Fix issue #116 - allow relative paths in mounts. (#123)

* Fix issue #116 - allow relative paths in mounts.
* Add test.

Signed-off-by: Shishir Mahajan <[email protected]>

Author: shishir-a412ed

containerd/containerd.go

@@ -251,6 +251,12 @@ func (d *Driver) createContainer(containerConfig *ContainerConfig, config *TaskC
 			return nil, fmt.Errorf("Options cannot be empty for mount type: %s. You need to atleast pass rbind and ro.", mount.Type)
 		}
 
+		// Allow paths relative to $NOMAD_TASK_DIR.
+		// More details: https://github.com/Roblox/nomad-driver-containerd/issues/116#issuecomment-983171458
+		if mount.Type == "bind" && strings.HasPrefix(mount.Source, "local") {
+			mount.Source = containerConfig.TaskDirSrc + mount.Source[5:]
+		}
+
 		m := buildMountpoint(mount.Type, mount.Target, mount.Source, mount.Options)
 		mounts = append(mounts, m)
 	}

example/mosquitto.nomad

@@ -0,0 +1,39 @@
+job "mosquitto" {
+  datacenters = ["dc1"]
+
+  group "msq-group" {
+    task "msq-task" {
+      driver = "containerd-driver"
+
+      config {
+        image           = "ubuntu:16.04"
+        command         = "sleep"
+        args            = ["600s"]
+        mounts = [
+           {
+                type    = "bind"
+                target  = "/mosquitto/config/mosquitto.conf"
+                source  = "local/mosquitto.conf"
+                options = ["rbind", "rw"]
+           }
+        ]
+      }
+
+      template {
+        destination = "local/mosquitto.conf"
+        data = <<EOF
+bind_address 0.0.0.0
+allow_anonymous true
+persistence true
+persistence_location /mosquitto/data/
+log_dest stdout
+EOF
+      }
+
+      resources {
+        cpu    = 500
+        memory = 256
+      }
+    }
+  }
+}

tests/010-test-template-stanza.sh

@@ -0,0 +1,50 @@
+#!/bin/bash
+
+source $SRCDIR/utils.sh
+
+job_name=mosquitto
+filename="/mosquitto/config/mosquitto.conf"
+
+# test template stanza
+test_template_stanza_nomad_job() {
+    pushd ~/go/src/github.com/Roblox/nomad-driver-containerd/example
+
+    echo "INFO: Starting nomad $job_name job using nomad-driver-containerd."
+    nomad job run -detach $job_name.nomad
+
+    # Even though $(nomad job status) reports job status as "running"
+    # The actual container process might not be running yet.
+    # We need to wait for actual container to start running before trying exec.
+    echo "INFO: Wait for ${job_name} container to get into RUNNING state, before trying exec."
+    is_container_active ${job_name} true
+
+    echo "INFO: Checking status of $job_name job."
+    job_status=$(nomad job status -short $job_name|grep Status|awk '{split($0,a,"="); print a[2]}'|tr -d ' ')
+    if [ "$job_status" != "running" ];then
+        echo "ERROR: Error in getting ${job_name} job status."
+        exit 1
+    fi
+
+    # Check if bind mount exists.
+    echo "INFO: Checking if bind mount was successful and $filename exists."
+    nomad alloc exec -job $job_name cat $filename >/dev/null 2>&1
+    rc=$?
+    if [ $rc -ne 0 ]; then
+       echo "ERROR: bind mount was unsuccessful. $filename does not exist."
+       exit 1
+    fi
+
+    echo "INFO: Stopping nomad ${job_name} job."
+    nomad job stop -detach ${job_name}
+    job_status=$(nomad job status -short ${job_name}|grep Status|awk '{split($0,a,"="); print a[2]}'|tr -d ' ')
+    if [ $job_status != "dead(stopped)" ];then
+        echo "ERROR: Error in stopping ${job_name} job."
+        exit 1
+    fi
+
+    echo "INFO: purge nomad ${job_name} job."
+    nomad job stop -detach -purge ${job_name}
+    popd
+}
+
+test_template_stanza_nomad_job