TGTDIR is a convenience option for developers for building multipath-tools such
that compiled-in paths of the plugins, config files, etc. match an
installation under some optional path. See README.md for instructions and
examples.
Signed-off-by: Martin Wilck <mwilck@xxxxxxxx>
---
.github/actions/spelling/expect.txt | 2 ++
Makefile.inc | 8 +++----
README.md | 33 +++++++++++++++++++++++++++++
3 files changed, 39 insertions(+), 4 deletions(-)
diff --git a/.github/actions/spelling/expect.txt b/.github/actions/spelling/expect.txt
index 5906403..fc9f22f 100644
--- a/.github/actions/spelling/expect.txt
+++ b/.github/actions/spelling/expect.txt
@@ -167,6 +167,7 @@ retrigger
rhabarber
rootprefix
rootprefixdir
+rpmbuild
rport
rtpi
sas
@@ -200,6 +201,7 @@ tcp
TESTDEPS
testname
tgill
+TGTDIR
TIDS
tmo
tpg
diff --git a/Makefile.inc b/Makefile.inc
index 5668e63..81b86cd 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -101,9 +101,9 @@ WARNFLAGS := -Werror -Wall -Wextra -Wformat=2 $(WFORMATOVERFLOW) -Werror=implici
$(WNOCLOBBERED) -Werror=cast-qual $(ERROR_DISCARDED_QUALIFIERS) $(W_URCU_TYPE_LIMITS)
CPPFLAGS := $(FORTIFY_OPT) $(CPPFLAGS) $(D_URCU_VERSION) \
-D_FILE_OFFSET_BITS=64 \
- -DBIN_DIR=\"$(bindir)\" -DMULTIPATH_DIR=\"$(plugindir)\" \
- -DRUNTIME_DIR=\"$(runtimedir)\" -DCONFIG_DIR=\"$(configdir)\" \
- -DDEFAULT_CONFIGFILE=\"$(configfile)\" -DSTATE_DIR=\"$(statedir)\" \
+ -DBIN_DIR=\"$(bindir)\" -DMULTIPATH_DIR=\"$(TGTDIR)$(plugindir)\" \
+ -DRUNTIME_DIR=\"$(runtimedir)\" -DCONFIG_DIR=\"$(TGTDIR)$(configdir)\" \
+ -DDEFAULT_CONFIGFILE=\"$(TGTDIR)$(configfile)\" -DSTATE_DIR=\"$(TGTDIR)$(statedir)\" \
-DEXTRAVERSION=\"$(EXTRAVERSION)\" -MMD -MP
CFLAGS := -std=gnu99 $(CFLAGS) $(OPTFLAGS) $(WARNFLAGS) -pipe
BIN_CFLAGS := -fPIE -DPIE
@@ -149,4 +149,4 @@ NV_VERSION_SCRIPT = $(DEVLIB:%.so=%-nv.version)
%: %.in
@echo creating $@
- $(Q)sed 's:@CONFIGFILE@:'$(configfile)':g;s:@CONFIGDIR@:'$(configdir)':g;s:@STATE_DIR@:'$(statedir)':g;s:@RUNTIME_DIR@:'$(runtimedir)':g;s/@MODPROBE_UNIT@/'$(MODPROBE_UNIT)'/g;s:@BINDIR@:'$(bindir)':g' $< >$@
+ $(Q)sed 's:@CONFIGFILE@:'$(TGTDIR)$(configfile)':g;s:@CONFIGDIR@:'$(TGTDIR)$(configdir)':g;s:@STATE_DIR@:'$(TGTDIR)$(statedir)':g;s:@RUNTIME_DIR@:'$(runtimedir)':g;s/@MODPROBE_UNIT@/'$(MODPROBE_UNIT)'/g;s:@BINDIR@:'$(bindir)':g' $< >$@
diff --git a/README.md b/README.md
index d4f35f5..7207b14 100644
--- a/README.md
+++ b/README.md
@@ -151,6 +151,39 @@ sufficient control. See `Makefile.inc` for even more fine-grained control.
On such distributions, override `unitdir` and `libudevdir` to use systemd's
`rootprefix`: `make libudevdir=/lib/udev unitdir=/lib/systemd/system`
+### prefix, DESTDIR and TGTDIR
+
+`prefix` and related variables are included in compiled-in paths like
+`plugindir` and are used by `make install`. Using `prefix` is useful if
+multipath-tools is built locally on the same host where it's supposed to be
+installed.
+
+By convention, the `DESTDIR` variable is prepended to all paths by `make
+install`, but not to any compiled-in paths.
+It is useful if the software is built on one system (build host) but intended
+to be run on another system (installation host). This is typically used in build
+systems like *rpmbuild* to set a root directory for all the installed
+files.
+
+On the contrary, the `TGTDIR` variable is used for compiled-in paths only, and
+ignored by `make install`. It is useful for running multipath-tools in a separate
+subdirectory in the installation host, mostly for testing / development
+purposes.
+
+For example,
+
+ make prefix=/opt DESTDIR=/build TGTDIR=/test install
+
+will install plugins into `/build/opt/lib64/multipath` on the build
+host. On the installation host, the plugins will be expected to be found under
+`/test/opt/lib64/multipath`. If the developer runs
+
+ rsync -a $BUILD_HOST:$DESTDIR/ $INSTALL_HOST:$TGTDIR/
+
+and adds `$TGTDIR/lib64` to `LD_LIBRARY_PATH` on the installation host, the
+multipath binaries installed under `$TGTDIR` will find their plugins and
+configuration files in the expected compiled-in paths.
+
### Compiler Options
Use `OPTFLAGS` to change optimization-related compiler options;
--
2.44.0
