Allow custom config-path default with ./configure --with-configdir.

Add --with-confdir=DIR option to configure, which can be used to override the default configuration directory of /etc/pgbackrest.

Probably in the future it would be better to just leverage ${sysconfdir} which is based on prefix, but since previously the config directory was hard coded to /etc/pgbackrest, we retain that default value by not relying on sysconfdir for now.

doc/xml/release.xml

@@ -36,6 +36,17 @@
                     </release-item>
                 </release-bug-list>
 
+                <release-improvement-list>
+                    <release-item>
+                        <release-item-contributor-list>
+                            <release-item-contributor id="michael.schout"/>
+                            <release-item-reviewer id="david.steele"/>
+                        </release-item-contributor-list>
+
+                        <p>Allow custom <setting>config-path</setting> default with <id>./configure --with-configdir</id>.</p>
+                    </release-item>
+                </release-improvement-list>
+
                 <release-development-list>
                     <release-item>
                         <commit subject="Enhance expire command multi-repo support."/>
@@ -9490,6 +9501,11 @@
             <contributor-id type="github">terrorobe</contributor-id>
         </contributor>
 
+        <contributor id="michael.schout">
+            <contributor-name-display>Michael Schout</contributor-name-display>
+            <contributor-id type="github">mschout</contributor-id>
+        </contributor>
+
         <contributor id="michael.vitale">
             <contributor-name-display>Michael Vitale</contributor-name-display>
             <contributor-id type="github">MichaelDBA</contributor-id>

src/build/configure.ac

@@ -152,7 +152,10 @@ AC_CHECK_LIB(
 
 # Set configuration path
 # ----------------------------------------------------------------------------------------------------------------------------------
-AC_DEFINE_UNQUOTED([CFGOPTDEF_CONFIG_PATH], ["/etc/" PROJECT_BIN], [Path for configuration files])
+AC_ARG_WITH(
+    [configdir], [AS_HELP_STRING([--with-configdir=DIR], [default configuration path])],
+    [AC_DEFINE_UNQUOTED([CFGOPTDEF_CONFIG_PATH], ["${withval}"])],
+    [AC_DEFINE_UNQUOTED([CFGOPTDEF_CONFIG_PATH], ["/etc/" PROJECT_BIN])])
 
 # Write output
 # ----------------------------------------------------------------------------------------------------------------------------------

src/configure

@@ -688,6 +688,7 @@ ac_user_opts='
 enable_option_checking
 enable_test
 enable_optimize
+with_configdir
 '
       ac_precious_vars='build_alias
 host_alias
@@ -1309,6 +1310,11 @@ Optional Features:
                           debugging
   --disable-optimize      disable compiler optimizations
 
+Optional Packages:
+  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
+  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
+  --with-configdir=DIR    default configuration path
+
 Some influential environment variables:
   CC          C compiler command
   CFLAGS      C compiler flags
@@ -4311,10 +4317,19 @@ fi
 # Set configuration path
 # ----------------------------------------------------------------------------------------------------------------------------------
 
-cat >>confdefs.h <<_ACEOF
+# Check whether --with-configdir was given.
+if test "${with_configdir+set}" = set; then :
+  withval=$with_configdir; cat >>confdefs.h <<_ACEOF
+#define CFGOPTDEF_CONFIG_PATH "${withval}"
+_ACEOF
+
+else
+  cat >>confdefs.h <<_ACEOF
 #define CFGOPTDEF_CONFIG_PATH "/etc/" PROJECT_BIN
 _ACEOF
 
+fi
+
 
 # Write output
 # ----------------------------------------------------------------------------------------------------------------------------------
@@ -5594,4 +5609,4 @@ if test -n "$ac_unrecognized_opts" && test "$enable_option_checking" != no; then
 $as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
 fi
 
-# Generated from src/build/configure.ac sha1 af35157cc6b32faa6d20e46790a4ea22bd24ed3c
+# Generated from src/build/configure.ac sha1 ec5b8676addeca8533091a1cc8a3d12005667a6d