How to take Oracle-xe-11g backup from running Docker container - docker

I am running oracle-xe-11g on rancher os. I want to take the data backup of my DB. When I tried with the command
docker exec -it $Container_Name /bin/bash
then I entered:
exp userid=username/password file=test.dmp
It is working fine, and it created the test.dump file.
But I want to run the command with the docker exec command itself. When I tried this command:
docker exec $Container_Name sh -C exp userid=username/password file=test.dmp
I am getting this error message: sh: 0: Can't open exp.

The problem is:
When running bash with -c switch it is not running as interactive or a login shell so bash won't read the same startup scripts. Anything set in /etc/profile, ~/.bash_profile, ~/.bash_login, or ~/.profile would be skipped.
Workaround:
run your container with following command:
sudo docker run -d --name Oracle-DB -p 49160:22 -p 1521:1521 -e ORACLE_ALLOW_REMOTE=true -e ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe -e PATH=/u01/app/oracle/product/11.2.0/xe/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin -e ORACLE_SID=XE -e SHLVL=1 wnameless/oracle-xe-11g
What I'm doing is specifying the environment variables set in the container using docker.
Now for generating the backup file:
sudo docker exec -it e0e6a0d3e6a9 /bin/bash -c "exp userid=system/oracle file=/test.dmp"
Please note the file will be created inside the container, so you need to copy it to docker host via docker cp command

This is how I did it. Mount a volume to the container e.g. /share/backups/ then execute:
docker exec -it oracle /bin/bash -c "ORACLE_HOME=/u01/app/oracle/product/11.2.0/xe ORACLE_SID=XE /u01/app/oracle/product/11.2.0/xe/bin/exp userid=<username>/<password> owner=<owner> file=/share/backups/$(date +"%Y%m%d")_backup.dmp"

Related

Change selected directory at startup of docker container

Is it possible to save the selected directory in docker before exiting the container?
As a default, docker does not remember the selected directory before it exits.
In the example below, I changed the directory inside docker to home.
Example:
> docker exec -it loving_mccarthy /bin/bash
root#6bd70522dd17:/# cd /home
root#6bd70522dd17:/home# exit
exit
> docker exec -it loving_mccarthy /bin/bash
/#
You can achieve this behavior by setting up a bash function, which you can configure to run on terminal exit, that writes the current working directory to the .bashrc file, which you can then use the second time you run a bash terminal in the container with cd -.
Here's a full example:
Start the container:
$ docker run -it --name=example -d ubuntu /bin/bash
Run docker exec the first time, and configure the function for trap:
$ docker exec -it example /bin/bash
root#ecfc612fe6b8:/# set_workdir_on_exit() { echo "export OLDPWD=$PWD" >> $HOME/.bashrc ;}
root#ecfc612fe6b8:/# trap 'set_workdir_on_exit' EXIT
root#ecfc612fe6b8:/# cd /home
root#ecfc612fe6b8:/home# exit
Run docker exec the second time:
$ docker exec -it example /bin/bash
root#6a491ad1aee5:/# cd -
/home
root#6a491ad1aee5:/home#

How to run commands in Docker container

Hello I m trying to follow the step by step guid to build jpeg xl (I m on windows and try to build a x64 version for linux)
after:
docker run -u root:root -it --rm -v C:\Users\fred\source\tools\jpegxl\jpeg-xl-master -w /jpeg-xl gcr.io/jpegxl/jpegxl-builder
I have the container running but I don't know how to run the command inside :
CC=clang-6.0 CXX=clang++-6.0 ./ci.sh opt
I tried CC=clang-6.0 CXX=clang++-6.0 ./ci.sh opt and I get ./ci.sh: No such file or directory no command seems to work when I do "ls" it display nothing
Does someone knows how to get this to build?
Make sure that you start a bash terminal inside the container:
docker run -it <image> /bin/bash
I believe /bin/bash is missing from your docker run command. As a result, you are executing the command for clang inside your own environment, not the container.
You can set the environment variables by using -e
Example
-e CC=clang-6.0 -e CXX=clang++-6.0
The full command to log in into your container:
docker run -u root:root -it --rm -e CC=clang-6.0 -e CXX=clang++-6.0 -v C:\Users\fred\source\tools\jpegxl\jpeg-xl-master -w /jpeg-xl gcr.io/jpegxl/jpegxl-builder /bin/bash
They have updated the image without updating the command so the command is
CC=clang-7 CXX=clang++-7 ./ci.sh opt
The discution is here:
Can't build from docker image "Unknown clang version"

How to check mysql version inside mysql docker container

Is it possible to check it without getting inside the container?
something like
docker container exec -it <container name> ....
You can check the version using Docker inspect.
docker inspect mysql8 | grep MYSQL_MAJOR
#Or to print version plus major both
docker inspect mysql8 | grep MYSQL_
or without running the container
docker run -it mysql8 bash -c "printenv | grep MYSQL_VERSION"
Or if the container is already running
docker exec mysql bash -c "mysql -V"
You can use exec to run commands against a container:
docker exec -it <container_name> bash -c "mysql -V"
get Container ID:
docker ps
Ex image: enter image description here
Remote to docker & using bash in it:
docker exec -it <container_name> bash
Input command:
mysql -V

Alpine execute command in a new shell

I'm using an Alpine image in docker and I wanted to know if there is a command to open a new terminal and execute a command.
Like :
gnome-terminal -e <command>
I've already searched in ash man but didn't find what I wanted
You always have a choice of running commands on running containers irrespective of the OS type.
docker image pull nginx
docker container run -d --name nginx -p 80:80 nginx
docker exec -ti nginx sh -c "echo 'Hello World'"

Running a script in docker container and not killing the script when leaving terminal

I have got some docker container for instance my_container
I Want to run a long living script in my container, but not killing it while leaving the shell
I would like to do something like that
docker exec -ti my_container /bin/bash
And then
screen -S myScreen
Then
Executing my script in screen and exit the terminal
Unfortunately, I cannot execute screen in docker terminal
this maybe help you.
docker exec -i -t c2ab7ae71ab8 sh -c "exec >/dev/tty 2>/dev/tty </dev/tty && /usr/bin/screen -r nmsrv -s /bin/bash"
and this is the reference link
Only way I can think of is to run your container with your script at the start;
docker run -d --name my_container nginx /etc/init.d/myscript
If you have to run the script directly in an already running container, you can do that with exec:
docker exec my_container /path/to/some_script.sh
or if you wanna run it through Php:
docker exec my_container php /path/to/some_script.php
That said, you typically don't want to run scripts in already running containers, but to just use the same image as some already running container. You can do that with a standard docker run:
docker run -a stdout --rm some_repo/some_image:some_tag php /path/to/some_script.php

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