# Unable to connect to PostgreSQL database – Peer authentication failed **URL:** \ **Category:** Support - Assistance technique\ **Tags:** server-admin\ **Created:** [9 June 2026 14:07 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771 "2026-06-09T14:07:05Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![fernando](https://dhis2.b-cdn.net/letter_avatar_proxy/v4/letter/f/779978/32.png) [@fernando](https://community.dhis2.org/u/fernando)\ **Post date:** [9 June 2026 14:07 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771/1 "2026-06-09T14:07:06Z")
Hi everyone, I’m trying to connect DHIS2 to a PostgreSQL database named `test`, but I keep running into a connection issue. When I attempt to connect via `psql`, I get the following error: paul@tracker:~$ lxc exec postgres – bash root@postgres:~# psql -U test -d test psql: error: connection to server on socket “/var/run/postgresql/.s.PGSQL.5432” failed: FATAL: Peer authentication failed for user “test” Here is some context about my setup: **Containers:** lxc list ±---------±--------±-------------------±-----±----------±----------+ | NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS | ±---------±--------±-------------------±-----±----------±----------+ | test | RUNNING | 17x.x.x.x (eth0) | | CONTAINER | 0 | | dhis | RUNNING | 17x.x.x.x (eth0) | | CONTAINER | 0 | | postgres | RUNNING | 17x.x.x.x (eth0) | | CONTAINER | 0 | ±---------±--------±-------------------±-----±----------±----------+ **DHIS2 `dhis.conf`:** # Database connection for PostgreSQL connection.dialect = org.hibernate.dialect.PostgreSQLDialect connection.driver\_class = org.postgresql.Driver connection.url = jdbc:postgresql://17x.x.x.x/viva connection.username = test connection.password = test123 **PostgreSQL databases:** postgres=# \l List of databases Name | Owner | Encoding | Locale Provider | Collate | Ctype -----------±---------±---------±----------------±--------±-------- test | app | UTF8 | libc | C.UTF-8 | C.UTF-8 postgres | postgres | UTF8 | libc | C.UTF-8 | C.UTF-8 template0 | postgres | UTF8 | libc | C.UTF-8 | C.UTF-8 template1 | postgres | UTF8 | libc | C.UTF-8 | C.UTF-8 **`pg_hba.conf`:** # “local” is for Unix domain socket connections only local all all peer # IPv4 local connections: host all all 127.0.0.1/32 scram-sha-256 # IPv6 local connections: host all all ::1/128 scram-sha-256 # Allow replication connections local replication all peer host replication all 127.0.0.1/32 scram-sha-256 host replication all ::1/128 scram-sha-256 # Custom connection for user ‘test’ host test test 17x.x.x.x/32 scram-sha-256 I suspect this may be related to the authentication method (`peer` vs `scram-sha-256`) in PostgreSQL, but I’m not sure how to fix it Has anyone faced a similar issue connecting DHIS2 to PostgreSQL when using peer authentication, and how did you resolve it? Thanks in advance for any guidance! ---
**Author:** ![jason](https://dhis2.b-cdn.net/user_avatar/community.dhis2.org/jason/32/32739_2.png) [@jason](https://community.dhis2.org/u/jason)\ **Post date:** [10 June 2026 06:41 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771/2 "2026-06-10T06:41:35Z")
Try `psql -U test -d -h 127.0.0.1 test` ---
**Author:** ![fernando](https://dhis2.b-cdn.net/letter_avatar_proxy/v4/letter/f/779978/32.png) [@fernando](https://community.dhis2.org/u/fernando)\ **Post date:** [10 June 2026 08:49 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771/3 "2026-06-10T08:49:46Z")
Hi @jason, Should I run this from the host paul@tracker:~$ or within postgres container? > [@](#): > > psql -U test -d -h 127.0.0.1 test Thanks in advance ---
**Author:** ![jason](https://dhis2.b-cdn.net/user_avatar/community.dhis2.org/jason/32/32739_2.png) [@jason](https://community.dhis2.org/u/jason)\ **Post date:** [10 June 2026 09:19 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771/4 "2026-06-10T09:19:34Z")
Inside the Postgres container. And noticed a typo. 😃 psql -U test -h 127.0.0.1 -d test ---
**Author:** ![fernando](https://dhis2.b-cdn.net/letter_avatar_proxy/v4/letter/f/779978/32.png) [@fernando](https://community.dhis2.org/u/fernando)\ **Post date:** [10 June 2026 09:47 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771/5 "2026-06-10T09:47:01Z")
Hi @jason Thanks again for your help. I have one more question to better understand the `pg_hba.conf` setup: In your suggestion you used `127.0.0.1` (IPv4 local connections), which matches this rule: host all all 127.0.0.1/32 scram-sha-256 My question is: **when should I use the custom rule instead?** host test test 17x.x.x.x/32 scram-sha-256 Specifically, in which cases is it appropriate to connect using `127.0.0.1` (loopback inside the container) versus using the container’s actual IP address (`17x.x.x.x`) with a dedicated database/user rule? ---
**Author:** ![jason](https://dhis2.b-cdn.net/user_avatar/community.dhis2.org/jason/32/32739_2.png) [@jason](https://community.dhis2.org/u/jason)\ **Post date:** [10 June 2026 10:05 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771/6 "2026-06-10T10:05:11Z")
Well, it depends on what you are trying to achieve. Your original question was based on trying to access Postgres from within the container using psql. If you need an external app (like DHIS2) to connect to the database from an external container, then you would need to use the IP address (e.g. 17x.x.x.x). ---
**Author:** ![fernando](https://dhis2.b-cdn.net/letter_avatar_proxy/v4/letter/f/779978/32.png) [@fernando](https://community.dhis2.org/u/fernando)\ **Post date:** [10 June 2026 10:24 UTC](https://community.dhis2.org/t/unable-to-connect-to-postgresql-database-peer-authentication-failed/73771/7 "2026-06-10T10:24:58Z")
Hi @jason, Thanks a lot for the clear explanation. I appreciate your time and support.