A virtual FS using Go and Fuse native binding.
Execute configurable commands that define the content of files or patterns of filenames on read calls.
Have a virtual readonly filesystem defined by a config file and generate file contents on each read access by running configurable commands and returning their output as content.
create a config.conf file, the structure of the contents should look like this:
# set the title of the running triggerFS instance
title = "triggerfs"
# cache the filesize after executing command
size_cache = true
# run all exec commands from the file section to determine # the correct size before mounting. Requires size_cache=true
prebuild_cache = false
# add files matching patters to fs tree after they've been accessed once
update_tree = true
# directory definitions
dir {
# create a directory by defining a new section with the path as name.
# leading and trailing slashes will be cut at runtime, so they don't need to be given necessarily.
# attributes will be inherited by parent directories if not defined otherwise.
/foo/bar/ {
permission = "0775"
size = 4096
ctime = 1524234000
atime = 1524234000
mtime = 1524234000
}
}
# file definitions
file {
# create a file by defining a new section with the path to the file as name
# attributes will be inherited by parent directories if not defined otherwise
/testfile {
# set the fileattributes and the command that will define the content
# this string will be executed with /bin/sh -c '<exec>' each time the file is read
# %FILE% and %PATH% can be used as patterns that get replaced by the file name or full path
exec = "echo foobar"
# most programs are strict about the size given by getattr() and won't process larger contents.
# depending on the nature of the given exec command the global "size_cache" option might be of use.
# to get the correct size after running once. set size_cache = true at the top to enable it.
# in doubt, set the size higher than the expected size of the command output.
size = 50
# set the permission of the file
permission = "0644"
# supported time attributes: ctime,mtime,atime
ctime = 1524234000
mtime = 1524234000
}
}
# pattern definitions
pattern {
# create a filepattern by defining a new section with the path and the pattern as name.
# the basename of <name> will be used as pattern.
# attributes will be inherited by parent directories if not defined otherwise.
# here we create a pattern for all *.txt files
/testdir/.*.txt {
# this string will be executed with /bin/sh -c '<exec>' each time a file matching the pattern is read
# %FILE% and %PATH% can be used as patterns that get replaced by the file name or full path
exec = "echo %FILE%"
# set the permission of the file
permission = "0644"
# most programs are strict about the size given by getattr() and won't process larger contents.
# depending on the nature of the given exec command the global "size_cache" option might be of use.
# to get the correct size after running once. set size_cache = true at the top to enable it.
# in doubt, set the size higher than the expected size of the command output.
size = 100
# supported time attributes: ctime,mtime,atime
ctime = 1524234000
mtime = 1524234000
atime = 1524234000 }
}
You can use %FILE% or %PATH% in your exec command wich will get replaced with the filename or the full path.
go get
go build
mkdir mountpoint
./triggerfs -c config.conf mountpoint/ ls mountpoint
cat mountpoint/testfile
fusermount -u mountpoint