Concourse resource cache flushing

Question

Sometimes when a concourse pipeline is getting build, it tries to use the previous version of resource, not the latest one. I could confirm this because the resource hash don't match. Please let me know a solution to flush the resource hash.

Answer 1

Concourse v7.4.0 (released August 2021) adds the command

fly clear-resource-cache -r <pipeline>/<resource>

which will do what you are looking for.

See:

• the documentation for clear-resource-cache.
• the release notes for v7.4.0

Answer 2

The only way to flush the resource cache is to restart all the workers, as this will clear your ephemeral disks.

Answer 3

The fly clear-resource-cache -r <pipeline>/<resource> command doesn't work for older versions.

To achieve similar results, you can use

fly -t ci clear-task-cache -j <pipeline>/<resource> -s <step-name>

Check the help command for more info:

Usage:
  fly [OPTIONS] clear-task-cache [clear-task-cache-OPTIONS]

Application Options:
  -t, --target=              Concourse target name
  -v, --version              Print the version of Fly and exit
      --verbose              Print API requests and responses
      --print-table-headers  Print table headers even for redirected output

Help Options:
  -h, --help                 Show this help message

[clear-task-cache command options]
      -j, --job=             Job to clear cache from
      -s, --step=            Step name to clear cache from
      -c, --cache-path=      Cache directory to clear out
      -n, --non-interactive  Destroy the task cache(s) without confirmation

Answer 4

For resources:

fly -t example clear-resource-cache -r my-pipeline/my-resource

Corresponding documenation link.

For tasks: I've tested this on 7.9.1 (fairly recently as of this post - about 3 weeks ago).

fly -t demo clear-task-cache --job java-api-pipeline/compile-app-task --step task1

To see this in action see the online course " Getting Started with Concourse CI" on Pluralsight, Module 4: Composing and Managing Pipelines, Clip 4: Demo: Running and Managing Pipelines.

Corresponding documentation link.

Answer 5

As of the time of this writing 2023-06-21, the command to clear the cache requires a target, so:

fly -t <target> clear-resource-cache -r <pipeline>/<resource>

Sample:

fly -t demo destroy-pipeline -p java-api-pipeline