Allow omit_containers[db], fixes ddev#1490

docs/users/extend/config_yaml.md

@@ -25,7 +25,7 @@ the .ddev/config.yaml is the primary configuration for the project.
 | additional_fqdns | extra fully-qualified domain names | `additional_fqdns: ["example.com", "sub1.example.com"]` would provide http and https URLs for "example.com" and "sub1.example.com". Please take care with this because it can cause great confusion and adds extraneous items to your /etc/hosts file. |
 | upload_dir | Relative path to upload directory used by `ddev import-files` | |
 | working_dir | explicitly specify the working directory used by `ddev exec` and `ddev ssh` | `working_dir: { web:  "/var/www", db: "/etc" }` would set the working directories for the web and db containers. |
-| omit_containers | Allows the project to not load specified containers | For example, `omit_containers: ["dba", "ddev-ssh-agent"]`. Currently only these containers are supported. These containers can also be omitted globally in the ~/.ddev/global_config.yaml. |
+| omit_containers | Allows the project to not load specified containers | For example, `omit_containers: ["db", dba", "ddev-ssh-agent"]`. Currently only these containers are supported. Some containers can also be omitted globally in the ~/.ddev/global_config.yaml. Note that if you omit the "db" container, several standard features of ddev that access the database container will be unusuable. |
 | nfs_mount_enabled | Allows using NFS to mount the project into the container for performance reasons | See [nfsmount_enabled documentation](../../performance.md). This requires configuration on the host before it can be used. |
 | host_https_port | Specify a specific and persistent https port for direct binding to the localhost interface | This is not commonly used, but a specific port can be provided here and the https URL will always remain the same. For example, if you put "59001", the project will always use "https://127.0.0.1:59001". for the localhost URL. (Note that the named URL is more commonly used and for most purposes is better.) If this is not set the port will change from `ddev start` to `ddev start` |
 | host_webserver_port | Specify a specific and persistent http port for direct binding to the localhost interface | This is not commonly used, but a specific port can be provided here and the https URL will always remain the same. For example, if you put "59000", the project will always use "http://127.0.0.1:59000". for the localhost URL. (Note that the named URL is more commonly used and for most purposes is better.) If this is not set the port will change from `ddev start` to `ddev start` |

pkg/ddevapp/config.go

@@ -589,6 +589,7 @@ type composeYAMLVars struct {
 	DBBuildContext       string
 	BgsyncBuildContext   string
 	SSHAgentBuildContext string
+	OmitDB               bool
 	OmitDBA              bool
 	OmitSSHAgent         bool
 	WebcacheEnabled      bool
@@ -636,6 +637,7 @@ func (app *DdevApp) RenderComposeYAML() (string, error) {
 		DdevGenerated:        DdevFileSignature,
 		HostDockerInternalIP: hostDockerInternalIP,
 		ComposeVersion:       version.DockerComposeFileFormatVersion,
+		OmitDB:               nodeps.ArrayContainsString(app.OmitContainers, "db"),
 		OmitDBA:              nodeps.ArrayContainsString(app.OmitContainers, "dba"),
 		OmitSSHAgent:         nodeps.ArrayContainsString(app.OmitContainers, "ddev-ssh-agent"),
 		WebcacheEnabled:      app.WebcacheEnabled,

pkg/ddevapp/ddevapp.go

@@ -191,18 +191,20 @@ func (app *DdevApp) Describe() (map[string]interface{}, error) {
 
 	// Only show extended status for running sites.
 	if app.SiteStatus() == SiteRunning {
-		dbinfo := make(map[string]interface{})
-		dbinfo["username"] = "db"
-		dbinfo["password"] = "db"
-		dbinfo["dbname"] = "db"
-		dbinfo["host"] = "db"
-		dbPublicPort, err := app.GetPublishedPort("db")
-		util.CheckErr(err)
-		dbinfo["dbPort"] = GetPort("db")
-		util.CheckErr(err)
-		dbinfo["published_port"] = dbPublicPort
-		dbinfo["mariadb_version"] = app.MariaDBVersion
-		appDesc["dbinfo"] = dbinfo
+		if !nodeps.ArrayContainsString(app.OmitContainers, "db") {
+			dbinfo := make(map[string]interface{})
+			dbinfo["username"] = "db"
+			dbinfo["password"] = "db"
+			dbinfo["dbname"] = "db"
+			dbinfo["host"] = "db"
+			dbPublicPort, err := app.GetPublishedPort("db")
+			util.CheckErr(err)
+			dbinfo["dbPort"] = GetPort("db")
+			util.CheckErr(err)
+			dbinfo["published_port"] = dbPublicPort
+			dbinfo["mariadb_version"] = app.MariaDBVersion
+			appDesc["dbinfo"] = dbinfo
+		}
 
 		appDesc["mailhog_url"] = "http://" + app.GetHostname() + ":" + app.MailhogPort
 		if !nodeps.ArrayContainsString(app.OmitContainers, "dba") {
@@ -759,7 +761,10 @@ func (app *DdevApp) Start() error {
 		return err
 	}
 
-	requiredContainers := []string{"db", "web"}
+	requiredContainers := []string{"web"}
+	if !nodeps.ArrayContainsString(app.OmitContainers, "db") {
+		requiredContainers = append(requiredContainers, "db")
+	}
 	if app.WebcacheEnabled {
 		requiredContainers = append(requiredContainers, "bgsync")
 		err = app.precacheWebdir()

pkg/ddevapp/templates.go

@@ -5,6 +5,7 @@ package ddevapp
 const DDevComposeTemplate = `version: '{{ .ComposeVersion }}'
 {{ .DdevGenerated }}
 services:
+{{if not .OmitDB }}
   db:
     container_name: {{ .Plugin }}-${DDEV_SITENAME}-db
     build: 
@@ -47,6 +48,7 @@ services:
       retries: 30
       start_period: 20s
       timeout: 120s
+{{end}}
   web:
     container_name: {{ .Plugin }}-${DDEV_SITENAME}-web
     build: 
@@ -186,7 +188,6 @@ services:
       interval: 120s
       timeout: 2s
       retries: 1
-
 {{end}}
 networks:
   default:

pkg/ddevapp/values.go

@@ -70,6 +70,7 @@ const (
 )
 
 var ValidOmitContainers = map[string]bool{
+	DBContainer:           true,
 	DdevSSHAgentContainer: true,
 	DBAContainer:          true,
 }