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#
# ovs-ctl.py
#
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ovs-ctl manages the initialization and execution of OVS instances as targets
for OFTest execution. 


-------------------------------------------------------------------------------
INSTALLATION
-------------------------------------------------------------------------------

ovs-ctl requires OVS be built and installed on your local machine. 
If you are new to OVS, the preferred method is:

1. Download openvswitch-X.Y.Z from http://openvswitch.org/releases
2. Untar, configure, build, and install openvswitch into a useful location:

   # All OVS installations will go in to /opt/ovs:
   > mkdir -p /opt/ovs
   
   # All OVS Source distributions will live in /opt/ovs/src:
   > mkdir -p /opt/ovs/src

   # Download and untar source for openvswitch 1.4.0:
   > curl http://openvswitch.org/releases/openvswitch-1.4.0.tar.gz | tar -xzC /opt/ovs/src

   # build and install:
   > cd /opt/ovs/openvswitch-1.4.0
   > ./configure --prefix=/opt/ovs/1.4.0 --with-linux=/lib/modules/`uname -r`/build
   > make
   > sudo make install

   # Copy the OVS kernel module out of the build tree into the install tree:
   > sudo cp /opt/ovs/src/openvswitch-1.4.0/datapath/linux/openvswitch_mod.ko /opt/ovs/1.4.0/sbin


3. READ the comments and instructions in ovs-ctl-default.example.conf

4. Copy ovs-ctl-default.example.conf from the local directory to /opt/ovs:
   
   > sudo cp ovs-ctl-default.example.conf /opt/ovs/ovs-ctl-default.conf

5. Modify /opt/ovs/ovs-ctl-default.conf to match your existing installation(s). 
   If you followed the directions and used the paths suggested in Step 2, then the default 
   configuration file should work without modification. 
   Otherwise, edit to point to your installation directorie(s). 


-------------------------------------------------------------------------------
EXAMPLE USAGE
-------------------------------------------------------------------------------

You can initialize and run your default configuration (as specified in the config files) as follows:

> ./ovs-ctl

You can stop a running configuration as follows:

> ./ovs-ctl --kill

You can initialize and run any configuration (as specified in the config files) as follows:

> ./ovs-ctl --config 1.3.0
> ./ovs-ctl --config 1.4.0
> ./ovs-ctl --config MySomeOtherConfiguration

You can output logging and verbose information with the --log and --verbose options. 

By default, OVS is initialized with 4 veth ports. You can change this with the --port-count option. 


CONFIG FILES
------------

The configuration file options are just convenient methods of storing values for the command line
arguments. Every command line argument can be specified as a key in your configuration file. 

You do not need a configuration file at all -- you can specify all required paths and values
from the command line -- but this is not recommended for regular usage. 

The precedence for these settings is in the following order:

1. Command Line option, if specified, THEN
2. The [ConfigName] section of all config files, both default, user, or command-line specified, THEN
3. The [Defaults] section of all config files


Note that you may have a section defined in the ovs-ctl-default.conf file, AND in your ~/.ovs-ctl file. 
The settings will be merged together, with the values in ~/.ovs-ctl taking precedence:

So, for example, you can have the local installation information for 1.4.0 specified in /opt/ovs/ovs-ctl-default.conf as follows:

    [1.4.0]
    # ovs-1.4.0, configured and built into /opt/ovs/1.4.0
    # Can be selected with 'ovs-ctl.py --config 1.4.0'
    ovs_src_dir:/opt/ovs/src/openvswitch-1.4.0
    ovs_base_dir:/opt/ovs/1.4.0
    ovs_runtime_dir:/var/run/ovs/1.4.0

This can be used by everyone. 

You can also have user-specific settings in ~/.ovs-ctl for your own execution:

    [1.4.0]
    # Put logfiles for my personal runs in my ~/ovs-logfiles directory:
    ovs_vswitchd_log=~/.ovs-logfiles/vswitchd.log


-------------------------------------------------------------------------------
OPTIONS AND HELP
-------------------------------------------------------------------------------

This documentation is minimal.

Please see ./ovs-ctl --help for a full list of options:

usage: ovs-ctl.py [-h] [-cf FILE [FILE ...]] [-c CONFIG] [-d FILE] [-nd]
                  [--dump-config] [--ovs-vswitchd-schema OVS_VSWITCHD_SCHEMA]
                  [--ovs-vswitchd-log OVS_VSWITCHD_LOG]
                  [--ovs-vswitchd OVS_VSWITCHD] [--ovs-vsctl OVS_VSCTL]
                  [--ovs-ofctl OVS_OFCTL] [--ovsdb-tool OVSDB_TOOL]
                  [--ovsdb-server OVSDB_SERVER] [--ovs-kmod OVS_KMOD]
                  [--ovs-src-dir OVS_SRC_DIR] [--ovs-log-dir OVS_LOG_DIR]
                  [--ovs-version OVS_VERSION] [--ovs-base-dir OVS_BASE_DIR]
                  [--ovs-runtime-dir OVS_RUNTIME_DIR]
                  [--ovs-db-sock OVS_DB_SOCK] [--ovs-db-file OVS_DB_FILE]
                  [--dry] [--log] [--verbose] [--kill] [--keep-veths]
                  [--no-kmod] [--vlog] [-p PORT_COUNT] [--bridge BRIDGE]
                  [--cip CIP] [--cport CPORT] [--max_backoff MAX_BACKOFF]
                  [--keep-db]

optional arguments:
  -h, --help            show this help message and exit
  -cf FILE [FILE ...], --config-file FILE [FILE ...]
                        Load settings from the given config file
  -c CONFIG, --config CONFIG
                        Use the specified configuration section
  -d FILE, --default-config-file FILE
                        Location of the local default config file
  -nd, --no-default     Do not load the default config file
  --dump-config         Dump the loaded configuration settings
  --ovs-vswitchd-schema OVS_VSWITCHD_SCHEMA
                        Path to the vswitchd.ovsschema file
  --ovs-vswitchd-log OVS_VSWITCHD_LOG
                        Path to the vswitchd log file
  --ovs-vswitchd OVS_VSWITCHD
                        Path to the target ovs-vswitchd binary
  --ovs-vsctl OVS_VSCTL
                        Path to the target ovs-vsctl binary
  --ovs-ofctl OVS_OFCTL
                        Path to the target ovs-ofctl binary
  --ovsdb-tool OVSDB_TOOL
                        Path to the target ovsdb-tool binary
  --ovsdb-server OVSDB_SERVER
                        Path to the target ovsdb-server binary
  --ovs-kmod OVS_KMOD   Path to the OVS kernel module
  --ovs-src-dir OVS_SRC_DIR
                        Directory for the OVS Source Files
  --ovs-log-dir OVS_LOG_DIR
                        Directory for the OVS Runtime Log Files
  --ovs-version OVS_VERSION
  --ovs-base-dir OVS_BASE_DIR
                        OVS Base Installation Directory
  --ovs-runtime-dir OVS_RUNTIME_DIR
                        OVS Runtime Directory
  --ovs-db-sock OVS_DB_SOCK
                        Domain Socket Location
  --ovs-db-file OVS_DB_FILE
                        Location for the OVS database file
  --dry                 Dry run only. Don't actually do anything
  --log                 Enable logging
  --verbose             Enable verbose output information
  --kill                Kill running OVS
  --keep-veths          By default, all existing veths will be destroyed and
                        the veth module removed before initializing. If you
                        don't want the veth module removed, specify this
                        argument. Your mileage may vary if you use this.
  --no-kmod             Do not attempt to insert or remove the OVS kernel
                        module. Your mileage may vary.
  --vlog                Tail the running vswitch.log file in a new xterm
  -p PORT_COUNT, --port-count PORT_COUNT
                        Number of veth ports to connect.
  --bridge BRIDGE       Name of OF OVS Bridge
  --cip CIP             Controller Connection
  --cport CPORT         Controller Port
  --max_backoff MAX_BACKOFF
                        VSwitchD max backoff value
  --keep-db             By default, a new database is initialized at each
                        execution. If you want to keep and use the old
                        database (if it exists), use this option


-------------------------------------------------------------------------------
TODO
-------------------------------------------------------------------------------

1. Better documentation. 
2. Option for automatic downloading, configuration, and installation of OVS. 
3. Symlinks or alias generation for selecting the correct ovs-* tools for
   debugging the running configuration.