Allow special characters in pg-su-username

[dineshba]

If we are having special characters in su username like below

./stolon-keeper --pg-su-username=user-name # other flags

We are getting below error

INFO    postgresql/postgresql.go:534    setting superuser password
2019-06-01 01:34:40.031 IST [60923] ERROR:  syntax error at or near "-" at character 14

But in postgres, having role as user-name is allowed. So it is better if stolon also allow this.

I just added double quotes for username in alter role command.

There are two more places in stolon where we are altering role. In those two places we are already using double quotes. https://github.com/sorintlab/stolon/blob/master/internal/postgresql/utils.go#L104 and https://github.com/sorintlab/stolon/blob/master/internal/postgresql/utils.go#L115

[sgotti]

@dineshba Good catch!

What about using consistent single quotes (or double quotes, I don't know which is better in such case) like in with password '%s'.

As a note if someone is going to ask:

I'll have preferred to use sql prepared statements with arguments like:
dbExec(ctx, db, "alter role $1 with password $2", username, password)

but unfortunately this doesn't work (returning a syntax error) since in postgres prepared statements works only for SELECT, INSERT, UPDATE, DELETE, or VALUES statement: https://www.postgresql.org/docs/11/sql-prepare.html

[dineshba]

Thanks for the quick review @sgotti. For consistency, I made everything as single quotes and amended to the same commit.
Initially, I made everything as single quotes. But it is not working

Below is the combination of different tries:

postgres=# alter role 'db-role' password "abcd";
ERROR:  syntax error at or near "'db-role'"
LINE 1: alter role 'db-role' password "abcd";
                   ^
postgres=# alter role "db-role" password "abcd";
ERROR:  syntax error at or near ""abcd""
LINE 1: alter role "db-role" password "abcd";
                                      ^
postgres=# alter role "db-role" password 'abcd';
ALTER ROLE

Conclusion:

• For alter/create role we should use double quotes only ( no quotes if there is no special character in role name
• For password we should use only single quotes (not optional)

[sgotti]

@dineshba you're right. Merging. Thanks!

[dineshba]

@sgotti Thanks 👍