legacy-entlib-runtime-bootstrap

name	legacy-entlib-runtime-bootstrap
description	Wire legacy .NET Framework service hosts through Enterprise Library-flavored appSettings so Unity, service location, exception policies, logging, and database aliases all hang off one configuration seam.
domain	services
confidence	high
source	earned

Context

Use this when a WCF or ASMX host needs to feel like Enterprise Library/Unity-era infrastructure without dragging in a full modern DI stack or inventing a new infrastructure project.

Patterns

• Read composition data from enterpriseLibrary:* keys so hosts can swap registrations without reopening Global.asax every time.
• Keep type aliases, container registrations, log-writer defaults, exception policies, and database aliases in the same configuration reader; legacy operators expected one ugly seam, not five competing ones.
• Bootstrap Unity from shared core code, then let the service locator expose resolved services to WCF/ASMX surfaces.
• Treat logging and exception policy as first-class bootstrap outputs, not afterthoughts; service methods should route failures through the configured policy before throwing back across the SOAP boundary.
• Keep the database factory thin and configuration-driven so connection aliases can drift per host while repository/gateway code still talks in old connection-name terms.

Anti-Patterns

• Hardcoding repository/service registrations directly in each service host after the repo already has a shared composition seam.
• Building a sprawling fake EntLib clone with custom XML sections before the sample proves it needs them.
• Letting the gateway resolve raw connection strings everywhere; the connection-name seam is part of the modernization story.