1 files changed, 41 insertions, 0 deletions
diff --git a/pkg/monitor/errors.go b/pkg/monitor/errors.go
new file mode 100644
index 0000000..4d676af
--- /dev/null
+++ b/pkg/monitor/errors.go
@@ -0,0 +1,41 @@
+package monitor
+
+import (
+	"fmt"
+
+	ct "github.com/google/certificate-transparency-go"
+)
+
+// ErrorFetch occurs if there's a problem hitting the log's HTTP API.  An STH is
+// provided if available, since it might carry evidence of some log misbehavior.
+type ErrorFetch struct {
+	URL string
+	Msg string
+	Err error
+	STH *ct.SignedTreeHead
+}
+
+func (e ErrorFetch) Error() string {
+	return fmt.Sprintf("%s: %s: %v", e.URL, e.Msg, e.Err)
+}
+
+// ErrorMerkleTree occurs if the log's Merkle tree can't be verified.  An STH is
+// provided if available (i.e., won't be available for internal tree building).
+type ErrorMerkleTree struct {
+	URL string
+	Msg string
+	Err error
+	STH *ct.SignedTreeHead
+}
+
+func (e ErrorMerkleTree) Error() string {
+	return fmt.Sprintf("%s: %s: %v", e.URL, e.Msg, e.Err)
+}
+
+// TODO: MMD violations
+// TODO: Growing read-only logs
+
+// noout implements the Logger interface to discard unwanted output
+type noout struct{}
+
+func (n *noout) Printf(string, ...interface{}) {}