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How to Configure Blobber

Customize blobber behavior through configuration files, environment variables, or command-line flags.

Prerequisites​

  • blobber installed

Create a Configuration File​

Initialize the default configuration:

blobber config init

Output:

Created config file: /home/user/.config/blobber/config.yaml

View Current Configuration​

Display all settings and their effective values:

blobber config

Output:

cache:
  dir: ""
  enabled: true
  verify: false
sign:
  enabled: false
  fulcio: https://fulcio.sigstore.dev
  rekor: https://rekor.sigstore.dev
verify:
  enabled: false
insecure: false
no-cache: false
verbose: false

Find the Config File Location​

blobber config path

Output:

/home/user/.config/blobber/config.yaml

Disable Caching Permanently​

Edit the config file or use the set command:

blobber config set cache.enabled false

Verify:

blobber config

Use a Custom Cache Directory​

blobber config set cache.dir /path/to/custom/cache

Bypass Cache for a Single Command​

Use --no-cache to skip caching without changing configuration:

blobber --no-cache pull ghcr.io/myorg/config:v1 ./output

Use Environment Variables​

Set environment variables for session-wide configuration:

export BLOBBER_CACHE_ENABLED=false
export BLOBBER_CACHE_DIR=/tmp/blobber-cache

Add to your shell profile (~/.bashrc, ~/.zshrc) for persistence.

Override Config with Flags​

Command-line flags take highest priority:

# Uses --no-cache even if cache.enabled=true in config
blobber --no-cache pull ghcr.io/myorg/config:v1 ./output

Configuration Precedence​

Settings resolve in this order (highest priority first):

  1. Command-line flags
  2. Environment variables
  3. Config file
  4. Defaults

Edit the Config File Directly​

The config file is plain YAML:

cat ~/.config/blobber/config.yaml
cache:
  enabled: true
  dir: ""
  verify: false
sign:
  enabled: false
  fulcio: https://fulcio.sigstore.dev
  rekor: https://rekor.sigstore.dev
verify:
  enabled: false

Edit with any text editor:

vim ~/.config/blobber/config.yaml

Reset to Defaults​

Remove the config file to restore defaults:

rm ~/.config/blobber/config.yaml

Use XDG Paths on Different Systems​

Blobber respects XDG environment variables:

# Custom config location
export XDG_CONFIG_HOME=/custom/config
blobber config path  # /custom/config/blobber/config.yaml

# Custom cache location
export XDG_CACHE_HOME=/custom/cache
blobber cache info   # Shows /custom/cache/blobber

Configure Signing Defaults​

Via Config File​

sign:
  enabled: true
  key: /path/to/private-key.pem  # For key-based signing
  fulcio: https://fulcio.internal.example.com
  rekor: https://rekor.internal.example.com

Via Environment Variables​

export BLOBBER_SIGN_ENABLED=true
export BLOBBER_SIGN_KEY=/path/to/private-key.pem
export BLOBBER_SIGN_FULCIO=https://fulcio.internal.example.com
export BLOBBER_SIGN_REKOR=https://rekor.internal.example.com

Via Command-Line Flags​

blobber push --sign --fulcio-url https://fulcio.internal --rekor-url https://rekor.internal ./config ghcr.io/org/config:v1

Configure Verification Defaults​

Via Config File​

verify:
  enabled: true
  issuer: https://accounts.google.com
  subject: ci@company.com
  trusted-root: /path/to/trusted-root.json

Via Environment Variables​

export BLOBBER_VERIFY_ENABLED=true
export BLOBBER_VERIFY_ISSUER=https://accounts.google.com
export BLOBBER_VERIFY_SUBJECT=ci@company.com
export BLOBBER_VERIFY_TRUSTED_ROOT=/path/to/trusted-root.json

See Also​