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− | This page describes the CRiu Image Tool. CRIT is a feature-rich replacement for existing "criu show". | + | ''This page describes the CRIT Python tool. For the Go library, see [[CRIT (Go library)]]''. |
| + | |
| + | CRiu Image Tool is a feature-rich replacement for existing "criu show". |
| It is written completely in Python, so it is quite easy to read the code and extend its features. | | It is written completely in Python, so it is quite easy to read the code and extend its features. |
| | | |
| == Usage == | | == Usage == |
| <pre> | | <pre> |
− | usage: crit [-h] [-i IN] [-o OUT] [-f {raw,nice}] {decode,encode} | + | usage: crit [-h] {decode,encode,info,x,show} ... |
| | | |
| CRiu Image Tool | | CRiu Image Tool |
| | | |
| positional arguments: | | positional arguments: |
− | {decode,encode} decode/encode - convert criu image from/to binary type | + | {decode,encode,info,x,show} |
− | to/from json
| + | Use crit CMD --help for command-specific help |
| + | decode convert criu image from binary type to json |
| + | encode convert criu image from json type to binary |
| + | info show info about image |
| + | x explore image dir |
| + | show convert criu image from binary to human-readable json |
| | | |
| optional arguments: | | optional arguments: |
| -h, --help show this help message and exit | | -h, --help show this help message and exit |
− | -i IN, --in IN input file (stdin by default)
| |
− | -o OUT, --out OUT output file (stdout by default)
| |
− | --pretty multi-line with indentation and some fields printed in more human-readable format
| |
| </pre> | | </pre> |
| | | |
| === Pretty output === | | === Pretty output === |
| | | |
− | By default CRIT prints JSON text in one line. This can be read by any further JSON-aware tool for parsing. For human eyes it's more convenient to read JSON multi-line with indentation. However, CRIT does a little bit more and prints some fields in even more pretty manner.
| + | <code>crit decode</code> prints JSON text in one line. This can be read by any further JSON-aware tool for parsing. For human eyes it's more convenient to read JSON multi-line with indentation. CRIT can do this when using the <code>show</code> action or the <code>--pretty</code> option. |
| + | |
| + | Wend doing pretty optput CRIT does a little bit more, than just multiline indented JSON. |
| | | |
| ; Addresses and registers | | ; Addresses and registers |
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| ; IP addresses | | ; IP addresses |
| : By default those a printed in decimal, but the "1.2.3.4" for v4 or "::1" for v6 can be seen in the --pretty mode. | | : By default those a printed in decimal, but the "1.2.3.4" for v4 or "::1" for v6 can be seen in the --pretty mode. |
| + | |
| + | ; Symbolic names for flags |
| + | : Some known bit sets (e.g. MAP_PRIVATE, MAP_ANONYMOUS, etc. for vma->flags) are shown with names. |
| + | |
| + | ; Device numbers |
| + | : If the field is known to be of <code>dev_t</code> type, it's printed in the <code>major:minor</code> manner |
| | | |
| == Functionality == | | == Functionality == |
| | | |
− | === Convert images to JSON and back === | + | === Convert images from IMG to JSON === |
| | | |
− | {{Status|ready}}
| |
| | | |
− | This is the replacement for (rather nasty) criu show code. Also this is the way to edit the images before restoring from them.
| + | <code>crit decode</code> is the replacement for the (rather nasty) <code>criu show</code> code. This is also the way to edit the images before restoring from them. |
| | | |
| It uses [https://developers.google.com/protocol-buffers/docs/reference/python/google.protobuf.text_format-module text_format] as a human-readable format for protobuf messages. | | It uses [https://developers.google.com/protocol-buffers/docs/reference/python/google.protobuf.text_format-module text_format] as a human-readable format for protobuf messages. |
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| </div> | | </div> |
| </div> | | </div> |
| + | |
| + | Decode also supports input via STDIN instead of the "-i" flag. |
| + | |
| + | <pre> |
| + | cat "core-5679.img" | crit decode |
| + | </pre> |
| + | |
| + | === Convert images from JSON to IMG === |
| + | |
| + | <code>crit encode</code> converts the image from JSON to IMG. Standard usage would look like: |
| + | |
| + | <pre> |
| + | crit encode -i core-5679.json -o core-5679.img |
| + | </pre> |
| + | |
| + | Encode also supports input via STDIN instead of the "-i" flag. |
| + | |
| + | <pre> |
| + | cat "core-5679.json" | crit encode |
| + | </pre> |
| + | |
| + | Incase a "-o" flag is not specified the input is piped out to STDOUT. |
| | | |
| === Generate core files out of task images === | | === Generate core files out of task images === |
| | | |
− | {{Status|in progress}}
| + | Moved into separate project called [[criu-coredump]]. |
| | | |
− | All the needed information is in core-$pid.img and pagemap-$pid.img
| + | === Show images statistics === |
| | | |
− | === On-the-fly conversion ===
| + | <code>crit x</code> allows you to explore image statistics. |
| + | E.g. Total number of processes, files, memory, sockets, etc. |
| + | |
| + | <pre> |
| + | crit x $directory_with_images <explore type> |
| + | </pre> |
| + | |
| + | Supported explorers are |
| + | ;'ps' |
| + | :to show process tree |
| + | |
| + | ;'fds' |
| + | :to show files used by tasks |
| | | |
− | {{Status|not ready}}
| + | ;'mems' |
| + | :to show memory mappings info |
| | | |
− | There's an idea to make CRIU spawn CRIT and read images "through" it, to allow for at-the-restore-time modifications
| + | === Show images Info === |
| | | |
− | === Convert between different image versions === | + | Image of a info such as its "COUNT" and "MAGIC" can be displayed using the INFO command. |
| + | <div class="toccolours mw-collapsible mw-collapsed" style="width:800px"> |
| + | <b>Example("crit info core-5679.img")</b> |
| + | <div class="mw-collapsible-content"> |
| + | <pre> |
| + | { |
| + | "count": 1, |
| + | "magic": "CORE" |
| + | } |
| + | </pre> |
| + | </div> |
| + | </div> |
| | | |
− | {{Status|not ready}}
| + | == Planned functionality == |
| | | |
− | Right now we store the images version in inventory.img and collect info about [[what's bad with V1 images]]. If some day we have v2, CRIT will convert from v1. And for backward compatibility we'll use on-the-fly conversion when restoring from old images.
| + | === On-the-fly conversion === |
| | | |
− | === Show images statistics ===
| + | There's an idea to make CRIU spawn CRIT and read images "through" it, to allow for at-the-restore-time modifications. For details, see https://github.com/checkpoint-restore/criu/issues/59. |
| | | |
− | {{Status|not ready}}
| + | === Convert between different image versions === |
| | | |
− | E.g. -- total number of processes, files, memory, sockets, etc.
| + | Right now we store the images version in inventory.img and collect info about [[what's bad with V1 images]]. If some day we have v2, CRIT will convert from v1. And for backward compatibility we'll use on-the-fly conversion when restoring from old images. |
| | | |
| === Check/validate images === | | === Check/validate images === |
− |
| |
− | {{Status|not ready}}
| |
| | | |
| Check that | | Check that |
| * all images are present | | * all images are present |
| * the inter-images IDs are in consistent state | | * the inter-images IDs are in consistent state |
| + | |
| + | For details, see https://github.com/checkpoint-restore/criu/issues/44. |
| + | |
| + | === [[Anonymize image files]] === |
| + | |
| + | Since images contain raw memory dumps people may refuse to send us images for debugging. Need to anonymize them, i.e. -- remove this sensitive information. |
| | | |
| [[Category:Images]] | | [[Category:Images]] |
| [[Category:API]] | | [[Category:API]] |