cloudapi: use Recover middleware to handle panics

recover from panics such as out-of-bounds array access & nil
pointer access, print a stack trace and return 5xx error
instead of the service crashing and relying on Execution
framework to handle crashes

vendor/github.com/labstack/echo/v4/middleware/rewrite.go

@@ -0,0 +1,81 @@
+package middleware
+
+import (
+	"regexp"
+
+	"github.com/labstack/echo/v4"
+)
+
+type (
+	// RewriteConfig defines the config for Rewrite middleware.
+	RewriteConfig struct {
+		// Skipper defines a function to skip middleware.
+		Skipper Skipper
+
+		// Rules defines the URL path rewrite rules. The values captured in asterisk can be
+		// retrieved by index e.g. $1, $2 and so on.
+		// Example:
+		// "/old":              "/new",
+		// "/api/*":            "/$1",
+		// "/js/*":             "/public/javascripts/$1",
+		// "/users/*/orders/*": "/user/$1/order/$2",
+		// Required.
+		Rules map[string]string `yaml:"rules"`
+
+		// RegexRules defines the URL path rewrite rules using regexp.Rexexp with captures
+		// Every capture group in the values can be retrieved by index e.g. $1, $2 and so on.
+		// Example:
+		// "^/old/[0.9]+/":     "/new",
+		// "^/api/.+?/(.*)":     "/v2/$1",
+		RegexRules map[*regexp.Regexp]string `yaml:"regex_rules"`
+	}
+)
+
+var (
+	// DefaultRewriteConfig is the default Rewrite middleware config.
+	DefaultRewriteConfig = RewriteConfig{
+		Skipper: DefaultSkipper,
+	}
+)
+
+// Rewrite returns a Rewrite middleware.
+//
+// Rewrite middleware rewrites the URL path based on the provided rules.
+func Rewrite(rules map[string]string) echo.MiddlewareFunc {
+	c := DefaultRewriteConfig
+	c.Rules = rules
+	return RewriteWithConfig(c)
+}
+
+// RewriteWithConfig returns a Rewrite middleware with config.
+// See: `Rewrite()`.
+func RewriteWithConfig(config RewriteConfig) echo.MiddlewareFunc {
+	// Defaults
+	if config.Rules == nil && config.RegexRules == nil {
+		panic("echo: rewrite middleware requires url path rewrite rules or regex rules")
+	}
+
+	if config.Skipper == nil {
+		config.Skipper = DefaultBodyDumpConfig.Skipper
+	}
+
+	if config.RegexRules == nil {
+		config.RegexRules = make(map[*regexp.Regexp]string)
+	}
+	for k, v := range rewriteRulesRegex(config.Rules) {
+		config.RegexRules[k] = v
+	}
+
+	return func(next echo.HandlerFunc) echo.HandlerFunc {
+		return func(c echo.Context) (err error) {
+			if config.Skipper(c) {
+				return next(c)
+			}
+
+			if err := rewriteURL(config.RegexRules, c.Request()); err != nil {
+				return err
+			}
+			return next(c)
+		}
+	}
+}