Merge pull request #2491 from baude/healtcheckphase1

podman healthcheck run (phase 1)

4 files changed, 148 insertions, 0 deletions

diff --git a/libpod/container.go b/libpod/container.go
index 75f4a4a4f..2381f53ad 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/containernetworking/cni/pkg/types"
 	cnitypes "github.com/containernetworking/cni/pkg/types/current"
+	"github.com/containers/image/manifest"
 	"github.com/containers/libpod/libpod/lock"
 	"github.com/containers/libpod/pkg/namespaces"
 	"github.com/containers/storage"
@@ -365,6 +366,9 @@ type ContainerConfig struct {
 
 	// Systemd tells libpod to setup the container in systemd mode
 	Systemd bool `json:"systemd"`
+
+	// HealtchCheckConfig has the health check command and related timings
+	HealthCheckConfig *manifest.Schema2HealthConfig
 }
 
 // ContainerStatus returns a string representation for users
@@ -1085,3 +1089,14 @@ func (c *Container) ContainerState() (*ContainerState, error) {
 	deepcopier.Copy(c.state).To(returnConfig)
 	return c.state, nil
 }
+
+// HasHealthCheck returns bool as to whether there is a health check
+// defined for the container
+func (c *Container) HasHealthCheck() bool {
+	return c.config.HealthCheckConfig != nil
+}
+
+// HealthCheckConfig returns the command and timing attributes of the health check
+func (c *Container) HealthCheckConfig() *manifest.Schema2HealthConfig {
+	return c.config.HealthCheckConfig
+}
diff --git a/libpod/healthcheck.go b/libpod/healthcheck.go
new file mode 100644
index 000000000..81addb9a8
--- /dev/null
+++ b/libpod/healthcheck.go
@@ -0,0 +1,92 @@
+package libpod
+
+import (
+	"os"
+	"strings"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+// HealthCheckStatus represents the current state of a container
+type HealthCheckStatus int
+
+const (
+	// HealthCheckSuccess means the health worked
+	HealthCheckSuccess HealthCheckStatus = iota
+	// HealthCheckFailure means the health ran and failed
+	HealthCheckFailure HealthCheckStatus = iota
+	// HealthCheckContainerStopped means the health check cannot
+	// be run because the container is stopped
+	HealthCheckContainerStopped HealthCheckStatus = iota
+	// HealthCheckContainerNotFound means the container could
+	// not be found in local store
+	HealthCheckContainerNotFound HealthCheckStatus = iota
+	// HealthCheckNotDefined means the container has no health
+	// check defined in it
+	HealthCheckNotDefined HealthCheckStatus = iota
+	// HealthCheckInternalError means somes something failed obtaining or running
+	// a given health check
+	HealthCheckInternalError HealthCheckStatus = iota
+	// HealthCheckDefined means the healthcheck was found on the container
+	HealthCheckDefined HealthCheckStatus = iota
+)
+
+// HealthCheck verifies the state and validity of the healthcheck configuration
+// on the container and then executes the healthcheck
+func (r *Runtime) HealthCheck(name string) (HealthCheckStatus, error) {
+	container, err := r.LookupContainer(name)
+	if err != nil {
+		return HealthCheckContainerNotFound, errors.Wrapf(err, "unable to lookup %s to perform a health check", name)
+	}
+	hcStatus, err := checkHealthCheckCanBeRun(container)
+	if err == nil {
+		return container.RunHealthCheck()
+	}
+	return hcStatus, err
+}
+
+// RunHealthCheck runs the health check as defined by the container
+func (c *Container) RunHealthCheck() (HealthCheckStatus, error) {
+	var newCommand []string
+	hcStatus, err := checkHealthCheckCanBeRun(c)
+	if err != nil {
+		return hcStatus, err
+	}
+	hcCommand := c.HealthCheckConfig().Test
+	if len(hcCommand) > 0 && hcCommand[0] == "CMD-SHELL" {
+		newCommand = []string{"sh", "-c"}
+		newCommand = append(newCommand, hcCommand[1:]...)
+	} else {
+		newCommand = hcCommand
+	}
+	// TODO when history/logging is implemented for healthcheck, we need to change the output streams
+	// so we can capture i/o
+	streams := new(AttachStreams)
+	streams.OutputStream = os.Stdout
+	streams.ErrorStream = os.Stderr
+	streams.InputStream = os.Stdin
+	streams.AttachOutput = true
+	streams.AttachError = true
+	streams.AttachInput = true
+
+	logrus.Debugf("executing health check command %s for %s", strings.Join(newCommand, " "), c.ID())
+	if err := c.Exec(false, false, []string{}, newCommand, "", "", streams, 0); err != nil {
+		return HealthCheckFailure, err
+	}
+	return HealthCheckSuccess, nil
+}
+
+func checkHealthCheckCanBeRun(c *Container) (HealthCheckStatus, error) {
+	cstate, err := c.State()
+	if err != nil {
+		return HealthCheckInternalError, err
+	}
+	if cstate != ContainerStateRunning {
+		return HealthCheckContainerStopped, errors.Errorf("container %s is not running", c.ID())
+	}
+	if !c.HasHealthCheck() {
+		return HealthCheckNotDefined, errors.Errorf("container %s has no defined healthcheck", c.ID())
+	}
+	return HealthCheckDefined, nil
+}
diff --git a/libpod/image/image.go b/libpod/image/image.go
index b20419d7b..8c98de3d3 100644
--- a/libpod/image/image.go
+++ b/libpod/image/image.go
@@ -1151,3 +1151,32 @@ func (i *Image) Save(ctx context.Context, source, format, output string, moreTag
 
 	return nil
 }
+
+// GetConfigBlob returns a schema2image.  If the image is not a schema2, then
+// it will return an error
+func (i *Image) GetConfigBlob(ctx context.Context) (*manifest.Schema2Image, error) {
+	imageRef, err := i.toImageRef(ctx)
+	if err != nil {
+		return nil, err
+	}
+	b, err := imageRef.ConfigBlob(ctx)
+	if err != nil {
+		return nil, errors.Wrapf(err, "unable to get config blob for %s", i.ID())
+	}
+	blob := manifest.Schema2Image{}
+	if err := json.Unmarshal(b, &blob); err != nil {
+		return nil, errors.Wrapf(err, "unable to parse image blob for %s", i.ID())
+	}
+	return &blob, nil
+
+}
+
+// GetHealthCheck returns a HealthConfig for an image.  This function only works with
+// schema2 images.
+func (i *Image) GetHealthCheck(ctx context.Context) (*manifest.Schema2HealthConfig, error) {
+	configBlob, err := i.GetConfigBlob(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return configBlob.ContainerConfig.Healthcheck, nil
+}
diff --git a/libpod/options.go b/libpod/options.go
index 1e8592a25..5ad2824d9 100644
--- a/libpod/options.go
+++ b/libpod/options.go
@@ -7,6 +7,7 @@ import (
 	"regexp"
 	"syscall"
 
+	"github.com/containers/image/manifest"
 	"github.com/containers/libpod/pkg/namespaces"
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/idtools"
@@ -1469,3 +1470,14 @@ func WithInfraContainerPorts(bindings []ocicni.PortMapping) PodCreateOption {
 		return nil
 	}
 }
+
+// WithHealthCheck adds the healthcheck to the container config
+func WithHealthCheck(healthCheck *manifest.Schema2HealthConfig) CtrCreateOption {
+	return func(ctr *Container) error {
+		if ctr.valid {
+			return ErrCtrFinalized
+		}
+		ctr.config.HealthCheckConfig = healthCheck
+		return nil
+	}
+}