I am working on an open source application that has PostgreSQL as its default DBMS. Now when I install it on my system, its configuration is so that PostgreSQL also gets installed with it.
My problem is with getting access to the installed PostgreSQL database. The database that gets created during installation is named iviewdb.
I read at many forums that the default superuser is postgres, but when I try to get access to the database using this username through a command prompt, it prompts me for password that I don't have.
I wanted to know from where in the PostgreSQL installation directory
the default username and password with the port number to access the database is stored. I have even tried changing the pg_hba.conf file, but that creates a problem with the application and it won't start then.
How can I find the password for this database? I am working in a Windows environment.
The password isn't stored in an easily recoverable manner, and if you change the password, the application may not be able to access the database properly. You may find the password in the application settings or documentation, though.
If you decide to risk changing the postgres user's password, stop the application and PostgreSQL service, and then edit pg_hba.conf. Add (or change if it already exists) a line (if it doesn't exist, add it before any other "host...." lines):
host all all 127.0.0.1/32 trust
And restart the PostgreSQL service. That should give you access from localhost, where you could change the postgres user's password, or add yourself another user with the permissions you want. Then set the pg_hba.conf file back the way it was and restart.
I've encountered this similar problem, and I noticed that the default being set for PostgreSQL upon installation in my case is as follows:
username = postgres
password = ' '
Related
I stumbled upon PostgreSQL installations, where there is a PostgreSQL user with the same name as an operating system (Linux) user. If you are logged into the operating system as such a user, you can usually login to psql without specifying a username and password as this user.
How does this work? Is this a pure convention, or is there a special mechanism in PostgreSQL for this kind of behavior?
There are cases, where no corresponding PostgreSQL user is present for an operating system user. In this case, how do I create one, that can be logged into without having to specify username and password once I am logged into the operating system as this user?
There are several mechanisms. I don't know what makes a mechanism a special one, though.
The client always sends a username to the server. If you don't specify one to use then libpq-based clients look up the operating system name and use that. Some non-libpq-based clients might adopt the same convention.
For not requiring a password, maybe local connections are set to 'trust' in pg_hba.conf, in which case anyone else on the same machine can also log in to PostgreSQL as you, just by specifying your username to use, such as with -U martinw. Or maybe a password is required, but it is provided automatically via .pgpass file or via PGPASSWORD env variable, but if you set that up presumably you would remember doing so. Or maybe you have local connections set to peer in pg_hba, in which case the db server asks the OS "who is on the other end of this socket?" and verifies the answer matches the requested username (this is a common default setup, for example on Ubuntu Linux) or if a pg_ident map is in use, then it verifies the response system username is allowed to log in as the specified db username.
https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-PASSFILE
create a pgpass file: vim ~/.pgpass
fill your credentials: hostname:port:database:username:password
exit file. and change ~/.pgpassfile access permission:
https://www.postgresql.org/docs/current/libpq-pgpass.html
chmod 0600 ~/.pgpass
If your linux user is the same as one of the pgpassfile user, then just type psql to connect to database.
i am using pg lib in strapi application, where initially it creates postgres connection using correct postgresql username(postgres), database name(strapi_db) and password(postgres) but after login it changed it to connect using my windows 10 username(rayappan.a, and database as rayappan.a). it seems strange to me because i never configured anywhere to use my windows credentials for POSTGRESQL connection. please any one tell me how to fix username connection issue
Regards,
Rayappan Antoniraj
Take a look into https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING . It states that username:
Defaults to be the same as the operating system name of the user running the application."
The database name:
Defaults to be the same as the user name.
So it seems a new connection with parameters not set is made.
In PostgreSQL we can just change local md5 to trust in pg_hba.conf. then we can access all data in database using psql without need of password.So anyone can change this line who can access local machine.
So, Is there way to password protect our database even someone change pg_hba.conf to trust
( I want to create offline app and need to protect client database,I need something like ms access, once we set the password it always ask for password )
As long as client has root/administrator acces on the computer you can't do much about pg_hba. You could make it read only but root can overyde anything. You could mount config file on read only file system but this is too complicated.
Solution can be only at database level(not OS or application): crypted data and triggers where you implement supplimentary security.
I don't think postresql is the answer for your requirement, maybe SQLite is the right one.
For a system that I am using, I run into the problem pasted on the title when I try to drop a database and recreate it. More specifically, this is the exact problem that I am facing:
Couldn't drop staging_databse : #<PG::ConnectionBad: FATAL: no pg_hba.conf entry for host xxx.xx.xxxx.xxx, user "ruby", database "postgres", SSL off
I've done some research regarding this problem and it seems that the solution is simply to turn on SSL. I've consulted Postgresql Documentation on pg_hba.conf but I'm unable to find this configuration file.
I typed in locate postgresql and I noticed that there is a postgresql-client-9.2 installed on the system. From what I have determined, I won't find this pg_hba.conf file because the client doesn't have it. I've also looked for the postgresql.conf file on SSL according to the official documentation but this file is not included either.
Finally, the documentation shows me this configuration option of the pgsql 9.2 client shown below:
libpq reads the system-wide OpenSSL configuration file. By default,
this file is named openssl.cnf and is located in the directory reported by
openssl version -d. This default can be overridden by setting environment
variable OPENSSL_CONF to the name of the desired configuration file.
However, this too isn't in my system. I've run the linux find command and this file doesn't seem to be there. I've run out of leagues and I have a sneaking suspicion that I am overlooking something very simple. Is there any other leads I can go on? Thanks.
Based on this message and the rest of the context:
FATAL: no pg_hba.conf entry for host xxx.xx.xxxx.xxx, user "ruby", database "postgres", SSL off
It looks plausible that:
you're connecting to a remote PostgreSQL instance which you don't administrate because you're acting as developer, not admin.
the db management layer tries to connect to the database named postgres in order to drop another database (staging_database) . It's necessary indeed because we can't drop a database when we're connected to it (in fact, a database can't be dropped when anyone is connected to it).
the admin policy established by the remote pg_hba.conf is such that your login and IP address together are not allowed to connect to the database named postgres
These facts combined together imply that you're missing the necessary rights to drop your database, even if indirectly.
At this point you want to submit the problem to the admin responsible for that PostgreSQL server.
As I attempt to create my initial user account on postgresql, I am prompted for my password, though when I enter the correct one I recieve:
createdb: could not connect to database template1: FATAL: password authentication failed for user "thomasmurphy"
I am installing through brew. My thought is that somewhere along the line I've set a password different from my system one. How do I remove all users so I can reset this pass.
I get my permission denied even if I su to postgres. I have gone through every thread on stackoverflow on this issue, and have tried:
*modifying my pg hba_conf
*updating my gems and developer tools
*running brew doctor
*reinstalling postgres
*all the other command line ideas through the thread
My situation seems to not have cropped up before, which convinces me I've set a password at some point that is now tripping all of my attempts. Adding to this theory is that I have a postgres setup on my work computer, also on mavericks, function perfectly.
Note that unless you changed defaults, homebrew installs Postgres with you as the superuser rather than as the postgres user. The issue might be that you're trying to use postgres "as normal" whereas it doesn't need or event want the usual postgres user references.
You see the list of users on the system using cat /etc/passwd, and you can change an arbitrary password by running chpass as root.