Doc for cchost (#7090)

Co-authored-by: Eddy Ashton <[email protected]>

Author: achamayou

doc/operations/cli.rst

@@ -0,0 +1,28 @@
+Command-Line Interface
+======================
+
+The cchost executable exposes the following command-line interface (CLI) options:
+
+.. code-block:: bash
+
+    $ cchost --help
+
+        CCF Host launcher. Runs a single CCF node, based on the given configuration file.
+        Some parameters are marked "(security critical)" - these must be passed on the CLI rather than within a configuration file, so that (on relevant platforms) their value is captured in an attestation even if the configuration file itself is unattested.
+
+        Usage: ./cchost [OPTIONS]
+
+        Options:
+        -h,--help                   Print this help message and exit
+        -c,--config TEXT REQUIRED   Path to JSON configuration file
+        --config-timeout TEXT       Configuration file read timeout, for example 5s or 1min
+        --check                     Verify configuration file and exit
+        -v,--version                Display CCF host version and exit
+        --enclave-log-level ENUM:value in {debug->1,fail->3,fatal->4,info->2,trace->0} OR {1,3,4,2,0}
+                                    Logging level for the enclave code (security critical)
+        --enclave-file TEXT         Path to enclave application (security critical)
+
+Note that the ``--enclave-file`` and ``--enclave-log-level`` options are security critical.
+They must be passed on the command line rather than in a configuration file, so that their values are captured in an attestation even if the configuration file itself is not attested, for example because it is mounted from an external, un-attested, filesystem.
+
+The ``--config-timeout`` option specifies how long to wait for the configuration file to be available before giving up. This is useful when running CCF in a container, where the configuration file may not be immediately available.

doc/operations/index.rst

@@ -26,6 +26,13 @@ This section describes how :term:`Operators` manage the different nodes constitu
 
     ---
 
+    :fa:`laptop-code` :doc:`cli`
+    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+    Command-Line Interface for the `cchost` executable.
+
+    ---
+
     :fa:`upload` :doc:`ledger_snapshot`
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -100,6 +107,7 @@ This section describes how :term:`Operators` manage the different nodes constitu
     run_setup
     start_network
     configuration
+    cli
     ledger_snapshot
     data_persistence
     code_upgrade