PMM-11717: backward compatibility with older pmm-client (#1860)

Makefile.include

@@ -139,8 +139,8 @@ api-test:             ## Run API tests on dev env. Use `PMM_KUBECONFIG=/path/to/
 	go test -count=1 -race -p 1 -v ./api-tests/... -pmm.server-insecure-tls
 
 check:                ## Run required checkers and linters
-	LOG_LEVEL=error bin/golangci-lint run
-	bin/go-sumtype ./...
+	LOG_LEVEL=error bin/golangci-lint run ; \
+	bin/go-sumtype ./... ; \
 	bin/go-consistent -pedantic ./...
 
 check-license:          ## Run license header checks against source files

managed/services/agents/mysql.go

@@ -29,6 +29,8 @@ import (
 	"github.com/percona/pmm/version"
 )
 
+var mysqlExporterVersionWithPluginCollector = version.MustParse("2.36.0-0")
+
 // mysqldExporterConfig returns desired configuration of mysqld_exporter process.
 func mysqldExporterConfig(service *models.Service, exporter *models.Agent, redactMode redactMode, pmmAgentVersion *version.Parsed) *agentpb.SetStateRequest_AgentProcess {
 	tdp := exporter.TemplateDelimiters(service)
@@ -65,7 +67,6 @@ func mysqldExporterConfig(service *models.Service, exporter *models.Agent, redac
 		"--collect.custom_query.lr.directory=" + pathsBase(pmmAgentVersion, tdp.Left, tdp.Right) + "/collectors/custom-queries/mysql/low-resolution",
 		"--collect.custom_query.mr.directory=" + pathsBase(pmmAgentVersion, tdp.Left, tdp.Right) + "/collectors/custom-queries/mysql/medium-resolution",
 		"--collect.custom_query.hr.directory=" + pathsBase(pmmAgentVersion, tdp.Left, tdp.Right) + "/collectors/custom-queries/mysql/high-resolution",
-		"--collect.plugins",
 
 		"--exporter.max-idle-conns=3",
 		"--exporter.max-open-conns=3",
@@ -74,6 +75,11 @@ func mysqldExporterConfig(service *models.Service, exporter *models.Agent, redac
 		"--web.listen-address=:" + tdp.Left + " .listen_port " + tdp.Right,
 	}
 
+	if !pmmAgentVersion.Less(mysqlExporterVersionWithPluginCollector) {
+		args = append(args,
+			"--collect.plugins")
+	}
+
 	if exporter.IsMySQLTablestatsGroupEnabled() {
 		// keep in sync with Prometheus scrape configs generator
 		tablestatsGroup := []string{

managed/services/agents/mysql_test.go

@@ -78,7 +78,6 @@ func TestMySQLdExporterConfig(t *testing.T) {
 			"--collect.perf_schema.indexiowaits",
 			"--collect.perf_schema.tableiowaits",
 			"--collect.perf_schema.tablelocks",
-			"--collect.plugins",
 			"--collect.slave_status",
 			"--collect.standard.go",
 			"--collect.standard.process",
@@ -178,7 +177,6 @@ func TestMySQLdExporterConfigTablestatsGroupDisabled(t *testing.T) {
 			"--collect.perf_schema.eventsstatements",
 			"--collect.perf_schema.eventswaits",
 			"--collect.perf_schema.file_events",
-			"--collect.plugins",
 			"--collect.slave_status",
 			"--collect.standard.go",
 			"--collect.standard.process",
@@ -218,6 +216,18 @@ func TestMySQLdExporterConfigTablestatsGroupDisabled(t *testing.T) {
 		actual := mysqldExporterConfig(mysql, exporter, exposeSecrets, pmmAgentVersion)
 		assert.Equal(t, "DATA_SOURCE_NAME=tcp(1.2.3.4:3306)/?timeout=1s&tls=custom", actual.Env[0])
 	})
+
+	t.Run("V236_EnablesPluginCollector", func(t *testing.T) {
+		pmmAgentVersion := version.MustParse("2.36.0")
+		actual := mysqldExporterConfig(mysql, exporter, exposeSecrets, pmmAgentVersion)
+		assert.Contains(t, actual.Args, "--collect.plugins")
+	})
+
+	t.Run("beforeV236_NoPluginCollector", func(t *testing.T) {
+		pmmAgentVersion := version.MustParse("2.35.0")
+		actual := mysqldExporterConfig(mysql, exporter, exposeSecrets, pmmAgentVersion)
+		assert.NotContains(t, actual.Args, "--collect.plugins")
+	})
 }
 
 func TestMySQLdExporterConfigDisabledCollectors(t *testing.T) {
@@ -266,7 +276,6 @@ func TestMySQLdExporterConfigDisabledCollectors(t *testing.T) {
 			"--collect.perf_schema.indexiowaits",
 			"--collect.perf_schema.tableiowaits",
 			"--collect.perf_schema.tablelocks",
-			"--collect.plugins",
 			"--collect.slave_status",
 			"--collect.standard.go",
 			"--collect.standard.process",