fix: Add trap to agent startup script to sleep on failure (#2873)

* fix: Add `trap` to agent startup script to sleep on failure

The Docker Terraform provider removes containers immediately on exit, making
it difficult to debug a failed container start with Coder. This will sleep on
exit and output a friendly log, which should assist with debugging failures.

* Update provisionersdk/agent.go

Co-authored-by: Mathias Fredriksson <mafredri@gmail.com>

* Update provisionersdk/agent.go

Co-authored-by: Mathias Fredriksson <mafredri@gmail.com>

Co-authored-by: Mathias Fredriksson <mafredri@gmail.com>

provisionersdk/scripts/bootstrap_darwin.sh

@@ -1,5 +1,6 @@
 #!/usr/bin/env sh
 set -eux pipefail
+trap 'echo === Agent script exited with non-zero code. Sleeping 24h to preserve logs... && sleep 86400' EXIT
 BINARY_DIR=$(mktemp -d -t coder.XXXXXX)
 BINARY_NAME=coder
 cd "$BINARY_DIR"

provisionersdk/scripts/bootstrap_linux.sh

@@ -1,5 +1,6 @@
 #!/usr/bin/env sh
 set -eux pipefail
+trap 'echo === Agent script exited with non-zero code. Sleeping 24h to preserve logs... && sleep 86400' EXIT
 BINARY_DIR=$(mktemp -d -t coder.XXXXXX)
 BINARY_NAME=coder
 BINARY_URL=${ACCESS_URL}bin/coder-linux-${ARCH}