Implement rudimentary dependency model with start_order

Any container definitions in ccl.toml can be given a `start_order` tag
(integer). It is recommended to not put a start_order unless a container
depends on another one (e.g. synapse needs postgres), in which case all
dependents and dependees should be given a `start_order`, with dependees
having a lower number than their dependents. It is guaranteed that the
dependees will be started first, although the container startup
procedure is outside of our control. Containers without a `start_order`
will have their operations applied asynchronously, but those with
a start order are started, well, in order from lowest to highest. "Stop"
operations are applied in the reverse order.

cmd/create.go

@@ -38,6 +38,7 @@ var createCmd = &cobra.Command{
 names or categories. Multiple arguments are supported.`,
 	Run: func(_ *cobra.Command, args []string) {
 		conts := config.Union(args, contMask)
+		container.Reorder(conts, container.Start)
 		execForEach(conts, func(c *container.Container) command.CommandSet { return c.CreateCommands() })
 	},
 }

cmd/execute.go

@@ -32,9 +32,11 @@ import (
 func execForEach(tgts []container.Container, getSet func(*container.Container) command.CommandSet) {
 	var wg sync.WaitGroup
 	for i := range tgts {
-		wg.Add(1)
+		async := !tgts[i].StartOrder.Valid
-		go func(cont *container.Container) {
+		runSet := func(cont *container.Container) {
+			if async {
 				defer wg.Done()
+			}
 			set := getSet(cont)
 			for _, cmd := range set.Commands {
 				if err := cmd.Execute(output, fake, set.ID); err != nil {
@@ -45,7 +47,13 @@ func execForEach(tgts []container.Container, getSet func(*container.Container) c
 					return
 				}
 			}
-		}(&tgts[i])
+		}
+		if async {
+			wg.Add(1)
+			go runSet(&tgts[i])
+		} else {
+			runSet(&tgts[i])
+		}
 	}
 	wg.Wait()
 }

cmd/pull.go

@@ -39,6 +39,7 @@ affected: the old image will still remain, though untagged, and any defined cont
 will still use it.`,
 	Run: func(cmd *cobra.Command, args []string) {
 		conts := config.Union(args, contMask)
+		container.Reorder(conts, container.Start)
 		execForEach(conts, func(c *container.Container) command.CommandSet { return c.PullCommands() })
 	},
 }

cmd/recreate.go

@@ -38,7 +38,11 @@ var recreateCmd = &cobra.Command{
 one or more container names or categories. If empty, "all" is assumed.`,
 	Run: func(_ *cobra.Command, args []string) {
 		conts := config.Union(args, contMask)
+		container.Reorder(conts, container.Stop)
+		execForEach(conts, func(c *container.Container) command.CommandSet { return c.StopCommands() })
+		container.Reorder(conts, container.Start)
 		execForEach(conts, func(c *container.Container) command.CommandSet { return c.RecreateCommands() })
+		execForEach(conts, func(c *container.Container) command.CommandSet { return c.ConditionalStartCommands() })
 	},
 }
 

cmd/restart.go

@@ -38,7 +38,10 @@ var restartCmd = &cobra.Command{
 one or more container names or categories. If empty, "all" is assumed.`,
 	Run: func(_ *cobra.Command, args []string) {
 		conts := config.Union(args, contMask)
-		execForEach(conts, func(c *container.Container) command.CommandSet { return c.RestartCommands() })
+		container.Reorder(conts, container.Stop)
+		execForEach(conts, func(c *container.Container) command.CommandSet { return c.StopCommands() })
+		container.Reorder(conts, container.Start)
+		execForEach(conts, func(c *container.Container) command.CommandSet { return c.StartCommands() })
 	},
 }
 

cmd/rm.go

@@ -39,6 +39,8 @@ var rmCmd = &cobra.Command{
 If running, they will first be stopped.`,
 	Run: func(cmd *cobra.Command, args []string) {
 		conts := config.Union(args, contMask)
+		container.Reorder(conts, container.Stop)
+		execForEach(conts, func(c *container.Container) command.CommandSet { return c.StopCommands() })
 		execForEach(conts, func(c *container.Container) command.CommandSet { return c.RemoveCommands() })
 	},
 }

cmd/start.go

@@ -38,6 +38,7 @@ var startCmd = &cobra.Command{
 one or more container names or categories. If empty, "all" is assumed.`,
 	Run: func(_ *cobra.Command, args []string)  {
 		conts := config.Union(args, contMask)
+		container.Reorder(conts, container.Start)
 		execForEach(conts, func(c *container.Container) command.CommandSet { return c.StartCommands() })
 	},
 }

cmd/stop.go

@@ -38,6 +38,7 @@ var stopCmd = &cobra.Command{
 one or more container names or categories. If empty, "all" is assumed.`,
 	Run: func(_ *cobra.Command, args []string) {
 		conts := config.Union(args, contMask)
+		container.Reorder(conts, container.Stop)
 		execForEach(conts, func(c *container.Container) command.CommandSet { return c.StopCommands() })
 	},
 }

cmd/update.go

@@ -38,7 +38,10 @@ var updateCmd = &cobra.Command{
 one or more container names or categories. If empty, "all" is assumed.`,
 	Run: func(_ *cobra.Command, args []string) {
 		conts := config.Union(args, contMask)
+		container.Reorder(conts, container.Stop)
 		execForEach(conts, func(c *container.Container) command.CommandSet { return c.UpdateCommands() })
+		container.Reorder(conts, container.Start)
+		execForEach(conts, func(c *container.Container) command.CommandSet { return c.ConditionalStartCommands() })
 	},
 }
 

internal/pkg/container/container.go

@@ -19,6 +19,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
+
 package container
 
 import (
@@ -56,9 +57,11 @@ type Container struct {
 	ExposeUdp  []uint16          `toml:"expose_udp,omitempty"`
 	PortsTcp   map[uint16]uint16 `toml:"ports,omitempty"`
 	NetNS      string            `toml:"netns,omitempty"`
+	StartOrder null.Int          `toml:"start_order,omitempty"`
 
 	conn  context.Context
 	cdata *define.InspectContainerData
+	wasRunning null.Bool
 }
 
 func (c *Container) Init(conn context.Context, nets []network.Network) error {
@@ -102,7 +105,9 @@ func (c *Container) Init(conn context.Context, nets []network.Network) error {
 		return fmt.Errorf("conn is nil: %s", c.Name)
 	}
 	c.conn = conn
-	return c.populateCData()
+	err := c.populateCData()
+	c.wasRunning.SetValid(c.IsRunning())
+	return err
 }
 
 func (c *Container) LogEntry() *log.Entry {
@@ -244,32 +249,14 @@ func (c *Container) CreateCommands() cmd.CommandSet {
 }
 
 func (c *Container) RecreateCommands() cmd.CommandSet {
-	wasRunning := false
 	return c.newCommandSet("RECREATE", cmd.Commands{
-		cmd.NewFunc("stash_run_state", func() error {
+		cmd.NewSet(c.RemoveCommands()),
-			wasRunning = c.IsRunning()
-			return nil
-		}),
-		cmd.NewSet(c.StopCommands()),
-		cmd.NewSet(c.removeCommands()),
 		cmd.NewSet(c.CreateCommands()),
-		cmd.NewConditional("start_if_was_running",
-			func() bool { return wasRunning },
-			cmd.NewSet(c.StartCommands()),
-			cmd.NewNop(),
-		),
-	})
-}
-
-func (c *Container) RemoveCommands() cmd.CommandSet {
-	return c.newCommandSet("REMOVE", cmd.Commands{
-		cmd.NewSet(c.StopCommands()),
-		cmd.NewSet(c.removeCommands()),
 	})
 }
 
 // unexported version just removes the container without attempting a stop.
-func (c *Container) removeCommands() cmd.CommandSet {
+func (c *Container) RemoveCommands() cmd.CommandSet {
 	return c.newCommandSet("remove", cmd.Commands{
 		cmd.NewFunc("remove_if_exists", func() error {
 			if c.cdata.ID == "" {
@@ -293,7 +280,11 @@ func (c *Container) StartCommands() cmd.CommandSet {
 			if err != nil {
 				return err
 			}
-			_, err = containers.Wait(c.conn, c.cdata.ID, &containers.WaitOptions{Condition: []define.ContainerStatus{define.ContainerStateRunning}})
+			_, err = containers.Wait(
+				c.conn,
+				c.cdata.ID,
+				&containers.WaitOptions{Condition: []define.ContainerStatus{define.ContainerStateRunning}},
+			)
 			if err != nil {
 				return err
 			}
@@ -312,13 +303,6 @@ func (c *Container) StartCommands() cmd.CommandSet {
 	})
 }
 
-func (c *Container) RestartCommands() cmd.CommandSet {
-	return c.newCommandSet("RESTART", cmd.Commands{
-		cmd.NewSet(c.StopCommands()),
-		cmd.NewSet(c.StartCommands()),
-	})
-}
-
 func (c *Container) IsRunning() bool {
 	if c.cdata != nil && c.cdata.State != nil {
 		return c.cdata.State.Running
@@ -334,21 +318,18 @@ func (c *Container) IsCreated() bool {
 }
 
 func (c *Container) UpdateCommands() cmd.CommandSet {
-	wasRunning := false
 	return c.newCommandSet("UPDATE", cmd.Commands{
-		cmd.NewFunc("pull_image", func() error {
+		cmd.NewSet(c.PullCommands()),
-			err := c.pull()
-			if err != nil {
-				return err
-			}
-			wasRunning = c.cdata != nil && c.cdata.State != nil && c.cdata.State.Running
-			return nil
-		}),
 		cmd.NewSet(c.StopCommands()),
-		cmd.NewSet(c.removeCommands()),
+		cmd.NewSet(c.RemoveCommands()),
 		cmd.NewSet(c.CreateCommands()),
+	})
+}
+
+func (c *Container) ConditionalStartCommands()  cmd.CommandSet {
+	return c.newCommandSet("CONDSTART", cmd.Commands{
 		cmd.NewConditional("restart_if_was_running",
-			func() bool { return wasRunning },
+			c.wasRunning.ValueOrZero,
 			cmd.NewSet(c.StartCommands()),
 			cmd.NewNop(),
 		),
@@ -367,7 +348,11 @@ func (c *Container) StopCommands() cmd.CommandSet {
 			if err != nil {
 				return err
 			}
-			_, err = containers.Wait(c.conn, c.cdata.ID, &containers.WaitOptions{Condition: []define.ContainerStatus{define.ContainerStateExited}})
+			_, err = containers.Wait(
+				c.conn,
+				c.cdata.ID,
+				&containers.WaitOptions{Condition: []define.ContainerStatus{define.ContainerStateExited}},
+			)
 			if err != nil {
 				return err
 			}

internal/pkg/container/ordering.go

@@ -0,0 +1,61 @@
+/*
+Copyright © 2022 Joel D. Elkins <joel@elkins.co>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+package container
+
+import "golang.org/x/exp/slices"
+
+type operation bool
+
+const (
+	Start operation = true
+	Stop  operation = false
+)
+
+func Reorder(conts []Container, op operation) {
+	// null orderings go first for either start or stop, as they are executed asynchronously
+	norm := func(a, b Container) bool {
+		if !a.StartOrder.Valid {
+			return true
+		}
+		if !b.StartOrder.Valid {
+			return false
+		}
+		return a.StartOrder.ValueOrZero() < b.StartOrder.ValueOrZero()
+	}
+	rev := func(a, b Container) bool {
+		if !a.StartOrder.Valid {
+			return true
+		}
+		if !b.StartOrder.Valid {
+			return false
+		}
+		return b.StartOrder.ValueOrZero() > a.StartOrder.ValueOrZero()
+	}
+	var sorter func(a, b Container) bool
+	if op == Start {
+		sorter = norm
+	} else {
+		sorter = rev
+	}
+	slices.SortFunc(conts, sorter)
+}