Put the password generator into a real .sh file

Use my-passwords.yml in sandbox.sh

util/install/generate-passwords.sh

+#!/usr/bin/env bash
+#
+# Read a list of Ansible variables that should have generated values, and make
+# a new file just like it, with the generated values.
+
+TARGET=${OPENEDX_RELEASE-master}
+wget -q "https://raw.githubusercontent.com/edx/configuration/$TARGET/playbooks/sample_vars/passwords.yml" -O passwords-template.yml
+
+while IFS= read -r line; do
+    # Make a random string. SECRET_KEY's should be longer.
+    length=35
+    if [[ $line == *SECRET_KEY* ]]; then
+        length=100
+    fi
+    REPLACE=$(LC_ALL=C < /dev/urandom tr -dc 'A-Za-z0-9' | head -c$length)
+    # Change "!!null"-to-end-of-line to the password.
+    echo "$line" | sed "s/\!\!null.*/\'$REPLACE\'/"
+done < passwords-template.yml > my-passwords.yml

util/install/sandbox.sh

@@ -66,6 +66,11 @@ for var in ${VERSION_VARS[@]}; do
   fi
 done
 
+# my-passwords.yml is the file made by generate-passwords.sh.
+if [[ -f my-passwords.yml ]]; then
+    EXTRA_VARS="-e@$(pwd)/my-passwords.yml $EXTRA_VARS"
+fi
+
 CONFIGURATION_VERSION=${CONFIGURATION_VERSION-${OPENEDX_RELEASE-master}}
 
 ##