calling ansible-playbook from execute shell of jenkins adds extra quotes - jenkins

While tryting to execute an ansible-playbook from jenkins execute shell, extra quotes are being added by jenkins which causes the ansible-playbook execution to fail. Any work around on this ?
/usr/local/bin/ansible-playbook -i $env $role -e"var1=$var1, var2=$var2, var3=$var3"
The output of the above is :
/usr/local/bin/ansible-playbook -i env-value role-value '-evar1=var1-value, var2=var2-value, var3=var3-value'
If i escape quotes as follows:
/usr/local/bin/ansible-playbook -i $env $role -e\"var1=$var1, var2=$var2, var3=$var3\"
the output of the above is :
/usr/local/bin/ansible-playbook -i env-value role-value '-e"var1=var1-value,' 'var2=var2-value,' 'var3=var3-value"'

What I would do to avoid this quoting issue is to use a -e for every argument:
extra_args+="-e var1=$var1 -e var2=$var2 -e var3=$var3"
ansible-playbook -i $env $role $extra_args
It's also useful when specifying an optional argument that's read in from a jenkins parameter, for example:
if [[ -z $var1 ]]; then
extra_args+="-e var1=$var1"
fi
Also note that if you specify multiple extra vars using -e on the command line you should separate them with spaces, not commas.

Related

How to see the PATH inside a shell without opening a shell

Use the command flag looked like a solution but it doesn't work
Inside the following shell:
nix shell github:nixos/nixpkgs/nixpkgs-unstable#hello
the path contain a directory with an executable hello
I've tried this:
nix shell github:nixos/nixpkgs/nixpkgs-unstable#hello --command echo $PATH
I can't see the hello executable
My eyes are not the problem.
diff <( echo $PATH ) <( nix shell github:nixos/nixpkgs/nixpkgs-unstable#hello --command echo $PATH)
It see no difference. It means that the printed path doesn't not contains hello.
Why?
The printed path does not contain hello because if your starting PATH was /nix/var/nix/profiles/default/bin:/run/current-system/sw/bin, then you just ran:
nix shell 'github:nixos/nixpkgs/nixpkgs-unstable#hello' --command \
echo /nix/var/nix/profiles/default/bin:/run/current-system/sw/bin
That is to say, you passed your original path as an argument to the nix shell command, instead of passing it a reference to a variable for it to expand later.
The easiest way to accomplish what you're looking for is:
nix shell 'github:nixos/nixpkgs/nixpkgs-unstable#hello' --command \
sh -c 'echo "$PATH"'
The single quotes prevent your shell from expanding $PATH before a copy of sh invoked by nix is started.
Of course, if you really don't want to start any kind of child shell, then you can run a non-shell tool to print environment variables:
nix shell 'github:nixos/nixpkgs/nixpkgs-unstable#hello' --command \
env | grep '^PATH='

Shell script unknown operand alpine

I am running into a problem where my shell script doesn't work if the variable is not set/set to empty string.
For this I am using the alpine image
docker run -dt alpine
docker exec -it <container> sh
Here is the problematic code:
x=""
sh -c "if [ "$x" != "required" ]; then sed; fi"
When x is not set, I get the error:
sh: required: unknown operand
This seems to only be the problem on an empty string. If I set x="lkajsdfasl", it will work just fine.
This just breaks down on an empty string/not set.
Due to the way my docker-compose is setup, I can only use sh and have to use sh -c
It's a quoting issue. Use single quotes around the command like this
sh -c 'if [ "$x" != "required" ]; then sed; fi'

How do you properly escape a sed command in a Jenkinsfile

I can run this command from the command line to get the value for the latest release in a GitHub repo:
curl --silent "https://api.github.com/repos/MyOrg/MyRepo/releases/latest"|grep "tag_name"|sed -E 's/."([^"]+)"./\1/'
I'd like to use this in a Jenkinsfile, but I can't seem to properly escape the special characters.
pipeline {
agent any
stages {
stage('Test') {
steps {
sh """
latest=`curl --silent \\\"https://api.github.com/repos/MyOrg/MyRepo/releases/latest\\\"|
grep \\\"tag_name\\\"|
sed -E \\\'s/.*\\\"([^\\\"]+)\\\".*/\1/\\\'`
""".stripIndent()
}
}
}
}
When run in a pipeline, I get the following error:
[Pipeline] sh
curl --silent "https://api.github.com/repos/MyOrg/MyRepo/releases/latest"
grep "tag_name"
sed -E 's/.*"
sed: -e expression #1, char 1: unknown command: `''
instead of wrapping the large expression in backticks, try instead wrapping it in
$(command_1 | command_2 | command_3)
Also add, at the start of the shell command:
set -x;
and you'll get debug output in the console output (possibly). You should then see how your script is being evaluated.

issues in accessing docker environment variables in systemd service files

1) I am running a docker container with following cmd (passing few env variables with -e option)
$ docker run --name=xyz -d -e CONTAINER_NAME=xyz -e SSH_PORT=22 -e NWMODE=HOST -e XDG_RUNTIME_DIR=/run/user/0 --net=host -v /mnt:/mnt -v /dev:/dev -v /etc/sysconfig/network-scripts:/etc/sysconfig/network-scripts -v /:/hostroot/ -v /etc/hostname:/etc/host_hostname -v /etc/localtime:/etc/localtime -v /var/run/docker.sock:/var/run/docker.sock --privileged=true cf3681e04bfb
2) After running the container as above, i check the env variable NWMODE inside the container, and it shows correctly as shown below :
$ docker exec -it xyz bash
$ env | grep NWMODE
NWMODE=HOST
3) Now, i created a sample service 'b' shown below which executes a script b.sh (where i try to access NWMODE) :
root#ubuntu16:/etc/systemd/system# cat b.service
[Unit]
Description=testing service b
[Service]
ExecStart=/bin/bash /etc/systemd/system/b.sh
root#ubuntu16:/etc/systemd/system# cat b.sh
#!/bin/bash`
systemctl import-environment
echo "NWMODE:" $NWMODE`
4) Now if i start service 'b' and see its logs, it shows that it is not able to access NWMODE env variable
$ systemctl start b
$ journalctl -fu b
...
systemd[1]: Started testing service b.
bash[641]: NWMODE: //blank for $NWMODE here`
5) Now rather than having 'systemctl import-environment' in b.sh, if i do following then the b.service logs show the correct value of NWMODE env variable:
$ systemctl import-environment
$ systemctl start b
Though the step 5 above works i can't go for it, as all the services in my system will be started automatically by systemd. In that case, can anyone please let me know how can i access the environment variables (passed using 'docker run...' cmd above) in a service file (say for e.g. in b.sh above). Can this be achieved somehow with systemctl import-environment or there is some other way ?
systemd unsets all environment variables to provide a clean environment. Afaik that is intended to be a security feature.
Workaround: Create a file /etc/systemd/system.conf.d/myenvironment.conf:
[Manager]
DefaultEnvironment=CONTAINER_NAME=xyz NWMODE=HOST XDG_RUNTIME_DIR=/run/user/0
systemd will set the environment variables declared in this file.
You can set up an ENTRYPOINT script that automatically creates this file before running systemd. Example:
RUN echo '#! /bin/bash \n\
echo "[Manager] \n\
DefaultEnvironment=$(while read -r Line; do echo -n "$Line" ; done < <(env) \n\
" >/etc/systemd/system.conf.d/myenvironment.conf \n\
exec /lib/systemd/systemd \n\
' >/usr/local/bin/setmyenv && chmod +x /usr/bin/setmyenv
ENTRYPOINT /usr/bin/setmyenv
Instead of creating the script within Dockerfile you can store it outside and add it with COPY:
#! /bin/bash
echo "[Manager]
DefaultEnvironment=$(while read -r Line; do echo -n "$Line" ; done < <(env)
" >/etc/systemd/system.conf.d/myenvironment.conf
exec /lib/systemd/systemd
TL;DR
Run the the command using bash, first store the docker environment variables to a file (or just pipe them two awk), extract & export the variable and finally run your main script.
ExecStart=/bin/bash -c "cat /proc/1/environ | tr '\0' '\n' > /home/env_file; export MY_ENV_VARIABLE=$(awk -F= -v key="MY_ENV_VARIABLE" '$1==key {print $2}' /home/env_file); /usr/bin/python3 /usr/bin/my_python_script.py"
Whatever #mviereck is saying is true, still I have found another solution to this problem.
My use case is to pass an environment variable to my system-d container in the Docker run command (docker run -e MY_ENV_VARIABLE="some_val") and use that in the python script that is run through the system-d unit file.
According to this post (https://forums.docker.com/t/where-are-stored-the-environment-variables/65762) the container environment variables can be found in the running process /proc/1/environ inside the container. Performing a cat does show that the environment variable MY_ENV_VARIABLE=some_val does exist, though in some mangled form.
$ cat /proc/1/environ
HOSTNAME=271fbnd986bdMY_ENV_VARIABLE=some_valcontainer=dockerLC_ALL=CDEBIAN_FRONTEND=noninteractiveHOME=/rootroot#271fb0d986bd
The main task now would be to extract MY_ENV_VARIABLE="some_val" value and pass it to the ExecStart directive in the system-d unit file.
(extraction code referenced from How to grep for value in a key-value store from plain text)
# this outputs a nice key,value pair
$ cat /proc/1/environ | tr '\0' '\n'
HOSTNAME=861f23cd1b33
MY_ENV_VARIABLE=some_val
container=docker
LC_ALL=C
DEBIAN_FRONTEND=noninteractive
HOME=/root
# we can store this in a file for use, too
$ cat /proc/1/environ | tr '\0' '\n' > /home/env_var_file
# we can then reuse the file to extract the value of interest against a key
$ awk -F= -v key="MY_ENV_VARIABLE" '$1==key {print $2}' /home/env_file
some_val
Now in the ExecStart directive in the system-d unit file we can do this:
[Service]
Type=simple
ExecStart=/bin/bash -c "cat /proc/1/environ | tr '\0' '\n' > /home/env_file; export MY_ENV_VARIABLE=$(awk -F= -v key="MY_ENV_VARIABLE" '$1==key {print $2}' /home/env_file); /usr/bin/python3 /usr/bin/my_python_script.py"

Why is capistrano interpreting a flag passed with a command to `run` as input?

I'm trying to do this:
run "echo -n 'foo' > bar.txt"
and the contents of bar.txt ends up being:
-n foo \n
(With \n representing an actual newline)
I use run for other commands like rm -rf and, to my knowledge, it works fine.
I just found this in man echo:
Some shells may provide a builtin echo command which is similar or identical to this utility. Most notably, the builtin echo in sh(1) does not accept the -n option. Consult the builtin(1) manual page.
My version of bash has an echo builtin but seems to be respecting the -n flag. It looks like the shell on your deployment machine doesn't, in which case using the full path to the echo binary might do what you want here:
run "/bin/echo -n 'foo' > bar.txt"
It appears as though the -n flag isn't being interpreted as a flag by the shell. If, from the command line, one executes echo -Y hi, the output will be -Y hi.

Resources