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 mapping — idmapped (shift=true) mounts or a per-instance raw.idmap, selected automatically per host/filesystem — 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.

See Also

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