Previously, integer gucs, for example `max_connections` would not pass the validation, as these settings have no unit, if and only if they were specified as a string.
This causes problems if the `max_connections` is configured in `patroni.yaml` as a string, for example, the following configuration would not result in the right `max_connections` settings, as `max_connections` is configured as a string:
bootstrap:
dcs:
postgresql:
parameters:
log_checkpoints: "on"
log_connections: "off"
max_connections: "57"
Allowing a user to specify *all* parameters as a string was accepted before in Patroni and also seems very useful, as many of us will be using Ansible/Helm/Golang to build a Patroni configuration, in which creating a `map[string]string` is easier than having to deal with data types.
Attemps to address issue #2735
Regression was introduced in https://github.com/zalando/patroni/commit/76b3b99de2f2bfaa8ab2df9e47dbfc3749d14e84
pg_stat_statements is enabled by many by default, but will by default also track utility commands including an
ALTER USER john WITH PASSWORD 's3cret'
We can prevent this leaking by ensuring that our session currently does not track utility commands when running a sensitive query.
Local testing shows that this command works fine, even for those that do not have `pg_stat_statements` configured in their
`shared_preload_libraries`.
For init processes that use a symlinked WAL directory, or use custom scripts that create new tablespaces, these directories should also be renamed after a failed init attempt, as currently the following errors occur if the first init attempt failed, but a second one might succeed:
fixing permissions on existing directory /var/lib/postgresql/data ... ok
initdb: error: directory "/var/lib/postgresql/wal/pg_wal" exists but is not empty
[...]
File "/usr/lib/python3/dist-packages/patroni/ha.py", line 1173, in post_bootstrap
self.cancel_initialization()
File "/usr/lib/python3/dist-packages/patroni/ha.py", line 1168, in cancel_initialization
raise PatroniException('Failed to bootstrap cluster')
patroni.exceptions.PatroniException: 'Failed to bootstrap cluster'
In the remove_data_directory function the same happens for removing the data directory, it seems the same kind of thing should also happen when moving a data directory.
To ensure the data directory can still be used, the symlinks will point to the renamed directories.
Skip missing values from pg_controldata
When calling controldata(), it may return an empty dictionary, which in
turn caused the following error to occur:
effective_configuration
cvalue = parse_int(data[cname])
KeyError: 'max_wal_senders setting'
Instead of causing a crash of this part, we now log the error and
continue.
This is the full output of the error:
```
2020-04-17 14:31:54,791 ERROR: Exception during execution of long running task restarting after failure
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/patroni/async_executor.py", line 97, in run
wakeup = func(*args) if args else func()
File "/usr/lib/python3/dist-packages/patroni/postgresql/__init__.py", line 707, in follow
self.start(timeout=timeout, block_callbacks=change_role, role=role)
File "/usr/lib/python3/dist-packages/patroni/postgresql/__init__.py", line 409, in start
configuration = self.config.effective_configuration
File "/usr/lib/python3/dist-packages/patroni/postgresql/config.py", line 983, in effective_configuration
cvalue = parse_int(data[cname])
KeyError: 'max_wal_senders setting'
```
The KUBERNETES_ environment variables are not required for PostgreSQL, yet having them exposed to the postmaster will also expose them to backends and to regular database users (using pl/perl for example).
The previous documentation was wrong and will throw the following error
when used:
Exception when parsing list {[{"name": "postgresql", "port": 5432}]}
When removing the surrounding braces, the error goes away and the
endpoint is updated with the correct Port name.
