Escape sequences cannot be used inside quoted strings

[milas]

Description of the issue

Docker Compose v2 (compose-go) is stripping out escape characters when inside of a quoted string in a command (might happen in other circumstances).

If it's not in a quoted string, they are left as-is. For example, command: printf 'Hello\tworld\n' works while command: sh -c "printf 'Hello\tworld\n'" does not.

Context information (for bug reports)

• Using Compose V2 docker compose ...
• Using Compose V1 docker-compose ...

Output of docker(-)compose version

Docker Compose version v2.0.0-rc.2

Output of docker version

Client:
 Cloud integration: 1.0.17
 Version: 20.10.8
 API version: 1.41
 Go version: go1.16.6
 Git commit: 3967b7d
 Built: Fri Jul 30 19:55:20 2021
 OS/Arch: darwin/amd64
 Context: default
 Experimental: true

Server: Docker Engine - Community
 Engine:
 Version: 20.10.8
 API version: 1.41 (minimum version 1.12)
 Go version: go1.16.6
 Git commit: 75249d8
 Built: Fri Jul 30 19:52:10 2021
 OS/Arch: linux/amd64
 Experimental: true
 containerd:
 Version: 1.4.9
 GitCommit: e25210fe30a0a703442421b0f60afac609f950a3
 runc:
 Version: 1.0.1
 GitCommit: v1.0.1-0-g4144b63
 docker-init:
 Version: 0.19.0
 GitCommit: de40ad0

Output of docker-compose config
w/ v2 (v2.0.0-rc.2):

services:
 hello-world:
 command:
 - sh
 - -c
 - printf 'Hellotworldn'
 image: busybox
 networks:
 default: null
networks:
 default:
 name: escape-repro_default

w/ v1 (1.29.2, build 5becea4):

services:
 hello-world:
 command: sh -c "printf 'Hello\tworld\n'"
 image: busybox
version: '3.9'

Steps to reproduce the issue

1. Use an escape sequence (e.g. \t or \n) inside of a quoted string in command

Observed result

• Docker Compose v2 (compose-go) strips out the \ characters

Expected result

• Docker Compose leaves the \ characters as-is

Stacktrace / full error message

n/a

Additional information

n/a

[ndeloof]

compose v2 config do render the fully parsed compose model, as it is used to invoke on engine API and create container. Doing so, command is parsed into a slice of command and arguments.

but getting \t converted into unescaped character t is definitively a bug.

[milas]

Yeah - the conversion from string -> list isn't surprising, just the stripping out of \ characters.

Output of running under both versions:

v1:

$ docker-compose -p escape-repro -f escape-repro.yml up
Creating network "escape-repro_default" with the default driver
Creating escape-repro_hello-world_1 ... done
Attaching to escape-repro_hello-world_1
hello-world_1 | Hello	world
escape-repro_hello-world_1 exited with code 0

v2:

$ docker-compose -p escape-repro -f escape-repro.yml up
[+] Running 2/2
 ⠿ Network escape-repro_default Created 0.1s
 ⠿ Container escape-repro_hello-world_1 Created 0.1s
Attaching to hello-world_1
hello-world_1 exited with code 0

(FWIW There's also a subtle difference here in v2 which is that if the last log line doesn't end in \n it is never printed - in v1 it would get printed although it kinda messes with the output since then the "exited with code" line from compose is on the same line as it but 🤷)

[ulyssessouza]

It actually works with double backslash.
Ex. \\t and \\n

Looks like the backslash is escaped too.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[milas]

I can confirm this is still the case as of v2.3.3

[stale]

This issue has been automatically marked as not stale anymore due to the recent activity.

[dragonsahead]

seems that all my bash scripts that were passed in the command to bash containers broke because of this

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically closed because it had not recent activity during the stale period.