Authentication backends (LDAP, OAuth) in Apache Airflow - Step-by-Step Execution

Process Flow - Authentication backends (LDAP, OAuth)

User tries to login

↓

Select Auth Backend

↓

LDAP Backend

↓

Validate creds

↓

Success?

No→Fail Login

Yes↓

Grant Access

User login triggers selection of LDAP or OAuth backend, which validates credentials or redirects for OAuth, then grants or denies access.

Execution Sample

Apache Airflow

auth_backend = 'LDAP'
if auth_backend == 'LDAP':
    result = ldap_auth(username, password)
else:
    result = oauth_auth()
if result == 'success':
    grant_access()

This code chooses LDAP or OAuth authentication and grants access if successful.

Process Table

Step	Action	Auth Backend	Credentials Check	Result	Next Step
1	User submits login	LDAP	username/password provided	Pending	Check backend
2	Select backend	LDAP	N/A	N/A	Call ldap_auth()
3	Call ldap_auth()	LDAP	Verify username/password	success	Grant access
4	Grant access	LDAP	N/A	success	User logged in
5	End	LDAP	N/A	N/A	Stop execution

💡 User credentials verified by LDAP, login successful, execution ends.

Status Tracker

Variable	Start	After Step 2	After Step 3	Final
auth_backend	None	LDAP	LDAP	LDAP
result	None	None	success	success

Key Moments - 2 Insights

Why does the code call ldap_auth() only when auth_backend is 'LDAP'?

Because the execution_table row 2 shows backend selection, and only if 'LDAP' is chosen does the code call ldap_auth() to verify credentials.

What happens if ldap_auth() returns 'failure'?

Though not shown in this trace, the code would skip granting access and likely show a login failure message, as success is required to proceed (see row 3 and 4).

Visual Quiz - 3 Questions

Look at the execution table, what is the value of 'result' after Step 3?

A failure

B None

C success

D Pending

💡 Hint

Check the 'result' column in row 3 of the execution_table.

At which step does the system decide to grant access?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look at the 'Action' column and find when 'Grant access' happens in the execution_table.

If auth_backend was set to 'OAuth', which step would change in the execution_table?

A Step 2 would call oauth_auth() instead of ldap_auth()

B Step 3 would verify username/password

C Step 4 would deny access

D Step 5 would be skipped

💡 Hint

Refer to the concept_flow where OAuth backend redirects to OAuth provider instead of LDAP verification.

Concept Snapshot

Authentication backends in Airflow:
- Choose backend: LDAP or OAuth
- LDAP: verify username/password directly
- OAuth: redirect user to provider for login
- On success, grant access
- On failure, deny login
Simple if-else logic controls flow.

Full Transcript

This visual execution shows how Airflow handles authentication using backends like LDAP and OAuth. When a user tries to login, the system selects the authentication backend. If LDAP is chosen, it verifies the username and password directly. If OAuth is chosen, the user is redirected to an external provider for login. The execution table traces the steps for LDAP: user submits credentials, backend selection, LDAP verification, and granting access on success. Variables like 'auth_backend' and 'result' track the flow. Key moments clarify why ldap_auth() is called only for LDAP and what happens on failure. The quiz tests understanding of variable values and step actions. The snapshot summarizes the flow simply for quick recall.