From 6a4e482b3788230ac5ab61db46401540ee8cbbdc Mon Sep 17 00:00:00 2001
From: Rahul Sharma <rahulait@users.noreply.github.com>
Date: Thu, 20 Jun 2024 11:19:46 -0400
Subject: [PATCH] add timeout for linodego http client (#219)

* add timeout for linodego http client

* address review comments

---------

Co-authored-by: Rahul Sharma <rahsharm@akamai.com>
---
 README.md                     | 13 +++++++++++--
 cloud/linode/client/client.go | 29 +++++++++++++++++++++++++----
 cloud/linode/cloud.go         | 15 ++++++++++-----
 3 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/README.md b/README.md
index de3381da..5c2987f9 100644
--- a/README.md
+++ b/README.md
@@ -286,6 +286,15 @@ sessionAffinityConfig:
     timeoutSeconds: 100
 ```
 
+## Additional environment variables
+To tweak CCM based on needs, one can overwrite the default values set for caches and requests by setting appropriate environment variables when applying the manifest or helm chart.
+
+Environment Variable | Default | Description
+---|---|---
+`LINODE_INSTANCE_CACHE_TTL` | `15` | Default timeout of instance cache in seconds
+`LINODE_ROUTES_CACHE_TTL_SECONDS` | `60` | Default timeout of route cache in seconds
+`LINODE_REQUEST_TIMEOUT_SECONDS` | `120` | Default timeout in seconds for http requests to linode API
+
 ## Generating a Manifest for Deployment
 Use the script located at `./deploy/generate-manifest.sh` to generate a self-contained deployment manifest for the Linode CCM. Two arguments are required.
 
@@ -320,7 +329,7 @@ helm repo update ccm-linode
 ### To deploy ccm-linode. Run the following command:
 
 ```sh
-export VERSION=v0.3.22
+export VERSION=v0.4.8
 export LINODE_API_TOKEN=<linodeapitoken>
 export REGION=<linoderegion>
 helm install ccm-linode --set apiToken=$LINODE_API_TOKEN,region=$REGION ccm-linode/ccm-linode
@@ -335,7 +344,7 @@ _See [helm uninstall](https://helm.sh/docs/helm/helm_uninstall/) for command doc
 
 ### To upgrade when new changes are made to the helm chart. Run the following command:
 ```sh
-export VERSION=v0.3.22
+export VERSION=v0.4.8
 export LINODE_API_TOKEN=<linodeapitoken>
 export REGION=<linoderegion>
 
diff --git a/cloud/linode/client/client.go b/cloud/linode/client/client.go
index ce7ff307..abf5bee7 100644
--- a/cloud/linode/client/client.go
+++ b/cloud/linode/client/client.go
@@ -4,8 +4,19 @@ package client
 
 import (
 	"context"
+	"fmt"
+	"net/http"
+	"os"
+	"time"
 
 	"github.com/linode/linodego"
+	"golang.org/x/oauth2"
+	"k8s.io/klog/v2"
+)
+
+const (
+	// DefaultClientTimeout is the default timeout for a client Linode API call
+	DefaultClientTimeout = 120 * time.Second
 )
 
 type Client interface {
@@ -47,15 +58,25 @@ type Client interface {
 // linodego.Client implements Client
 var _ Client = (*linodego.Client)(nil)
 
-// New creates a new linode client with a given token, userAgent, and API URL
-func New(token, userAgent, apiURL string) (*linodego.Client, error) {
-	linodeClient := linodego.NewClient(nil)
+// New creates a new linode client with a given token and default timeout
+func New(token string, timeout time.Duration) (*linodego.Client, error) {
+	userAgent := fmt.Sprintf("linode-cloud-controller-manager %s", linodego.DefaultUserAgent)
+	apiURL := os.Getenv("LINODE_URL")
+
+	tokenSource := oauth2.StaticTokenSource(&oauth2.Token{AccessToken: token})
+	oauth2Client := &http.Client{
+		Transport: &oauth2.Transport{
+			Source: tokenSource,
+		},
+		Timeout: timeout,
+	}
+	linodeClient := linodego.NewClient(oauth2Client)
 	client, err := linodeClient.UseURL(apiURL)
 	if err != nil {
 		return nil, err
 	}
 	client.SetUserAgent(userAgent)
-	client.SetToken(token)
 
+	klog.V(3).Infof("Linode client created with default timeout of %v", timeout)
 	return client, nil
 }
diff --git a/cloud/linode/cloud.go b/cloud/linode/cloud.go
index a7d5fc54..f1138988 100644
--- a/cloud/linode/cloud.go
+++ b/cloud/linode/cloud.go
@@ -4,9 +4,10 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"strconv"
 	"sync"
+	"time"
 
-	"github.com/linode/linodego"
 	"github.com/spf13/pflag"
 	"golang.org/x/exp/slices"
 	"k8s.io/client-go/informers"
@@ -20,7 +21,6 @@ const (
 	ProviderName       = "linode"
 	accessTokenEnv     = "LINODE_API_TOKEN"
 	regionEnv          = "LINODE_REGION"
-	urlEnv             = "LINODE_URL"
 	ciliumLBType       = "cilium-bgp"
 	nodeBalancerLBType = "nodebalancer"
 )
@@ -95,10 +95,15 @@ func newCloud() (cloudprovider.Interface, error) {
 		return nil, fmt.Errorf("%s must be set in the environment (use a k8s secret)", regionEnv)
 	}
 
-	url := os.Getenv(urlEnv)
-	ua := fmt.Sprintf("linode-cloud-controller-manager %s", linodego.DefaultUserAgent)
+	// set timeout used by linodeclient for API calls
+	timeout := client.DefaultClientTimeout
+	if raw, ok := os.LookupEnv("LINODE_REQUEST_TIMEOUT_SECONDS"); ok {
+		if t, err := strconv.Atoi(raw); err == nil && t > 0 {
+			timeout = time.Duration(t) * time.Second
+		}
+	}
 
-	linodeClient, err := client.New(apiToken, ua, url)
+	linodeClient, err := client.New(apiToken, timeout)
 	if err != nil {
 		return nil, fmt.Errorf("client was not created succesfully: %w", err)
 	}