Good use of contexts

EAC lets you combine Talend contexts with centralized context files and task-level overrides. This gives you repeatable deployments while keeping sensitive or environment-specific values out of jobs.

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When and how to use contexts efficiently

Use contexts to:

• Parameterize your jobs (paths, hosts, credentials, feature flags).
• Promote the same job from dev → test → prod without code changes.
• Centralize values that must be consistent across many tasks.
• Override a few values for a specific task only (without forking context files).

Key rule: Define multiple context groups (by project or environment), but only one effective context set applies per task run (computed by precedence below).

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Sources & precedence (low → high)

When EAC prepares a run, each context key is resolved using this order:

1. Talend job defaults
   The values embedded in the job for the Default context.
2. Talend environment selected in Task setup
   The context = dev/test/prod… chosen for the task.
3. Global context file (Context Files page)
   If a context file group is linked, keys from the file override Talend values. Only keys that exist in the Talend job are applied; extra keys are ignored.
4. Task-level overrides (Task setup)
   Per-task key/value overrides take final precedence.

UI hint: Values that are actually used are highlighted with a green background in the Task setup preview.

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Context files

Centralize values outside the job and reuse them across tasks.

• Where: Context files
  Group files by Project.
  
• Format: Talend-style .properties (UTF-8)
  
  • Spaces are allowed after =.
  • Unknown keys (not declared in the job) are ignored.
  • Prefer one file per environment.
• Attach to tasks: In Task setup, select the Context file group to apply.
  

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Applying contexts in Task setup

Open Tasks → {Task} → Task setup to configure:

1. Talend environment (context) to run with: Default | dev | test | prod | …
2. Context file group (optional): link a centralized file to override job values.
3. Task overrides (optional): add/modify individual key/values for this task only.

You’ll see a preview of the effective context with green highlights on applied values.

Keep overrides minimal: add only what must differ for this task.

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Execution details

Every run captures the context snapshot used to launch the job:

• Open Tasks → {Task} → Last executions → {Execution}.
• The header and logs remind the Talend env, any context file applied, and overrides.
  

This is essential for auditability and post-mortems.

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Best practices

• Define once, reuse widely
  Put shared values in context files (per project/environment). Use task overrides sparingly.
• Name clearly
  projectA-dev.properties, projectA-prod.properties, etc.
• Separate secrets
  Avoid plain-text secrets in files. Prefer vault-backed injection or environment-level secrets; if you must store them, restrict OS permissions.
• Keep types stable
  Don’t switch a key from string to numeric between envs; Talend components may enforce types.
• Version context files
  Store under VCS (private repo) and review changes like code.
• DRY on overrides
  If many tasks share the same overrides, move them up into the context file.

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Quick recipes

A) Promote dev → prod with a single job

1. Upload projectA-prod.properties.
2. In Task setup: set context = prod, link projectA (prod) file.
3. Remove any task overrides. Save. Launch.

B) One task, slightly different endpoint

1. Reuse the shared prod context file.
2. Add one task override: api.base=https://api.alt.example.com.
3. Save. Launch.

C) Audit a failed run

1. Open the execution detail.
2. Confirm Talend env, context file, and overrides used.
3. Compare with expected values; adjust in Task setup or update the context file.