Make Sage relocatable

binary_pkg/templates/relocate-once.py

@@ -1,10 +1,12 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 """
 Rewrite Paths
 
-This script can be used exactly once to move the directory to a
-different location.
+This script replaces incidences of the root path installed by buildbot with the
+path to a symlink which points to the root of this installation.  The installation
+is identified by a uuid created in this script, which runs only once because it
+deletes itself upon successful completion.
 """
 
 from __future__ import (absolute_import, division, print_function,
@@ -13,21 +15,23 @@
 import os
 import getopt
 import sys
+import uuid
 
+buildbot_path = "{{search_string}}"
 
 def usage():
-    print("relocate-once.py -d <destination>")
-    
+    print("relocate-once.py -d<destination>")
+
 
 try:
     opts, args = getopt.getopt(sys.argv[1:], "hd:", ["help", "destination="])
 except getopt.GetoptError:
     usage()
     sys.exit(2)
 
-    
-ROOT_PATH = DESTINATION = os.path.abspath(os.path.dirname(__file__))
-    
+ROOT_PATH = os.path.abspath(os.path.dirname(__file__))
+DESTINATION = ""
+
 for opt, arg in opts:
     if opt in ('-h', '--help'):
         usage()
@@ -38,14 +42,60 @@ def usage():
 
 {% include 'patch.py' %}
 
+if not DESTINATION:
+    print("""
+This appears to be a brand new Sage installation. Some configuration is needed
+before it can be used.
+""")
+    # Generate an identifier for this Sage installation.
+    install_uuid = uuid.uuid4().hex
+    if os.geteuid() == 0:
+        # Always make the installation public if Sage is being installed by root.
+        DESTINATION = '/var/tmp/sage-%s'%install_uuid
+    else:
+        print("""
+Normally Sage is installed for use by all users. In that case an administrator
+password is needed to complete the configuration process. If you are not an
+administrator for this system you may install a private version of Sage.
+""")
+        answer = None
+        print("Would you like to create a private Sage installation?")
+        try:
+            while answer not in ("yes", "no"):
+                answer = input("Please answer yes or no (or ^C to exit): ")
+        except KeyboardInterrupt:
+            sys.exit(3)
+        if answer == "yes":
+            print("Creating a private Sage installation for %s."%os.environ["USER"])
+            home = os.getenv("HOME")
+            if not home or not os.path.exists(home):
+                print("No home directory!  Private installation is not possible.")
+                sys.exit(1)
+            dot_sage = os.path.join(home, '.sage')
+            if not os.path.exists(dot_sage):
+                os.mkdir(dot_sage, mode=0o700)
+            locations = os.path.join(home, '.sage', 'locations')
+            os.mkdir(locations, mode=0o755)
+            DESTINATION = os.path.join(locations, install_uuid)
+        else:
+            DESTINATION = '/var/tmp/sage-%s'%install_uuid
+    # Save the installation-specific symlink in a bash script which
+    # can be sourced by the sage startup script.
+    script_path = os.path.join(ROOT_PATH, "runpath.sh")
+    with open(script_path, "w") as script:
+        script.write('SAGE_SYMLINK="%s"\n'%DESTINATION)
+    os.chmod(script_path, 0o755)
+    # Create the symlink.
+    os.symlink(ROOT_PATH, DESTINATION)
+
 print("""
-Rewriting paths for your new installation directory
-===================================================
+Configuring your new Sage installation
+======================================
 
 This might take a few minutes but only has to be done once.
 """)
-        
-p = SearchAndReplace(ROOT_PATH, '{{search_string}}', DESTINATION)
+
+p = SearchAndReplace(ROOT_PATH, buildbot_path, DESTINATION)
 
 {% for filename, patches in patches.items() %}
     {% if isinstance(patches, SearchReplacePatch) %}
@@ -60,3 +110,9 @@ def usage():
 {% endfor %}
 
 os.remove(__file__)
+
+# If we are being run as root, exit with status 2 as a signal to the sage
+# script that it should exit, to avoid messing up the permissions on the
+# user's .sage directory.
+if os.geteuid() == 0:
+    sys.exit(2)

relocate-sage.patch

@@ -0,0 +1,75 @@
+diff --git a/sage b/sage
+index 3fad670c83..871c02cca7 100755
+--- a/sage
++++ b/sage
+@@ -124,16 +124,46 @@ fi
+
+ export SAGE_ROOT
+
+-# If this is a freshly-unpacked binary tarball then run the installer
++# If this is a freshly-unpacked binary tarball then run the installer.
++# For multi-user installations this must be done by a superuser, since
++# it will create the symlink for this Sage installation.
+ # Note: relocate-once.py deletes itself upon successful completion
+ if [ -x "$SAGE_ROOT/relocate-once.py" ]; then
+     "$SAGE_ROOT/relocate-once.py"
++    if [ $? -eq 3 ]; then
++        echo >&2 "\nAborted."
++        exit 1
++    fi
++    if [ $? -eq 2 ]; then
++        echo >&2 "You may now restart sage as a normal user."
++        exit 0
++    fi
+     if [ $? -ne 0 ]; then
+         echo >&2 "Error running the script 'relocate-once.py'."
+         exit 1
+     fi
+ fi
+
++# Check that the installation-specific symlink points to this sage
++# root directory and reset it if necessessary.  If the symlink is
++# in /var/tmp then it must be owned by root, so we use sudo
++# to reset it.
++. "$SAGE_ROOT"/runpath.sh
++OLD_ROOT=`readlink $SAGE_SYMLINK`
++if [ "$SAGE_ROOT" != "$OLD_ROOT" ]; then
++    echo "This sage installation has been moved!"
++    echo old location: $OLD_ROOT
++    echo new location: $SAGE_ROOT
++    echo "Reconfiguring Sage for its new home ..."
++    if [ "$(dirname "$SAGE_SYMLINK")" == "/var/tmp" ]; then
++        sudo -p "Please enter your admin password: " rm -f $SAGE_SYMLINK
++        sudo ln -s "$SAGE_ROOT" "$SAGE_SYMLINK"
++    else
++        rm -f $SAGE_SYMLINK
++        ln -s "$SAGE_ROOT" "$SAGE_SYMLINK"
++    fi
++fi
++
+ # Run the actual Sage script
+ if [ -x "$SAGE_ROOT/src/bin/sage" ]; then
+     exec "$SAGE_ROOT/src/bin/sage" "$@"
+diff --git a/src/bin/sage-env b/src/bin/sage-env
+index 1f02564f5c..6ac935ce25 100644
+--- a/src/bin/sage-env
++++ b/src/bin/sage-env
+@@ -138,12 +138,14 @@ NEW_SAGE_ROOT=`cd "$NEW_SAGE_ROOT" && pwd -P`
+
+ # Warn if NEW_SAGE_ROOT does not equal the old SAGE_ROOT
+ if [ "$SAGE_ROOT" != "$NEW_SAGE_ROOT" -a -n "$SAGE_ROOT" ]; then
+-    echo >&2 "Warning: overwriting SAGE_ROOT environment variable:"
+-    echo >&2 "Old SAGE_ROOT=$SAGE_ROOT"
+-    echo >&2 "New SAGE_ROOT=$NEW_SAGE_ROOT"
++    # But don't warn if we are just dereferencing the symlink
++    if ! [[ -L "$SAGE_ROOT" ]]; then
++        echo >&2 "Warning: overwriting SAGE_ROOT environment variable:"
++        echo >&2 "Old SAGE_ROOT=$SAGE_ROOT"
++        echo >&2 "New SAGE_ROOT=$NEW_SAGE_ROOT"
++    fi
+ fi
+
+-
+ # Don't execute the commands more than once for the same version of
+ # sage-env.  Check this after checking the validity of SAGE_ROOT, but
+ # before modifying its value.