File Transfer

File Transfer

Transfer files and directories between host and containers.

Push Files to Container

Copy files from your host into a container:

# Push single file
coi file push ./config.json my-container:/workspace/config.json

# Push directory (recursive)
coi file push -r ./src my-container:/workspace/src

# Push with custom permissions
coi file push ./script.sh my-container:/usr/local/bin/script.sh

Pull Files from Container

Copy files from a container to your host:

# Pull single file
coi file pull my-container:/workspace/build.log ./build.log

# Pull directory (recursive)
coi file pull -r my-container:/home/code/.claude ./saved-sessions/session-123/

# Pull build artifacts
coi file pull -r my-container:/workspace/dist ./output/

Common Use Cases

Backup Session Data

# Save AI tool session to host
coi file pull -r my-container:/home/code/.claude ./backups/session-$(date +%Y%m%d)/

Inject Configuration

# Push config files before starting session
coi file push ./custom-config.toml my-container:/home/code/.config/tool/config.toml

Extract Build Artifacts

# Copy compiled binaries or build output
coi file pull -r my-container:/workspace/build ./artifacts/

Share Files Between Containers

# Pull from one container, push to another
coi file pull my-container-1:/workspace/data.json ./temp.json
coi file push ./temp.json my-container-2:/workspace/data.json

Notes

• File ownership is preserved when possible
• Use -r flag for recursive directory operations
• Paths in containers must be absolute
• Works with both running and stopped containers

File Ownership and UID Shifting

COI containers use Incus UID shifting (idmap) so that files owned by your host user appear as the code user (UID 1000) inside the container. When pushing files, the ownership is shifted automatically — you do not need to chown files after pushing.

When pulling files, the reverse shift applies: files owned by code inside the container appear owned by your host user on the filesystem.

Note: Pushing to System Paths Pushing files to paths outside /home/code and /workspace (e.g., /usr/local/bin) may require the file to be owned by root inside the container. Use coi container exec <name> -- chown root:root /path/to/file after pushing if the tool requires root ownership.

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See Also

• Container Operations - Full list of container management commands
• Container Lifecycle and Sessions - Session save, resume, and slot management