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Policy Storage

Casbin implements policy storage through adapters.

Loading policy from a .CSV file

Loading from a CSV file is the standard approach. This method is straightforward for beginners and convenient when seeking help from the Casbin team.

Here's an example CSV file examples/rbac_policy.csv:

p, alice, data1, read
p, bob, data2, write
p, data2_admin, data2, read
p, data2_admin, data2, write
g, alice, data2_admin
note

When CSV fields contain commas, wrap them in double quotes:

p, alice, "data1,data2", read    --correct
p, alice, data1,data2, read --incorrect (the whole phrase "data1,data2" should be wrapped in double quotes)

When fields contain both commas and double quotes, wrap the field in double quotes and escape embedded quotes by doubling them:

p, alice, data, "r.act in (""get"", ""post"")"        --correct
p, alice, data, "r.act in ("get", "post")" --incorrect (you should use "" to escape "")

Related issue: casbin#886

Adapter API

MethodTypeDescription
LoadPolicy()basicLoad all policy rules from the storage
SavePolicy()basicSave all policy rules to the storage
AddPolicy()optionalAdd a policy rule to the storage
RemovePolicy()optionalRemove a policy rule from the storage
RemoveFilteredPolicy()optionalRemove policy rules that match the filter from the storage

Database Storage Format

Your policy file

p, data2_admin, data2, read
p, data2_admin, data2, write
g, alice, admin

Corresponding database structure (such as MySQL)

idptypev0v1v2v3v4v5
1pdata2_admindata2read
2pdata2_admindata2write
3galiceadmin

Meaning of each column

  • id: Database primary key, not part of the Casbin policy. Generation method depends on the adapter implementation.

  • ptype: Corresponds to p, g, g2, etc.

  • v0-v5: Generic column names that map to policy CSV values from left to right. The number of columns depends on your policy definition. Most adapters implement 6 columns, though theoretically unlimited columns are possible. Submit an issue to the adapter repository if you need more columns.

Adapter Details

For more information about the adapter API and database structure design, see /docs/adapters.