Get root access inside mssql docker container - sql-server

I created a MSSQL docker container based on the official image provided by Microsoft (https://hub.docker.com/_/microsoft-mssql-server).
I started a bash shell inside the running container and tried to delete some files.
sudo docker exec -it sql1 "bash"
Inside the container it is using the mssql account (by default).
And there seems to be some permission issues when I tried to delete the files.
rm -f *.csv
rm: cannot remove 'xxx.csv': Operation not permitted
How can I obtain the root permission to delete the file? I am not sure what default password I can use to run rm as root.
Thanks a lot!

You can specify the user as an argument:
sudo docker exec -it --user root sql1 "bash"

If you are on docker-compose
user:
0:0

Related

Why docker with SQL Server disappeared?

I run SQL Server in container
docker run --network=bridge --name sql29 -h sql29 -it --rm -v h:/sql219data:/var/opt/mssql -e "ACCEPT_EULA=Y" -e "SA_PASSWORD=sQL_19[pwd]" -p 12433:1433 -d mcr.microsoft.com/mssql/server:2019-latest
as described here:
https://learn.microsoft.com/en-us/sql/linux/tutorial-restore-backup-in-sql-server-container?view=sql-server-ver15
I see the active docker
docker ps
But if I try to create the new folder :
docker exec -it sql29 mkdir /var/opt/mssql/bkp22
then the docker disappeared.
docker ps
.........
How to understand: why the docker disappeared? Maybe the volume was mapped incorrectly?
As #Zeitounator commented, the tutorial you linked has a note saying that bind mounts don't work on Windows with the /var/opt/mssql directory:
Host volume mapping for Docker on Windows does not currently support mapping the complete /var/opt/mssql directory. However, you can map a subdirectory, such as /var/opt/mssql/data to your host machine.
You commented that your goal was to keep or restore databases between docker runs. You don't need a bind mount to do that, this is the primary purpose of a volume.
You can create a volume using docker volume create:
docker volume create sql219data
Then run your container using this volume:
docker run -v sql219data:/var/opt/mssql # ...
For debugging purposes you can remove the --rm option from your docker run command so the container won't be removed when stopped. You will then be able to read the logs of the container (even if it stopped):
docker logs sql29
# Then remove it to run the same `docker run` command again
docker rm sql29
docker run # ...

Docker container exec errors out

I have a Dockerfile that builds a SQL Server image. I am copying a SQL create table script into the image and an execs.sh that invokes this SQL script using docker exec -it "execs.sh".
What I am seeing is that it errors out if I invoke execs.sh using "docker exec -it" but if I shell into the container and run execs.sh it works. What am I doing wrong?
Dockerfile:
FROM microsoft/mssql-server-linux
COPY create_tables.sql .
COPY execs.sh .
# set environment variables
ENV MSSQL_SA_PASSWORD=P#ssw0rd
ENV ACCEPT_EULA=Y
execs.sh contents (this gets invoked from docker exec -it):
echo "Executing SQL scripts"
/opt/mssql-tools/bin/sqlcmd -S localhost -U SA -P 'P#ssw0rd' -i ./create_tables.sql
Script build container, run it, and execute commands:
docker build -t mssql_test .
docker run -p 1433:1433 --name mssql2 -d mssql_test
docker exec -it mssql2 "/execs.sh"
docker exec -it mssql2 "ls"
Output:
OCI runtime exec failed: exec failed: container_linux.go:349: starting container process
caused "exec format error": unknown
bin create_tables.sql execs.sh lib mnt root srv usr
boot dev home lib64 opt run sys var
etc install.sh media proc sbin tmp
You're missing an interpreter at the top of the script. When you run that from a shell like bash or sh, it assumes you want to run it as a shell script with the current shell. But when you run it with an OS exec there's no shell assuming how you want to run it. Therefore you want the following in the first line of your script:
#!/bin/sh
And be sure that's done with Linux linefeeds, not Windows linefeeds, else it will give you a file not found.
The problem is, that the command which your are try to force when the docker container starts (in your case: ./create_tables.sql) will be run at the same second the docker starts.
The SQL Server hasnt started yet, so the sql file could not even run against this service.
You have to work with either a great waiting time within your script or build a loop (e.g. check every second if the SQL server is reachable 100 times before exit).

Switch to Root User in a Dockerfile

I ran this command:
docker pull mcr.microsoft.com/mssql/server:2019-latest
I then made a dockerfile to use this container image as a base image for another container
# escape=`
FROM mcr.microsoft.com/mssql/server:2019-latest
SHELL ["/bin/bash", "-c"]
COPY ./CompanyCert.crt /usr/local/share/ca-certificates/CompanyCert.crt
RUN update-ca-certificates
When I try to build that docker file, I get this error:
ln: failed to create symbolic link '/etc/ssl/certs/CompanyCert.pem': Permission denied
So I added a RUN whoami to my docker file and it returns mssql. When I run id -u it returns 10001. So it seems that the user mssql does not have root permissions.
I tried putting sudo in front of my call to update-ca-certificates but it says:
/bin/bash: sudo: command not found
I tried to RUN su - and that returns:
su: must be run from a terminal
I have successfully used the above dockerfile to install my company certificates on other containers from Microsoft, but it is failing spectacularly this time.
How can I get root access so I can install my company certificate on this SQL Server Container?
Add USER root to your Dockerfile:
FROM mcr.microsoft.com/mssql/server:2019-latest
USER root
SHELL ["/bin/bash", "-c"]
COPY ./CompanyCert.crt /usr/local/share/ca-certificates/CompanyCert.crt
RUN update-ca-certificates

Docker postgres starting automation can not create database due to error

I want to create a shell script which automates the creation and running and creating database in a postgres database using docker.
I want to use the docker postgres official package for postgres in docker.
The script that I use is as follows:
docker network create --subnet=172.18.0.0/16 shared_network;
docker kill postgres_linker;
docker rm postgres_linker;
docker run --name postgres_linker -e POSTGRES_PASSWORD=blahblahblah -d --net shared_network --ip 172.18.0.2 postgres:10-alpine;
docker exec -it postgres_linker psql -U postgres -c "create database linker;";
But when I run this I get the following output without any database being created:
Error response from daemon: network with name shared_network already exists
postgres_linker
postgres_linker
b2a9fd4d6e25b62d60adb05c8b6b653a1b55ec7a869c4728677d6289f5cddd63
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
The first line of this log is OK, the second and third are too, The problem is that psql does not run the command on the postgres container althogh the command I am trying to run is correct. If I run the last command seperately from my shell script:
docker exec -it postgres_linker psql -U postgres -c "create database linker;";
It does not give me error! and it works!
Why is this behavior happening?
I found the solution to my problem.
Unfortunately I thought that when postgres container is run the server is up and running immediately.
It was not true and it takes some time to come up. so I have needed to add some delay.
So the resulting script file should look like this:
docker network create --subnet=172.18.0.0/16 shared_network;
docker kill postgres_linker;
docker rm postgres_linker;
docker run --name postgres_linker -e POSTGRES_PASSWORD=blahblahblah -d --net shared_network --ip 172.18.0.2 postgres:10-alpine;
sleep 5;
docker exec -it postgres_linker psql -U postgres -c "create database linker;";

Backup/Restore a dockerized PostgreSQL database

I'm trying to backup/restore a PostgreSQL database as is explained on the Docker website, but the data is not restored.
The volumes used by the database image are:
VOLUME ["/etc/postgresql", "/var/log/postgresql", "/var/lib/postgresql"]
and the CMD is:
CMD ["/usr/lib/postgresql/9.3/bin/postgres", "-D", "/var/lib/postgresql/9.3/main", "-c", "config_file=/etc/postgresql/9.3/main/postgresql.conf"]
I create the DB container with this command:
docker run -it --name "$DB_CONTAINER_NAME" -d "$DB_IMAGE_NAME"
Then I connect another container to insert some data manually:
docker run -it --rm --link "$DB_CONTAINER_NAME":db "$DB_IMAGE_NAME" sh -c 'exec bash'
psql -d test -h $DB_PORT_5432_TCP_ADDR
# insert some data in the db
<CTRL-D>
<CTRL-D>
The tar archive is then created:
$ sudo docker run --volumes-from "$DB_CONTAINER_NAME" --rm -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /etc/postgresql /var/log/postgresql /var/lib/postgresql
Now I remove the container used for the db and create another one, with the same name, and try to restore the data inserted before:
$ sudo docker run --volumes-from "$DB_CONTAINER_NAME" --rm -v $(pwd):/backup ubuntu tar xvf /backup/backup.tar
But the tables are empty, why is the data not properly restored ?
Backup your databases
docker exec -t your-db-container pg_dumpall -c -U postgres > dump_`date +%d-%m-%Y"_"%H_%M_%S`.sql
Restore your databases
cat your_dump.sql | docker exec -i your-db-container psql -U postgres
Backup Database
generate sql:
docker exec -t your-db-container pg_dumpall -c -U your-db-user > dump_$(date +%Y-%m-%d_%H_%M_%S).sql
to reduce the size of the sql you can generate a compress:
docker exec -t your-db-container pg_dumpall -c -U your-db-user | gzip > ./dump_$(date +"%Y-%m-%d_%H_%M_%S").gz
Restore Database
cat your_dump.sql | docker exec -i your-db-container psql -U your-db-user -d your-db-name
to restore a compressed sql:
gunzip < your_dump.sql.gz | docker exec -i your-db-container psql -U your-db-user -d your-db-name
PD: this is a compilation of what worked for me, and what I got from here and elsewhere. I am beginning to make contributions, any feedback will be appreciated.
I think you can also use a postgres backup container which would backup your databases within a given time duration.
pgbackups:
container_name: Backup
image: prodrigestivill/postgres-backup-local
restart: always
volumes:
- ./backup:/backups
links:
- db:db
depends_on:
- db
environment:
- POSTGRES_HOST=db
- POSTGRES_DB=${DB_NAME}
- POSTGRES_USER=${DB_USER}
- POSTGRES_PASSWORD=${DB_PASSWORD}
- POSTGRES_EXTRA_OPTS=-Z9 --schema=public --blobs
- SCHEDULE=#every 0h30m00s
- BACKUP_KEEP_DAYS=7
- BACKUP_KEEP_WEEKS=4
- BACKUP_KEEP_MONTHS=6
- HEALTHCHECK_PORT=81
cat db.dump | docker exec ... way didn't work for my dump (~2Gb). It took few hours and ended up with out-of-memory error.
Instead, I cp'ed dump into container and pg_restore'ed it from within.
Assuming that container id is CONTAINER_ID and db name is DB_NAME:
# copy dump into container
docker cp local/path/to/db.dump CONTAINER_ID:/db.dump
# shell into container
docker exec -it CONTAINER_ID bash
# restore it from within
pg_restore -U postgres -d DB_NAME --no-owner -1 /db.dump
Okay, I've figured this out. Postgresql does not detect changes to the folder /var/lib/postgresql once it's launched, at least not the kind of changes I want it do detect.
The first solution is to start a container with bash instead of starting the postgres server directly, restore the data, and then start the server manually.
The second solution is to use a data container. I didn't get the point of it before, now I do.
This data container allows to restore the data before starting the postgres container. Thus, when the postgres server starts, the data are already there.
The below command can be used to take dump from docker postgress container
docker exec -t <postgres-container-name> pg_dump --no-owner -U <db-username> <db-name> > file-name-to-backup-to.sql
The top answer didn't work for me. I kept getting this error:
psql: error: FATAL: Peer authentication failed for user "postgres"
To get it to work I had to specify a user for the docker container:
Backup
docker exec -t --user postgres your-db-container pg_dumpall -c -U postgres > dump_`date +%d-%m-%Y"_"%H_%M_%S`.sql
Restore
cat your_dump.sql | docker exec -i --user postgres your-db-container psql -U postgres
Another approach (based on docker-postgresql-workflow)
Local running database (not in docker, but same approach would work) to export:
pg_dump -F c -h localhost mydb -U postgres export.dmp
Container database to import:
docker run -d -v /local/path/to/postgres:/var/lib/postgresql/data postgres #ex runs container as `CONTAINERNAME` #find via `docker ps`
docker run -it --link CONTAINERNAME:postgres --volume $PWD/:/tmp/ postgres bash -c 'exec pg_restore -h postgres -U postgres -d mydb -F c /tmp/sonar.dmp'
I had this issue while trying to use a db_dump to restore a db. I normally use dbeaver to restore- however received a psql dump, so had to figure out a method to restore using the docker container.
The methodology recommended by Forth and edited by Soviut worked for me:
cat your_dump.sql | docker exec -i your-db-container psql -U postgres -d dbname
(since this was a single db dump and not multiple db's i included the name)
However, in order to get this to work, I had to also go into the virtualenv that the docker container and project were in. This eluded me for a bit before figuring it out- as I was receiving the following docker error.
read unix #->/var/run/docker.sock: read: connection reset by peer
This can be caused by the file /var/lib/docker/network/files/local-kv.db .I don't know the accuracy of this statement: but I believe I was seeing this as I do not user docker locally, so therefore did not have this file, which it was looking for, using Forth's answer.
I then navigated to correct directory (with the project) activated the virtualenv and then ran the accepted answer. Boom, worked like a top. Hope this helps someone else out there!
dksnap (https://github.com/kelda/dksnap) automates the process of running pg_dumpall and loading the dump via /docker-entrypoint-initdb.d.
It shows you a list of running containers, and you pick which one you want to backup. The resulting artifact is a regular Docker image, so you can then docker run it, or share it by pushing it to a Docker registry.
(disclaimer: I'm a maintainer on the project)
This is the command worked for me.
cat your_dump.sql | sudo docker exec -i {docker-postgres-container} psql -U {user} -d {database_name}
for example
cat table_backup.sql | docker exec -i 03b366004090 psql -U postgres -d postgres
Reference: Solution given by GMartinez-Sisti in this discussion.
https://gist.github.com/gilyes/525cc0f471aafae18c3857c27519fc4b
Solution for docker-compose users:
At First run the docker-compose file by any on of following commands: $ docker-compose -f loca.yml up OR docker-compose -f loca.yml up -d
For taking backup: $ docker-compose -f local.yml exec postgres backup
To see list of backups inside container: $ docker-compose -f local.yml exec postgres backups
Open another terminal and run following command: $ docker ps
Look for the CONTAINER ID of postgres image and copy the ID. Let's assume the CONTAINER ID is: ba78c0f9bcee
Now to bring that backup into your local file system, run the following command: $ docker cp ba78c0f9bcee:/backups ./local_backupfolder
Hope this will help someone who was lost just like me..
N.B: The full details of this solution can be found here.
Another way to do it is to run the pg_restore (of course if you have postgres set up in your host machine) command from the host machine.
Assuming that you have port mapping "5436:5432" for the postgres service in your docker-compose file. Having this port mapping will let you access the container's postgres (running on port 5432) via your host machine's port 5436
pg_restore -h localhost -p 5436 -U <POSTGRES_USER> -d <POSTGRES_DB> /Path/to/the/.psql/file/in/your/host_machine
This way you do not have to dive into the container's terminal or copy the dump file to the container.
I would like to add the official docker documentation for backups and restores. This applies to all kinds of data within a volume, not just postegres.
Backup a container
Create a new container named dbstore:
$ docker run -v /dbdata --name dbstore ubuntu /bin/bash
Then in the next command, we:
Launch a new container and mount the volume from the dbstore container
Mount a local host directory as /backup
Pass a command that tars the contents of the dbdata volume to a backup.tar file inside our /backup directory.
$ docker run --rm --volumes-from dbstore -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /dbdata
When the command completes and the container stops, we are left with a backup of our dbdata volume.
Restore container from backup
With the backup just created, you can restore it to the same container, or another that you made elsewhere.
For example, create a new container named dbstore2:
$ docker run -v /dbdata --name dbstore2 ubuntu /bin/bash
Then un-tar the backup file in the new container`s data volume:
$ docker run --rm --volumes-from dbstore2 -v $(pwd):/backup ubuntu bash -c "cd /dbdata && tar xvf /backup/backup.tar --strip 1"
You can use the techniques above to automate backup, migration and restore testing using your preferred tools.
Using a File System Level Backup on Docker Volumes
Example Docker Compose
version: "3.9"
services:
db:
container_name: pg_container
image: platerecognizer/parkpow-postgres
# restart: always
volumes:
- postgres_data:/var/lib/postgresql/data/
environment:
POSTGRES_USER: admin
POSTGRES_PASSWORD: admin
POSTGRES_DB: admin
volumes:
postgres_data:
Backup Postgresql Volume
docker run --rm \
--user root \
--volumes-from pg_container \
-v /tmp/db-bkp:/backup \
ubuntu tar cvf /backup/db.tar /var/lib/postgresql/data
Then copy /tmp/db-bkp to second host
Restore Postgresql Volume
docker run --rm \
--user root \
--volumes-from pg_container \
-v /tmp/db-bkp:/backup \
ubuntu bash -c "cd /var && tar xvf /backup/db.tar --strip 1"

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