Follow-up for the FUSE PoC: integrate with make check-NIT prepared sandboxes

scripts/fuse/README.adoc

@@ -26,18 +26,43 @@ to rebuild and restart a daemon).
 
 Installation:
 
+* Get pre-requisites to build FUSE clients, e.g. `apt install libfuse-dev`
+  on Debian-like systems, or `brew install --cask macfuse@dev` on MacOS with
+  Homebrew community packaging.
+* Download and build the `execfuse` daemon:
 ----
 :; git clone https://github.com/vi/execfuse
 :; cd execfuse
-:; make
+:; make && ls -la execfuse
 ----
 
 That's about it, an `execfuse` binary should appear.
 
-To run with the PoC scripts here, assuming a built NUT in `~/nut` location:
+NOTE: Examples below assume a built NUT in `~/nut` location, and a temporary
+mount point in `/tmp/nut-fuse`.
 
+You can also prepare an enviroment using NUT Integration Tests (NIT) scripts:
 ----
-:; mkdir /tmp/nut-fuse
+:; ( cd ~/nut && DEBUG_SLEEP=600 make check-NIT ) &
+
+# ...wait a few seconds for it to say the sandbox is ready
+:; . "${HOME}/nut/tests/NIT/tmp/etc/NIT.env"
+----
+
+Before mounting the FUSE file system, you can also request to debug the PoC
+scripts:
+----
+:; NUT_DEBUG_FUSE=true
+:; export NUT_DEBUG_FUSE
+
+# After running some queries, so the log-files to watch appear:
+:; tail -F /tmp/nut-debug-fuse-*.log &
+----
+
+To run with the PoC scripts here:
+
+----
+:; mkdir -p /tmp/nut-fuse
 :; PATH="$HOME/nut/clients:$PATH" \
    ./execfuse "$HOME/nut/scripts/fuse/execfuse-nut" /tmp/nut-fuse
 ----
@@ -76,17 +101,23 @@ total 23
 drwxr-xr-x  16 root root  4096 Jan  1  1970 .
 drwxrwxrwt 154 root root 20480 Aug 13 23:55 ..
 drwxr-xr-x  16 root root  4096 Jan  1  1970 by-server
+-r--r--r--   1 root root     0 Jan  1  1970 client-location
 -r--r--r--   1 root root     0 Jan  1  1970 client-version
 
-:; cat /tmp/nut-fuse/client-version
+:; cat /tmp/nut-fuse/client-location
 /home/abuild/nut/clients/upsc
+
+:; cat /tmp/nut-fuse/client-version
 Network UPS Tools upsc 2.8.2.901.2-903-g533aa7eaf (development iteration after 2.8.2)
 ----
 
 Eventually, to stop this experiment:
 
 ----
 :; fusermount -u /tmp/nut-fuse
+
+# Or if user-land programs are missing, like in "macfuse@dev", just `umount`:
+:; umount /tmp/nut-fuse
 ----
 
 As far as a PoC goes, this is already a fun and quickly achieved result,

scripts/fuse/execfuse-nut/getattr

@@ -32,7 +32,7 @@ case "$1" in
         # UPSSRV
         D="`basename "$1"`"
         ;;
-    /client-version)
+    /client-location|/client-version)
         F="$1"
         ;;
     *)

scripts/fuse/execfuse-nut/read_file

@@ -26,12 +26,15 @@ case "$1" in
         upsc "$UPS" "$VARNAME"
         exit $?
         ;;
+    /client-location)
+        command -v upsc
+        exit $?
+        ;;
     /client-version)
         if [ x"$NUT_DEBUG_FUSE" = xtrue ] ; then
             #echo "+upsc '$UPS' '$VARNAME'" >&2
             set -x
         fi
-        command -v upsc
         NUT_DEBUG_LEVEL=6 upsc -V
         exit $?
         ;;

scripts/fuse/execfuse-nut/readdir

@@ -31,13 +31,18 @@ case "$1" in
         for D in "by-server" ; do
             printf 'ino=1 mode=drwxr-xr-x nlink=4 uid=0 gid=0 rdev=0 size=4096 blksize=512 blocks=2 atime=0 mtime=0 ctime=0 %s\0' "$D"
         done
-        for F in "client-version" ; do
+        for F in "client-location" "client-version" ; do
             printf 'ino=1 mode=-r--r--r-- nlink=1 uid=0 gid=0 rdev=0 size=4096 blksize=512 blocks=2 atime=0 mtime=0 ctime=0 %s\0' "$F"
         done
         ;;
     /by-server)
         print_dots
-        printf 'ino=1 mode=drwxr-xr-x nlink=16 uid=0 gid=0 rdev=0 size=16 blksize=512 blocks=1 atime=0 mtime=0 ctime=0 %s\0' "localhost:3493"
+        printf 'ino=1 mode=drwxr-xr-x nlink=16 uid=0 gid=0 rdev=0 size=16 blksize=512 blocks=1 atime=0 mtime=0 ctime=0 %s\0' "localhost"
+        # Primarily this is a value arranged by `make check-NIT`:
+        set -x
+        if [ -n "${NUT_PORT-}" ] && [ x"${NUT_PORT}" != x3493 ]; then
+            printf 'ino=1 mode=drwxr-xr-x nlink=16 uid=0 gid=0 rdev=0 size=16 blksize=512 blocks=1 atime=0 mtime=0 ctime=0 %s\0' "localhost:${NUT_PORT}"
+        fi
         ;;
     /by-server/*/*/*) # Don't want subdirs here
         exit 2 # ENOENT