file to `.env-<printer name>`,
+review the configuration parameters and start the instance with `./docker-compose-multi.sh <printer name> up -d`.
+
+Main points of attention:
+
+- Do not configure more than one Raspberry Pi camera!  
+  (There is no limitation on the number of USB cameras)
+- Ensure all instances have their own unique HTTP and HTTPS ports.
+
+Sample session:
+
+```shell
+# Start the main instance
+$ docker-compose up -d
+Creating network "octoprint_default" with the default driver
+Creating octoprint_octoprint_1 ... done
+Creating octoprint_webcam_1    ... done
+Creating octoprint_haproxy_1   ... done
+$ docker-compose ps
+        Name                       Command               State                    Ports
+---------------------------------------------------------------------------------------------------------
+octoprint_haproxy_1     /usr/bin/entry.sh /opt/hap ...   Up      0.0.0.0:443->443/tcp, 0.0.0.0:80->80/tcp
+octoprint_octoprint_1   /usr/bin/entry.sh /opt/oct ...   Up      5000/tcp
+octoprint_webcam_1      /usr/bin/entry.sh /opt/web ...   Up      5200/tcp, 8080/tcp
+
+# Start an additional instance for the "extra" printer:
+$ cp .env-extra-distr .env-extra
+$ vi .env-extra
+$ ./docker-compose-multi.sh extra up -d
+Creating network "extra_default" with the default driver
+Creating volume "extra_octoprint_vol" with default driver
+Creating extra_webcam_1    ... done
+Creating extra_octoprint_1 ... done
+Creating extra_haproxy_1   ... done
+$ ./docker-compose-multi.sh extra ps
+      Name                     Command               State                      Ports
+--------------------------------------------------------------------------------------------------------
+extra_haproxy_1     /usr/bin/entry.sh /opt/hap ...   Up      0.0.0.0:8443->443/tcp, 0.0.0.0:8080->80/tcp
+extra_octoprint_1   /usr/bin/entry.sh /opt/oct ...   Up      5000/tcp
+extra_webcam_1      /usr/bin/entry.sh /opt/web ...   Up      5200/tcp, 8080/tcp
+```
+
+Notes:
+
+- As you can see in the above output, instances use a different network namespace as well as a different volume for storing data,
+  so they are completely separated and independent.
+- Depending on when your printers / cameras are detected they might get different device names on your Raspberry Pi...
+  Always check that you are driving the right printer!

docker-compose-multi.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+# Wrapper to docker-compose for multiple environemnts
+
+if [[ $# -lt 1 ]]; then
+    echo "Usage: $0 <env> <docker-compose args>" >&2
+    exit 1
+fi
+
+environ="$1"
+shift
+env_file=".env-${environ}"
+
+if [[ ! -f "${env_file}" ]]; then
+    echo "$0: environment file ${env_file} does not exist" >&2
+    exit 1
+fi
+
+docker-compose --project-name "${environ}" --env-file "${env_file}" "$@"

docker-compose.yml

@@ -4,7 +4,7 @@
 version: '2.1'
 
 volumes:
-  octoprint_vol: {}
+  octoprint_vol:
 
 services:
   # Octoprint itself
@@ -49,5 +49,5 @@ services:
     volumes:
       - octoprint_vol:/opt/haproxy/data
     ports:
-      - "80:80"
-      - "443:443"
+      - "${HTTP_PORT:-80}:80"
+      - "${HTTPS_PORT:-443}:443"

webcam/Dockerfile.template

@@ -5,16 +5,16 @@ FROM balenalib/${OP_MACHINE_NAME:-%%RESIN_MACHINE_NAME%%}-debian:buster
 
 RUN apt-get update && \
     apt-get install python3 python3-flask git build-essential subversion \
-	    libjpeg62-turbo-dev imagemagick ffmpeg libv4l-dev cmake \
+            libjpeg62-turbo-dev imagemagick ffmpeg libv4l-dev cmake \
             libraspberrypi-dev && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/*
 
 WORKDIR /opt/webcam
 
 RUN git clone https://github.com/jacksonliam/mjpg-streamer.git /opt/webcam/mjpg-streamer && \
-	cd mjpg-streamer/mjpg-streamer-experimental && \
-	LD_LIBRARY_PATH=. make
+    cd mjpg-streamer/mjpg-streamer-experimental && \
+    LD_LIBRARY_PATH=. make
 
 COPY run.py run.py