Allow LaMachine to build against a custom Python 3, by setting python…

…_bin and pip_bin (building the custom Python is not included in LaMachine) #159

bootstrap.sh

@@ -1293,6 +1293,8 @@ if [ $NOSYSUPDATE -ne 0 ]; then
     echo "nosysupdate: $NOSYSUPDATE #Skips updating the global packages provided by the distribution" >> $STAGEDCONFIG
 fi
     if [[ $FLAVOUR == "local" ]] || [[ "$OS" == "mac" ]]; then
+        echo "python_bin: python3 #The Python interpreter to use to set up the virtual environment, may be an absolute path" >> $STAGEDCONFIG
+        echo "pip_bin: pip3 #The pip tool belonging to the above interpreter, may be an absolute path" >> $STAGEDCONFIG
         echo "web_user: \"$USERNAME\"" >> $STAGEDCONFIG
         echo "web_group: \"$GROUP\"" >> $STAGEDCONFIG
     else

roles/lamachine-core/defaults/main.yml

@@ -10,6 +10,8 @@ global_prefix: "/usr/local" #where global packages are installed
 data_path: "/data"
 locality: "global" #Install everything globally
 localenv_type: "virtualenv" #Local environment type, can be conda or virtualenv
+python_bin: "python3" #path to the global python3 interpreter, may be an absolute path
+pip_bin: "pip3" #must correspond to the one belonging to the above python interpreter
 webserver: false
 webservertype: "nginx"
 unix_group: "{{unix_user}}"

roles/lamachine-core/tasks/main.yml

@@ -461,7 +461,7 @@
           when: ansible_distribution|lower == "centos" or ansible_distribution|lower == "rhel"
 
         - block:
-            - name: Obtaining Python version
+            - name: Obtaining local environment's Python version
               shell: python3 -c 'import sys; print(".".join(map(str, sys.version_info[:2])))'
               register: python_version
               environment: "{{lm_env}}"
@@ -488,7 +488,9 @@
         - name: Obtaining global Python version
           shell: |
                  #!/bin/bash
-                 [[ -f /usr/bin/python3 ]] && /usr/bin/python3 -c 'import sys; print(".".join(map(str, sys.version_info[:2])))'
+                 if which "{{ python_bin }}"; then
+                  {{python_bin}} -c 'import sys; print(".".join(map(str, sys.version_info[:2])))'
+                 fi
           args:
             executable: /bin/bash
           register: global_python_version
@@ -558,21 +560,21 @@
         - name: Upgrade pip #we need at least pip10, this is not always the case in distro-supplied packages
           become: "{{lm_become}}"
           become_user: root
-          shell: pip3 install --upgrade pip {% if locality == 'global' %}--prefix "{{ lm_prefix }}"{% endif %}
+          shell: pip install --upgrade pip {% if locality == 'global' %}--prefix "{{ lm_prefix }}"{% endif %}
           environment: "{{lm_env}}"
           tags: fullrunonly
 
         - name: "Finding global pip3"
-          shell: hash -r pip3 && which pip3
+          shell: hash -r {{pip_bin}} && which {{pip_bin}}
           register: pip
           environment: "{{lm_env}}"
           when: locality == "global"
 
         - name: "Testing global pip3"
           shell: |
             #!/bin/bash
-            python3 -c "import pip; print(pip.__path__[0])"
-            pip3 list
+            {{python_bin}} -c "import pip; print(pip.__path__[0])"
+            {{pip_bin}} list
           environment: "{{lm_env}}"
           args:
             executable: /bin/bash

roles/lamachine-core/tasks/virtualenv.yml

@@ -9,7 +9,7 @@
     - when: virtualenv.stat.isdir is not defined or not virtualenv.stat.isdir
       block:
            - name: Creating bare virtualenv environment for LaMachine
-             shell: "virtualenv --python=python3 {{ local_prefix }}"
+             shell: "virtualenv --always-copy --python={{ python_bin }} {{ local_prefix }}"
 
     - name: Adapting activation script for virtualenv
       blockinfile: