invalid mount config for type "bind": bind source path does not exist: /host/data

TL;DR: Create the host directory first (mkdir -p /host/data), then re-run. Unlike named volumes, bind mounts require the source path to exist; docker will not create it for you with --mount (and -v only auto-creates directories, not files, and with root ownership that causes its own problems).

The error

invalid mount config for type "bind": bind source path does not exist: /host/data

Fix it

1. Create the path on the host:

mkdir -p /host/data Expected: no output.

1. Fix ownership if the container runs as non-root:

sudo chown -R 1000:1000 /host/data Expected: container user can write.

1. Re-run the container.

When this applies

• --mount type=bind with a missing source (strict: always fails)
• -v bind of a specific FILE that does not exist (creates a directory instead, then the app fails weirdly)

When this does NOT apply

• Named volumes (docker creates those automatically)
• "permission denied" writing to an existing bind (ownership/SELinux, separate skill)

Versions

All Docker versions. --mount has always been strict; -v auto-creates missing source DIRS.

Why it happens

--mount validates the source before creating the container and refuses to guess. The -v shorthand is lenient for directories but that leniency backfires for files: -v /host/app.conf:/etc/app.conf with a missing file creates a DIRECTORY at /host/app.conf, and the app then fails to read its "config file".

Edge cases

• Prefer --mount in scripts precisely because it fails fast instead of creating wrong-typed paths.
• Docker Desktop file sharing: the path must also be shared (Settings > Resources > File Sharing) or the bind appears empty.
• Symlinked source paths resolve on the host; a dangling symlink gives this error.