feat(CR-31802): add configurable http client transpor (#174)

## What
http client can be configured via environment variables
## Why
it potentialy helps prevent "connection reset by peer" errors
## Notes
<!-- Add any notes here -->

## Checklist

* [x] _I have read
[CONTRIBUTING.md](https://github.com/codefresh-io/terraform-provider-codefresh/blob/master/CONTRIBUTING.md)._
* [ ] _I have [allowed changes to my fork to be
made](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/allowing-changes-to-a-pull-request-branch-created-from-a-fork)._
* [ ] _I have added tests, assuming new tests are warranted_.
* [ ] _I understand that the `/test` comment will be ignored by the CI
trigger [unless it is made by a repo admin or
collaborator](https://codefresh.io/docs/docs/pipelines/triggers/git-triggers/#support-for-building-pull-requests-from-forks)._

Author: pysarenko-bohdan

codefresh/cfclient/client.go

@@ -7,6 +7,9 @@ import (
 	"io"
 	"net/http"
 	"strings"
+	"time"
+
+	"github.com/codefresh-io/terraform-provider-codefresh/codefresh/envutil"
 )
 
 // Client token, host, htpp.Client
@@ -28,19 +31,41 @@ type RequestOptions struct {
 	XAccessToken string
 }
 
-// NewClient returns a new client configured to communicate on a server with the
-// given hostname and to send an Authorization Header with the value of
-// token
-func NewClient(hostname string, hostnameV2 string, token string, tokenHeader string) *Client {
+// HttpClient returns a client which can be configured to communicate on a server with custom timeout settings
+func NewHttpClient(hostname string, hostnameV2 string, token string, tokenHeader string) *Client {
 	if tokenHeader == "" {
 		tokenHeader = "Authorization"
 	}
+
+	// Configurable HTTP transport with proper connection pooling and timeouts to prevent "connection reset by peer" errors,
+	// default values are equivalent to default &http.Client{} settings
+	transport := &http.Transport{
+		// Limit maximum idle connections per host to prevent connection exhaustion
+		MaxIdleConnsPerHost: envutil.GetEnvAsInt("CF_HTTP_MAX_IDLE_CONNECTIONS_PER_HOST", 2),
+		// Limit total idle connections
+		MaxIdleConns: envutil.GetEnvAsInt("CF_HTTP_MAX_IDLE_CONNECTIONS", 100),
+		// Close idle connections after specified seconds to prevent server-side timeouts
+		IdleConnTimeout: time.Duration(envutil.GetEnvAsInt("CF_HTTP_IDLE_CONNECTION_TIMEOUT", 90)) * time.Second,
+		// Timeout for TLS handshake in seconds
+		TLSHandshakeTimeout: time.Duration(envutil.GetEnvAsInt("CF_HTTP_TLS_HANDSHAKE_TIMEOUT", 10)) * time.Second,
+		// Timeout for expecting response headers in seconds, 0 - no limits
+		ResponseHeaderTimeout: time.Duration(envutil.GetEnvAsInt("CF_HTTP_RESPONSE_HEADER_TIMEOUT", 0)) * time.Second,
+		// Disable connection reuse for more stable connections
+		DisableKeepAlives: envutil.GetEnvAsBool("CF_HTTP_DISABLE_KEEPALIVES", false),
+	}
+
+	httpClient := &http.Client{
+		Transport: transport,
+		// Overall request timeout in seconds, 0 - no limits
+		Timeout: time.Duration(envutil.GetEnvAsInt("CF_HTTP_GLOBAL_TIMEOUT", 0)) * time.Second,
+	}
+
 	return &Client{
 		Host:         hostname,
 		HostV2:       hostnameV2,
 		Token:        token,
 		TokenHeader:  tokenHeader,
-		Client:       &http.Client{},
+		Client:       httpClient,
 		featureFlags: map[string]bool{},
 	}
 

codefresh/cfclient/gql_client.go

@@ -37,8 +37,7 @@ func (client *Client) SendGqlRequest(request GraphQLRequest) ([]byte, error) {
 	req.Header.Set(tokenHeader, client.Token)
 	req.Header.Set("Content-Type", "application/json; charset=utf-8")
 
-	httpClient := &http.Client{}
-	resp, err := httpClient.Do(req)
+	resp, err := client.Client.Do(req)
 	if err != nil {
 		return nil, err
 	}

codefresh/cfclient/user.go

@@ -144,7 +144,7 @@ func (client *Client) AddUserToTeamByAdmin(userID string, accountID string, team
 		return err
 	}
 	// new Client for accountAdmin
-	accountAdminClient := NewClient(client.Host, "", accountAdminToken, "x-access-token")
+	accountAdminClient := NewHttpClient(client.Host, "", accountAdminToken, "x-access-token")
 	usersTeam, err := accountAdminClient.GetTeamByName(team)
 	if err != nil {
 		return err

codefresh/envutil/env.go

@@ -0,0 +1,35 @@
+// Package envutil provides utility functions for working with environment variables.
+package envutil
+
+import (
+	"os"
+	"strconv"
+)
+
+// GetEnvAsString retrieves an environment variable as a string, returning the default value if not set
+func GetEnvAsString(key, defaultValue string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return defaultValue
+}
+
+// GetEnvAsInt retrieves an environment variable as an integer, returning the default value if not set or invalid
+func GetEnvAsInt(key string, defaultValue int) int {
+	if value := os.Getenv(key); value != "" {
+		if intValue, err := strconv.Atoi(value); err == nil {
+			return intValue
+		}
+	}
+	return defaultValue
+}
+
+// GetEnvAsBool retrieves an environment variable as a boolean, returning the default value if not set or invalid
+func GetEnvAsBool(key string, defaultValue bool) bool {
+	if value := os.Getenv(key); value != "" {
+		if boolValue, err := strconv.ParseBool(value); err == nil {
+			return boolValue
+		}
+	}
+	return defaultValue
+}

codefresh/provider.go

@@ -3,9 +3,10 @@ package codefresh
 import (
 	"fmt"
 
+	"os"
+
 	"github.com/codefresh-io/terraform-provider-codefresh/codefresh/cfclient"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
-	"os"
 )
 
 func Provider() *schema.Provider {
@@ -91,5 +92,5 @@ func configureProvider(d *schema.ResourceData) (interface{}, error) {
 		token = os.Getenv(ENV_CODEFRESH_API_KEY)
 	}
 
-	return cfclient.NewClient(apiURL, apiURLV2, token, ""), nil
+	return cfclient.NewHttpClient(apiURL, apiURLV2, token, ""), nil
 }

main.go

@@ -4,6 +4,7 @@ import (
 	"os"
 
 	"github.com/codefresh-io/terraform-provider-codefresh/codefresh"
+	"github.com/codefresh-io/terraform-provider-codefresh/codefresh/envutil"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/plugin"
 )
 
@@ -12,10 +13,7 @@ import (
 
 func main() {
 	debugMode := (os.Getenv(codefresh.ENV_CODEFRESH_PLUGIN_DEBUG) != "")
-	providerAddr := os.Getenv(codefresh.ENV_CODEFRESH_PLUGIN_ADDR)
-	if providerAddr == "" {
-		providerAddr = codefresh.DEFAULT_CODEFRESH_PLUGIN_ADDR
-	}
+	providerAddr := envutil.GetEnvAsString(codefresh.ENV_CODEFRESH_PLUGIN_ADDR, codefresh.DEFAULT_CODEFRESH_PLUGIN_ADDR)
 	plugin.Serve(&plugin.ServeOpts{
 		ProviderAddr: providerAddr,
 		ProviderFunc: codefresh.Provider,