--volume)The --volume parameter must be one of the following:
Each volume mount has the following format:
<host path>:<target path>[:<mode>] <host path>This is the name of the volume, it is unique on a given host machine.
<target path>The path where the file or directory is available in the container.
[:<mode>]An optional comma separated list of mount options. If no options are provided, the read-only option will be used. A mount option must be one of the following:
ro, volume contents are read-only.rw, volume contents are readable and writeable.volume-opt=key=value, can be specified more than once, takes a key-value pair consisting of the option name and its value.For the following examples we will use our samples repo for simplicity.
Here we bind mount a local folder into our container and display its contents during a pack build.
We’ll create a new docker volume:
docker volume create test-volume Next, we’ll create a text file on the volume:
docker run --rm \ --volume test-volume:/tmp/volume:rw \ bash \ bash -c 'echo "Hello from a volume!" > /tmp/volume/volume_contents.txt' Now, we can mount this volume during pack build:
ls -al pack build volume-example \ --builder cnbs/sample-builder:noble \ --buildpack samples/buildpacks/hello-world \ --path samples/apps/bash-script \ --volume test-volume:/platform/volume:ro The above pack build ... command will mount the test-volume volume in the /platform directory of the container.
Since we are using the samples/hello-world buildpack, we should see the /platform directory files listed:
[builder] platform_dir files: ... [builder] /platform/volume: [builder] total 12 [builder] drwxr-xr-x 2 root root 4096 Sep 17 20:17 . [builder] drwxr-xr-x 1 root root 4096 Sep 17 20:18 .. [builder] -rw-r--r-- 1 root root 21 Sep 17 20:18 volume_contents.txt