I have troubles restarting a dockerized postgres database (I use Core OS). The database is started in a bash script using the command
# boot.sh
sudo -i -u postgres /usr/lib/postgresql/9.3/bin/postgres -D /var/lib/postgresql/9.3/main -c config_file=/etc/postgresql/9.3/main/postgresql.conf
which works. I have another script called by confd which is run when some etcd keys change (this part is ok, the file is correctly called) and must restart postgres (not reload, because some config changes require a restart). Here are the main options I tried, which failed...
# restart.sh
sudo -u postgres /usr/lib/postgresql/9.3/bin/pg_ctl --pgdata=/var/lib/postgresql/9.3/main restart
systematically raises an error:
%FATAL: lock file "postmaster.pid" already exists
%HINT: Is another postmaster (PID 273) running in data directory "/var/lib/postgresql/9.3/main"?
Furthermore,
# restart.sh
rm /var/lib/postgresql/9.3/main/postmaster.pid
sudo -i -u postgres /usr/lib/postgresql/9.3/bin/postgres -D /var/lib/postgresql/9.3/main -c config_file=/etc/postgresql/9.3/main/postgresql.conf
,
rm /var/lib/postgresql/9.3/main/postmaster.pid
/etc/init.d/postgresql start
,
/etc/init.d/postgresql restart
and
exec su postgres -c "/usr/lib/postgresql/9.3/bin/postgres -D /var/lib/postgresql/9.3/main -c config_file=/etc/postgresql/9.3/main/postgresql.conf"
fail with
ERROR exit status 1
Any thought? Thank you in advance!
For me, changing the config and doing
$ docker restart <postgres_container>
on the host works just fine.
Related
I am trying to run psql with user postgres. When I run sudo su - postgres AND THEN psql from within the new session, it is working smoothly. In fact, the ~/.bashrc in that session with use postgres has the correct PATH.
However, if I run sudo -u postgres psql, I get sudo: psql: command not found. Even though the session where I am running this command (I use the FISH shell) has the correct PATH as well, and I can invoke psql without the full path with my user.
I need to invoke the command as sudo -u postgres psql, how can this behavior be explained?
Edit: if (from FISH) I switch to BASH and run sudo -u postgres psql, it works! I guess it has to do with the FISH path then...
Edit 2: The issue seems to be that the PATH is reset when using sudo.
➜ ~ psql
psql: error: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: FATAL: role "opc" does not exist
➜ ~ sudo -u postgres psql
sudo: psql: command not found
➜ ~ echo $PATH
/home/opc/.local /home/opc/.local/bin /usr/pgsql-15/bin /usr/pgsql-15/bin /usr/local/bin /usr/bin /usr/local/sbin /usr/sbin
➜ ~ sudo echo $PATH
/home/opc/.local /home/opc/.local/bin /usr/pgsql-15/bin /usr/pgsql-15/bin /usr/local/bin /usr/bin /usr/local/sbin /usr/sbin
➜ ~ sudo -u postgres /usr/pgsql-15/bin/psql
could not change directory to "/home/opc": Permission denied
psql (15.1)
Type "help" for help.
postgres=#
But if I echo $PATH with sudo, it seems fine...
This is caused by a sudo configuration that has the "secure_path" setting. This causes sudo to reset $PATH to a hardcoded "known safe" value. This might be enabled by your distribution.
When you run sudo bash, that bash will read its settings, including .bashrc, and if you set $PATH in that it will then, of course, have that $PATH again.
But if you run a command without going through a shell that resets $PATH, you'll get the hardcoded setting.
It's possible to change that setting by running sudo visudo and changing the line that says
Defaults secure_path="some:path:here"
to
Defaults !secure_path
An alternative is to just run the command via the fully qualified path, like
sudo -u postgres (command -s psql)
One more comment about your tests:
sudo echo $PATH
This doesn't do what you want. The $PATH will be expanded by the shell that runs sudo, and so sudo won't ever see anything but the value of it. It is exactly equivalent to running sudo echo /home/opc/.local /home/opc/.local/bin /usr/pgsql-15/bin ....
You might want to use something like
sudo env
or
sudo sh -c 'echo $PATH'
instead.
I have developed a shell script whose job is to take the dump of postgres DB. Below is the snippet:
#!/bin/sh
today=$(date +"%Y-%m-%d")
yes "password" | sudo -S sudo su - postgres <<EOF
/usr/pgsql-11/bin/pg_dump -U postgres -d db_name > /home/db_backup/db_name_$today.sql
EOF
exit
However, this script is NOT running because of the below reason:
[sudo] password for user: Sorry, Try again
However, when I use sudo su - postgres and then provide password, it is working as expected. And interestingly, if now I run the above shell script after the login, it runs absolutely fine.
What I am missing here.
It is dangerous to store passwords in scripts, so please do not do it.
Modify your /etc/sudoers file by running sudo visudo and adding a line like this at the bottom:
%sudo ALL=(postgres) NOPASSWD: /usr/bin/psql
This allows anyone with sudo permission to run /usr/bin/psql to postgres on any host (ALL) with no password.
Now your script should work this way:
#!/bin/sh
today=$(date +"%Y-%m-%d")
sudo -b -n -H -u postgres /usr/pgsql-11/bin/pg_dump -U postgres -d db_name > /home/db_backup/db_name_$today.sql
Make sure postgres can write to the directory /home/db_backup/.
I have postgres installed on an ubuntu machine, and I am able to enter into the command line via something along the lines of:
$ sudo -u postgres psql
psql (10.15 (Ubuntu 10.15-0ubuntu0.18.04.1))
Type "help" for help.
postgres=#
And I can start/stop the server by doing something like:
$ sudo service postgresql
Usage: /etc/init.d/postgresql {start|stop|restart|reload|force-reload|status} [version ..]
Those both seem fine. However, I would like to run postgres in single-user mode to do a couple tests. On the postgres page it gives a few examples, such as:
To start a single-user mode server, use a command like
postgres --single -D /usr/local/pgsql/data other-options my_database
However, if I use the 'postgres' command, I just get an error saying I don't have that command:
$ postgres
Command 'postgres' not found, did you mean:
What do I need to install to run the 'postgres' command in order to enter single-user mode?
as you have not export the binary path that's why it's can't find your binary of postgres.
use this command:
/usr/lib/postgresql/10/bin/postgres --single -D /usr/local/pgsql/data other-options my_database
or,
you can export the path in bash
first open the bashrc with this command:nano ~/.bashrc
add this line in the end :PATH="/usr/lib/postgresql/10/bin/:$PATH"
run this command source ~/.bashrc
the just use postgres --single -D /usr/local/pgsql/data other-options my_database
you can also find where your binary is with this command : find /usr/lib -iname 'postgres'
It is already installed, it is just not in your PATH, as it is not anticipated you would use it manually.
It is probably somewhere like "/usr/lib/postgresql/10/bin/postgres", or you can use locate or find to find it.
Ubuntu has conf files spread over several places so:
/usr/lib/postgresql/13/bin/postgres --single -D /var/lib/postgresql/13/main -c "config_file=/etc/postgresql/13/main/postgresql.conf"
I install Postgresql on my Ubuntu with:
brew install postgres
now I have:
psql --version
psql (PostgreSQL) 9.5.0
How can I start the service automatically?
On my Mac with homebrew I can do it with:
ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
but how on Ubuntu with Linuxbrew?
I try with:
brew services start postgresql
but it says:
sh: 1: list: not found
Error: Could not read the plist for `postgresql`!
What to do?
Not quite automatic but a step in the right direction. On my system I did the following:
$ pg_ctl start -D $HOME/.linuxbrew/var/postgres -l logfile
You could simple create an alias in your .bash_profile or .bashrc something like:
alias poston="pg_ctl start -D $HOME/.linuxbrew/var/postgres -l logfile"
alias postoff="pg_ctl stop -D $HOME/.linuxbrew/var/postgres"
To test it all out (assuming you do not yet have a database on your machine) you can also create a database for your current user:
$ poston
$ createdb `whoami`
$ psql
All the tutorials point out to running postgres in the format of
docker run -d -p 5432 \
-t <your username>/postgresql \
/bin/su postgres -c '/usr/lib/postgresql/9.2/bin/postgres \
-D /var/lib/postgresql/9.2/main \
-c config_file=/etc/postgresql/9.2/main/postgresql.conf'
Why can't we in our Docker file have:
ENTRYPOINT ["/etc/init.d/postgresql-9.2", "start"]
And simply start the container by
docker run -d psql
Is that not the purpose of Entrypoint or am I missing something?
the difference is that the init script provided in /etc/init.d is not an entry point. Its purpose is quite different; to get the entry point started, in the background, and then report on the success or failure to the caller. that script causes a postgres process, usually indirectly via pg_ctl, to be started, detached from the controlling terminal.
for docker to work best, it needs to run the application directly, attached to the docker process. that way it can usefully and generically terminate it when the user asks for it, or quickly discover and respond to the process crashing.
Exemplify that IfLoop said.
Using CMD into Dockerfiles:
USE postgres
CMD ["/usr/lib/postgresql/9.2/bin/postgres", "-D", "/var/lib/postgresql/9.2/main", "-c", "config_file=/etc/postgresql/9.2/main/postgresql.conf"]
To run:
$docker run -d -p 5432:5432 psql
Watching PostgeSQL logs:
$docker logs -f POSTGRES_CONTAINER_ID