Docker attach gives empty new line

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AI-generated summary

The user bquast encountered an issue where docker attach resulted in an empty line with no command response. pfaffman suggested using docker exec -it app bash, which worked for running commands like ls. bquast confirmed this solved the problem but wanted to understand why docker attach failed. Ed_S clarified that docker exec provides a shell inside the container, which is the intended functionality. bquast later found that the issue stemmed from a web server running in the container, making docker attach ineffective. pfaffman also recommended using the data explorer plugin or administrative bulk operations for database exploration.

1

Hello, I have an instance of docker (the supported image).

When I try to docker attach it just shows the cursor blinking on an empty line, there is no response to commands like ls.

2

How about

docker exec -it app bash -c "your command here"
3

Yes that worked (with ls)

4

Great! Please mark as solved so the topic gets closed. Glad that worked!

5

Done!

But I’d still like to know what the problem was

and

How can I functionally attach?

6

Is it something like ./launcher enter app that you’re looking for? That’ll give you a shell prompt inside the container. I don’t know how to do it with docker directly, but maybe docker exec -it app bash

7

Indeed that is my objective, I want to sniff around the database tables.

I will try docker exec -it app bash

I thought that this was what docker attach was for, but I’m not an expert.

8

Looking further based on the hints fomr @pfaffman and @Ed_S, this answer from SO explained it well (accepted answer)

EDIT: the point is that a web server is running on the image, so docker attach doesn’t work, but the exec command does

9

Then maybe use the data explorer plugin. That’s a much better way to explore the database.

But maybe you’d be interested in Administrative Bulk Operations