Fix warnings in PF documentation generation

Geeneration of documents in the Policy Framework issued many warnings,
for example missing links, hanging references, unreferenced pages and
missing swagger, as well as bad formatting for code blocks.

This commit cleans up all the warnings.

Issue-ID: POLICY-3337
Change-Id: I20db6ff76cfb58a603317f5faf20c7479b77c13b
Signed-off-by: liamfallon <liam.fallon@est.tech>

1 files changed, 295 insertions, 0 deletions

diff --git a/docs/system-attributes/policy-db-migrator.rst b/docs/system-attributes/policy-db-migrator.rst
new file mode 100644
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@@ -0,0 +1,295 @@
+.. This work is licensed under a  Creative Commons Attribution
+.. 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+Using Policy DB Migrator
+########################
+
+Policy DB Migrator is a set of shell scripts used to
+install the database tables required to run ONAP Policy Framework.
+
+.. note::
+   Currently the Istanbul versions of the PAP and API components require
+   ``db-migrator`` to run prior to initialization.
+
+Package contents
+================
+
+Policy DB Migrator is run as a docker container and consists of the following scripts:
+
+.. code::
+  :number-lines:
+
+    prepare_upgrade.sh
+    prepare_downgrade.sh
+    db-migrator
+
+
+``prepare_upgrade.sh`` is included as part of the docker image and is used
+to copy the upgrade sql files to the run directory.
+This script takes one parameter: <SCHEMA NAME>.
+
+``prepare_downgrade.sh`` is included as part of the docker image and is used
+to copy the downgrade sql files to the run directory.
+This script takes one parameter: <SCHEMA NAME>.
+
+``db-migrator`` is included as part of the docker image and is used
+to run either the upgrade or downgrade operation depending on user requirements.
+This script can take up to four parameters:
+
+.. list-table::
+   :widths: 20 20 20
+   :header-rows: 1
+
+   * - Parameter Name
+     - Parameter flag
+     - Value (example)
+   * - operation
+     - -o
+     - upgrade/downgrade/report
+   * - schema
+     - -s
+     - policyadmin
+   * - to
+     - -t
+     - 0800/0900
+   * - from
+     - -f
+     - 0800/0900
+
+The container also consists of several sql files which are used to upgrade/downgrade
+the policy database.
+
+The following environment variables need to be set to enable ``db-migrator``
+to run and connect to the database.
+
+.. list-table::
+   :widths: 20 20
+   :header-rows: 1
+
+   * - Name
+     - Value (example)
+   * - SQL_HOST
+     - mariadb
+   * - SQL_DB
+     - policyadmin
+   * - SQL_USER
+     - policy_user
+   * - SQL_PASSWORD
+     - policy_user
+   * - POLICY_HOME
+     - /opt/app/policy
+
+Prepare Upgrade
+===============
+
+Prior to upgrading the following script is run:
+
+.. code::
+
+   /opt/app/policy/bin/prepare_upgrade.sh <SCHEMA NAME>
+
+This will copy the upgrade files from ``/home/policy/sql`` to ``$POLICY_HOME/etc/db/migration/<SCHEMA NAME>/sql/``
+
+Each individual sql file that makes up that release will be run as part of the upgrade.
+
+
+Prepare Downgrade
+=================
+
+Prior to downgrading the following script is run:
+.. code::
+
+   /opt/app/policy/bin/prepare_downgrade.sh <SCHEMA NAME>
+
+This will copy the downgrade files from ``/home/policy/sql`` to ``$POLICY_HOME/etc/db/migration/<SCHEMA NAME>/sql/``
+
+Each individual sql file that makes up that release will be run as part of the downgrade.
+
+Upgrade
+=======
+
+.. code::
+
+   /opt/app/policy/bin/db-migrator -s <SCHEMA NAME> -o upgrade -f 0800 -t 0900
+
+If the ``-f`` and ``-t`` flags are not specified, the script will attempt to run all available
+sql files greater than the current version.
+
+The script will return either 1 or 0 depending on successful completion.
+
+Downgrade
+=========
+
+.. code::
+
+   /opt/app/policy/bin/db-migrator -s <SCHEMA NAME> -o downgrade -f 0900 -t 0800
+
+If the ``-f`` and ``-t`` flags are not specified, the script will attempt to run all available
+sql files less than the current version.
+
+The script will return either 1 or 0 depending on successful completion.
+
+Logging
+=======
+
+After every upgrade/downgrade ``db-migrator`` runs the report operation to show the
+contents of the db-migrator log table.
+
+.. code::
+
+   /opt/app/policy/bin/db-migrator -s <SCHEMA NAME> -o report
+
+Console output will also show the sql script command as in the example below:
+
+.. code::
+
+   upgrade 0100-jpapdpgroup_properties.sql
+   --------------
+   CREATE TABLE IF NOT EXISTS jpapdpgroup_properties (name VARCHAR(120) NULL, version VARCHAR(20) NULL,
+   PROPERTIES VARCHAR(255) NULL, PROPERTIES_KEY VARCHAR(255) NULL)
+
+
+migration schema
+================
+
+The migration schema contains two tables which belong to ``db-migrator``.
+
+* schema_versions - table to store the schema version currently installed by ``db-migrator``
+
+.. list-table::
+   :widths: 20 20
+   :header-rows: 1
+
+   * - name
+     - version
+   * - policyadmin
+     - 0900
+
+* policyadmin_schema_changelog - table which stores a record of each sql file that has been run
+
+.. list-table::
+   :widths: 10 40 10 10 10 20 10 20
+   :header-rows: 1
+
+   * - ID
+     - script
+     - operation
+     - from_version
+     - to_version
+     - tag
+     - success
+     - atTime
+   * - 1
+     - 0100-jpapdpgroup_properties.sql
+     - upgrade
+     - 0
+     - 0800
+     - 1309210909250800u
+     - 1
+     - 2021-09-13 09:09:26
+
+* ID: Sequence number of the operation
+* script: name of the sql script which was run
+* operation: operation type - upgrade/downgrade
+* from_version: starting version
+* to_version: target version
+* tag: tag to identify operation batch
+* success: 1 if script succeeded and 0 if it failed
+* atTime: time script was run
+
+
+Partial Upgrade/Downgrade
+=========================
+
+If an upgrade or downgrade ends with a failure status (success=0) the next time an upgrade
+or downgrade is run it will start from the point of failure rather than re-run scripts
+that succeeded. This allows the user to perform a partial upgrade or downgrade depending
+on their requirements.
+
+Running db-migrator
+===================
+
+The script that runs ``db-migrator`` is part of the database configuration and is in the following directory:
+
+.. code::
+
+   oom/kubernetes/policy/resources/config/db_migrator_policy_init.sh
+
+This script is mounted from the host file system to the policy-db-migrator container.
+It is setup to run an upgrade by default.
+
+.. code::
+
+   /opt/app/policy/bin/prepare_upgrade.sh ${SQL_DB}
+   /opt/app/policy/bin/db-migrator -s ${SQL_DB} -o upgrade
+   rc=$?
+   /opt/app/policy/bin/db-migrator -s ${SQL_DB} -o report
+   exit $rc
+
+The following table describes what each line does:
+
+.. list-table::
+   :widths: 30 30
+   :header-rows: 1
+
+   * - code
+     - description
+   * - /opt/app/policy/bin/prepare_upgrade.sh ${SQL_DB}
+     - prepare the upgrade scripts for the <SQL_DB> schema
+   * - /opt/app/policy/bin/db-migrator -s ${SQL_DB} -o upgrade
+     - run the upgrade
+   * - rc=$?
+     - assign the return code from db-migrator to a variable
+   * - /opt/app/policy/bin/db-migrator -s ${SQL_DB} -o report
+     - run the db-migrator report for the <SQL_DB> schema
+   * - exit $rc
+     - exit with the return code from db-migrator
+
+To alter how ``db-migrator`` is run the first two lines need to be modified.
+The first line can be changed to call either ``prepare_upgrade.sh`` or ``prepare_downgrade.sh``.
+The second line can be changed to use different input parameters for ``db-migrator`` :
+
+.. list-table::
+   :widths: 10 20 10
+   :header-rows: 1
+
+   * - flag
+     - value
+     - required
+   * - ``-o``
+     - upgrade/downgrade
+     - ``Y``
+   * - ``-s``
+     - ${SQL_DB}
+     - ``Y``
+   * - ``-f``
+     - current version (e.g. 0800)
+     - ``N``
+   * - ``-t``
+     - target version (e.g. 0900)
+     - ``N``
+
+This is an example of how a downgrade from version 0900 to version 0800 could be run:
+
+.. code::
+
+   /opt/app/policy/bin/prepare_downgrade.sh ${SQL_DB}
+   /opt/app/policy/bin/db-migrator -s ${SQL_DB} -o downgrade -f 0900 -t 0800
+   rc=$?
+   /opt/app/policy/bin/db-migrator -s ${SQL_DB} -o report
+   exit $rc
+
+Additional Information
+======================
+If the target version of your upgrade or downgrade is the same as the current version,
+no sql files are run.
+
+If an upgrade is run on a database where tables already exist in the policy schema, the
+current schema version is set to 0800 and only sql scripts from later versions are run.
+
+.. note::
+   It is advisable to take a backup of your database prior to running this utility.
+   Please refer to the mariadb documentation on how to do this.
+
+End of Document