diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6767ccd
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+Personal_notes.md
+README.html
+README_files
\ No newline at end of file
diff --git a/Dockerfile b/Dockerfile
index a5e81dd..ea88e54 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,12 +4,31 @@ WORKDIR /opt
 
 RUN apt-get update && apt-get install -y \
     python3-pip \
+    git \
+    ffmpeg \
+    cron \
+    moreutils \
+    bsdextrautils \
+    htop \
+    vim \
+    nano \
     && rm -rf /var/lib/apt/lists/*
 
-RUN pip3 install sigal
+RUN python3 -m pip install 'sigal @ git+https://github.com/saimn/sigal.git'
 
-COPY run.sh sigal.conf.py auth.conf auth.htpasswd ./
+RUN mkdir -p /themes
+RUN mkdir -p /config
+RUN mkdir -p /plugins/local_plugins
+RUN touch /plugins/local_plugins/__init__.py
 
-ENV LANG C.UTF-8
+COPY run.sh auth.conf auth.htpasswd ./
+
+ENV JPEG_QUALITY=90
+ENV LANG=C.UTF-8
+ENV PYTHONPATH="/themes:/plugins:/config"
+
+COPY build_sigal.sh /usr/local/bin/build_sigal
+RUN chmod +x /usr/local/bin/build_sigal
 
 CMD ["./run.sh"]
+
diff --git a/README.md b/README.md
index 6ba0fa0..8f20a33 100644
--- a/README.md
+++ b/README.md
@@ -1,33 +1,65 @@
-# docker-sigal
+# sigal Docker image
 
-Docker image based on nginx official one for [sigal](http://sigal.saimon.org/en/latest/) gallery.
+This project is a fork of the [remche/docker-sigal](https://github.com/remche/docker-sigal) project.
+The Docker image, based on nginx official one, includes the code for running a [sigal](http://sigal.saimon.org/en/latest/) gallery website.
 
-Run with :
+Default configuration use the galleria theme, keep original and put gallery in /usr/share/nginx/html. You can use a docker volume if you want it permanent
+## Exposed volumes
 
-    docker run -p 80:80 -v /path/to/your/pictures/:/pictures --name sigal-ct -d remche/docker-sigal
+- `/pictures` : Where your data files are stored.
+- `/config` : Where you can find and edit the configuration file
+- `/themes` : Where you can store external themes
+- `/plugins` : Where you can store external plugins
+- `/usr/share/nginx/html` : Where the generated HTML code is stored. 
+              Decalring it as a volume allows for making it permanent
 
+docker run command setting all these volumes
 
-Default configuration use the galleria theme, keep original and put gallery in /usr/share/nginx/html. You can use a docker volume if you want it permanent :
+```bash
+mkdir -p pictures config themes plugins html
 
-    docker run -p 80:80 -v /path/to/your/pictures/:/pictures -v sigal-html:/usr/share/nginx/html --name sigal-ct -d remche/docker-sigal
+docker run -p 8888:80 \
+    -v ./pictures:/pictures \
+    -v ./config:/config \
+    -v ./themes:/themes \
+    -v ./plugins:/plugins \
+    -v ./html:/usr/share/nginx/html \
+    -n sigal-server \
+    -d zafacs/sigal
+```
 
-    
-If you want to override this conf, you can use your own sigal.conf.py :
+## Environment variables
 
-    docker run -p 80:80 -v /path/to/your/pictures/:/pictures -v/path/to/your/sigal.conf.py:/opt/sigal.conf.py --name sigal-ct -d remche/docker-sigal
+- `JPEG_QUALITY`: set the default quality for *JPEG* conversion.
+             Option to be added to the docker run command :
+- `HTPASSWD`: Allows for setting a basic authentication in `htpasswd`.
+              You might then use SSL with 
+              [nginx-proxy](https://hub.docker.com/r/jwilder/nginx-proxy/).
+- `CRONJOB`: Allows to define a `cron` task in the docker container that will
+             update the website. The value of the CRONJOB variable is a text
+             constituted of 5 items defining at witch time the update has to be done.
+             The syntax follows the [crontab syntax](https://tecadmin.net/crontab-in-linux-with-20-examples-of-cron-schedule/)
+    + `* * * * *` : The site is updated every minute.
+    + `10 * * * *` : The site is updated every hour at the $10^{th}$ minute.
+    + `*/15 * * * *` : The site is updated every 15 minutes.
+  
 
+```bash
+docker run -p 8888:80 \
+    -v ./pictures:/pictures \
+    -v ./config:/config \
+    -v ./themes:/themes \
+    -v ./plugins:/plugins \
+    -v ./html:/usr/share/nginx/html \
+    -n sigal-server \
+    -e JPEG_QUALITY=80 \
+    -e HTPASSWD='foo:$apr1$odHl5EJN$KbxMfo86Qdve2FH4owePn.' \
+    -e CRONJOB='*/15 * * * *' \
+    -d zafacs/sigal
+ ```
 
-You can set a basic authentication in htpasswd format by setting HTPASSWD env variable :
+You can use the following command to force the regeneration of gallery :
 
-    docker run -p 80:80 -v /path/to/your/pictures/:/pictures -e HTPASSWD='foo:$apr1$odHl5EJN$KbxMfo86Qdve2FH4owePn.' --name sigal-ct -d remche/docker-sigal
-
-
-You might then use SSL with [nginx-proxy](https://hub.docker.com/r/jwilder/nginx-proxy/).
-
-
-You can use the following command to regenerate gallery :
-
-    docker exec sigal-ct sigal build
-
-
-Using a cron or incron to run it is a good way to keep your gallery up to date.
+```bash
+docker exec sigal-ct  build_sigal
+```
diff --git a/build_sigal.sh b/build_sigal.sh
new file mode 100644
index 0000000..7ee7b4a
--- /dev/null
+++ b/build_sigal.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+cd /opt || exit
+
+rm -f ./sigal.conf.py 
+if [[ -f /config/sigal.conf.py ]] ; then
+   ln -s /config/sigal.conf.py sigal.conf.py 
+else
+    sigal init
+fi
+
+/usr/local/bin/sigal build 2>&1 \
+    | col -b \
+    | /usr/bin/ts '%Y/%m/%d %H:%M:%S [sigal build]:' \
+    | tee /proc/1/fd/1
diff --git a/run.sh b/run.sh
index 49c4612..02f52b5 100755
--- a/run.sh
+++ b/run.sh
@@ -1,11 +1,31 @@
 #!/bin/bash
 
-if [[ $HTPASSWD ]]
+if [[ -n "$HTPASSWD" ]]
   then
     cp auth.conf /etc/nginx/conf.d/default.conf
     envsubst < auth.htpasswd > /etc/nginx/auth.htpasswd
 fi
 
-sigal build
+if [[ ! -f /config/sigal.conf.py ]] ; then 
+sed -E 's@#? *source = .*$@source = "/pictures"@' \
+          "$(find /usr -name sigal.conf.py)"  | \
+          sed -E 's@#? *destination = .*$@destination = "/usr/share/nginx/html"@'| \
+          sed -E 's@#? *keep_orig = .*$@keep_orig = True@' | \
+          sed -E 's@#? *zip_gallery = .*$@zip_gallery = "archive.zip"@' | \
+          sed -E 's@#? *orig_link = .*$@orig_link = True@' | \
+          sed -E 's@quality: *[0-9]+ *,$@quality: '$JPEG_QUALITY',@'  \
+          > /config/sigal.conf.py
+fi
+ 
+build_sigal
+
+if [[ -n "$CRONJOB" ]]
+  then
+    ( echo "${CRONJOB} root /usr/local/bin/build_sigal 2>&1 > /dev/null" > /etc/cron.d/sigal \
+      && echo "Create sigal build crontab" ) 2>&1 | /usr/bin/ts '%Y/%m/%d %H:%M:%S [cronjob]:'
+
+    service cron start 2>&1 | /usr/bin/ts '%Y/%m/%d %H:%M:%S [cronjob]:'
+fi
+
 exec nginx -g "daemon off;"