The following command issued on a Mac terminal is failing the docker command on the remote shell.
However it works if I log in to the server and issue the command there with replacing ";" with "&&"
ssh -i "myKey.pem" user#host ‘docker stop $(docker ps -a -q --filter ancestor=name/kind); docker rm $(docker ps -a -q --filter ancestor=name/kind); docker rmi name/kind; docker build -t name/kind .; sudo docker run -it -d -p 80:80 name/kind’
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
I need to run this command form the local terminal because if is part of bigger command which first build the project locally and scp it to the server.
`$bigger-command && then-the-ssh-as-shown-above.
How do I go about it? Thanks
The best way to pass very complex commands to ssh is the create a script on the server side.
If you need to pass some parameters, proceed this way:
create a .sh file on your localhost
scp it to your remote host
run `ssh user#remotehost 'bash scriptfile.sh'
This should do the trick without giving you headaches about escapement.
Related
First: I have searched the forum and also went through documentation, but still cannot get it right.
So, I have a docker command I want to run on a remote server, from my bash script. I want to pass an environment variable – on the local machine running the script – to the remote server. Furthermore, I need a response from the remote command.
Here is what I actually am trying to do and what I need: the script is a tiny wrapper around our Traefik/Docker/Elixir/Phoenix app setup to be able to connect easily to the running Elixir application, inside the Erlang observer. With the script, the steps would be:
ssh into the remote machine
docker ps to see all running containers, since in our blue/green deploy the active one changes name
docker exec into the correct container
execute a command inside the docker container to connect to the running Elixir application
The command I am using now is:
CONTAINER=$(ssh -q $USER#$IP 'sudo docker ps --format "{{.Names}}" | grep ""$APP_NAME"" | head -n 1')
The main problem is the part with the grep and the ENV var... It is empty, and does not get replaced. It makes sence, since that var does not exist on the remote machine, it does on my local machine. I tried single quotes, $(), ... Either it just does not work, or the solutions I find online execute the command but then I have no way of getting the container name, which I need for the subsequent command:
ssh -o 'RequestTTY force' $USER#$IP "sudo docker exec -i -t $CONTAINER /bin/bash -c './bin/app remote'"
Thanks for your input!
First, are you sure you need to call sudo docker stop? as stopping the containers did not seem to be part of the workflow you mentioned. [edit: not applicable anymore]
Basically, you use a double-double-quote, grep ""$APP_NAME"", but it seems this variable is not substituted (as the whole command 'sudo docker ps …' is singled-quoted); according to your question, this variable is available locally, but not on the remote machine, so you may try writing:
CONTAINER=$(ssh -q $USER#$IP 'f() { sudo docker ps --format "{{.Names}}" | grep "$1" | head -n 1; }; f "'"$APP_NAME"'"')
You can try this single command :
ssh -t $USER#$IP "docker exec -it \$(docker ps -a -q --filter Name=/$APP_NAME) bash -c './bin/app remote'"
You will need to redirect the command with the local environmental variable (APP_NAME) into the ssh command using <<< and so:
CONTAINER=$(ssh -q $USER#$IP <<< 'sudo docker ps --format "{{.Names}}" | grep "$APP_NAME" | head -n 1 | xargs -I{} sudo docker stop {}')
completely new to the shell script. I want to run the sql image (image is just there to take a db dump) and take a dump of the db and copy file to the host using shell script.
how i do manually is
1) docker run -it <image_name> bash (this takes in image bash)
2) mysqldump -h <ip> -u <user> -p db > filename.sql
3) docker cp <containerId>:/file/path/within/container /host/path/target (running this in host machine)
doing this i get the dump from container to host manually.
but while making shell script, i am having problem with the point 1) docker run -it <image_name> bash (this takes in image bash) since this takes me to the bash and i have to manually type the command.
how can i do it in the shell script.
any help will be greatly appreciated!
If I understand this correctly, you don't want to type those command manually and instead shell script should execute your command as and when you container is up and running. Now if you can modify sql related Dockerfile and can re-create image then use ENTRYPOINT [and if needed CMD] to execute shell script at startup. Check this link for details on ENTRYPOINT shell script.
Else, if you cannot recreate image then check this post i.e. how to run bash script from run command.
NOTE in both these cases you will have to mount your directory/volume and your sqldump command should copy dump this map volume/directory
You can pass the command to Bash as a parameter:
docker run -it <image_name> --name sqldump bash -c "mysqldump -h <ip> -u <user> -p db > /tmp/filename.sql"
docker cp sqldump:/tmp/filename.sql /path/on/host/filename.sql
Ignore the Docker steps, and just run mysqldump on your host. The -h option is the IP address or DNS name of the host running the database (can be 127.0.0.1 if the container is running on the same host, but not localhost because MySQL misinterprets that); if you mapped the database external port to a non-default port, you also need a -P (capital P) option to specify that port.
For example, if you started the container with
docker run -p 5433:5432 ... mysql:8
then you can take the dump from the host with
mysqldump -h 127.0.0.1 -P 5433 -p db > dump.sql
and not worry about the Docker details at all.
I am trying to get a shell inside the Docker container moul/phoronix-test-suite on Docker Hub using this command
docker run -t -i moul/phoronix-test-suite /bin/bash
but just after executing the command (binary file), the container stops and I get no shell into it.
[slazer#localhost ~]$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
0993189463e6 moul/phoronix-test-suite "phoronix-test-suite " 7 seconds ago Exited (0) 3 seconds ago kickass_shockley
It is a ubuntu:trusty container. How can I get a shell into it, so that I can send arguments to the command phoronix-test-suite?
docker run -t -i moul/phoronix-test-suite /bin/bash will not give you a bash (contrary to docker run -it fedora bash)
According to its Dockerfile, what it will do is execute
phoronix-test-suite /bin/bash
Meaning, it will pass /bin/bash as parameter to phoronix-test-suite, which will exit immediately. That leaves you no time to execute a docker exec -it <container> bash in order to open a bash in an active container session.
Have you tried restarting your docker? It might need to restart or even reboot the host.
I am running Docker (1.10.2) on Windows. I created a script to echo 'Hello World' on my machine and stored it in C:/Users/username/MountTest. I created a new container and mounted this directory (MountTest) as a data volume. The command I ran to do so is shown below:
docker run -t -i --name mounttest -v /c/Users/sarin/MountTest:/home ubuntu /bin/bash
Next, I run the command to execute the script within the container mounttest.
docker exec -it mounttest sh /home/helloworld.sh
The result is as follows:
: not foundworld.sh: 2: /home/helloworld.sh:
Hello World
I get the desired output (echo Hello World) but I want to understand the reason behind the not found errors.
Note: This question might look similar to Run shell script on docker from shared volume, but it addresses permission related issues.
References:
The helloworld.sh file:
#!/bin/sh
echo 'Hello World'
The mounted volumes information is captured below.
Considering the default ENTRYPOINT for the 'ubuntu' image is sh -c, the final command executed on docker exec is:
sh -c 'sh /home/helloworld.sh'
It looks a bit strange and might be the cause of the error message.
Try simply:
docker exec -it mounttest /home/helloworld.sh
# or
docker exec -it mounttest sh -c '/home/helloworld.sh'
Of course, the docker exec should be done in a boot2docker ssh session, simalar to the shell session in which you did a docker run.
Since the docker run opens a bash, you should make a new boot2docker session (docker-machine ssh), and in that new boot2docker shell session, try the docker exec.
Trying docker exec from within the bash made by docker run means trying to do DiD (Docker in Docker). It is not relevant for your test.
To be honest, I have always been confused about docker exec -it …, docker exec -i … and docker exec -t …, so I decide to do a test:
docker exec -it …:
# docker exec -it 115c89122e72 bash
root#115c89122e72:/# ls
bin boot dev etc home lib lib64 media mnt opt proc root run sbin srv sys tmp usr var
It works normally.
docker exec -i …:
# docker exec -i 115c89122e72 bash
^C
The command hangs and I have to use Ctl + c to interrupt it.
docker exec -t …:
# docker exec -t 115c89122e72 bash
root#115c89122e72:/# ls
^C
It enters the container successfully but hangs on executing the first command.
So it seems there is no point in having the docker exec -i … and docker exec -t … commands. Could anyone elaborate on why there exist -i and -t options for the docker exec command?
-i, --interactive keeps STDIN open even if not attached, which you need if you want to type any command at all.
-t, --tty Allocates a pseudo-TTY, a pseudo terminal which connects a user's "terminal" with stdin and stdout. (See container/container.go)
If you do an echo, only -t is needed.
But for an interactive session where you enter inputs, you need -i.
Since -i keeps stdin open, it is also used in order to pipe input to a detached docker container. That would work even with -d (detach).
See "When would I use --interactive without --tty in a Docker container?":
$ echo hello | docker run -i busybox cat
hello
-i keeps STDIN open even if not attached, what is the status of STDOUT in this case?
It is, for docker exec, the one set by docker run.
But, regarding docker exec, there is a current issue (issue 8755: Docker tty is not a tty with docker exec
unfortunately your discovery only amounts to a difference between the behaviour of tty in centos6 vs ubuntu:14.04. There is still not a functional tty inside the exec - just do ls -la /proc/self/fd/0 and see that it's a broken link pointing to a pts which doesn't exist.
the actual bug we're dealing with is that certain standard libraries assume that the symlinks in /proc/self/fds/ must be valid symlinks
The problem is that the tty is created outside on the host and there is no reference to it in the container like how /dev/console is setup in the primary container.
One options to fix this would be allocate and bind mount the devpts from the host in to the containers.
Note (Q4 2017): this should been fixed by now (docker 17.06-ce).
See PR 33007.
That PR now allows (since 17.06):
zacharys-pro:dev razic$ docker run --rm -t -d ubuntu bash
83c292c8e2d13d1b1a8b34680f3fb95c2b2b3fef71d4ce2b6e12c954ae50965a
zacharys-pro:dev razic$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
83c292c8e2d1 ubuntu "bash" 2 seconds ago Up 1 second xenodochial_bardeen
zacharys-pro:dev razic$ docker exec -ti xenodochial_bardeen tty
/dev/pts/1
(before 17.06, tty was returning "not a tty")