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Questions tagged [chroot]

A chroot on Unix operating systems is an operation that changes the apparent root directory for the current running process and its children.

A chroot on Unix operating systems is an operation that changes the apparent root directory for the current running process and its children, i.e., the current running process and its children will "see" the root directory as the fake/apparent one, rather than seeing the real one. A program that is run in such a modified environment cannot name (and therefore normally not access) files outside the designated directory tree. The term "chroot" may refer to the chroot system call or the chroot wrapper program. The modified environment is called a "chroot jail".

History

The chroot system call was introduced during development of Version 7 Unix in 1979, and added to BSD by Bill Joy on 18 March 1982 – 17 months before 4.2BSD was released – in order to test its installation and build system.

Wikipedia Reference

ArchWiki Reference

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Chroot vs Docker

I'm trying to learn the basics about containers (Docker in this case). As far as I learn from the Docker doc and several readings, Docker basically provides isolation by running the container using runc (previously using LXC). Either ways it uses…
rkachach
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Shared library in containers

For two processes A and B, the both use the library libc.so, libc.so is loaded into memory only once. This is a normal situation when A and B both run on the same host and the same rootfs. When it comes to container, if A and B are running in…
Xinli Niu
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debootstrap inside a docker container

Here's my problem: I want to build a chroot environment inside a docker container. The problem is that debootstrap cannot run, because it cannot mount proc in the chroot: W: Failure trying to run: chroot /var/chroot mount -t proc proc /proc (in the…
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How to run a command in a chroot jail not as root and without sudo?

I'm setting up a minimal chroot and want to avoid having sudo or su in it but still run my processes as non-root. This is a bit of a trick as running chroot requiers root. I could write a program that does this that would look something like: uid =…
BCS
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Detecting a chroot jail from within

How can one detect being in a chroot jail without root privileges? Assume a standard BSD or Linux system. The best I came up with was to look at the inode value for "/" and to consider whether it is reasonably low, but I would like a more accurate…
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Chrooted PHP-FPM script cannot resolve DNS after a moment

I need some help to understand why a PHP-FPM chrooted PHP script fails to resolve an FQDN few instants after the PHP-FPM service started. When I (re)start the PHP-FPM service, it works (resolution succeeds) a few seconds and then resolution fails. I…
CDuv
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Bash: executing commands from within a chroot and switch user

Im writing a script that should do this... chroot /chroot_dir/ su - ./startup.sh (This should run within the su environment) I have tried this approach: chroot /chroot_dir /bin/bash -c " su -; ./startup.sh" This tries to execute the user switching…
dgrandes
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Shell Script that does chroot and execute commands in chroot

If in shell script I write chroot /home/mayank/chroot/codebase cd SBC when I run this shell script It does go in the chroot but does not execute the command cd SBC, when I exit chroot then it executes cd SBC. How can I achieve something that does…
Mayank Kataruka
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Public key authorization on sftp chroot directory

I want to add public key authorization to my sftp chroot directory but I allways get: debug1: Next authentication method: publickey debug1: Offering RSA public key: /home/test/.ssh/id_rsa debug3: send_pubkey_test debug2: we sent a publickey packet,…
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How can I get DNS resolution to work inside a Mac OS X `chroot` on El Capitan?

I'm trying to create a chroot to run a program that needs internet access to build myself a sandboxed, immutable developer environment. So far my jail is working well: I can run bash inside it and run simple programs from there! DNS resolution…
hornairs
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Python: Securing untrusted scripts/subprocess with chroot and chjail?

I'm writing a web server based on Python which should be able to execute "plugins" so that functionality can be easily extended. For this I considered the approach to have a number of folders (one for each plugin) and a number of shell/python…
BastiBen
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Can I restrict access to certain files for a certain process?

Is it possible to start a process in Linux, and restrict its access to certain files/directories? For example: $ start-process --enable-dir=./sandbox --exec="some-script.sh" some-script.sh won't be able to do anything outside of ./sandbox.
yegor256
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How does chroot affect dynamic libraries memory use?

Although there is another question with similar topic, it does not cover the memory use by the shared libraries in chrooted jails. Let's say we have a few similar chroots. To be more specific, exactly the same sets of binary files and shared…
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Is it possible let chroot jails share directories(read-only) outside the jail?

I have muliple chroot jails, I want them to share some directories, currently I have to copy these directories into jails which I think is not elegant. The directories are read-only, like '/usr/bin'.
freestyler
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run chroot within docker

I've a commercial app, that is shipped in a chroot environment : the startup script is making the chroot, and starting the exe. The App is pretty complex, and also for support purposes, I don't want to change the all environment. Is it possible to…
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