I am using K8S
I want to calculate a string that that is a result of kubectl exec -it ... -c
after the -c option there is a string.
How can I pass a string with double quotes inside.
The following example doesn't work properly.
x="$(kubectl exec -it mysql-pod -- /bin/sh -c \"mysql -uroot -p12345
-e 'show databases'\" 2>/dev/null)"
echo $x
Thanks.
when only a command needs to be executed on a pod , -it option is not required as it stands for attaching an interactive teminal
when mysql is itself an executable command , no need to use /bin/sh -c
no need to encapsulate whole command in " "
So try following
x=$(kubectl exec mysql-pod -- mysql -uroot -p12345 -e 'show databases ;' 2>/dev/null)
echo $x
Related
I have a PostgresDB query which I want to run directly using kubectl exec:
kubectl exec -it -n <ns> <pod_name> -- psql -U <user> -d <db> -c "select * from <table> where id=1234;"
I want to toggle expanded output (\x on option) only for this command. I do not want to permanently enable this for all queries.
I have tried various things, such as chaining commands together with a semi-colon (i.e. \x on; select * from <table>;). I'm not getting this to work.
How do I get this to work?
There are several ways to do that, but the simplest is to use the -x option of psql.
I have the following command that I'm running (renamed some variables):
docker exec docker_name sh -c 'psql dbname -U joeadmin -c "update table set field='really_longstringwithabunf3493829#########=';"'
When I run this, it will throw the following error:
ERROR: syntax error at or near ";"
LINE 1: ...longstringwithabunf3493829#########=;
^
How can I escape or retain the single quotes so this will work. Also, if this is just a horrible way of approaching this, I'm open to other suggestions. The use case is making changes to a db on a docker container before exporting data out of it.
Working with strings can be a bit ugly at times with Docker. In your case, I would suggest using double-quotes first, then escape inner double-quotes with \:
docker exec docker_name sh -c "psql dbname -U joeadmin -c \"update table set field='really_longstringwithabunf3493829#########=';\""
A cleaner option would be to create an environment variable:
STR="really_longstringwithabunf3493829#########="
docker exec docker_name sh -c "psql dbname -U joeadmin -c \"update table set field='${STR}';\""
Bear in mind that string interpolation happens in the host OS, not in the container (unless you escape the dollar-sign with \${STR}
Still cleaner would just be to create a file and then copy it into the container:
echo "update table set field='really_longstringwithabunf3493829#########=';" > ~/myfile.txt
docker cp ~/myfile.txt docker_name:/tmp
docker exec docker_name sh -c "psql dbname -U joeadmin -f /tmp/myfile.txt"
I'm trying to write a script that runs some commands inside the container using kubectl exec. I'd like to use the environment variables that exist inside the container, but struggling to figure out how to prevent my local shell from evaluating the var and still have it evaluated in the container.
This was my first try, but $MONGODB_ROOT_PASSWORD get evaluated by my local shell instead of inside the container:
kubectl -n enterprise exec mycontainer -- mongodump --username root --password $MONGODB_ROOT_PASSWORD --out /dump
I tried this, but the had the same issue with pipe, it was evaluated in my local instead of in the container:
kubectl -n enterprise exec mycontainer -- echo 'mongodump --username root --password $MONGODB_ROOT_PASSWORD --out /dump' | sh
Is there a way to do this with kubectl exec?
You need a sh -c in there, like exec -- sh -c 'whatever $PASSWORD'.
I'm writing a shell script which needs to login into the pod and execute a series of commands in a kubernetes pod.
Below is my sample_script.sh:
kubectl exec octavia-api-worker-pod-test -c octavia-api bash
unset http_proxy https_proxy
mv /usr/local/etc/octavia/octavia.conf /usr/local/etc/octavia/octavia.conf-orig
/usr/local/bin/octavia-db-manage --config-file /usr/local/etc/octavia/octavia.conf upgrade head
After running this script, I'm not getting any output.
Any help will be greatly appreciated
Are you running all these commands as a single line command? First of all, there's no ; or && between those commands. So if you paste it as a multi-line script to your terminal, likely it will get executed locally.
Second, to tell bash to execute something, you need: bash -c "command".
Try running this:
$ kubectl exec POD_NAME -- bash -c "date && echo 1"
Wed Apr 19 19:29:25 UTC 2017
1
You can make it multiline like this:
$ kubectl exec POD_NAME -- bash -c "date && \
echo 1 && \
echo 2"
The following should work
kubectl -it exec podname -- bash -c "ls && ls"
bin dev etc home proc root run sys tmp usr var bin
dev etc home proc root run sys tmp usr var
If above command doesn't work then try too replace bash with one of the following /bin/bash, sh or /bin/sh
-t
can solve your task
For example, I run here few cmd:
kubectl get pods |grep nginx|cut -f1 -d\ |\
while read pod; \
do echo "$pod writing:";\
kubectl exec -t $pod -- bash -c \
"dd if=/dev/zero of=/feeds/test.bin bs=260K count=4 2>&1|\
grep copi |cut -d, -f4; \
a=$SECONDS; echo -ne 'reading:'; cat /feeds/test.bin >/dev/null ; \
let a=SECONDS-a ; \
echo $a sec"
done
p.s. your example will be:
kubectl exec -t octavia-api-worker-pod-test -c octavia-api -- bash -c "unset http_proxy https_proxy ; mv /usr/local/etc/octavia/octavia.conf /usr/local/etc/octavia/octavia.conf-orig ; /usr/local/bin/octavia-db-manage --config-file /usr/local/etc/octavia/octavia.conf ; upgrade ; head"
Posting here because google search still brings you to this post...
I'd like to throw out using a HEREDOC as an additional possibility.
kubectl exec -i --tty-false PODNAME -- bash << EOF
echo "insert all your commands here."
echo "this subprocess will even pickup any variables you have in"
echo "the shell script that is calling this"
EOF
I want to close the mongo shell after executing the following in a docker command:
#!/bin/bash
docker run -it --link sonams-mongo:mongo --rm mongo sh -c 'exec mongo "$MONGO_PORT_27017_TCP_ADDR:$MONGO_PORT_27017_TCP_PORT/test"'
if [ $? -eq 0 ]; then \
echo "connected to mongo successful"; \
else \
echo "mongo connection NOT successful"; \
fi; \
When it connects it goes to a shell prompt within mongo. Is there a way to pass a shell command to do an exit right in or after the docker command?
thanks
Usually (of course it depends on the base image you're using) you wouldn't need to invoke "sh -c". Also, the -it combination is usually what makes the shell open and wait for input. Try to change your command a little bit, like below, without -it and sh -c:
docker run --link sonams-mongo:mongo --rm mongo mongo "$MONGO_PORT_27017_TCP_ADDR:$MONGO_PORT_27017_TCP_PORT/test"
if that doesn't help, try this:
echo "$MONGO_PORT_27017_TCP_ADDR:$MONGO_PORT_27017_TCP_PORT/test" | docker run --link sonams-mongo:mongo --rm mongo mongo