<p>I searched for the <strong>healthcheck/postgres:alpine</strong> and I found the following repository with the <strong>Dockerfile</strong>:</p>

<p><a href="https://github.com/docker-library/healthcheck/blob/master/postgres/Dockerfile.alpine" rel="nofollow noreferrer">https://github.com/docker-library/healthcheck/blob/master/postgres/Dockerfile.alpine</a></p>

<p>Assuming this is the correct repo for your docker image, the dockerfile specifies:</p>

<pre><code>FROM postgres

COPY docker-healthcheck /usr/local/bin/

HEALTHCHECK CMD ["docker-healthcheck"]
</code></pre>

<p>So it extends the postgres docker image which is documented here:</p>

<p><a href="https://hub.docker.com/_/postgres" rel="nofollow noreferrer">https://hub.docker.com/_/postgres</a></p>

<p>Specifically for the password they mention the following:</p>

<blockquote>
  <p>POSTGRES_PASSWORD This environment variable is recommended for you to
  use the PostgreSQL image. This environment variable sets the superuser
  password for PostgreSQL. The default superuser is defined by the
  POSTGRES_USER environment variable.</p>
  
  <p>Note 1: The PostgreSQL image sets up trust authentication locally so
  you may notice a password is not required when connecting from
  localhost (inside the same container). However, a password will be
  required if connecting from a different host/container...</p>
</blockquote>

<p>Read the whole documentation at the image homepage.</p>

CC BY-SA 4.0
2019-04-21T20:40:29.713Z
2019-04-21T20:40:29.713Z
petrchpetr
<p>postgres:</p>

<pre><code>image: healthcheck/postgres:alpine
environment:
  POSTGRES_USER: postgres
</code></pre>

<ul>
<li>What is the default user of postgresql?</li>
<li>How does hardcoding the postgres user improve security?</li>
<li>What special rights does the postgres user have?</li>
<li>What is the upside and downside of using an unprivileged user in this scenario?</li>
<li>Is it necessary in our scenario to have an unprivileged user?</li>
</ul>

<docker-compose><postgresql>
i have questions about docker-compose
omar amine
# i have questions about docker-compose

(Asked by: username_0 on 2019-04-21)

postgres:
image: healthcheck/postgres:alpine
environment:
  POSTGRES_USER: postgres


What is the default user of postgresql?
How does hardcoding the postgres user improve security?
What special rights does the postgres user have?
What is the upside and downside of using an unprivileged user in this scenario?
Is it necessary in our scenario to have an unprivileged user?

**Tags:** docker-compose, postgresql


---

## 1 answers

### Answer by username_1 on 2019-04-21. Score: 1

I searched for the healthcheck/postgres:alpine and I found the following repository with the Dockerfile:
https://github.com/docker-library/healthcheck/blob/master/postgres/Dockerfile.alpine
Assuming this is the correct repo for your docker image, the dockerfile specifies:
FROM postgres

COPY docker-healthcheck /usr/local/bin/

HEALTHCHECK CMD ["docker-healthcheck"]

So it extends the postgres docker image which is documented here:
https://hub.docker.com/_/postgres
Specifically for the password they mention the following:

POSTGRES_PASSWORD This environment variable is recommended for you to
  use the PostgreSQL image. This environment variable sets the superuser
  password for PostgreSQL. The default superuser is defined by the
  POSTGRES_USER environment variable.
Note 1: The PostgreSQL image sets up trust authentication locally so
  you may notice a password is not required when connecting from
  localhost (inside the same container). However, a password will be
  required if connecting from a different host/container...

Read the whole documentation at the image homepage.


---

