How do I specify the key file for sshfs?

Question

I looked at the sshfs --help and there's nothing mentioning a key file. I have multiple pub/priv key pairs (for different servers) on my computer and I want to specify which key to use. How would I do this?

  usage: sshfs [user@]host:[dir] mountpoint [options]

  general options:
  -o opt,[opt...]        mount options
  -h   --help            print help
  -V   --version         print version

  SSHFS options:
  -p PORT                equivalent to '-o port=PORT'
  -C                     equivalent to '-o compression=yes'
  -F ssh_configfile      specifies alternative ssh configuration file
  -1                     equivalent to '-o ssh_protocol=1'
  -o reconnect           reconnect to server
  -o delay_connect       delay connection to server
  -o sshfs_sync          synchronous writes
  -o no_readahead        synchronous reads (no speculative readahead)
  -o sshfs_debug         print some debugging information
  -o cache=BOOL          enable caching {yes,no} (default: yes)
  -o cache_timeout=N     sets timeout for caches in seconds (default: 20)
  -o cache_X_timeout=N   sets timeout for {stat,dir,link} cache
  -o workaround=LIST     colon separated list of workarounds
      none             no workarounds enabled
      all              all workarounds enabled
      [no]rename       fix renaming to existing file (default: off)
      [no]nodelaysrv   set nodelay tcp flag in sshd (default: off)
      [no]truncate     fix truncate for old servers (default: off)
      [no]buflimit     fix buffer fillup bug in server (default: on)
  -o idmap=TYPE          user/group ID mapping, possible types are:
      none             no translation of the ID space (default)
      user             only translate UID of connecting user
  -o ssh_command=CMD     execute CMD instead of 'ssh'
  -o ssh_protocol=N      ssh protocol to use (default: 2)
  -o sftp_server=SERV    path to sftp server or subsystem (default: sftp)
  -o directport=PORT     directly connect to PORT bypassing ssh
  -o transform_symlinks  transform absolute symlinks to relative
  -o follow_symlinks     follow symlinks on the server
  -o no_check_root       don't check for existence of 'dir' on server
  -o password_stdin      read password from stdin (only for pam_mount!)
  -o SSHOPT=VAL          ssh options (see man ssh_config)

  FUSE options:
  -d   -o debug          enable debug output (implies -f)
  -f                     foreground operation
  -s                     disable multi-threaded operation

  -o allow_other         allow access to other users
  -o allow_root          allow access to root
  -o nonempty            allow mounts over non-empty file/dir
  -o default_permissions enable permission checking by kernel
  -o fsname=NAME         set filesystem name
  -o subtype=NAME        set filesystem type
  -o large_read          issue large read requests (2.4 only)
  -o max_read=N          set maximum size of read requests

  -o hard_remove         immediate removal (don't hide files)
  -o use_ino             let filesystem set inode numbers
  -o readdir_ino         try to fill in d_ino in readdir
  -o direct_io           use direct I/O
  -o kernel_cache        cache files in kernel
  -o [no]auto_cache      enable caching based on modification times (off)
  -o umask=M             set file permissions (octal)
  -o uid=N               set file owner
  -o gid=N               set file group
  -o entry_timeout=T     cache timeout for names (1.0s)
  -o negative_timeout=T  cache timeout for deleted names (0.0s)
  -o attr_timeout=T      cache timeout for attributes (1.0s)
  -o ac_attr_timeout=T   auto cache timeout for attributes (attr_timeout)
  -o intr                allow requests to be interrupted
  -o intr_signal=NUM     signal to send on interrupt (10)
  -o modules=M1[:M2...]  names of modules to push onto filesystem stack

  -o max_write=N         set maximum size of write requests
  -o max_readahead=N     set maximum readahead
  -o async_read          perform reads asynchronously (default)
  -o sync_read           perform reads synchronously
  -o atomic_o_trunc      enable atomic open+truncate support
  -o big_writes          enable larger than 4kB writes
  -o no_remote_lock      disable remote file locking

  Module options:

  [subdir]
  -o subdir=DIR           prepend this directory to all paths (mandatory)
  -o [no]rellinks         transform absolute symlinks to relative

  [iconv]
  -o from_code=CHARSET   original encoding of file names (default: UTF-8)
  -o to_code=CHARSET      new encoding of the file names (default: UTF-8)

Answer 1

Notice this option:

-o SSHOPT=VAL ssh options (see man ssh_config)

And if you look at man ssh_config, there is an option to set the path to your private key file, called IdentityFile, so you can do this:

sshfs -oIdentityFile=/abs/path/to/id_rsa server: path/to/mnt/point

The path to the identity file must be an absolute path.