Add cache ttl support (#3)

* Add ability to use `@cached(ttl: 120)`

* Update documentation.

Makefile

@@ -11,7 +11,7 @@ help:  ## display this help
 
 .PHONY: run
 run: build ## run application
-	@LOG_LEVEL=warn BLOCK_SCHEMA_INTROSPECTION=false JWT_ROLE_RATE_LIMIT=false JWT_ROLE_CLAIM_PATH="Hasura.x-hasura-default-role" JWT_USER_CLAIM_PATH="Hasura.x-hasura-user-id" HOST_GRAPHQL=https://hasura8.lan/v1/graphql ./graphql-proxy
+	@LOG_LEVEL=debug BLOCK_SCHEMA_INTROSPECTION=false JWT_ROLE_RATE_LIMIT=false JWT_ROLE_CLAIM_PATH="Hasura.x-hasura-default-role" JWT_USER_CLAIM_PATH="Hasura.x-hasura-user-id" HOST_GRAPHQL=https://hasura8.lan/v1/graphql ./graphql-proxy
 
 .PHONY: build
 build: ## build the binary

README.md

@@ -45,7 +45,10 @@ I wanted to monitor the queries and responses of our graphql endpoint, but we di
 ### Caching
 
 Cache engine is enabled in background as it does not use any additional resources.
-You can then start using the cache by setting the `ENABLE_GLOBAL_CACHE` environment variable to `true` - which will enable the cache for all queries, without introspection of the query. You can leave the global cache disabled and enable the cache for specific queries by adding the `@cache` directive to the query.
+You can then start using the cache by setting the `ENABLE_GLOBAL_CACHE` environment variable to `true` - which will enable the cache for all queries, without introspection of the query. You can leave the global cache disabled and enable the cache for specific queries by adding the `@cached` directive to the query.
+
+In case of the `@cached` you can add additional parameters to the directive which will set the cache for specific query to provided time.
+For example `query MyCachedQuery @cached(ttl: 90) ....` will set the cache for the query to 90 seconds.
 
 ### Role based rate limiting
 

go.mod

@@ -42,7 +42,7 @@ require (
 	github.com/valyala/tcplisten v1.0.0 // indirect
 	github.com/wI2L/jsondiff v0.4.0 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
-	golang.org/x/net v0.16.0 // indirect
+	golang.org/x/net v0.17.0 // indirect
 	golang.org/x/sync v0.4.0 // indirect
 	golang.org/x/sys v0.13.0 // indirect
 	golang.org/x/term v0.13.0 // indirect

go.sum

@@ -90,8 +90,8 @@ github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavM
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
-golang.org/x/net v0.16.0 h1:7eBu7KsSvFDtSXUIDbh3aqlK4DPsZ1rByC8PFfBThos=
-golang.org/x/net v0.16.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE=
+golang.org/x/net v0.17.0 h1:pVaXccu2ozPjCXewfr1S7xza/zcXTity9cCdXQYSjIM=
+golang.org/x/net v0.17.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE=
 golang.org/x/sync v0.4.0 h1:zxkM55ReGkDlKSM+Fu41A+zmbZuaPVbGMzvvdUPznYQ=
 golang.org/x/sync v0.4.0/go.mod h1:FU7BRWz2tNW+3quACPkgCx/L+uEAv1htQ0V83Z9Rj+Y=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

graphql.go

@@ -1,6 +1,8 @@
 package main
 
 import (
+	"strconv"
+
 	fiber "github.com/gofiber/fiber/v2"
 	"github.com/graphql-go/graphql/language/ast"
 	"github.com/graphql-go/graphql/language/parser"
@@ -33,7 +35,7 @@ var retrospection_queries = []string{
 // Saving the introspection queries as a map O(1) operation instead of O(n) for a slice.
 var retrospectionQuerySet = make(map[string]struct{}, len(retrospection_queries))
 
-func parseGraphQLQuery(c *fiber.Ctx) (operationType, operationName string, cacheRequest bool, should_block bool) {
+func parseGraphQLQuery(c *fiber.Ctx) (operationType, operationName string, cacheRequest bool, cache_time int, should_block bool) {
 	m := make(map[string]interface{})
 	err := json.Unmarshal(c.Body(), &m)
 	if err != nil {
@@ -68,6 +70,16 @@ func parseGraphQLQuery(c *fiber.Ctx) (operationType, operationName string, cache
 			for _, dir := range oper.Directives {
 				if dir.Name.Value == "cached" {
 					cacheRequest = true
+					for _, arg := range dir.Arguments {
+						if arg.Name.Value == "ttl" {
+							cache_time, err = strconv.Atoi(arg.Value.GetValue().(string))
+							if err != nil {
+								cfg.Logger.Error("Can't parse the ttl", map[string]interface{}{"ttl": arg.Value.GetValue().(string)})
+								cfg.Monitoring.Increment(libpack_monitoring.MetricsFailed, nil)
+								return
+							}
+						}
+					}
 				}
 			}
 			if cfg.Security.BlockIntrospection {

server.go

@@ -63,11 +63,16 @@ func processGraphQLRequest(c *fiber.Ctx) error {
 		}
 	}
 
-	opType, opName, cacheFromQuery, shouldBlock := parseGraphQLQuery(c)
+	opType, opName, cacheFromQuery, cache_time, shouldBlock := parseGraphQLQuery(c)
 	if shouldBlock {
 		return nil
 	}
 
+	if cache_time > 0 {
+		cfg.Logger.Debug("Cache time set via query", map[string]interface{}{"cache_time": cache_time})
+		cache_time = cfg.Cache.CacheTTL
+	}
+
 	wasCached := false
 
 	// Handling Cache Logic
@@ -81,7 +86,7 @@ func processGraphQLRequest(c *fiber.Ctx) error {
 			wasCached = true
 		} else {
 			cfg.Logger.Debug("Cache miss", map[string]interface{}{"hash": queryCacheHash, "user_id": extractedUserID})
-			proxyAndCacheTheRequest(c, queryCacheHash)
+			proxyAndCacheTheRequest(c, queryCacheHash, cache_time)
 		}
 	} else {
 		proxyTheRequest(c)
@@ -96,9 +101,9 @@ func processGraphQLRequest(c *fiber.Ctx) error {
 }
 
 // Additional helper function to avoid code repetition
-func proxyAndCacheTheRequest(c *fiber.Ctx, queryCacheHash string) {
+func proxyAndCacheTheRequest(c *fiber.Ctx, queryCacheHash string, cache_time int) {
 	proxyTheRequest(c)
-	cfg.Cache.CacheClient.Set(queryCacheHash, c.Response().Body(), time.Duration(cfg.Cache.CacheTTL)*time.Second)
+	cfg.Cache.CacheClient.Set(queryCacheHash, c.Response().Body(), time.Duration(cache_time)*time.Second)
 	c.Send(c.Response().Body())
 }