Issues with using grep in Drone Pipeline

Drone Support
1

Hello,

I am having some issues with drone parsing a grep command in my pipeline. Essentially, I am using grep to pull a version number of one of my container images in order to promote the image from dev -> stage and eventually stage->prod. I am doing this through gcloud. My command to grab the image using gcloud syntax is:

gcloud container images list-tags <my-image-repository> --filter="tags:latest" --format="table[noheading](tags)" | grep -o '\bv\w*.*'

This command parses the correct information when I log directly into the docker container that I am using to execute this step, however, when I run it with Drone it appears to yank the \b from my grep command completely. I tested this with a pipeline by just running grep -o '\bv\w*.*' against a test.txt file that included a string v1.0.30841303 and the pipeline fails out with the last step showing the following:

+ grep -o 'v\w*.*' test.txt

Is there something I am doing wrong or is there something in Drone that would cause it to incorrectly parse the \b in my grep syntax?

Thank you!

2

you probably need to escape the value (e.g. \\b) so that yaml preserves the literal value, or you can do something like this:

steps:
- |
  gcloud container images list-tags <my-image-repository> --filter="tags:latest" --format="table[noheading](tags)" | grep -o '\bv\w*.*'

Drone is going to unmarhsal your commands to a []string variable and is then going to use these commands to generate a bash file. It will write the commands as-is and will not change them in any way. If the command is changing, it would have to be related to the yaml parsing (which is done by a third party library).