-Mount types
+{% comment %}
+Copyright (C) The Arvados Authors. All rights reserved.
+
+SPDX-License-Identifier: CC-BY-SA-3.0
+{% endcomment %}
+
+h2. Mount types
The "mounts" hash is the primary mechanism for adding data to the container at runtime (beyond what is already in the container image).
"kind":"collection",
"uuid":"..."
}</code></pre>|
-|Git tree|@git_tree@|One of { @"git-url"@, @"repository_name"@, @"uuid"@ } must be provided.
-One of { @"commit"@, @"revisions"@ } must be provided.
-"path" may be provided. The default path is "/".
-At container startup, the target path will have the source tree indicated by the given revision. The @.git@ metadata directory _will not_ be available: typically the system will use @git-archive@ rather than @git-checkout@ to prepare the target directory.
-- If a value is given for @"revisions"@, it will be resolved to a set of commits (as desribed in the "ranges" section of git-revisions(1)) and the container request will be satisfiable by any commit in that set.
-- If a value is given for @"commit"@, it will be resolved to a single commit, and the tree resulting from that commit will be used.
-- @"path"@ can be used to select a subdirectory or a single file from the tree indicated by the selected commit.
-- Multiple commits can resolve to the same tree: for example, the file/directory given in @"path"@ might not have changed between commits A and B.
-- The resolved mount (found in the Container record) will have only the "kind" key and a "blob" or "tree" key indicating the 40-character hash of the git tree/blob used.|<pre><code>{
+|Git tree|@git_tree@|@"uuid"@ must be the UUID of an Arvados-hosted git repository.
+@"commit"@ must be a full 40-character commit hash.
+@"path"@, if provided, must be "/".
+At container startup, the target path will have the source tree indicated by the given commit. The @.git@ metadata directory _will not_ be available.|<pre><code>{
"kind":"git_tree",
"uuid":"zzzzz-s0uqq-xxxxxxxxxxxxxxx",
- "commit":"master"
+ "commit":"f315c59f90934cccae6381e72bba59d27ba42099"
}
-{
- "kind":"git_tree",
- "uuid":"zzzzz-s0uqq-xxxxxxxxxxxxxxx",
- "commit_range":"bugfix^..master",
- "path":"/crunch_scripts/grep"
-}</code></pre>|
+</code></pre>|
|Temporary directory|@tmp@|@"capacity"@: capacity (in bytes) of the storage device.
-@"device_type"@ (optional, default "network"): one of @{"ram", "ssd", "disk", "network"}@ indicating the acceptable level of performance.
+@"device_type"@ (optional, default "network"): one of @{"ram", "ssd", "disk", "network"}@ indicating the acceptable level of performance. (*note: not yet implemented as of v1.5*)
At container startup, the target path will be empty. When the container finishes, the content will be discarded. This will be backed by a storage mechanism no slower than the specified type.|<pre><code>{
"kind":"tmp",
"capacity":100000000000
"kind":"json",
"content":{"foo":"bar"}
}</pre>|
+
+h2(#pre-populate-output). Pre-populate output using Mount points
+
+When a container's output_path is a tmp mount backed by local disk, this output directory can be pre-populated with content from existing collections. This content can be specified by mounting collections at mount points that are subdirectories of output_path. Certain restrictions apply:
+
+1. Only mount points of kind @collection@ are supported.
+
+2. Mount points underneath output_path which have @"writable":true@ are copied into output_path during container initialization and may be updated, renamed, or deleted by the running container. The original collection is not modified. On container completion, files remaining in the output are saved to the output collection. The mount at output_path must be big enough to accommodate copies of the inner writable mounts.
+
+3. If any such mount points are configured as @exclude_from_output":true@, they will be excluded from the output.
+
+If any process in the container tries to modify, remove, or rename these mount points or anything underneath them, the operation will fail and the container output and the underlying collections used to pre-populate are unaffected.
+
+h3. Example mount point configurations
+
+All the below examples are based on this collection:
+<pre><code>
+portable_data_hash cdfbe2e823222d26483d52e5089d553c+175
+
+manifest_text: ./alice 03032680d3fa0561ef4f85071140861e+13+A04e9d06459cda00aa997565bd78001061cf5bffb@58ab593d 0:13:hello.txt\n./bob d820b9df970e1b498e7723c50b107e1b+11+A42d162a60210479d1cfaf9fbb98d494ac6322ae6@58ab593d 0:11:hello.txt\n./carol cf72b172ff969250ae14a893a6745440+13+A476a2fd39e14e9c03af3076bd17e3612c075ff66@58ab593d 0:13:hello.txt\n
+</code></pre>
+
+table(table table-bordered table-condensed).
+|{width:40%}. *Mount point*|{width:30%}. *Description*|{width:30%}. *Resulting collection manifest text*|
+|<pre><code>"mounts": {
+ "/tmp/foo": {
+ "kind": "collection",
+ "portable_data_hash": "cdfbe2...+175"
+ },
+},
+"output_path": "/tmp"
+</code></pre>|No path specified and hence the entire collection will be mounted.|./*foo/*alice 030326... 0:13:hello.txt\n
+./*foo/*bob d820b9... 0:11:hello.txt\n
+./*foo/*carol cf72b1... 0:13:hello.txt\n
+*Note:* Here the "." in streams is replaced with *foo*.|
+|<pre><code>"mounts": {
+ "/tmp/foo/bar": {
+ "kind": "collection",
+ "portable_data_hash": "cdfbe2...+175"
+ "path": "alice"
+ },
+},
+"output_path": "/tmp"
+</code></pre>|Specified path refers to the subdirectory *alice* in the collection.|./*foo/bar* 030326... 0:13:hello.txt\n
+*Note:* only the manifest text segment for the subdirectory *alice* is included after replacing the subdirectory *alice* with *foo/bar*.|
+|<pre><code>"mounts": {
+ "/tmp/foo/bar": {
+ "kind": "collection",
+ "portable_data_hash": "cdfbe2...+175"
+ "path": "alice/hello.txt"
+ },
+},
+"output_path": "/tmp"
+</code></pre>|Specified path refers to the file *hello.txt* in the *alice* subdirectory|./*foo* 030326... 0:13:*bar*\n
+*Note:* Here the subdirectory *alice* is replaced with *foo* and the filename *hello.txt* from this subdirectory is replaced with *bar*.|
+
+h2(#symlinks-in-output). Symlinks in output
+
+When a container's output_path is a tmp mount backed by local disk, this output directory can contain symlinks to other files in the output directory, or to collection mount points. If the symlink leads to a collection mount, efficiently copy the collection into the output collection. Symlinks leading to files or directories are expanded and created as regular files in the output collection. Further, whether symlinks are relative or absolute, every symlink target (even targets that are symlinks themselves) must point to a path in either the output directory or a collection mount.
projects / arvados.git / blobdiff