Re-add apt-based installation instructions.

1 files changed, 29 insertions, 35 deletions

diff --git a/content/docs/user_guide/install.md b/content/docs/user_guide/install.md
index bc8a60b5b..a76383b06 100644
--- a/content/docs/user_guide/install.md
+++ b/content/docs/user_guide/install.md
@@ -13,12 +13,21 @@ release channels. You should pick the version you'd like to install. For
 experimentation, the nightly release is recommended. For production use, the
 latest release is recommended.
 
-<!--
-
 After selecting an appropriate release channel from the options below, proceed
 to the preferred installation mechanism: manual or from an `apt` repository.
 
- -->
+### HEAD
+
+Binaries are available for every commit on the `master` branch, and are
+available at the following URL:
+
+   `https://storage.googleapis.com/gvisor/releases/master/latest/runsc`
+
+Checksums for the release binary are at:
+
+   `https://storage.googleapis.com/gvisor/releases/master/latest/runsc.sha512`
+
+For `apt` installation, use the `master` as the `${DIST}` below.
 
 ### Nightly
 
@@ -37,10 +46,7 @@ Specific nightly releases can be found at:
 
 Note that a release may not be available for every day.
 
-<!--
-
-To use a nightly release, use one of the above URLs for `URL` in the manual
-instructions below. For `apt`, use `nightly` for `DIST` below.
+For `apt` installation, use the `nightly` as the `${DIST}` below.
 
 ### Latest release
 
@@ -48,8 +54,7 @@ The latest official release is available at the following URL:
 
    `https://storage.googleapis.com/gvisor/releases/release/latest`
 
-To use the latest release, use the above URL for `URL` in the manual
-instructions below. For `apt`, use `latest` for `DIST` below.
+For `apt` installation, use the `release` as the `${DIST}` below.
 
 ### Specific release
 
@@ -59,11 +64,10 @@ A given release release is available at the following URL:
 
 See the [releases][releases] page for information about specific releases.
 
+For `apt` installation of a specific release, which may include point updates,
+use the date of the release, e.g. `${yyyymmdd}`, as the `${DIST}` below.
 
-This will include point updates for the release, if required. To use a specific
-release, use the above URL for `URL` in the manual instructions below. For
-`apt`, use `${yyyymmdd}` for `DIST` below.
-
+> Note: only newer releases may be available as `apt` repositories.
 
 ### Point release
 
@@ -71,14 +75,9 @@ A given point release is available at the following URL:
 
   `https://storage.googleapis.com/gvisor/releases/release/${yyyymmdd}.${rc}`
 
+Note that `apt` installation of a specific point release is not supported.
 
-Unlike the specific release above, which may include updates, this release will
-not change. To use a specific point release, use the above URL for `URL` in the
-manual instructions below. For apt, use `${yyyymmdd}.${rc}` for `DIST` below.
-
- -->
-
-<!-- Install from an `apt` repository
+## Install from an `apt` repository
 
 First, appropriate dependencies must be installed to allow `apt` to install
 packages via https:
@@ -102,27 +101,21 @@ curl -fsSL https://gvisor.dev/archive.key | sudo apt-key add -
 Based on the release type, you will need to substitute `${DIST}` below, using
 one of:
 
- * `nightly`: For all nightly releases.
- * `latest`: For the latest release.
- * `${yyyymmdd}`: For specific releases.
- * `${yyyymmdd}.${rc}`: For a specific point release.
+ * `master`: For HEAD.
+ * `nightly`: For nightly releases.
+ * `release`: For the latest release.
+ * `${yyyymmdd}`: For a specific releases (see above).
 
 The repository for the release you wish to install should be added:
 
 ```bash
-sudo add-apt-repository \
-   "deb https://storage.googleapis.com/gvisor/releases" \
-   "${DIST}" \
-   main
+sudo add-apt-repository "deb https://storage.googleapis.com/gvisor/releases ${DIST} main"
 ```
 
 For example, to install the latest official release, you can use:
 
 ```bash
-sudo add-apt-repository \
-   "deb https://storage.googleapis.com/gvisor/releases" \
-   latest \
-   main
+sudo add-apt-repository "deb https://storage.googleapis.com/gvisor/releases release main"
 ```
 
 Now the runsc package can be installed:
@@ -133,10 +126,11 @@ sudo apt-get update && sudo apt-get install -y runsc
 
 If you have Docker installed, it will be automatically configured.
 
--->
+## Install directly
 
-For example, the latest nightly binary can be downloaded, validated, 
-and placed in an appropriate location by running:
+The binary URLs provided above can be used to install directly. For example, the
+latest nightly binary can be downloaded, validated, and placed in an appropriate
+location by running:
 
 ```bash
 (