* Track this will be disabled if SQL contains a create function statement
* Track this will be disabled if SQL contains a create table/view statement for a table/view which is already tracked
1. Haskel library `pg-client-hs` has been updated to expose a function that helps listen to `postgres` notifications over a `channel` in this [PR](https://github.com/hasura/pg-client-hs/pull/5)
2. The server records an event in a table `hdb_catalog.hdb_cache_update_event` whenever any `/v1/query` (that changes metadata) is requested. A trigger notifies a `cache update` event via `hasura_cache_update` channel
3. The server runs two concurrent threads namely `listener` and `processor`. The `listener` thread listens to events on `hasura_cache_update` channel and pushed into a `Queue`. The `processor` thread fetches events from that `Queue` and processes it. Thus server rebuilds schema cache from database and updates.
If returning field contains nested selections then mutation is performed in two steps
1. Mutation is performed with returning columns of any primary key and unique constraints
2. returning fields are queried on rows returned by selecting from table by filtering with column values returned in Step 1.
Since mutation takes two courses based on selecting relations in returning field, it is hard to maintain sequence of prepared arguments (PrepArg) generated while resolving returning field. So, we're using txtConverter instead of prepare to resolve mutation fields.
CircleCI jobs are run for any PR that is submitted to the repo. This PR adds a check to decide whether the job should be run or not.
Figured out that CircleCI has a way to gracefully terminate a job:
```
circleci-agent step halt
```
A `.ciignore` file is ran against all the changes in the PR to decide whether the PR should be built or not. If the answer comes out as `no`, a file is written at `/buid/skip_job.txt`. This is done in the `check_build_worthiness` step.
All further jobs, in the beginning, looks for this file and gracefully terminates the job if this file is present. The directory is passed down to the jobs as the workspace.
```yaml
skip_job_on_ciignore: &skip_job_on_ciignore
run: |
if [ -f /build/skip_job.txt ]; then
echo "halting job due to /build/skip_job.txt"
circleci-agent step halt
fi
```
ref: https://support.circleci.com/hc/en-us/articles/360015562253-Conditionally-end-a-running-job-gracefully
There are some known issues on jobs that are run when PR is merged to master, need to address them after this PR is merged.
A hello world schema is provided with local dev and deployment instructions for AWS Lambda, Google Cloud Functions and Azure Functions.
Older boilerplates are cleaned up.
* read cookie while initialising websocket connection (fix#1660)
* add tests for cookie on websocket init
* fix logic for tests
* enforce cors, and flag to force read cookie when cors disabled
- as browsers don't enforce SOP on websockets, we enforce CORS policy
on websocket handshake
- if CORS is disabled, by default cookie is not read (because XSS
risk!). Add special flag to force override this behaviour
* add log and forward origin header to webhook
- add log notice when cors is disabled, and cookie is not read on
websocket handshake
- forward origin header to webhook in POST mode. So that when CORS is
disabled, webhook can also enforce CORS independently.
* add docs, and forward all client headers to webhook
* removed trash icon to remove all permissions to avoid confusion. Same action can be done via the bulk section
* colour coded permissions symbols for better visual feedback
