add a readme file for parameters mapping workflow

PARAMETERS_MAPPING/README.parameters-mapping.md

@@ -0,0 +1,52 @@
+# Parameters Mapping or how to add a metadata header for CSV files
+
+1. Check that the parameters to add are listed in [data-services](https://github.com/aodn/data-services/tree/master/PARAMETERS_MAPPING)
+    * ```parameters.csv``` list of parameters and their ids
+    * ```qc_flags.csv``` list of the quality control flags and meanings
+    * ```qc_scheme.csv``` list of the quality control scheme and definitions
+    * ```unit_view.csv``` list of the units and their ids (cf names, longnames and id).
+
+2. New parameters
+    * needs to follow the IMOS vocabulary [BENE PLEASE UPDATE]
+
+3. Map the parameters for your dataset collection
+    * update ```parameters_mapping.csv```. This is the file where all the information from the other files is brought together, and where a variable name as written in the column name of the csv is matched to a unique id for each parameters find in ```parameters.csv```, units find in ```unit_view.csv```, and qc_scheme find in ```qc_scheme.csv``` and ```qc_flags.csv``` in case the data has quality control.
+
+4. Create view in Parameters mapping harvester: update the liquibase to update/include new views in the [harvester](https://github.com/aodn/harvesters/tree/master/workspace/PARAMETERS_MAPPING)
+    * start your stack restoring the paramaters_mapping schema and the schema you are working on. You can add ```restore_data: True``` under each schema if you want the data from a schema in your stack as well, this may be useful if you need to test the ```PARMETER_MAPPING_harvester```. 
+    ```
+
+    RestoreDatabaseSchemas:
+
+      - schema: parameters_mapping
+      - schema: working_schema
+    ```
+    * open pgadmin and access your stack-db to test the sql query that will be used to create/update the view in the parameters_mapping harvester, as it is easier to get a better understanding of the query before updating the liquibase via Talend
+    * start  your pipeline box and Talend 
+    * update liquidbase in the second components ```Create parameters_mapping views``` 
+        * the query will crash because of 6 views are calling their respective dataset collection schema: 
+    `aatams_biologging_shearwater_metadata_summary`; 
+    `aatams_biologging_snowpetrel_metadata_summary`; 
+    `aatams_sattag_dm_metadata_summary`; 
+    `aatams_sattag_nrt_metadata_summary`; 
+    `aodn_nt_sattag_hawksbill_metadata_summary`; 
+    `aodn_nt_sattag_oliveridley_metadata_summary`
+    * write the new view you are working on at the top of the liquidbase script, so Talend can run and create before crashing at `aatams_biologging_shearwater_metadata_summary` 
+    * check stack database that the views are created as expected.
+
+5. Merge the changes made in
+    * [data-services](https://github.com/aodn/data-services/tree/master/PARAMETERS_MAPPING) 
+    * [harvester](https://github.com/aodn/harvesters/tree/master/workspace/PARAMETERS_MAPPING) to test on RC before merging to production.
+
+6. Test on RC: check the csv files a user can download from the portal
+    * once the harvester is deployed in RC, in the terminal ssh to 4-nec-hob
+    * type the command `talend_run parameters_mapping-parameters_mapping`
+    * type `talend_log parameters_mapping-parameters_mapping` to check it run succesfully
+    * to confirm, check the new metadata additions are in the respective view in pgadmin, and ultimately in the downloaded csv file from the [rc-portal](http://portal-rc.aodn.org.au/).
+
+7. Promoting to production
+    * on Jenkins, go to [data-services_tag_promote](https://build.aodn.org.au/view/projectofficer/job/data-services_tag_promote/) and proceed to the next steps `tag_prod` and `push_prod`. At 5pm on the same day the changes will be in production.
+
+# Other information
+The [PARAMETERS_MAPPING harvester](https://github.com/aodn/harvesters/tree/master/workspace/PARAMETERS_MAPPING) runs on a cron job daily, Monday to Friday.
+It harvests the content of these 5 files (```parameters.csv```,```parameters_mapping.csv```,```qc_flags.csv```,```qc_scheme.csv```,```unit_view.csv```) into the parameters_mapping DB schema and create a `_metadata_summary` view for each of the collection listed (it is not IMOS specific, for example we have a mapping for the AODN `_WAVE_DM` + `NRT` collections).