preserve docker build cache on orchestra musician

produce docker build speedup

- git checkout produce docker cache invalidation, do it when needed
- use /opt/app PATH for the two containers
- use two different layers: one to do the pip requirements, the other
  for the rest of the sourcecode

docker/musician.Dockerfile

@@ -8,14 +8,16 @@ RUN apt update &&  apt-get install -y \
     python3-dev \
     python-is-python3
 
-WORKDIR /home
+WORKDIR /opt/musician
 
 RUN python3 -m pip install --upgrade pip
 RUN pip install wheel
 
-COPY django-musician .
+COPY django-musician/requirements.txt .
 RUN pip install -r requirements.txt
 
+COPY django-musician .
+
 COPY docker/musician.entrypoint.sh .
 ENTRYPOINT sh ./musician.entrypoint.sh
 

docker/orchestra.Dockerfile

@@ -3,12 +3,12 @@ FROM debian:bullseye-slim
 # based on https://github.com/glic3rinu/django-orchestra/blob/master/INSTALL.md
 # HOW TO RUN THIS
 #
-# 0. rsync -avhP root@109.69.8.140:/home/orchestra orchestra
+# 0. rsync -avhP root@109.69.8.140:/opt/orchestra orchestra
 # 1. copy this Dockerfile into a dir containing orchestra, like:
 #     $ ls
 #     Dockerfile  orchestra
 # 2. docker build -f orchestra .
-# 3. docker rm orchestra; docker run -v /Users/maymerichgubern/orchestra/orchestra/:/home/orchestra -p 8443:443 -p 8080:80 -it --name orchestra orchestra bash
+# 3. docker rm orchestra; docker run -v /Users/maymerichgubern/orchestra/orchestra/:/opt/orchestra -p 8443:443 -p 8080:80 -it --name orchestra orchestra bash
 # 4. sed -i "s/ALLOWED_HOSTS = .*/ALLOWED_HOSTS = ('orchestra.pangea.org', 'localhost')/" panel/settings.py
 # 5. service postgresql start; service uwsgi start; service nginx start
 # 6. goto https://localhost:8443/admin/
@@ -78,31 +78,32 @@ RUN apt clean && rm -rf /var/lib/apt/lists/*
 #     cracklib \
 #     lxml
 
+# this is to ensure django project is created on top of this working directory
+WORKDIR /opt/orchestra/
+
 # TODO maybe from here goes to docker entrypoint?
 # TODO assumes that the project already exists, and in some cases that would be interesting
-#COPY django-orchestra /home/orchestra
-COPY django-orchestra /home/orchestra
-
-# this is to ensure django project is created on top of this working directory
-WORKDIR /home/orchestra/
+COPY django-orchestra/requirements.txt .
 
 # TODO fix this better in the repo itself
 RUN pip3 install -r requirements.txt
 RUN pip3 install lxml==4.9.3
+
+COPY django-orchestra .
 #RUN sed -i 's/lxml==3.3.5/lxml==4.9.3/' requirements.txt
 # solves "No module named 'orchestra'"
 RUN pip install -e .
 
-RUN django-admin startproject panel --template=/home/orchestra/orchestra/conf/project_template/
+RUN django-admin startproject panel --template=/opt/orchestra/orchestra/conf/project_template/
 
 RUN adduser orchestra \
     && sudo adduser orchestra sudo \
     && su - orchestra
 
-ENV PATH=$PATH:/home/orchestra/django-orchestra/orchestra/bin
+ENV PATH=$PATH:/opt/orchestra/django-orchestra/orchestra/bin
 
-WORKDIR /home/orchestra/panel
-COPY docker/orchestra.migrate.exp /home/orchestra/panel
+WORKDIR /opt/orchestra/panel
+COPY docker/orchestra.migrate.exp /opt/orchestra/panel
 
 COPY docker/orchestra.entrypoint.sh .
 ENTRYPOINT sh ./orchestra.entrypoint.sh
@@ -114,10 +115,10 @@ ENTRYPOINT sh ./orchestra.entrypoint.sh
 # CMD ./manage.py runserver 0.0.0.0:9080
 # EXPOSE 9080:9080
 
-#RUN echo /home/orchestra/django-orchestra/ > /usr/local/lib/python3.9/dist-packages/orchestra.pth
+#RUN echo /opt/orchestra/django-orchestra/ > /usr/local/lib/python3.9/dist-packages/orchestra.pth
 
 # TODO move this to entrypoint, with fakedata
-#    && su postgres bash -c 'psql -f <(zcat /home/orchestra/orchestra_db_20230907.sql)' \
+#    && su postgres bash -c 'psql -f <(zcat /opt/orchestra/orchestra_db_20230907.sql)' \
 
 #RUN service postgresql start \
 #    && python3 manage.py setupnginx --user orchestra \

pull-repos.sh

@@ -8,22 +8,28 @@ set -x
 # clone or pull git repo
 _pull() {
         myurl="${1}"
+        expected_branch="${2}"
         mydir_raw="$(basename "${myurl}")"
         mydir="${mydir_raw%.git}"
-        mybranch="${2}"
 
         if [ -d "${mydir}" ]; then
                 cd "${mydir}"
-                git checkout "${mybranch}"
+                current_branch="$(git branch --show-current)"
+                # ensure we are in the right branch without invalidating docker build cache
+                #   yes, even without no branch switch and no new commits
+                if [ ! "${current_branch}" = "${expected_branch}" ]; then
+                        git checkout "${expected_branch}"
+                fi
                 git pull
                 cd -
         else
-                git clone -b "${mybranch}" "${myurl}" "${mydir}"
+                git clone -b "${expected_branch}" "${myurl}" "${mydir}"
         fi
 }
 
 
 main() {
+        figlet 'pull repositories'
         _pull 'https://gitea.pangea.org/pangea/django-orchestra' 'sso'
         _pull 'https://gitea.pangea.org/pangea/django-musician' 'sso'
         _pull 'git@gitea.pangea.org:trustchain-oc1-orchestral/IdHub.git' 'main'