» Command: fs

The fs command allows a user to navigate an allocation directory on a Nomad client. The following functionalities are available - cat, tail, ls and stat.

  • cat: If the target path is a file, Nomad will cat the file.
  • tail: If the target path is a file and -tail flag is specified, Nomad will tail the file.
  • ls: If the target path is a directory, Nomad displays the name of a file and directories and their associated information.
  • stat: If the -stat flag is used, Nomad will display information about a file.

» Usage 

nomad fs [options] <allocation> <path>

This command accepts a single allocation ID (unless the -job flag is specified, in which case an allocation is chosen from the given job) and a path. The path is relative to the root of the allocation directory. The path is optional and it defaults to / of the allocation directory.

» General Options

  • -address=<addr>: The address of the Nomad server. Overrides the NOMAD_ADDR environment variable if set. Defaults to http://127.0.0.1:4646.

  • -region=<region>: The region of the Nomad server to forward commands to. Overrides the NOMAD_REGION environment variable if set. Defaults to the Agent's local region.

  • -no-color: Disables colored command output.

  • -ca-cert=<path>: Path to a PEM encoded CA cert file to use to verify the Nomad server SSL certificate. Overrides the NOMAD_CACERT environment variable if set.

  • -ca-path=<path>: Path to a directory of PEM encoded CA cert files to verify the Nomad server SSL certificate. If both -ca-cert and -ca-path are specified, -ca-cert is used. Overrides the NOMAD_CAPATH environment variable if set.

  • -client-cert=<path>: Path to a PEM encoded client certificate for TLS authentication to the Nomad server. Must also specify -client-key. Overrides the NOMAD_CLIENT_CERT environment variable if set.

  • -client-key=<path>: Path to an unencrypted PEM encoded private key matching the client certificate from -client-cert. Overrides the NOMAD_CLIENT_KEY environment variable if set.

  • -tls-skip-verify: Do not verify TLS certificate. This is highly not recommended. Verification will also be skipped if NOMAD_SKIP_VERIFY is set.

» Fs Options

  • -H: Machine friendly output.

  • -verbose: Display verbose output.

  • -job: Use a random allocation from the specified job, preferring a running allocation.

  • -stat: Show stat information instead of displaying the file, or listing the directory.

  • -f: Causes the output to not stop when the end of the file is reached, but rather to wait for additional output.

  • -tail: Show the files contents with offsets relative to the end of the file. If no offset is given, -n is defaulted to 10.

  • -n: Sets the tail location in best-efforted number of lines relative to the end of the file.

  • -c: Sets the tail location in number of bytes relative to the end of the file.

» Examples 

$ nomad fs eb17e557
Mode        Size  Modified Time        Name
drwxrwxr-x  4096  28 Jan 16 05:39 UTC  alloc/
drwxrwxr-x  4096  28 Jan 16 05:39 UTC  redis/
-rw-rw-r--  0     28 Jan 16 05:39 UTC  redis_exit_status


$ nomad fs eb17e557 redis/local
Mode        Size  Modified Time        Name
-rw-rw-rw-  0     28 Jan 16 05:39 UTC  redis.stderr
-rw-rw-rw-  17    28 Jan 16 05:39 UTC  redis.stdout


$ nomad fs -stat eb17e557 redis/local/redis.stdout
Mode        Size  Modified Time        Name
-rw-rw-rw-  17    28 Jan 16 05:39 UTC  redis.stdout


$ nomad fs eb17e557 redis/local/redis.stdout
foobar
baz

$ nomad fs -tail -f -n 3 eb17e557 redis/local/redis.stdout
foobar
baz
bam
<blocking>

» Using Job ID instead of Allocation ID

Setting the -job flag causes a random allocation of the specified job to be selected. Nomad will prefer to select a running allocation ID for the job, but if no running allocations for the job are found, Nomad will use a dead allocation.

nomad fs -job <job-id> <path>

This can be useful for debugging a job that has multiple allocations, and it's not really required to use a specific allocation ID.