From f4e873c4e10502dd0a7fb14cc2fd87b12760a318 Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Tue, 10 Mar 2020 08:32:19 +0100 Subject: auto updates Add support to auto-update containers running in systemd units as generated with `podman generate systemd --new`. `podman auto-update` looks up containers with a specified "io.containers.autoupdate" label (i.e., the auto-update policy). If the label is present and set to "image", Podman reaches out to the corresponding registry to check if the image has been updated. We consider an image to be updated if the digest in the local storage is different than the one of the remote image. If an image must be updated, Podman pulls it down and restarts the container. Note that the restarting sequence relies on systemd. At container-creation time, Podman looks up the "PODMAN_SYSTEMD_UNIT" environment variables and stores it verbatim in the container's label. This variable is now set by all systemd units generated by `podman-generate-systemd` and is set to `%n` (i.e., the name of systemd unit starting the container). This data is then being used in the auto-update sequence to instruct systemd (via DBUS) to restart the unit and hence to restart the container. Note that this implementation of auto-updates relies on systemd and requires a fully-qualified image reference to be used to create the container. This enforcement is necessary to know which image to actually check and pull. If we used an image ID, we would not know which image to check/pull anymore. Fixes: #3575 Signed-off-by: Valentin Rothberg --- libpod/container.go | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'libpod/container.go') diff --git a/libpod/container.go b/libpod/container.go index dbd15e55f..d83de93bb 100644 --- a/libpod/container.go +++ b/libpod/container.go @@ -239,6 +239,12 @@ type ContainerConfig struct { // container has been created with. CreateCommand []string `json:"CreateCommand,omitempty"` + // RawImageName is the raw and unprocessed name of the image when creating + // the container (as specified by the user). May or may not be set. One + // use case to store this data are auto-updates where we need the _exact_ + // name and not some normalized instance of it. + RawImageName string `json:"RawImageName,omitempty"` + // TODO consider breaking these subsections up into smaller structs // UID/GID mappings used by the storage @@ -503,11 +509,17 @@ func (c *Container) Namespace() string { return c.config.Namespace } -// Image returns the ID and name of the image used as the container's rootfs +// Image returns the ID and name of the image used as the container's rootfs. func (c *Container) Image() (string, string) { return c.config.RootfsImageID, c.config.RootfsImageName } +// RawImageName returns the unprocessed and not-normalized user-specified image +// name. +func (c *Container) RawImageName() string { + return c.config.RawImageName +} + // ShmDir returns the sources path to be mounted on /dev/shm in container func (c *Container) ShmDir() string { return c.config.ShmDir -- cgit v1.2.3-54-g00ecf